CORNELL UNIVERSITY LIBRARY GIFT OF Estate Of Dr. Elsie Murray Cornell University Library BF692 .W91 1903 Mental traits of sex: an experimental olin 3 1924 029 178 675 The original of tiiis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924029178675 THE MENTAL TRAITS OF SEX THE MENTAL TRAITS OF SEX AN EXPERIMENTAL INVESTIGATION OF THE NORMAL MIND IN MEN AND WOMEN HELEN BRADFORD THOMPSON, Ph.D. SOMETIME FELLOW IN THE DEPARTMENT OF FHILOSOFHY, THE ONIVERSITY OF CHICAGO DIRECTOR OF THE FSYCHOLOGICAL LABORATORY, MOUNT HOLYOKE COLLEGE CHICAGO THE UNIVERSITY OF CHICAGO PRESS (,,>.e, i'^ H^^r^:' Copyright igo3 BY THE UNIVERSITY OF CHICAGO a AUTHOR'S NOTE. My sincerest thanks are due first to the fifty stu- dents who made this research possible by devoting to it so much time upon which other demands were heavy, and to Professor James Rowland Angell, of the University of Chicago, who suggested the problem, furthered the work in the laboratory in every way, and assisted throughout by his kindly criticism and counsel. I wish also to make a grateful acknowledg- ment to Dr. Edwin Campbell Woolley, of Ohio Wes- leyan University, to whose careful revision of the man- uscript and reading of the proof the book is chiefly indebted for whatever excellence of form it may pos- sess ; to Miss Jeanette A. Marks, of Mount Holyoke College, for reading and criticising the manuscript ; to Miss Eleanor Lauder Jones, for her assistance in mak- ing out the questions on personality and general infor- mation; to Dr. Paul Gerhardt Woolley, of McGill University, for suggesting and making the apparatus used in the fifth test on ingenuity, and to Miss Alice Rollins Little, of Mount Holyoke College, for her help in enlarging the drawings. H. B. T. Chicago, July 12, 1902. CONTENTS. FAGI Chapter I — Introduction - - . . . i Object of this research. Previous work in the same field. Criterion for the selection of individuals to furnish a basis for a comparison of the sexes. Individuals used for this series of tests. Methods in comparative work. Number of individuals experimented on and time required from each one. Field covered by the experiments. Plan of arrangement of the work. Method in making the experi- ments. Method of formulating results. Chapter II — Motor Ability ----- 8 List of tests. Reaction times : apparatus, method, results, types of reaction. Rapidity of finger movement and rate of fatigue : apparatus, method, result. Formation of co-or- dination — card -sorting : apparatus, method, result. Accu- racy of a formed co-ordination — target test : apparatus, method, result — precision of movement test: apparatus, method, result. Motor automatisms : apparatus, method, result. Summary of other experimental work on motor ability. General summary. Chapter III — Skin and Muscle Senses - - - 29 List of experiments. Threshold of impact: apparatus, method, result. Threshold for pain on the right and left temples: apparatus, method, result. Discriminative sensi- bility for pressure on the palm of the hand : apparatus, method, result. Discriminative sensibility for lifted weights : apparatus, method, result. Discrimination of two points on the volar side of the forearm : apparatus, method, result. Discriminative sensibility for temperature : apparatus, meth- od, result. Summary of other experimental work on skin and muscle senses. General summary. Chaper IV — Taste and Smell .... 50 List of tests. Apparatus for tests on taste. Thresholds of presence and of recognition in taste : method, result. Dis- criminative sensibility for taste : method, result. Appa- vi CONTENTS ratus for tests on smell. Modification of method in the case of smell. Threshold of presence for smell : method, result. Threshold of recognition for smell : method, re- sult. Discriminative sensibility in smell : method, result. Summary of the tests on taste and smell. Summary of other experimental work on taste and smell. General sum- mary. Chapter V — Hearing 69 List of tests. Upper limit of pitch : apparatus, method, result. Lower limit of pitch : apparatus, method, result. Discriminative sensibility for pitch : apparatus, method, result. Summary of other experimental work on hearing. General summary. Chapter VI — Vision 76 List of tests. Threshold for light: apparatus, method, re- sult. Discriminative sensibility for brightness : apparatus, method, resulfc Keenness of vision: apparatus, method, result. Discrimination of color and color-blindness : appa- ratus, method, result. Discrimination of visual areas : appa- ratus, method, result. Summary of other experimental work on vision. General summary. Chapter VII — Intellectual Faculties - - - 93 List of tests. Memory : material, method, results ; rate of memorizing, retentiveness, type of imagery used, methods of memorizing. Summary of tests on memory. Association : nature of test ; method ; counting of the total number of asso- ciations, result ; counting of the number of topics touched upon, results ; discussion of the two sets of results. Inge- nuity tests : nature of the ingenuity tests ; source of error ; Test I : apparatus, method, result ; Test II : apparatus, method, result j Test III : apparatus, method, result ; Test IV : apparatus, method, result ; Test V : apparatus, method, result. Summary of ingenuity tests. General informa- tion : questions ; treatment of answers ; source of error ; results ; total examination, English, history, physics, math- ematics, biology, question 25, literary subjects, scientific subjects. Summary of tests on general information. Sum- mary of other experimental work on intellectual faculties. General summary. CONTENTS vii Chapter VIII —Affective Processes - - - 136 List of tests. Effect of affective processes on respiration and circulation : apparatus, method, result. Questions on personality : purpose and value of the questions ; field cov- ered by the questions; questions on age, health, and nation- ality, answers ; questions on sensory experiences, answers ; questions on methods of rest and recreation, answers; questions on the individual aspects of personality, answers ; questions on the social aspects of personality, answers; questions on intellectual interests: methods of work and belief, answers. Summary of other experimental work on affective processes. General summary. Chapter IX — Conclusion 169 Summary of previous chapters. The biological theory of the psychological differences of sex. Comparison of our findings with this theory. Criticism of the biological the- ory of the psychological differences of sex. Explanation of the psychological differences of sex by differences of training. Bibliography 183 CHAPTER I. INTRODUCTION. The object of the present monograph is to fur- nish some accurate information on the much-discussed question of the psychology of the sexes. The main part of it consists in the report of a series of experi- ments carried on in the psychological laboratory of the University of Chicago during the years 1 898-99 and 1899-1900. To have an adequate setting, such a study should be prefaced by a review of the historical aspects of the problem, a critical summary of the large mass of argumentative literature on the subject, and a discussion of the facts of anatomy and physi- ology which are supposed to have a bearing on the psychology qf sex. The mass of material to be dealt with is far too great, however, to be satisfactorily treated within the necessary limits of the present work. It has therefore been necessary to restrict this monograph to a report of the experimental work which forms the real contribution to the field, a review of previous experimental work bearing on the subject, and a brief discussion of the results. The present research is the first attempt to obtain a complete and systematic statement of the psycho- logical likenesses and differences of the sexes by the experimental method. Needless to say, the goal has not been reached within the limits of such an investi- gation. All that has been done is to gather together some evidence bearing on the problem, which is trust- 2 THE MENTAL TRAITS OF SEX worthy so far as it goes. Previous experimental work has been in the form of detached experiments on some single sense or intellectual process. Usually the ex- periments have not been made for the purpose of a comparison of the sexes, but have been performed with some other interest in view, and have been incidentally formulated with reference to sex. Much of the mate- rial is the experimental work on school children done under the influence of the child-study movement. The only previous attempt to sum up the experimental evidence on the subject is that by Havelock Ellis (23),' in his book Man and Woman, published in 1894. The work contains no original investigation. In making a series of tests for comparative pur- poses, the first prerequisite is to obtain material that is really comparable. It has been shown that the simple sensory processes vary with age and with social condition (ii, 3o, 51, 54, 63, 64, 65, 67). No one would question that this statement is true for the intel- lectual processes also. In order to make a trustworthy investigation of the variations due to sex alone, there- fore, it is essential to secure as material for experi- mentation, individuals of both sexes who are near the same age, who have the same social status, and who have been subjected to like training and social sur- roundings. The complete fulfilment of these con- ditions, even in the most democratic community, is impossible. The social atmosphere of the sexes is different from the earliest childhood to maturity. Probably the nearest approach among adults to the ideal requirement is afforded by the undergraduate stu- •The numbers which appear in parentheses throughout the text refer to the bibliography at the end o£ the volume. INTRODUCTION 3 dents of a coeducational university. For most of them the obtaining of an education has been the one serious business of life. They have had at least the similarity of training and surroundings incident to school life. Most of those in a western university have received their preparatory education in coeducational schools. The individuals who furnished the basis for the present study were students of the University of Chi- cago. They were all juniors^ seniors, or students in the first year of their graduate work. The original intention was to limit the ages to the period from twenty to twenty-five years. Owing to the difficulty of obtaining a sufficient number of subjects within these limits, a few individuals of nineteen years, and a few over twenty-five were admitted (see Fig. 81). The subjects were obtained by requesting members of the classes in introductory psychology and ethics to serve. They were told nothing about the object of the tests except that they were for the purpose of determining psychological norms. The series of ques- tions on age, health, and nationality, reported in chap, viii, shows that in all these respects the men and women tested were closely comparabie. Two methods may be followed in planning a series of tests designed to yield material for the comparison of groups or classes. It is possible either to make rapid and more or less superficial measurements on a large number of individuals, depending on numbers to counterbalance the errors of single tests, or to make careful and accurate observations of a smaller number of persons. The ideal procedure would unquestion- ably be to make careful measurements of a large number of individuals, but since the amount of time 4 THE MENTAL TRAITS OF SEX available for any problem is limited, the practical question to be decided is — Given a limited amount of time, which of the two modes of procedure mentioned is more likely to yield valuable results? Accuracy of measurement seemed an indispensable requirement for such a study as the present one. Any reliable determi- nation of a threshold or a discriminative sensibility requires a somewhat extended series of experiments. With subjects untrained in psychological experiments — as most of these were — it is essential to take a large enough series of measurements to give some assurance that the results represent a characteristic reaction, and not haphazard answers. In so simple a test as that of dermal two-point discriminations the first few judg- ments are very likely to be little more than guesses. In a series of rapid tests like those employed at Columbia University (82) the subject is given only five stimulations with the zesthesiometer. The points are kept a fixed distance apart and the subject is given both one- and two-point stimulations in his series of five. It seems improbable that the results of such a test on unpracticed subjects mean anything more than random answers. The Columbia experiments on a large number of students failed to reveal any differ- ence of sex in the fineness of two-point discriminations, while the present accurate measurement of fifty subjects shows a clear difference. The series of tests employed in this investigation required from fiftgen to twenty hours of time from each subject. The hours were arranged from one sitting to the next according to the convenience of the subject. It was not possible to have the hours for any one test constant for all subjects, since the INTRODUCTION S schedules varied so widely No attempt was made to keep the order of experiments rigidly the same for all. Convenience and economy of time necessarily deter- mined the order to a great extent. In general, however, the simple sensory and motor tests were given in the early part of the series, and the intellectual tests in the latter part. The questions on personality usually came last, The taste and smell experiments had to be scattered through most of the periods, since only a few at a time could be performed without fatigue. The entire series was applied to fifty subjects, twenty- five men and twenty-five women. The experiments fell into seven groups, dealing respectively with motor ability, skin and muscle senses, taste and sjnell, hearing, vision, intellectual faculties, and affective processes. One chapter of this monograph is devoted to each group. A list of the experiments under each group will be found at the beginning of each chapter. At the end of each chap- ter there is a comparison of results with those of other investigators, and a general summary. The numbers in parentheses used in the summaries of other experi- mental work and throughout the text, refer to the bibliography at the end of the volume. The bibli- ography pretends to completeness only in its enumer- ation of the experimental researches bearing on the problem, and even here there are doubtless omissions, although it is hoped that all the important papers are mentioned. Whenever for the sake of brevity a dogmatic statement is made to the effect that there are no data on a certain point, or only such data as are quoted, the qualification, so far as the author knows, is to be understood. 6 THE MENTAL TRAITS OF SEX The report of each experiment includes a descrip- tion of the apparatus used, a statement of the method, and a formulation of the results. Since the value of experimental work, and the possibility of comparing one set of results with another depend so largely upon the method, the greatest pains has been taken to se- cure uniformity, and to describe the method in full in each case. The experiments were all performed by the author, with the exception of a part of the reaction-timei tests, which had to be repeated because of a source of error in the apparatus. For these the author is indebted to Dr. W. C. Gore and Mr. H. J. Pearce, of the Graduate School of the University of Chicago. A few words in general on the methods employed may not be out of place, in spite of the fact that each is described in full in connection with the test. The guiding principle in selecting the method was the desire to make the directions to the subject as clear and simple as possible and at the same time secure the greatest possible accuracy of result. In all the tests on discriminative sensibility this double end seemed best secured by requiring a simple judgment of com- parison (i. e., lighter or heavier, more or less cold, etc.) between two stimuli. The subject was told nothing of a standard stimulus, and the order of the standard and stimulus of comparison was varied. The differ- ence in intensity between the standard and the stimu- lus of comparison was varied until the point was found at which three-fourths of the judgments were correct. In the threshold tests of taste and smell, tasteless and odorless preparations were used to control the thresh- old illusions. The greatest care was taken to avoid INTRODUCTION 7 suggestion of all sorts in all the tests. The descrip- tions of method have been made explicit at the risk of their being perhaps somewhat tedious and need- lessly detailed. The results of the experiments have been presented graphically wherever possible. In all the curves, the dotted line is for women and the unbroken line for men. The ordinates always represent the number of subjects. In no case have the results been averaged. Wherever graphic representation was impracticable, they have been grouped. The purpose of the research was norms, not averages. CHAPTER II. MOTOR ABILITY. The subjects of the tests on motor ability were as follows : A. Reaction times. 1. Auditory. 2. Visual. B. Rapidity of finger movement and rate of fatigue. C. Co-ordination. 1 . Formation of a co-ordination. Card-sorting. 2. Accuracy of a formed co-ordination, (a) Striking a target. (6) Precision of movement in drawing lines. D. Motor automatisms. A. REACTION TIMES. Two sets of simple reaction times, the first auditory and the second visual, were taken from each subject. The Hipp chronoscope was used for both. The audi- tory stimulus was a click in a telephone receiver, made by breaking the circuit. A flash of pale purple light in a Geissler tube served as the visual stimulus. Between forty and fifty reactions of each kind were made by each subject. While reacting, the subject sat alone in the reaction room, placed in as comforta- ble a position as possible. His right forearm was sup- ported on the table, and the forefinger of his right hand rested lightly on the button of a break key which was in the chronoscope circuit. The telephone for the auditory stimulus was adjusted to the ear of the 8 MOTOR ABILITY subject. The Geissler tube for the visual stimulus was placed on the table in front of the subject. It was sus- pended before a black background, against which the flash of pale purple light was thrown out sharply. A warning signal consisting of two clicks of a telegraph instrument was given about two seconds before the stimulus. The time was varied slightly to counteract the widespread tendency to premature reactions. The signal for the release of the key after the reaction consisted of one click of the telegraph instrument. The reactions were taken in series of ten to twelve, with four- or five-minute periods of rest between. The subject was given no instructions about the direction in which his attention should be concentrated. He was merely told to make the reaction as nearly instan- taneous as possible. After the experiment he was asked in what direction his attention had been con- centrated while reacting. The results are recorded in terms of the mean re- action time and mean variation (74). Series of the first forty-one unquestioned reactions of each kind served as the basis of the calculation. Both the mean reaction time and the mean variation appear in the results in terms of sigma (.001 seconds). The num- ber of subjects represented by each ordinate in the TABLE I. Mean variations of reaction times. TO 12 cr 14 16 18 20 22 24 26 28 30 cr 32 36 40 THE MENTAL TRAITS OF SEX Fig. 1. Reaction times. Auditory.' Abscissas — sigma. Ordinates — number o{ persons. women ; men. curve is the number whose reaction times fell be- tween the point on the curve at which the ordinate is erected and the next previous one. Thus the num- ber of subjects represented at 1500- is the number whose reaction times fell between 1400- and 1500-. The curves repre- sented in Figs. I and 2 show that the men have, on the whole, shorter reaction times '^ than the women. In both auditory and visual reactions there are several men with shorter times than any of the women, and several women with longer times than any of the men. Moreover, the men are decidedly more numerous than the women in the region of short times. The average of the mean variation (Table I) is also smaller for the men than for the women. The difference is not ap- parent in the lowest ranges. It is shown by the smaller •number of women in the middle ranges, and their greater number in the re- gion of very large variations ' It will be noticed that only twenty-four men are recorded in the reaction-time curves. The reason is that in one case in which the results were unreliable because of irregularity in the apparatus, it was impossible to obtain the subject again for a repetition of the experi- ment. Fig. 2. Reaction times. Visual." Abscissas — sigma. Ordinates — number of persons. women; men. The fact that the mean MOTOR ABILITY II variations ot the visual reactions are in both sexes less than those of the auditory, is doubtless partly due to the fact that the auditory reactions were taken first. The effect of practice is shown in the greater evenness of the visual reactions. The shorter reaction time of the men is at least partly explained by special training in athletics. The man who made the most rapid reaction both to the auditory and to the visual stimuli was one of the best players on the football team. The other three men who made very quick auditory reactions were track athletes, one a bicycle rider and the other two run- ners. Two of these latter had visual reactions also which were shorter than the visual reactions of any woman. The type of the reaction was recorded under one of the three general heads, sensory, motor, and cen- tral. The central rubric includes all cases in which the subject reported that his attention had been equally divided between stimulus and movement. TABLE II. Types of reaction. Sensory, Motor, Central. fc- Women 19 13 s 8 I Men 3 < ^ 21 II 3 9 I 1 Men 4 > There is a decided preponderance of women with a sensory type of reaction. The adherents of the Leip- sic school would doubtless say that the shorter reac- 12 THE MENTAL TRAITS OF SEX tion time of the men is to be explained by the greater proportion of motor reactors among them. Probable as this theory looks from the tables, it is not borne out by a detailed examination of results. The men with the shortest reaction times were in most cases of the sensory type, while several of the motor type were among those with longest times. The real expla- nation of the greater frequency of the motor type among men is rather to be sought in the fact that they lead more active lives on the whole than women, and are more interested in learning new movements of various sorts. For this reason their attention is more likely to be directed to the technique of movement than is that of women. B. RAPIDITY OF FINGER MOVEMENT AND RATE OF FATIGUE. The apparatus used to ascertain the rapidity of fin- ger movement, and the rate at which the finger becomes fatigued, was a counting machine worked by a rod bearing a disc on which the finger rested. A dial on the front of the machine registered the number of times the rod was pressed. The machine was fas- tened in a wooden support on a table, with the rod projecting upward. The wooden support was extended into a rest for the arm. The subject sat at the table with his forearm from elbow to, wrist resting on the support, and the index finger of his right hand on the disc of the rod. When in this position, every downward movement of the finger pressed the rod down and was registered on the dial of the machine. The arm was bound in position at the wrist and at the elbow to confine the movement as much as possible to MOTOR ABILITY 13 the finger muscles. In spite of this precaution the arm came into play somewhat, particularly after fatigue set in. But although it was impossible to limit the motion strictly to the finger muscles, still they were principally involved, and the conditions were the same for all subjects. In pressing down the rod, the finger was working against a considerable resist- ance — about that of a stiff-action piano key. The subject was told that the object of the test was to find out how rapidly he could make the move- ment. He was not told how long he was to continue it. His only instruction was to start the instant the signal was given, and keep up the movement until he was told to stop. The dial readings were taken every twenty seconds by the second hand of a watch. The subject was stopped at the end of two minutes, if he had not already given out. The movement had by this time become painful in every case. The test was made twice. The second time the subject of course knew that it would have to be continued until it became painful, but he was told not on that account to try to save his strength by going slowly at first, but to go as fast as possible at the start, and let the running- down process take its natural course. The results which appear in the curves are averages of the two tests. TABLE III. Finger movement. Endurance, i. (,, number of seconds the movement was continued. 40 6a 80 100 Women Men I 2 3 2 2 17 23 H THE MENTAL TRAITS OF SEX The results given in Figs. 3 and 4 and Table III, show a striking advantage on the part of the men, both in the initial rate of the movement, and in the ability to sustain it. The men made on an average about ten more taps in twenty seconds than the women. Only two men gave out before the end of two minutes, while eight women did so. One of the two men had had his arm per- manently weakened by a fracture. The men had an average of about twenty taps in twenty seconds faster than the women at the close of the test. connection with this Fig. 3. Finger movement. Rate during the first twenty seconds. Abscissas — number o£ taps. Ordinates — number of subjects. - - - - women; men. m It is interesting to note test that it has been shown by Professor Oscar Reif of Berlin (70) that the rate of movement of the sepa- rate fingers is not great- er in piano players than in other people. The only way in which piano practice would give an advantage in this test is by increasing endur- ance through the general strengthening of the hand. In so far as this factor affects the results, it is in favor Fig. 4. Finger movement. Rate during the last twenty seconds. Abscissas — number of taps. Ordinates — number o£ subjects. women ; men. MOTOR ABILITY 15 of the women, since there were more piano-players among them than among the men. Professor Fere (24) makes the suggestion that probably the force and the rate of voluntary move- ments vary together. The present series of tests certainly tends to corroborate this theory. The amount of force required for the movement was even at the outset well within the limits of strength for both sexes, but the rate appears constantly as a function of the strength. The same relation between force and rate may account for the faster reaction times of men. C. CO-ORDINATION. I. Formation of a co-ordination. — The apparatus used for testing the ability to form a co-ordination was one of the boxes of the Jastrow card-sorting appa- ratus (39). Its four divisions were marked with discs- of the four pure colors, red, blue, green and yellow. There were forty cards in the pack, ten of each color. Before each test, the pack was so arranged that no two cards of the same color followed one another. The directions given to the subject were to sort the pack as rapidly as possible, throwing each card into the division marked with its own color, making no stops for mistakes and no attempt to correct them. The signal to start was the word "go," after a count of three. The time was taken with the second hand of a watch. The test was made three times for each subject. To shut out the effects of practice and in- sure a fresh co-ordination each time, the colors on the divisions of the box were arranged differently for each trial. The results are given in terms of the average time of the three trials in seconds and the average number of mistakes. i6 THE MENTAL TRAITS OF SEX The curves for the card-sorting test (Figs. 5 and 6) show that the women are decidedly more rapid than the men. The best record is that of a woman. The women's mean rate is about two seconds faster than that of the men, and there are several men with longer times than any woman. The women have also a somewhat higher degree of accu- racy than the men. To ascertain whether or not the handling of playing cards gave an advantage to the card \/^i players in this test, the subjects were ques- tioned as to their habits of card-playing. The fact that those who made the best records, both men and women, were people who played cards very little or not at all, indicates that practice in card playing is not of great importance in this test. In so far as it is a factor, it would be in favor of the men, since there were more card-players among them than among the women. In two cases of abnormal slowness among the men, a decided color-blindness is doubtless responsible. None of the subjects were so color-blind that they could not distinguish between the pure colors used on the cards, but in the two worst cases of color-blindness the discrimination was probably slower than the normal. The subject with the longest time reported a feeling 33> Fig. S- Card-sorting test. Rate. Abscissas — time in seconds. Ordinates — number of subjects. women ; men. MOTOR ABILITY 17 JT 9 ^ of slowness in recognizing the colors, but none of the others were conscious of this difficulty. That the poorer color discrimination of the men (see Fig. 47) could account for their slowness in sorting the cards is impossible, since there proved to be no co-ordination between the rate of card- sorting and the fineness of color discrimination. Several subjects with excellent color discrim- ination were slower than the average, while several of those with slight partial color- blindness were much faster than the average. The two factors of time and accuracy showed no co-ordination. Some subjects with the shortest times had also the highest degree of accuracy, and some with the longest times were very inaccurate. 2. Accuracy of a formed co-ordination. — The first of the tests on the accuracy of a formed co-ordination consisted in striking at the center of a target with a rapid free-arm movement. The target was a sheet of paper on which were inscribed nine concentric circles. The central circle had a diameter of 2 cm., the next one 4, the next 6, etc., giving a total diameter of 18 cm. to the target. The four radii at right angles were marked at each intersection with a circle, with the number of millimeters from the center ; the first one 10, the second 20, etc. The target was hung on the wall at such a height that its center was on a level Fig. 6. Card-sorting test. Accuracy. Abscissas — average number of mis- takes. Ordinates — number of subjects. women ; men. i8 THE MENTAL TRAITS OF SEX with the hand when the arm was stretched out straight from the shoulder. The subject then took his stand at such a distance that when his arm was extended before him the point of a pencil held in the hand just touched the center of the target. He was required to attempt to strike the inner circle with the pencil, in rapid thrusts from the shoulder. The rate of move- ment was timed with a metronome. Before beginning the test the subject was allowed to practice a few strokes on a blank paper for the purpose of learning the rhythm. He was then required to hit the target fifty times. The results were calculated by counting the num- ber of strokes which fell within each successive 5 mm. section of the target, measured from the center along the radii. Table IV gives the results in full, in terms of the percentage of dots falling within each section of the target. TABLE IV. Target test. Percentage of the total number of dots falling within each of the first four sections of the target. Sees. 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 55% 4 Women Men 3 5 2 2 I 3 I 6 4 3 3 I 3 3 6 2 S in Women Men I 3 5 4 II 8 2 7 3 3 I 2 VI Women 4 3 5 4 8 9 6 5 2 3 I A Men Women 8 12 7 S 3 3 6 S ■• A, Men MOTOR ABILITY Jf 4f Fig. 7 Target test. Percentage of dots falling within the S mm. section of the target. Abscissas — percentage of dots in 5 mm. section. Ordinates — number of subjects. women ; men. The general outcome of the test may most read- ily be seen by compar- ing the two curves (Figs. 7 and 8) plotted from Table IV. The first one is a graphic representation of the percentage of dots fall- ^^ ing within the inner- mostsection (?'. ^., 5 mm.) and the second one of the percentage of dots falling within the 15- 20 mm. section, which was the outermost one in which all subjects (except one) placed dots. The first curve shows a greater number of women than men iwith small percentages of dots in the center of the tar- get, and a greater number of men than women with large percentages. The sec- ond curve shows the reverse to be true for the outer sec- tion of the target. The men with small percentages are somewhat more numerous than the women, and the women with large percent- ages than the men. The two curves agree in showing better co-ordination on the part of the men. Table V, Fig. 8. Target test. Percentage of dots falling within the 15-20 mm. section of the target. Abscissas — percentage of dots in the 15-20 mm. section. Ordinates — number of subjects. women ; men. zo THE MENTAL TRAITS OF SEX showing the range of the dots farthest from the cen- ter, corroborates this conclusion. There are more men than women who put no dots outside the 20 mm. circle, and more women than men with dots falling beyond 20 or 25 mm., although the best record was that of a woman. The differences, though small in each case, are in accord in showing better co-ordina- tion on the part of the men. The second of the tests on the accuracy of a formed co-ordination was made with an apparatus modeled after that used by Bryan (11) in his tests on school children for determining the precision of move- ment. This apparatus, however, was made on a much larger scale than Bryan's, and was used for free-arm movements instead of finger movements. It consisted of two thin strips of copper 21 cm. long fastened to a glass surface in such a way that they were in contact at one end, and diverged very gradually toward the other, where they were about 5 mm. apart. A brass writing-point ending in a small knob was connected by a flexible wire with a battery whose circuit was closed whenever the writing-point touched either of the strips of metal. The closing of the circuit was announced by the click of a telegraph instrument. The point where TABLE V. Target test. Outer limits of dots on the target. Sections of Target. S 10 IS ao =5 30 35 40 II 0= Women Men I 6 10 9 8 5 4 3 3 I MOTOR ABILITY 21 Right Fig. 9. Precision of movement test, hand, toward. Abscissas — scale readings, in centi- meters. Ordinates — number of subjects. \iromen ; men. the strips of metal were such a distance apart that the knob of the writing-point when placed on the glass between them just made the contact with both strips of metal, was called the zero point. From the zero point to the ends of the strips millimeter scales were marked on both pieces of metal. The total length of the scale was twenty cm. The glass on which the metal strips rested was sunk into a board and set with putty on a level with the surface of the board. The board thus afforded a support for the hand in making the movement. For the first test the subject was seated at a table with the apparatus before him in such a position that the strips of metal con- verged toward him. He was told to start at the twenty cm. point of the scale and attempt to draw a line on the glass between the strips of metal without touching either one. In this po- sition the movement was, of course, toward the body. The subject was allowed to hold the writ- ing-point as he chose, and take his own rate of move- ment. The only regulation was that the movement Left Fig. 10. Precision of movement test, hand, toward. Abscissas — scale readings, in centi- meters. Ordinates — number of subjects. women ; men. 22 THE MENTAL TRAITS OF SEX Right Fig. II. Precision of movement test, hand, away. Abscissas — scale readings, in centi- meters. Ordinates — number of subjects. — - women ; men. must be continuous from start to finish, and must be a free-arm and not a finger, wrist, or elbow movement. As soon as a click of the telegraph instrument indi- cated a contact, the subject stopped and began again. The point on the scale where the click occurred was noted each time. The subject was allowed two or three trials to see how the apparatus worked, and then the readings of five successive trials with each hand, first the right and then the left, were taken. For the second test the apparatus was turned around, and the move- ment was made away from the body five times with each hand. Each of the four sets of results obtained from each subject (z. e., right hand, toward and away ; left hand, toward and away) was averaged, and its av- erage variation reckoned. In all four movements the men have a somewhat greater degree of preci- sion than the women (Figs. 9-12). The right- hand movements are bet- ter than the left for both sexes, and the movements toward the body better than those away from it. Left Precision of movement test, hand, away. Abscissas — scale readings, in cen- timeters. Ordinates — number of subjects. - - - - women ; men. MOTOR ABILITY «3 The average variations (Table VI) for the sexes approximate one another more closely than the averages. In the movements away from the body neither sex can be said to have greater uniformity. In the movements toward the body the variation of the men is somewhat less wide than that of the iromen. TABLE VI. Precision of movement. Average variation of five trials. o-S x.o l-S 2.0 2-5 3.0 3.5 *o 4-S 5.0 cm. cm. cm. cm. cm. cm. cm. cm. cm. cm. •O Women . I 3 6 2 4 2 3 2 2 Pis Men. . . . 2 6 6 6 4 I •• ■s Women . I 3 8 4 6 2 I 51 Men. . . . 4 s 3 7 2 2 I •• I ■a'^ Women . 3 8 4 S 2 3 s- Men.. .. 4 6 4 6 2 I 2 «r^ Women . I 9 5 3 3 2 2 5" Men.. .. 5 4 5 2 3 3 2 I D. MOTOR AUTOMATISMS. The object of the test on motor automatisms was merely to discover whether or not a tendency toward automatic movements was present in the subject. The apparatus employed was that used by Miss Stein (76) in her experiments in this field. It consisted of an oblong board suspended from a hook in the ceiling by ropes attached to its four corners. When adjusted, the board hung in a horizontal position about two inches above the surface of a table, on which was 24 THE MENTAL TRAITS OF SEX placed a large sheet of rough manila paper. The sub- ject sat at the table with his right arm, from wrist to elbow, resting on the board. He held in his hand, which hung over the edge of the board, a soft black lead pencil, whose point rested lightly on the paper. The board responded instantly to any movement of the arm. Each movement was registered on the paper by means of the pencil. The instructions given the subject were to place himself in a perfectly comfortable position, such that the arm would have no tendency to move through strain, and then to let his arm do as it pleased, — move if it wished or stay still if it wished, — not to inhibit any impulses to movement which arose, nor make any voluntary movements. The subject's attention was distracted during the test by asking him the series of questions on personality given in chap. viii. These questions proved to be a very efficient method of dis- traction, since the subjects were universally interested in them. The results were classified under four heads, with reference to the presence of automatisms, i. e., Absent, Doubtful, Present, and Marked. The cases where no movement was registered, or only such movement as was evidently due to slight changes of position, were marked " absent." Those where the amount of move- ment was greater, but still possibly due to changes of position, or to gradual accommodation to slight strain, were called " doubtful." Cases where the movements were unquestionably automatic arm movements, but slight in extent and number, were marked " present," while those having movements of considerable extent and variety were classified as " marked." MOTOR ABILITY TABLE VII. Prevalence of motor automatisms. as Absent. Doubtful. Present. Marked. Women Men 8 9 S 6 S 6 7 4 The results, given in Table VII, show a somewhat greater tendency on the part of women to display motor automatisms than on the part of men. The tendency is shown most clearly in the last column of the table. SUMMARY OF OTHER EXPERIMENTAL WORK ON MOTOR ABILITY. There are several researches on reaction time to compare with the present experiments. Lewis (46), after experimenting on a large number of American men and women, using both visual and auditory reac- tions, found that men are quicker than women in both kinds of reaction, and have a smaller mean variation. The Columbia University tests (82) included five audi- tory reactions for each subject. In these the women were slower than the men. The remaining reaction- time tests of which we have a record were made on children. Gilbert (30) has shown that boys are quicker than girls at all ages in auditory reaction, and that boys of over ten years have a smaller mean varia- tion than girls, MacDonald, from his work on the school children of Worcester, Mass. (55, p. 1106), reports a longer reaction time for girls of all ages. Herzen (33, Appendix), from a much less extended series of observations than those on school children, concludes that young girls are quicker in their reac- 26 THE MENTAL TRAITS OF SEX tions than boys, but that after adolescence the relation is reversed. As far as adults are concerned, therefore, the experimental evidence agrees unanimously with the present series of tests in showing that men have a shorter reaction time and a smaller mean variation than women. The same relation as to rate probably holds for children. The only comparable tests on the rapidity of finger movement and the rate of fatigue are those performed on school children by Bryan (ii,p. 173), Gilbert (30), and Bagley (3) ; and those reported by MacDonald (55, p. 1105). They are all in accord with the series of tests here reported in finding greater rapidity of finger movement among males than among females. Gilbert also r^orts that boys are somewhat less easily fatigued than girls, a conclusion which is again in accord with the present results. The Columbia Univer- sity tests (82) on fatigue show no difference between men and women in this respect. But in this case the experiment was performed with Cattell's ergometer and the subject was required to make fifty pressures on the instrument at the rate of one a second, condi- tions certainly not so well calculated to produce fatigue as those of the tapping test. The failure to indicate any sexual difference in fatigue may be due to the fact that the amount of fatigue induced by the experiment was so slight. In the tests recently made on Chicago school children (18) the boys sur- passed the girls in both strength and endurance at all ages. Bagley (3) in his experiments on school children used the card-sorting test in several forms as a test of mental ability. He reports that he found girls some- MOTOR ABILITY 27 what superior to boys in mental ability — a result which is in accord with that of the present test on card-sorting. Another experiment which, although not directly comparable with the card-sorting test, is still of the same type, is the one called a test for the rate of perception in the Columbia University series (82). The subject was given a card containing five hundred printed letters, of which one hundred were A's, arranged haphazard, and was asked to mark out all the A's as rapidly as possible. Here, again, the women were more rapid than the men. The essence of the test in this case also is the formation of a new eye-hand co-ordination. Both Bryan (11, pp. 192-6) and Bagley (3) find boys slightly superior to girls in precision of move- ment. Bryan's test was, like the present one, the drawing of a single straight line. Bagley's consisted in tracing a pattern. Bryan also found boys slightly superior to girls in a target test. All these tests on the accuracy of a formed co-ordination agree in show- ing the male child and adult slightly superior to the female. The experiments on involuntary movements, and movements influenced by the sight of moving objects carried on by Tucker (81, p. 404) with Jastrow's auto- matograph revealed no difference of sex in children. Miss Stein's experiments (76) on college students, in which she used the same apparatus which was used in the present tests, produced results which are in accord with those given above, in so far as they are comparable with them. She finds a somewhat greater proportion of women than men who display spontane- ous motor automatisms. 28 THE MENTAL TRAITS OF SEX GENERAL SUMMARY OF EXPERIMENTS ON MOTOR ABILITY. All the tests on motor ability of which we have record agree in showing that in most phases this ability is better developed in the male than in the female. Men have a shorter reaction time, with a smaller mean variation than women. They have a greater rapidity of movement than women, and become fatigued less rapidly. They have a somewhat greater accuracy of movement than women. Women excel men in the formation of a new motor co-ordination, such as that of card-sorting and of marking out A's, and are slightly more subject to motor automatisms than men. CHAPTER III. SKIN AND MUSCLE SENSES. Three groups of problems connected with the skin and muscle senses were investigated ; touch and pres- sure, cutaneous space, and temperature. The subjects under each heading were as follows : A. Touch and pressure. 1. Threshold of impact on the volar side of the forearm. 2. Threshold for pain through pressure on the right and left temples. 3. Discriminative sensibility for pressure on the palm of the hand. 4. Discriminative sensibility for lifted weights. B. Cutaneous space. 1. Discrimination of two points crosswise and lengthwise on the volar side of the forearm. 2. Discrimination of areas on the volar side of the forearm. C. Temperature. 1. Discriminative sensibility at the physiological zero. Standard, 30° C. 2. Discriminative sensibility for cold. Standard, S° C. 3. Discriminative sensibility for heat. Standard, 45° C. A. TOUCH AND PRESSURE SENSATIONS. I. Threshold of impact. — The piece of apparatus used in the determination of the threshold of impact was one designed by Professor James R. Angell for use in the laboratory of the University of Chicago (i) . In brief, the instrument is a delicate balance, and the stimulus is given by a cork surface at the end of a rod suspended from one arm of the balance. So long Z9 30 THE MENTAL TRAITS OF SEX as the amount of fall of the balance arm and the weight producing the fall are constant, the force of the impact must be constant. The instrument is noiseless, and the stimulations can be given at any rate desired. The area used in the present investigation was the middle of the volar side of the right forearm. The middle point between the wrist and the elbow was marked with an ink spot. The arm was then adjusted on padding under the balance arm; a flat uniform area, if possible with no hairs, was selected close to the ink spot ; and the balance arm was brought over this area. The cork surface was raised 3 mm. above the area, and a trial weight of 20 mg. placed in the weight pan. The stimulations were given in series of ten, with intervals of from twenty to sixty seconds between stimulations. Any rhythmic regularity in the series was carefully avoided. The subject was directed to count aloud every time he felt the stimulations — one for the first, two for the second, etc. The point at which he could count seven or eight in ten correct- ly was taken as the threshold. Not more than three series in succession were given without a rest and change of position. This test was made in combination with the one for the absolute threshold for vision (see chap, vi, sec. A). The subject was obliged to have his eyes completely protected from the light for three-quarters of an hour before the threshold for light could be tested. This time was used for the determination of the touch threshold, and the discriminative sensibility for area (see sec. B, 2, below). During the entire test, therefore, the subject sat with his head in the SKIN AND MUSCLE SENSES 31 Fig. 13. Threshold of impact. Abscissas — weight in milligrams. Ordinates — number of subjects. - - - - women : men. dark box. Since the ventilation of the box was not good, the conditions were not so favorable for the concentration of attention as in the other tests, but this distraction was the same for all subjects. Since the size of the contact surface (2 mm. square) and the height of the fall (3 mm.) were kept constant throughout the entire series of tests, and the weight in the weight pan was the only factor varied, the re- sults can be recorded for comparative purposes in terms of weight only. The determination of the threshold was rendered very difficult in some cases by a tendency to imagine stimulations as soon as the threshold was approached. Almost all of the subjects put a few imaginary sensations into the series. In a few the tendency was very marked. One subject — a man — counted a whole series of fifteen non-existent stimulations. The tendency was partially counter- acted by telling the subject of his error. The point where seven or eight of the real stimulations were correctly counted, regardless of the extra ones in- serted, was finally taken as the threshold. The curve for the threshold of impact (Fig. 1 3) shows a somewhat lower threshold in the women. In the region of very low thresholds the men and women are present in equal numbers, but the women are in excess in the middle lower ranges, and the men in the upper. The real difference is probably somewhat greater than 32 THE MENTAL TRAITS OF SEX the curve represents, because the region used — the forearm — is more plentifully supplied with hairs in men than in women. It is perhaps worth while to mention, in passing, a curious illusion experienced by several of the subjects in connection with this test. Although all the stimu- lations of any one series were given on exactly the same spot, several subjects volunteered the observa- tion that they could feel the changes of position of the stimulations very distinctly. One subject said that the successive stimulations described a long oval from wrist to elbow, and that they differed in distinctness in different regions. There was no opportunity to examine further into this phenomenon. 2. Threshold for pain on the right and left temples. — The thresholds for pain on the temples were taken with a spring algometer registering 4,000 g. (57). The subject was required to lay his head on a thin padding on the table, with one temple up. A piece of chamois skin was placed under the metal disc of the algometer to prevent temperature sensations. The subject was told that the pressure would be increased gradually and that he was expected to indi- cate the point at which he first began to feel pain. It was carefully explained to him that he was not to wait until the experience was decidedly painful, but was to indicate the point at which he could just begin to detect a feeling of pain in addition to a mere pressure sensation. The ease with which the discrimination was made differed very widely in different cases. Some subjects had a sudden sharp transition from mere pressure to pressure plus pain, which made it a simple matter to indicate the advent of pain. Others had a SKIN AND MUSCLE SENSES 33 very gradually increasing feeling of discomfort, almost from the beginning ; to mark any point at which pain could be said to begin was extremely difficult — in fact, almost arbitrary. In such cases, there was no criterion except the final judgment of the subject himself. The test was re- peated four times on each temple. The results which appear in the curves are averages of the four read- ings. Sometimes the right temple was taken first, and A period of four or five minutes' Fig. 14. Algometer test. Left temple.' Abscissas — pressure in grains. Ordinates — number of subjects, women : men. sometimes the left rest was allowed between the two. The curves for the two temples (Figs. 14 and 15) are alike in general outlitie. In both cases the interpre- tation of the curve, as a whole, is lower pain thresh- olds for the women than for the men; but it is also true that both curves show more men than women with very low thresholds. In general, more women than men are found in the middle ranges, and more men than women at both extremes, but the preponderance of men is most marked in the region of high thresholds. •Only twenty-four women are represented in Figs. 14 and 15, because one woman was unwilling to submit to the algometer tests, fear- ing headache. This subject would probably belong to the lowest range. £M /iec ilea sen jioo Fig. 15. Algometer test. Right temple.' Abscissas — pressure in grams. Ordinates — number of subjects. women ; men. 34 THE MENTAL TRAITS OF SEX The interpretation of the results offers the same apparently insurmountable difificulties as that of all similar experiments. Does it mean that women really feel pain more quickly than men, or that they are more apt to call a slightly disagreeable sensation painful than are men? There seems to be no possible criterion for a real decision of this question. The prob- lem is not peculiar to the comparison of pain sensa- tions of men and women. In attempting to make a quantitative comparison of the pain sensations of any two individuals the standard is absolutely subjective, and must be accepted as such. It must in consequence be admitted that quantitative measurements of pain are less capable of control and consequently less reliable than most quantitative measurements of sensation pro- cesses. But tfiis fact does not justify the assumption of a diflEerence in pain standard on the part of different classes of individuals. As far as we are capable of interpreting the results obtained, they indicate some- what greater sensitiveness to pain on the part of women than on the part of men. 3. Discriminative sensibility for pressure on the palm of the hand. — The apparatus used for testing the dis- crimination of pressure was a series of little wooden bottles weighted with shot. The series consisted of twenty-one bottles beginning with 80 g. and ending with 100 g. The uneducated hand, in most cases the left, was used for the test. The hand was supported on padding as comfortably as possible and was per- fectly relaxed. It had to be placed in such a position that it offered a flat space large enough to allow of setting the bottles upright. A small cork disc was placed on the hand first, to give a smooth surface of SKIN AND MUSCLE SENSES J$ Discriminative sensibility for pres- sure. Standard, lOO g. Abscissas — weight just discrimin- able from the standard. Ordinates — number of subjects. women ; men. contact and insure placing the bottles in approxi- mately the same spot each time. The two weights to be compared were placed suc- cessively on the same spot, and the subject, whose eyes were closed, was asked to say which of the two was heavier. The lOO-g. weight was used as the standard. The subject was not told anything about a standard. He was merely asked to make the comparison between the two weights given him, and did not know that one of them each time was the lOO-g. weight. The standard was put on sometimes first, and sometimes second, to avoid any constant errors of order. The series of tests began with the large differences, usually 80 and 100. If these were judged correctly every time, a smaller difference was tried. The number of tests with each pair of weights was increased as the limit of discrimina- tionwas approached. The point finally fixed upon as the discriminative sensibility was the point at which three- fourths of twelve or sixteen judgments were correct. The results (Fig. 16) show no marked difference between the men and the women. The women are a little more numerous in both the upper and the lower ranges, but the average is about the same for both sexes. 4. Discriminative sensibility for lifted weights. — The apparatus used for testing the discriminative sensi- 36 THE MENTAL TRAITS OF SEX / ' bility for lifted weights was the series of wooden bottles used for the previous test. The subject was required to lift the bottles with the thumb and fore- finger of the uneducated hand — usually the left. He sat with his eyes closed, and his hand held in such a position that the bottle could be placed between the thumb and forefinger. After lifting the first one, he set it on the table, and it was at once re- placed by the second. For the rest, the experiment was carried out in the same way as the pre- ceding one. The results represented in Fig. 17 show a much finer dis- crimination on the part of the men. There is a much larger proportion of men than of women who can discriminate a difference of 4 to lO g., while the reverse is true in the range of differences greater than log. Since the discrimination of lifted weights involves princi- pally the joint sensations, this test is closely allied with the motor tests. The finer discrimination of the men for weights is in accord with their better devel- oped motor ability in general. u " U 9t Fig. 17. Discriminative sensibility for lifted weights. Stan- dard loog. Abscissas — weight just dis- criminable from the standard. Ordinates — number of sub- jects. - - - women : men. B. SPACE SENSATIONS. I . Discrimination of two points crosswise and length- wise on the volar side of the forearm. — ^Jastrow's aesthesi- ometer was the instrument employed for testing the SKIN AND MUSCLE SENSES 37 discrimination of two points on the skin. Tiie instru- ment allowed the distance between the two points to be varied from i mm. to 100 mm. The region used was the middle of the volar side of the right forearm. The arm was supported on a padding in a comfortable position. The subject was told that he would be touched in the region described, sometimes with one point and sometimes with two, and that all that was re- quired of him was to tell whether he felt one point or two. The measurement of the discrimination crosswise of the arm was taken first, and the lengthwise test followed on another day. In making the test, stimulations with one point were frequently inserted in the series as a control. Often the judgments seemed to be pure guesses when the difference was really below the discriminative sensi- bility of the subject. In these cases the distance was increased until a reliable judgment could be made. In a few instances a genuine illusion seemed to be in- volved, which caused the judgments to remain diffi- cult and variable through a large range of differences. All that could be done was to fix an approximate point after a long series of experiments. Frequently the guessing process would be stopped, or at least much reduced by telling the subject that he was call- ing one point two. The series of tests was begun with a difference a little below the average discriminative sensibility and was increased or decreased as the case demanded, until the least difference was found at which three-fourths of the judgments of two points out of twelve or sixteen were correct. The women proved to have a somewhat finer dis- crimination in the crosswise direction (Fig. i8) and a decidedly finer discrimination in the lengthwise direc- 38 THE MENTAL TRAITS OF SEX tion (Fig. 19). In the former case the two curves occupy the same range. The difference is shown by the preponderance of women with a small discrimina- tive sensibility and the pre- ponderance of men with a large discriminative sensi- bility. In the latter case (the lengthwise discrimi- nation the diJBPerence is so great that the two curves occupy a different range; the women's curve from 20 to 65 mm., and the men's curve from 35 to 75 mm. There are two factors which doubtless combine to decrease the apparent difference in the discriminative sensibility of the two sexes in the tests made across the arm. The first is that the curve of the arm makes it very diffi- cult to put the instru- ment down crosswise in such a way that the two points strike simultane- ously and exert the same pressure. Inequalities of time and pressure are therefore much more likely to assist the judgment in the crosswise test than in the length- wise. The second factor is that the structure of the arm is much more differentiated crosswise than it is /Esthesiometer test. Crosswise. Abscissas — millimeters between the two pointy Ordinates — number of subjects. women ; men. Fig. 1 9. ^sthesiometer test. Lengthwise. Abscissas — millimeters between the two points. Ordinates • — number of subjects. women ; men. SKIN AND MUSCLE SENSES 39 lengthwise. If one point rests on one tendon and the other on another it is easy to distinguish two points by an indirect judgment, because the difference between the two tendons is already known. The judgment ceases to be a pure skin discrimination and becomes a complex judgment based on other sorts of experience. In the lengthwise test, on the other hand, the two points fall upon a homogeneous substructure, a single muscle or tendon, and the discrimination is much more nearly a pure skin judgment. 2. Discrimination of areas on the volar side of the forearm. — The apparatus used for determining the discriminative sensibility of the skin for area was a series of five cork blocks about 3 mm. thick, varying in size from 10 mm. square to 20 mm. square. A pre- liminary test was made with the blocks all weighted to the same amount — 20 g. It was found that in this case the smallest block felt so much heavier than the largest that the difference in pressure inter- fered seriously with the judgment of size. Either the smaller block was called larger, because the factor of pressure was not clearly separated from that of size, or the subject reported himself unable to make any reliable size judgment because of the disturbing differ- ence in weight. With the hope of remedying this evil the blocks were then weighted proportionately to their area, so that equal amounts of pressure should be exerted on equal skin areas in all stimulations. This attempt was only partly successful. The smallest block now felt lighter than the largest. The series of tests was nevertheless carried out with the latter blocks, because the difference of pressure was much smaller with them than with the former ; but the 40 THE MENTAL TRAITS OF SEX results cannot be regarded as entirely reliable. Until the relation of pressure and area in judgments of area on the skin has been made the object of special inves- tigation, and series of areas weighted to produce equal sensations of pressure have been determined, no thor- oughly reliable results in this field can be obtained. This series of tests, as well as all previous investigation, suffers from this defect. The area of skin employed for the discrimination of size was the same as that used for the touch and space thresh- olds — the middle of the volar side of the right forearm. This experiment, like that for the touch threshold, was made during the time required for the fatigue of the retina for the threshold of light (see p. 76). The method was that used for all the experiments in discriminative sensibility ; two areas were applied successively, and the subject was asked to report each time which of the two felt larger. The series began with the largest difference and worked down to the smallest difference, regarding which three-fourths of the judgments out of twelve or sixteen were correct. The curves presenting the results of the test (Fig. 20) show a somewhat better discrimination for area on the part of the men. Their curve culminates at 1 5, and that of the women at 12.5. The outer limits of the two curves are the same. Discriminative sensibility for area. Standard, a block 20 mm. square, weighing 20 g. Abscissas — size o£ the block just discriminable from the standard. Ordinates — number of sub- jects. - - - - women ; men. SKIN AND MUSCLE SENSES 41 C. TEMPERATURE SENSATIONS. The only aspect of temperature sensation experi- mented upon was that of the discriminative sensibility. It was tested with three different standards : one near the physiological zero, 30° C; one approaching the pain threshold for cold, 5° C; and one in the region of the pain threshold for heat, 45° C. The method of giving the stimulus was the same in all three cases, viz., immersing the first two fingers of the right hand to the second joint in water. To facili- tate preserving a constant temperature, a large mass of water was used. The apparatus consisted of two large zinc basins, eighteen inches long, ten inches wide, and six inches deep. They were filled to within an inch of the top. The basins were covered with asbestos jackets to prevent changes of temperature. Asbestos lids with openings for the thermometer and for the immersion of the fingers covered the basins. The thermometers, reading tenths of a degree, were hung very close to the place where the fingers were immersed, to insure the recording of the temperature of the water actually used in the stimulation. Each basin was set on a tripod, and supplied with a Bunsen burner for changing the temperature. For the cold stimulation, ice was used. The temperature changed very slowly, and by leaving a low flame, experimen- tally determined, under the basin, it was possible to keep the temperature constant through considerable periods of time. The changes of temperature required some time and patience. They could be produced rapidly enough, but it was difficult to bring them to a standstill at exactly the point required for the test. To economize time, the intervals required for chang- 10^ AA// Fig. 21, -Af 42 THE MENTAL TRAITS OF SEX ing the temperature were employed by the subjects in writing their answers to the questions on general infor- mation (see chap, vii, sec. D), and in sorting the worsteds for the test on color-blindness (see chap, vi, sec. D) . It required from half an hour to an hour to determine the dis- criminative sensibility with each standard. The method of mak- ing the discrimination was the same as that used in the other tests. The subject was told to put his fingers first in- to one basin and then into the other, and tell which felt the warmer. The fingers were dried after each discrimina- women ; men. . . j i • tion, and time was allowed for the effects of the extreme stimuli to dis- appear. It was not possible to make so many judg- ments for each stimulus difference as in the case of the other skin discriminations, partly because the effects of the extreme stimuli are so lasting that only a few tests can be made without long rest intervals, and partly because it was impossible to hold the tem- perature absolutely constant for many tests at a time. Consequently, three correct judgments out of four, or at most four out of six, were regarded as decisive. If further tests threw doubt on the accuracy of any determination, the same stimulus difference was tried a second time. Discriminative sensibility for tempera- ture. At the physiological zero. Standard, 30° C. Abscissas — temperature just discrim- inable from standard. Ordinates — number of subjects. SKIN AND MUSCLE SENSES 43 Since the order in which the stimuli are given is a very important factor in temperature discriminations, great care was taken to see that an equal number of judgments was made in each order. The summation of stimuli which tends to make the second stimulus feel more intense than the first is more marked in temperature than in any other sense. The difference re.quired to make the more intense stimulus feel more intense when it was given first was frequently very large in the cold and hot ranges, where- as when it came second, a very slight difference was sufficient. In fact, when the two were of the same temperature, or the second a little less intense, the second was judged more in- tense. In the form of tempera- ture test in which the subject is allowed to put his fingers back and forth from one basin to the other, much smaller absolute differences can be discrimi- nated than those reported in this test, but the judg- ment made is not a simple sense discrimination comparable with those made in the other senses. For example, if a discrimination with two very cold tem- peratures is being made, and the subject is allowed to have each stimulation but once for each judgment, he will say that the second one is colder each time, but that the difference in temperature is much greater in one order than in the other; and that he therefore believes that the basin which when second is a colder Fig. 22. Discriminative sensibility for temperature. Cold. Standard, S° C. Abscissas — temperature just discriminable from standard. Ordinates — number of sub- jects. women ; men. 44 THE MENTAL TRAITS OF SEX second, is really colder. The same process in less conscious form is what takes place when the subject is allowed to change back and forth from one basin to the other. Each stimulus, as he gets it, feels colder than the previous one, but the difference is much more intense when he .goes from the really less intense to the more intense than when he goes in the opposite direction. He reaches a correct judgment as to which is colder, but the judg- ment is not a simple temperature discrimi- nation ; it is an indirect judgment. The absolute values obtained for temperature discrimination are therefore largely dependent on the method. The results differ with the method far more in the extreme temperatures than in those near the physiological zero. The pres- ent results represent simple temperature discrimina- tions, and show correspondingly large values for the discriminative sensibility in extreme temperatures. The curves for the temperature tests (Figs. 21-23) show very slight variation in the sensibility of the two sexes. At the physiological zero no distinction can be made. In the two extreme temperatures the women have a slight advantage. They are grouped somewhat more toward the region of fine discrimina- tions, but the difference is scarcely large enough to be regarded as significant. i,t\ ift **^ »** 47 *> 4f Fig. 23. Discriminative sensibility for tempera- ture. Hot. Standard, 45° C. Abscissas — temperature just discrimin- able from standard. Ordinates — number of subjects. women ; men. SKIN AND MUSCLE SENSES 45 SUMMARY OF OTHER EXPERIMENTAL WORK ON SKIN AND MUSCLE SENSES. There are no results directly comparable with the test on the threshold for impact. The so-called meas- ure of the fineness of touch in the Italian investiga- tions (Lombroso, Ottolenghi, Di Mattei) is an aesthe- siometer test. The experiments on general sensibility, however, are often considered to be a measure of the delicacy of tactile sensations. Ottolenghi (66) calls general sensibility a sort of contact sensation. Its measure is the least amount of a faradic current which can be perceived. Lombroso (51, chap, iii) reports that women have a less keen general sensi- bility than men, while Dehn (20) experimenting with a small number of individuals, and Ottolenghi (66) from returns on eight hundred women and six hun- dred men, agree that women have a keener general sensibility than men. Di Mattei (21) corroborates this result for children of from four to twelve years. Griffin (31) has shown that sensitiveness to electrical stimulation and sensitiveness to pressure stimulation do not necessarily vary together. It is therefore impossible to argue directly from keener general sen- sibility to more acute touch. There is a much greater mass of material for the comparison of men and women with reference to sen- sitiveness to pain. Two methods of inducing pain have been employed ; one by electrical stimulation and the other by pressure. Lombroso (50, 51), Ottolenghi (66), Di Mattei (21), and Dehn (20) used the former method. The three Italians, the first two working with adults, and the last with children of from four to twelve years, all find the female less sensitive to pain 46 THE MENTAL TRAITS OF SEX through electrical stimulation than the male, while Dehn finds women more sensitive than men. The former result is based on a far greater mass of results than the latter. The experiments made by the second method, pain through pressure, all agree with the present series of tests in showing a lower threshold for women than for men. Wissler (82) and MacDonald (54) experi- mented on adults. Carman (16) on children, and Swift (78) on both adults and children. The relation holds for all ages. There is but one comparative test on passive pres- sure, that made by Dehn (20). He used an error method instead of a gradation method, but his results agree with ours in showing no difference between the sexes in this respect. The ability to discriminate lifted weights was found by Gilbert (quoted by MacDonald, 55, p. 1 107) to be greater in boys than in girls between the ages of thirteen and seventeen, a result which corrob- orates ours. Wolfe (83) in experimenting on the effects of size on judgments of lifted weights, finds women much more subject to illusion than men. Gil- bert (30) finds the same difference between boys and girls. Both are inclined to explain the fact by the greater suggestibility of the female. If it is true, however, that the actual ability to discriminate lifted weights is less in women than in men, this may explain in part the fact that they are more subject to the size- weight illusion than men. Other forms of test on the perception of weight do not agree with the discriminative tests in showing less accuracy on the part of women. Wissler (82) SKIN AND MUSCLE SENSES 47 reports a test in which the subject was required to lift against a spring to i kg. as a standard, and then attempt to lift the same amount several times from memory. He found no difference in the ability of men and women to do this. Jastrow (38) required his subjects to estimate a pound and an ounce in shot with no guide or standard. He found women more accurate than men. The results suggest the general- ization that men excel women in the direct discrimina- tion of lifted weights, but are equaled or excelled by women in tests where the memory of a given weight is involved ; but no stress can be laid on such a state- ment until more data are available. There are several comparative tests at hand on two- point discriminations. Galton (27), Dehn (20), Lom- broso (51, chap, iii, 50) and the Columbia University tests (82) dealt with adults. Galton measured about 1,200 men and women on the nape of the neck, using a method like that of the present test. His results are in accord with ours in showing a finer discrimination on the part of the women. Dehn's test and those on Columbia students failed to show any difference of sex in this respect. The method used is probably a sufficient explanation for the fact in both cases. The xsthesiometer points were kept a fixed distance apart, and the right and wrong answers on a small number of stimulations were recorded. The results thus yielded are too meager to give any reliable measure- ment. Lombroso, experimenting on 100 normal men and 100 normal women, finds women less sensitive than men. His subjects were of varying ages and social con- ditions, but he states that the general relation holds also for men and women of the educated class. He 48 THE MENTAL TRAITS OF SEX does not describe his method. The fact that in sev- eral other respects his results are contradictory to those of other observers, makes one hesitate to lay much stress on this discrepancy. There are two sesthesiometer tests on children, that by MacDonald (55, p. 1005) made on the palmar surface of the wrist, and that by Di Mattel (21) made on the index finger. MacDonald's method, and presumably Di Mattel's, though he is less explicit, were analogous to ours. Both sets of results agree with ours in showing the female to have a finer discrimination of two points than the male. There are no previous data known to the author on the comparative ability of the sexes to discrimi- nate area on the skin. One would expect to find that the class with the finer two-point discrimination was also the one with the greater ability to discriminate area on the skin, but this does not hold in the present case. Since the discrimination of area is a complicated judgment involving several factors, it is by no means sure that it need be correlated with a two-point discrim- ination. If the two results are contradictory, doubt should be thrown on the test in the discrimination of area rather than on the aesthesiometer test, since the conditions of the former were much less satisfactory than those of the latter. There are two tests on temperature discrimination in which a comparison of the sexes has been made ; one by Dehn (20) on adults, and one by MacDonald (55, p. 1005) on school children. The method in both cases differed from that employed in the present tests. It consisted in stimulation of the skin by metal surfaces of known temperature. Dehn used successive stimu- SKIN AND MUSCLE SENSES 49 lations and MacDonald simultaneous stimulations. Dehn's temperatures were near the physiological zero, MacDonald gives no standard, but one of the stimuli was certainly above the physiological zero, since the test is called a discrimination of heat. Dehn finds women more sensitive than men, MacDonald finds boys, on the whole, slightly more sensitive than girls. The present tests show no difference of sex. It seems safe to conclude that sexual jdifferences in ability to discriminate temperatures are very insignificant, if they exist at all. GENERAL SUMMARY OF EXPERIMENTS ON SKIN AND MUSCLE SENSES. The general outcome of the experimentation on the sensations mediated by the skin is to show that women have somewhat keener senses than men. This state- ment does not hold for all forms of sensation. The greater sensibility of women is marked in the two-point discrimination, in general sensibility, and in sensitive- ness to pain through pressure ; and is slight in delicacy of touch. In passive-pressure discrimination and in temperature there is no difference. In pain through electrical stimulation, the discrimination of lifted weights, and possibly, in the discrimination of area on the skin, men are more sensitive. CHAPTER IV. TASTE AND SMELL. The experiments in taste and smell dealt with the following subjects : A. Taste. 1. Threshold of presence' for sweet, salt, sour, and bitter. 2. Threshold of recognition" for sweet, salt, sour, and bitter. 3. Discriminative sensibility at T,. 4. Discriminative sensibility for strong tastes (viz., those of series B of Table VIII). B. Smell. 1. Threshold of presence for cloves and violet. 2. Threshold of recognition for cloves and violet. 3. Discriminative sensibility at Tj. 4. Discriminative sensibility for strong odors (viz., those of series B of Table IX). A. TASTE. The substances used for the four tastes were sac- charin, chemically pure salt, sulphuric acid, and sul- phate of quinine. Two series of solutions in distilled water were prepared from each substance. Series A began below the normal threshold of presence and extended above the average threshold of recognition. Series B consisted of solutions which were all strong to the normal taste. The limits of the series, and the gradations necessary in each one were determined experimentally. The bottles containing the solutions " The term " threshold of presence " is sometimes represented in this chapter by the symbol Tj, and the term "threshold of recognition" by the symbol T,. SO TASTE AND SMELL 51 were all alike in appearance. The series of solutions, in percentages, are given in Table VIII. No attempt was made to control the temperature of the solutions any more closely than the temperature of the room. TABLE VIII. Series of solutions used in testing taste. Sweet. Salt. Sour. Bitter. A B A B A B A B I .0005^ .025^ 01% 2. % .OOIjg .017^ .00004!? .001 % 2 .00075 .027 04 2.05 .003 .018 . 00008 .0012 3 .001 .029 08 2. I .005 .019 .0001 .0014 4 .0015 .031 I 2. IS .006 .02 .0002 .0016 5 .002 .033 II 2. 2 .007 .021 .0003 .0018 6 .0025 • 035 12 2. 3 .008 .022 .0004 .002 7 ■ 003 • 037 13 2. 4 .009 .023 .0005 .0022 8 • 003s ■ 039 14 2. 5 .01 .0006 .0024 9 .004 IS 2. 6 .oil .0007 .0026 10 .0045 .... 16 .012 .0008 II .005 18 .013 12 2 .... 13 22 .... I and 2. Thresholds of presence and of recognition. — The two thresholds of presence and of recognition were obtained by the same method and in the same series of experiments. The subject was seated with his back to the table containing the bottles, in order that he might not see which bottles in a series were taken. He was given a cup containing distilled water and was told that it was distilled water and would be his standard of comparison. The distilled water was not tasteless to most subjects, but tasted differently to different individuals. Sometimes it seemed sweet, sometimes bitter, and rarely salty or sour. In spite of the subjective tastes assigned to the distilled water it s* THE MENTAL TRAITS OF SEX Fig. 24. Taste, Tj for sweet. Abscissas — percentage of the solu- tions. Ordinates — number of subjects. women ; men. seemed necessary to use it as a basis for the solutions. It would have been extremely difficult, if not impossible, to find any one solution which would be pronounced tasteless by all subjects. Since the distilled water was constantly before the subject as a standard of comparison, the neces- ir sity for having a solution to start with which was subjectively tasteless was lessened. All the sub- ject was required to tell about the solutions given him was whether or not they were the same as the distilled water, and if not, how they differed. Since taste is a sense which, like smell, is pe- culiarly subject to illu- sions at the threshold, the subject was given two bottles at each test, one of which contained distilled water, and the other a weak solution. When a difference from the distilled water of the cup was reported, the subject was asked in which bottle he no- ticed it. If it was an illusion, it was quite as likely to be referred to the distilled water bottle as to the solution. Often the subject said that both bottles Fig. 25. Taste. Ti for salt. Abscissas — percentage of the solu- tions. Ordinates — number of subjects. women ; men. TASTE AND SMELL S3 Fig. 26. were different from the distilled water. If they seemed equally different, it was again counted as an illusion. If the bottle containing the solution was reported more different from the standard than the bottle containing dis- tilled water, the discrimination was regarded as genuine, but a threshold was determined only after three correct judg- ments out of four. The order of procedure was as follows : The subject was provided with a cup of Taste. Ti for sour. distilled water and a teaspoon. Abscissas— percentage of the A jar was placed beside him, Ordinates-number of sub- ^"'^ ^^ ^^^ ^°^'^ "°t to SWal- low the solution unless he wished. Two bottles just alike in appearance were placed before him, and he was directed to taste the distilled water in the cup first, and then taste half a tea- spoonful of the liquid in each bottle. He was told that he must make the solution touch all parts of the tongue in tasting, since not all parts were equally sensitive. After tasting each solution once, he was required to tell which one, if either, differed from the distilled water of the cup. Both bottles were then removed, and two more given him. jects. - - women ; Taste. Ti for bitter. Abscissas — percentage of the solutions. Ordinates — number of subjects. women ; men. 54 THE MENTAL TRAITS OF SEX Fig. 28. Taste. Tj for sweet. Abscissas — percentage of the solutions. Ordinates — number of sub- jects. - - - - women ; men. The tests always began with the weakest solutions, and worked up to the place where the discrimination from distilled water could be made. This procedure is par- ticularly necessary in taste and smell, because the nerves become fatigued so rapidly that it would be impossible for most subjects to detect the weaker solutions when the stronger ones had just been perceived. After reaching the point at which the subject was sure he could detect some- thing in the solution (Tj), the same process was continued until he was able to identify the taste (T^). The curves for the threshold of presence (Figs. 24- 27) show a lower threshold for the women in all four tastes. The difference is most marked in bitter, sec- ond in sour, third in salt, and least in sweet. As regards the thresh- old of recognition (Figs. 28-31) the women are un- questionably more sensitive to sour and bitter. In salt thewomen'scurveis slightly better. It has more entries in the region of very low thresholds, and no cases which fall beyond the limits of the series. The curve for sweet averages about the same for both sexes. Both the best records and the worst are those of women. 1 r' \ \ 1 \/ J 1 1 1 V . Fig. 29. Taste. Ts for salt. Abscissas — percentage of the solutions. Ordinates — number of subjects. women ; men. TASTE AND SMELL 55 Fig. 30. — t— Taste. Tj for sour.' Abscissas — percentage of the solu- tions. Ordinates — number of subjects. - - - - women ; men. 3 and 4. Discriminative sensibility. — The discrimina- tive sensibility for taste was tested with two stand- ards. The first was the solution marking each subject's threshold of recognition, the second was identical for all subjects, viz., the first solution in series B of Table VIII. The sub- ject sat as for the previ- ^ ous test. Two bottles were set before him, and he was required to judge which of the two solu- tions was the stronger. The mouth was rinsed with distilled water after each discrimination. Since the standard stimulus for the first discrimi- nation was the solution marking each subject's thresh- old of recognition, a compari- son of results is difficult. The thresholds of recognition were scattered over a wide range, and there proved to be so small a number of men and women having the same standard that there are not sufficient data for a comparison. What few rec- ords are comparable show no marked differences, but they are too few in number to be of any significance. A comparison by percentages was Fig. 31. Taste. Ts for bitter. Abscissas — percentage of the solutions. Ordinates — number of sub- jects. women ; men. 'Only twenty-four men are represented in this diagram, record was not taken. One 56 THE MENTAL TRAITS OF SEX not feasible because the gradations of the taste series were not sufficiently fine to warrant it. The discriminations in the second series of tests, since an arbitrary standard was adopted, offer material which is comparable. The stand- ard gave a strong taste to all subjects, except those abnormally ob- tuse. The method of making the discrimina- tion was the same as that described for the Fig. 32. Taste discrimination. Sweet. Stand- ard, .025 per cent, solution of sac- charin.' Abscissas — percentage of the solu- tions just discriminable from the standard. Ordinates — number of subjects. « - — women ; men. previous series. The results of the tests on the discrimination of strong tastes (Figs. 32-35) show that the men have a finer discrimination in all tastes but salt, in which the women discriminated somewhat better. The general result agrees very well with that for thresh- olds. The lower the thresh- old for a given sense the coarser the discrimination in very strong stimuli. The same solution in the so- called strong series tastes much stronger to a subject ' Only twenty-four ofeachsexare represented in this diagram. Two records were not taken. Taste discrimination. Salt. Stand- ard, 2 per cent, solution. Abscissas — percentage of the solu- tions just discriminable from the standard. Ordinates — number of subjects. women ; men. TASTE AND SMELL 57 with a low threshold than to one with a high thresh- old, and the fineness of dis- crimination is correspond- inglyreduced. Whetheror not this cause is sufficient to account for all the dif- ference in discrimination, it is impossible to say. It might be that if we could ard. .017 per cnCt^u^ti obtain a Subjectively iden- sulphuric acid." tical standard for all sub- ""'IrTurdSinlbtw J««^ts, we should still find the standard. . the men having a finer absolute discrimination. However that may be, the fact remains that, given an arbitrary objective stand- ard in the region of strong ' tastes, the men have a finer ' discrimination than the ,, women. B. SMELL. The tests for smell were analogous to those for taste as to apparatus and method. They were made with two series of solutions, one designed to determine the two thresh- ■" "I M< Fig. 34. Taste discrimination. Sour. Stand- Ordinates — number of subjects. women ; men. Fig. 3S. Taste discrimination. Bitter. Standard, .001 per cent, solu- tion of quinine.' Abscissas — percentage of the solu- tion just discriminable from the standard. Ordinates — number of subjects. women ; men. 'Only twenty-four men are represented in this diagram. One man could not distinguish sour. ' Only twenty-four women and twenty-two men are represented in this diagram. One woman and two men had thresholds for bitter which were above the standard. One man could not distinguish bitter at all. 58 THE MENTAL TRAITS OF SEX olds of presence and of recognition, and the other to test the fineness of discrimination in the strong odors. Two substances were used : violet water (Roget and Gallet violette de Parme), and oil of cloves. The violet was simply diluted the required amount with distilled water. As a basal mixture for the cloves, an emulsion was made by shaking i part of oil of cloves in 99 parts of distilled water. This mixture was then diluted to form the series, being shaken thoroughly at each step. The odors were both so persistent that great care was necessary in preparing the weaker solutions. The utensils which had been used for stronger solutions had to be thoroughly cleansed with alcohol and distilled water before being used to make the weaker ones. The solutions were placed in glass-stoppered bottles all alike, being prevented from touching the necks of the bottles when put in. The distance between the surface of the liquid and the mouth of the bottle was made constant for all the series. The series of solutions are given in Table IX. In the tests on smell (unlike those on taste and all others in the present set of experiments where judg- ment between two stimuli formed the modus operandi) the subject was allowed to have as many stimulations as he wished from each of the two bottles given him, in the determination both of the thresholds, and of the discriminative sensibility. The reason for this departure in the case of smell is that it is the only sense in which the contact between external stimulus and nerve-ending is produced so indirectly. The actual stimulation of the nerve-ending depends upon TASTE AND SMELL TABLE IX. Series of solutions used in testing smell. 59 Cloves. Violet. Series A. Series B. Series A. Series B. I .000001^ .001 % .0000001^ I. % 2 .000005 .0012 .000001 1.2 3 .00001 .0014 .00001 1.4 4 .00005 .0016 .00005 1.6 S .0001 .0018 .0001 1.8 6 .0002 .002 .0005 2. 7 .0003 .003 .001 2.2 8 .0004 .004 .01 2.4 9 10 .0006 .0008 the nature of the inhalation. Two successive smell- ings of the same bottle may give sensations differing widely in intensity, depending on slight differences in inhalation. The subject was directed to use the same nostril for both stimulations in any comparison, and was allowed to go back and forth from one bottle to the other, in the hope of equalizing the inequalities of the single stimulations. I and 2. Thresholds of presence and of recognition. — The determination of the smell thresholds was made by a method like that used for the taste thresholds, but differing in two respects. The first modification was that common to all the smell tests stated above ; the second was that the subject was not provided with a bottle of distilled water which he knew to be such, corresponding to his standard of reference in the experiments on taste. This did not seem to be neces- 6o THE MENTAL TRAITS OF SEX Fig. 36. Smell. Tj for cloves. Abscissas — number of the solu- tions (see Table IX). Ordinates — number of subjects. women ; men. sary, because distilled water showed no tendency to stimulate the nerves of smell in any definite direction, as it stimulated those of taste. For determining the threshold of presence two bottles were given to the subject, one of which each time contained distilled water. He then reported " whether or not he could distinguish any odor in either bottle. The point at which he could select the right bottle three times out of four was taken as the threshold. To avoid the fatigue effects which are so marked in the sense of smell, the series began with the weakest solutions and advanced to the stronger. The curves for the thresh- old of presence (Figs. 36 and 37) show a lower threshold for the women, though the difference is slight. It is in- dicated chiefly by the greater number of women in the regions of extremely low thresholds for both sexes. In the tests for determin- ing the threshold of recog- nition the subjects were not required to name the substance used as stimulus, but simply to name the class to which the odor belonged. Fig. 37. Smell. Tj for violet. Abscissas — number of the solutions (see Table IX). Ordinates — number of sub- jects. - - - - women ; men. TASTE AND SMELL 6i Fig. 38. , Smell, Tj for cloves. Abscissas — percentage of the solu- tions. Ordinates — number of subjects. women : men. "Spicy" was called a recognition for cloves, and "per- fume " for violet The effects of practice would have been a disturbing factor if a more definite recognition had been required, but the general classes of spice and perfume are familiar to all. The threshold of rec- ognition, like that of presence, is a little better in the women than in the men (Figs. 38 and 39). The women are some- what more numerous in the region of low thresh- olds, and the men in the region of high. Again the difference is slight. The objection might be made that the two odors selected, cloves and violet water, are more likely to be familiar to women than to men ; but since the recognition required was merely of spice or perfume, it does not seem probable that the greater familiarity of the women with the odors could have been a factor in the re- sult. The subject was told that he need not name the sub- stance, but merely describe it as best he could, or name the class of substances to which it belonged. 3 and 4. Discriminative sensibility. — Like the corre- for violet, percentage of Smell. Ts Abscissas — the solutions. Ordinates — ^number of sub- jects. — - women ; men. 62 THE MENTAL TRAITS OF SEX spending series for taste, the first series of tests on discrimination of odors was made at the threshold of recognition ; and as in the case of taste, so in that of smell the standards are so scattered that they do not afford material for comparison. In the second series ,,-". of tests under the present head, ^-'' /\ as in the second series on taste \/ \ discrimination, stronger stimuli \_ were used ; and as in that case, so in this the standard was arbi- ■"^ ' trary, viz., the first solution of "" ^ -^ ^ *•' series B in Table IX. This sec- FlG. 40. Smell discrimination. 0"^ series of tests yielded re- Cloves. Standard, .001 sults Capable of Comparison, per cent, solution of oil _,, 1 , /• 1 . of cloves. ihe method of makmg the Abscissas— percentage of discrimination was the same as the solutions just dis- 1 1 r^. criminable from the that usually employed. Two standard. bottles, one of which was the Ordinates — number of subjects. standard, were given to the sub- women; men. ject, and he was asked to decide which was the stronger of the two. The only modifi- cation has already been stated, viz., that instead of being allowed but one stimulation from each stimulus, as in all other discrimination tests, he was allowed to go back and forth from one bottle to the other as often as he wished. A period of several minutes was allowed between stimulations for the recovery of the nerve. The results (Figs. 40 and 41) show a somewhat bet- ter discrimination in cloves on the part of the women, while in violet the difference is too slight to be of any significance ; the curves are almost coincident. The difference is probably partly due to the fact that the TASTE AND SMELL 63 solution of cloves was much less intense than the vio- let. Many of the thresholds of recognition for cloves fell within the higher series (see Fig. 38), while those for violet were all far below the series. The reason for the difference between the two series is that cloves increase faster in intensity of odor with increased strength of solution than violet. A I per cent, solution of cloves is entirely too strong to serve as the standard for a series, while a i per cent, solution of violet is usable. In at- tempting to tone down the cloves to a point where the intensity of the after image was not sufficient to interfere seriously with discrimination, the standard was made far less in absolute intensity than that of the violet series. The fact that, using these series, we find the women's discrimi- nation better than the men's in cloves, and about the same in violet, accords with the lower thresholds of the women in both smells. We find, as we should expect, the class having the lower thresholds better in the discrimination of odors of medium intensity, but not in the discrimination of very strong odors. The results of the tests on taste and smell may be summarized as follows: In taste the women have lower thresholds than the men both for presence and for recognition The difference between the sexes is most marked in sour and bitter, much less so ' «y 't it Fig. 41. Smell discrimination. Violet. Standard, i per cent, solu- tion of Roget and Gallet violette de Parme. Abscissas — percentage of the solutions just discriminable from the standard. Ordinates — number of sub- jects. - - - - women ; men. 64 THE MENTAL TRAITS OF SEX in salt, and very slight in sweet. Thfe discrimina- tive sensibility for strong tastes is finer in the men in all tastes except salt, in which it is slightly better in the women. The differences between the men and the women in smell are less than those of taste, but are of the same order. The women have slightly lower thresholds in smell, both for presence and for recognition. In discriminative sensibility for strong smells, the women are better in cloves, while there is no difference in violet. The difference may be accounted for by the fact that the violet series was absolutely much stronger than the clove series. If this supposition is correct, the results for smell are in accord with those for taste ; the women have lower thresholds, but their discriminative sensibility in the strong series is as coarse or coarser than that of the men. SUMMARY OF OTHER EXPERIMENTAL WORK ON TASTE AND SMELL. Experiments on the comparative keenness of the sense of taste in men and women have been per- formed by Bailey and Nichols (6), Bailey (7), Lom- broso (51, chap, iii), Roncoroni (72), Ottolenghi (63), Dehn (20), and Di Mattel (21). In no case has the method been so exact as that employed in the tests here reported. Bailey and Nichols prepared series of each of five tastes — sweet, salt, bitter, sour, and alkaline. Each series varied in intensity from a solution below the threshold to a strong solution. All five series were mixed together and the subject was required to sort them by taste. The weakest solution recognized was taken as the measure of the keenness TASTE AND SMELL 65 of taste. To obtain a statement for each sex, the results for each were averaged. Neither the method of mak- ing the test nor the treatment of results is above criti- cism. All the disturbing influences of after images, fatigue, and contrast enter into such a procedure as sorting tastes of varying quality and intensity. Any or all of these factors might conceivably vary with sex. Moreover, an average of results is not a fair ex- pression of the ability of one class. One or two very abnormal individuals might change the average un- duly. The limits within which the majority of the normal individuals of a class fall is the measurement required. Dehn experimented on the four accepted tastes. He used a single weak solution of each taste and recorded the right and wrong judgments. Dehn, whose test is perhaps most closely compa- rable with the present one, finds women keener than men in all four tastes. Nichols and Bailey, in their tests on American students, find women keener than men in all tastes except salt, in which men are keener than women. Nichols obtains the same result in his experi- ments on Indians. Ottolenghi, experimenting with sweet, salt, and bitter, finds women somewhat keener than men, but attributes this fact to the use of to- bacco by men and concludes that they are probably naturally keener than women. Lombroso, using three tastes, sweet, salt, and bitter, finds women keener in sweet and salt and less keen in bitter. Di Mattei, ex- perimenting with children between the ages of four and twelve, finds the boys more sensitive than the girls in bitter, equal to them in salt and less sensitive in sweet. Roncoroni finds sensibility to sweet keener in women, but sensibility to bitter and salt keener in 66 THE MENTAL TRAITS OF SEX men. The general result of all these tests is to show that women have lower thresholds for taste than men. The question remains as to whether or not this state- ment holds for all tastes. Four of the eight series of tests find an exception in the case of salt, and three in the case of bitter. Since there is no agreement about the exceptions, and the most accurate methods show women to be somewhat keener in all tastes, it seems probable that this is a correct generalization. In discussions on the keenness of taste, the dis- tinction between the threshold and the discriminative sensibility has not always been observed. It is ordi- narily assumed that a low threshold means also a fine discriminative sensibility — an assumption which has no a priori iuslifica.tion, and which receives no support from the present series of tests. There are no other results on the discriminative sensibility for strong tastes to compare with the present series, but if these results are to be trusted, fine discriminative sensibility for strong tastes is to be correlated with a high thresh- old, rather than with a low one. When it is argued that women cannot have a finer taste than men, because all the professional wine- and tea-tasters are men, this dis- tinction is overlooked. The tasting of wine and tea depends on the ability to discriminate strong tastes. Threshold tests throw no light on this question. The tests here reported show that men have a better dis- criminative sensibility for strong tastes than women, although their thresholds are higher than those of women. There are on record eight sets of experiments on smell: those by Bailey and Powell (4), by Bailey and Nichols (s),by Ottolenghi (64), by Lombroso (51, TASTE AND SMELL 67 chap, iii), by Toulouse and Vaschide (80), by Garbini (28, 28a), and by Di Mattel (21). Lombroso does not state his method. Bailey and Powell, Bailey and Nichols, Ottolenghi, and Di Mattei used a method analogous to that of Bailey and Nichols in their experiments on taste, viz., sorting bottles. Bailey and his co-workers used five different odors and all the bottles were given to the subject at once. Ottolenghi used but one odor, and gave the bottles in groups, beginning with the weaker ones. This procedure diminished the disturbing factor of fatigue which is so important in smell. Di Mattei experimented on children of from four to twelve years. To the younger children he gave the bottles in two groups, while to the older ones he gave all the bottles at once. Both Ottolenghi and Bailey and his co-workers find that men are keener than women in smell, the latter report- ing that men are about twice as keen as women. These results apply only to the threshold of smell. They are flatly contradictory to the outcome of our test, which finds what little difference there is in favor of the women. The work that is most closely comparable to that of the present series of tests in method, is that of Toulouse and Vaschide, They used a single odor — camphor — began with the subliminal solutions, used distilled water as a control, and worked up to the threshold. Their subjects were hospital attendants. The outcome of the test is in accord with ours. They find a keener sense of smell in women than in men. Garbini's results, cited by Toulouse and Vaschide, agree with theirs. Di Mattei used the method of arranging intensities of a single odor with children, 68 THE MENTAL TRAITS OF SEX and found that girls could detect a fainter odor than boys, and could arrange the series more accurately. Observations of Garbini (28a) confirm this result. It is difficult to explaia the contradiction in these two sets of results. Those experiments from which the factors of fatigue and contrast arc excluded, show a keener sense of smell in women. Whether the pres- ence of these factors in the other set of tests is suffi- cient to explain the difference, it is impossible to say. GENERAL SUMMARY OF THE EXPERIMENTS ON TASTE AND SMELL. With reference to the thresholds for taste there is practical agreement among all observers that women have lower tjiresholds than men. The only tests made on discriminative sensibility for strong tastes indicate that men are somewhat superior to women, a result which is in accord with their higher threshold. There is a decided contradiction in the results of the experiments on smell. Three of the previous tests had indicated a lower smell threshold for men than for women. The tests performed with the greatest rigor of method, however — those of Toulouse and Vaschide and those of the present series — show a lower smell threshold for women. No difference in discriminative sensibility was demonstrated. CHAPTER V. HEARING. Sensibility to pitch was the only aspect of hearing experimented upon. No attempt was made to find the threshold for hearing, because the laboratory was not provided with a sound-proof room. Three deter- minations of sensibility to pitch were made, as fol- lows: A. The upper limit. B. The lower limit. C. Discriminatire sensibility, with the 512 fork as a standard. A. THE UPPER LIMIT. The Galton whistle was the instrument used to investigate the upper limit of sensibility to pitch. The contrast between the jf shrill sound of the whistle where the pitch is perfectly distinct and the sound of the rush of air in the regions above the possible limit of pitch, was first given to the subject. He was then told to listen carefully to each stimulation given him and tell whether he could distin- guish the shrill pitch sound, or whether it was merely the rush of air. The number of vibrations was gradually increased until the subject 69 Upper limit of pitch. Abscissas — scale readings of the Galton whistle. Ordinates — number of sub- jects. women : — men. 70 THE MENTAL TRAITS OF SEX lost the pitch, and was then decreased until he heard it again. In the regions near the limit of discrimina- tion he was given from four to six stimulations for each turn of a division in the vernier scale, and the point at which he heard the pitch three-fourths of the time was fixed upon as the upper limit. The diagram of results (Fig. 42) is made out for convenience in terms of the scale-readings of the whistle. It will be easily interpreted if it is borne in mind that the smaller numbers on the scale mean higher vibration rates. The following table gives the number of vibration rates per second for each scale- reading which appears in the table: 1.6=52,500 vibrations per second 1.7=49.411 1.8=46,667 1.9=44,210 2.0=42,000 2.2=38,181 2.4=35,000 3.0=28,000 4.0=21,000 The diagram shows no characteristic sex difference. The women are somewhat more numerous in the very high region, and the men in the very low region, but this difference is balanced by the fact that there are more men in the middle high ranges, and more women in the middle low ranges. B. THE LOWER LIMIT. The experiments on the lower limit of pitch were performed with the Appunn wire forks. There were eight forks in the series, ranging from twelve to fifty-six vibrations per second. Each fork is repre- HEARING 71 sented in the abscissas of the curves of results (Fig. 43). Since the lowest fork (twelve vibrations per second) was not below the possible limits of pitch, the subjects could not in this case be given the con- trast between pitch, and vibrations with no pitch. The experiments were be- fj ^ gun with the forks of high «'-\ vibration rate, and worked 7 ■ ^ down to the limit. The subject kept his eyes closed during the test. Each fork was sounded close to his ear several times. He was asked to tell each time whether the sound he heard could be called a tone or not. The lower limit of pitch is subjec- tively much harder to fix than the upper. As the vibration rate decreases, the smooth singing tone changes into a pulsating sound which still has a certain pitch quality. Many subjects found it very difficult to fix upon the point where the sound lost its pitch quality. An attempt was made to control the judg- ment by requiring discriminations of higher and lower in doubtful cases, but this proved to be impracticable; in the first place, because discriminative sensibility at the lower limit is so coarse ; and in the second place, because the difference of vibration rate could be felt as the air struck the ear and an indirect judgment as to pitch, based on vibration rate, was unavoidable. The results therefore contain the source of error due to differences in individual standards. »« it Jt Fig. 43. Lower limit of pitch. Abscissas — vibrations per second of the forks used. Ordinates — number of subjects. women ; men. 72 THE MENTAL TRAITS OF SEX The result (Fig. 43) seems to indicate a somewhat lower limit of pitch in the men. The limits of the two curves are the same — from twelve to above the series of forks; the difference in them is in the num- ber of lower limits falling on the twelve and sixteen forks. There are nine men and three women at twelve and vice versa at sixteen. Considering the source of error in the test, as small a difference as this is of doubtful significance. C. DISCRIMINATIVE SENSIBILITY. The tests on pitch discrimination were made with two tuning forks with the pitch Ut 3 (512 single vibra- tions per second). One of the forks bore a rider by which its rate could be reduced as much as seven vibrations per second. The forks were mounted on wooden resonators. The subject sat with his back to the apparatus, at a distance of about six feet. The forks were sounded by tapping them with a rubber- tipped hammer. The chief source of error in the test was the inequalities of intensity incident to striking the forks by hand. Long practice reduced this to a minimum, and any tests where the differences of in- tensity were noticeable were discarded. The usual directions for discriminative tests were given the subject. He was told that two tones would be sounded in succession and that he was to report each time which of the two was higher in pitch. The number of tests in each order was the same. The series began with the large differences — six or seven vibrations per second — and worked gradually down to the limit. Most of the subjects improved so rapidly with practice that it was found necessary to keep the HEARING 73 time devoted to this test approximately constant. A few subjects came to a standstill before the end of the half-hour usually allotted to it and proved unable to go farther even after repeated trials. In these cases the test was stopped when improvement ceased. In all other instances the fine- ness of discrimination reached at the end of the half-hour is what is recorded. It may not in all cases represent the limit of possible discrimination, but is a fair measure of the relative natural capa- cities. The results (Fig. 44) are recorded in terms of the difference of vibra- tion rate between the two forks at the limit of dis- crimination for each subject. The curves indicate finer discrimination in the women than in the men. The difference is shown principally by the greater number of women than men who could discriminate a differ- ence of less than one vibration a second, and the pre- ponderance of men who could not discriminate pitch at all within the limits allowed by these forks. The latter subjects seemed to have no clear idea of what the terms high and low meant with reference to pitch. Their attempts at discrimination were pure guesses, with no discernible regularities. Fig. 44. Pitch discrimination. Standard, Ut, (512 single vibrations per second). Abscissas — difference in the number of vibrations per second between the standard fork and the fork of comparison necessary for dis- crimination. Ordinates — number of subjects, women; men. 74 THE MENTAL TRAITS OF SEX SUMMARY OF OTHER EXPERIMENTAL WORK ON HEARING. The only test on pitch comparable with ours is the one made in the series of tests at Columbia University (82). The method consisted in requiring the subject to find again, after the bridge had been shifted, a note sounded on a monochord. The result agrees with that of the present test in showing that the women have a finer pitch discrimination than the men. The only other comparative tests on hearing are those by Lombroso, (51, chap, iii) and Roncoroni (72) on the limits of normal hearing. They both used as a measure the distance at which a watch could be heard. Although the number of persons tested was small, the method rough, and the results contradictory for the two ears, Lombroso comes to the conclusion that men's hear- ing is keener than women's. Roncoroni agrees with him. Reik (71) reports an interesting anatomical in- vestigation of the ears of 440 school children. He found abnormalities much more frequent in the ears of boys than in those of girls. He also made investi- gations on the physiological functions of the ear. Although he gives no report of his results on pitch discrimination, the presumption is that it would be poorer in the sex with the greater number of abnor- malities — a result which would be in accord with ours. The values he obtained for the upper limit of pitch agree very well with ours. Some of the children, however, could distinguish higher vibration rates than any of our adult subjects. He makes no comparison of sex with respect to the upper limit. Tests made under the direction of F. W. Smedley (71a) in the Chicago public schools revealed no great differences as regards defective hearing in boys and girls. HEARING 75 GENERAL SUMMARY OF TESTS IN HEARING. In the upper and lower limits of pitch the only difference of sex indicated was a possible lower limit for men. In pitch discrimination women are better than men. The tests on the threshold for hearing have been too few in number, too rough in method, and too contradictory in result to serve as a basis for any trustworthy generalization. CHAPTER VI. VISION. The experiments made on vision dealt with the fol- lowing subjects : A. The threshold for light. B. Discriminative sensibility for brightness. C. Keenness of vision. D. Discrimination of color. E. Discrimination of visual areas. A. THE THRESHOLD FOR LIGHT. The apparatus used in the experiments on the sen- sitiveness of the retina to light was a long wooden tube about eight inches square at the ends and four feet long. It was blackened on the inside and was made absolutely light-proof. At one end was a box-like cover under which the subject could sit, with his eyes on a level with the tube. When the subject was in position, the box was covered with a camera cloth in such a way that no light could reach his eyes. At the other end of the tube was a round opening one inch ' in diameter. It was found impossible to reduce white light to the threshold. The opening was therefore covered with violet glass. Since all light appears as mere brightness in its lowest intensities, the color of the glass was indifferent in the present case. The glass was held in place by a box-shaped cap which fitted over the end of the tube. The circular opening was closed by a round black disc. When the disc was in 76 VISION 77 position no light whatever could reach the eye of the subject. The only possible way to stimulate the retina was to move the disc away from the opening in the tube. The experiments were made in a completely dark room. The source of light was a Welsbach burner. One of the great difficulties in making experiments on the threshold of vision has been to find some way of reducing the light by measurable amounts. In this case no attempt was made to reduce the illumination itself: A source of light which would remain constant was all that was required, and other means presently to be described were taken to lessen the intensity. A year's experience with the apparatus previous to using it in this test was sufficient to convince us that the Welsbach burner, under full gas pressure, does furnish a constant source of light. The supply of gas is always sufficient to illuminate the mantel to its full extent, and that insures the maximum of light which the burner affords. It was found that the same thresh- old — allowing for variations in temporary condition — could be established for a given subject day after day with this apparatus. Assuming therefore that what variations of intensity there were in the source of light were beneath perception when applied in this way, the intensity was reduced to the amount required by shading the light in various ways and reducing re- flection in the room. A few inches in front of the open- ing of the tube was placed a black cardboard screen at a given angle with the box and with the burner. The burner was placed opposite the black screen about five feet away, and shed its light on the screen, from which it was reflected into the box whenever the open- 78 THE MENTAL TRAITS OF SEX ing was exposed. The burner itself was placed in a case with a window opening toward the screen. This reduced reflection from the walls of the room. By this means the amount of light admitted to the box was lowered to a point near the threshold. The further diminution of intensity was accomplished by a series of cheese-cloth curtains which hung in front of the window of thecasecontainingtheburner. Every curtain lowered reduced the illumination of the black screen and con- sequently the amount of light entering the box. Since all the other factors in the situation remained constant the absolute sensitiveness of the retina could be measured by the number of curtains necessary to reduce the illumination to the least visible amount. There werg two time factors in the experiment which it was necessary to keep constant. One was the length of time the eyes were rested in the dark box before the experiment began, and the other the time of exposure of the light for each stimulation. The former was important because the sensitiveness of the retina increases fast on being completely protected from light. If the experiments were made a few minutes after the subject was put into the apparatus, the threshold found would be much higher than that found balf an hour later. It was observed that after an hour the sensitiveness increased little if any. Con- sequently, the subjects were left entirely without stimulation of the retina for thirty or forty minutes. This time was used for determining the touch thresh- old (see chap, iii, sec. A, i) and the discriniinative sensibility for area on the skin (see chap, iii, sec. B, 2). At the end of that time the experiments on the eyes were begun, and were completed in twenty or twenty- VISION 79 five minutes. The sensitivity registered is that which obtains after protection of the retina from light — except the minimal stimulations of the test — for an hour. The second time element — the duration of the single stimulations — is important because a very faint light may be visible when exposed for a longer time but not visible when exposed for a shorter time. This time interval was controlled by a mechanical contriv- ance for raising and lowering the disc covering the opening in the dark box. The disc was fastened by a projection at one side to the end of a vertical rod, in such a way that when the rod was moved up about half an inch, the disc was thrown down, uncovering the opening. The other end of the rod was joined by a pivot to the end of one arm of a lever which was mounted on the table. The fulcrum of this lever was a ball and socket bearing at its middle point. The downward pressure of the rod on one arm was balanced by a movable weight on the other arm. By means of this adjustment it was possible to bring the system into a state of equilibrium such that the lever arms would remain as they were placed. When the arm connected with the rod was moved up by pressing down on the free lever arm, the disc was thrown down and the box opening remained uncovered. It was closed again at the end of the required interval by means of a metal ball which rolled down a trough and into a second short trough which was fastened to the upright rod. A catch was arranged which held the balls in place until time to release them. When the free lever arm was pushed down, it removed the disc from the box opening, and at the same instant released So THE MENTAL TRAITS OF SEX cur- the catch which held the ball. The opening remained uncovered until the ball rolled down the trough and into the short trough borne by the rod. The weight of the ball then carried the rod down and thus threw the disc up over the opening again. The duration of each stimulation was the time required for the ball to roll from the catch to the short trough. As long as the length of trough employed and its inclination remained the same, the ball's time remained prac- tically constant. Its varia- tions were far within the limits of the time error for this experiment. The troughs were padded to make them noiseless. A padded inclined plane was arranged which received the ball as it left the trough and returned it to the operator. The series of tests was begun with a light which was clearly above the threshold, to make sure that the subject was familiar with the stimulus. The stimula- tions were given in series of ten at irregular intervals. The subject was required to count aloud when he saw the light. As soon as the threshold was approached, two or three series were given for each grade of intensity. Rests of several minutes were allowed between series. When the subject was troubled with retinal activity which obscured the field of vision with clouds of gray or colored light, longer periods of rest were given for these to subside. As in other threshold tests, imaginary stimulations were inserted in the series i. 1 i Fig. 4S. Light threshold. Abscissas — numbec of tains down. Ordinates — number of sub jects. women ; men. VISION 8 1 by most subjects. If the tendency proved extreme, the subject was told of it, and in such cases it invariably decreased. The point taken as a threshold was the least intensity — measured in terms of the number of curtains lowered — at which three-fourths of the stimu- lations could be correctly counted, regardless of the imaginary ones inserted. The results (Fig. 45) show an appreciably greater sensitiveness of retina in the men than in the women. Men are decidedly more numerous in the region of greatest sensitiveness (six to seven curtains), and less numerous in the regions of slight sensitiveness (none to three curtains). B. DISCRIMINATIVE SENSIBILITY FOR BRIGHTNESS. The Bradley color wheel, with two sizes of black and white discs, was employed for testing the discrimi- nation of brightnesses. The smaller circle was made the standard. It remained half black and half white throughout the test. The proportion of black and white in the larger circle was shifted until the least amount of black necessary to make the outer ring appear darker than the inner circle was discovered. A disc with a circle divided into one hundred parts placed behind the large discs served to measure the amount of black added to the outer circle. The record was kept in terms of the percentage of black required in the outer ring to make it just perceptibly darker than the inner circle. To insure a constant illumination, the tests were made in a dark room, and the light was furnished by a Welsbach burner placed at a fixed distance behind the subject in such a way that the light came over the 82 THE MENTAL TRAITS OF SEX left shoulder. The subject was seated facing the wheel. His eyes were kept closed during the shifting of the discs, and were not opened until the wheel was in full motion again. The only direction given the subject was that he was to tell each time whether the inner circle or the outer was darker. To avoid the error of having the outer circle con- stantly the darker, frequent tests in which the outer circle was lighter were inserted in the series. The test began with clearly distinguishable differences, and worked down, shifting back and forth, to the finest possible discrimination. Three out of four correct judg- ments served to fix the limit of discrimination. The discrimi- nation was measured to fourths of I per cent. The results (Fig. 46) show a better discrimination on the part of the men. Their curve is above that of the women in the region of fine discriminations (51-53 percent.) and below it in the region of coarse discriminations (54-55 percent.). Fig. 46. Discriminative sensibility for brightness. Stand- ard, so per dfent. black and SO per cent, white. Abscissas — percentage of black necessary for dis- crimination. Ordinates — number of sub- jects. women ; men. C. KEENNESS OF VISION. The apparatus used for testing keenness of vision consisted of cards, one black and one white, about four inches long and five inches wide, on each of which were pasted little squares (2 mm.), of red, blue, green, and yellow. The black card had also a white square. VISION 83 and the white card a black square. The five squares were pasted at equal distances along the center of the cards. The subject was tested first with the white background, and second with the black back- ground. The tests were made in a dark room. The card was illuminated by the light of a Welsbach burner placed at a fixed distance from it. A screen behind the light protected the subject's eyes from it as he approached. The card was hung on the wall on a level with the subject's eyes. From the point below the middle of the card, asm. line was marked across the room on the floor. The subject was placed at the end of this line, with one eye bandaged. The card was hung upon the wall, and the subject was asked how much he could see on it. He was then directed to approach slowly, telling at each step how much he could see, until all the squares and their colors were visible. The point at which each square and each color became visible was noted. With thirteen subjects of each sex the right eye was used first, and with twelve the left eye. The spots were, of course, visible much farther away than their colors. In order to make the subject care- ful in observing, he was asked about the appearance of the spots at each step, and particularly whether or not they all looked gray or black. After testing one eye, a pretense was made of changing the card for the other eye, in order that the subject might not be influenced by a knowledge of what was really on the card The test did not prove to be altogether a satis- factory one, because the maximum distance from the 84 THE MENTAL TRAITS OF SEX card, 5 m., was not sufficient to make the spots dis- appear to the normal eye, on either background. The blue spot on the black ground, and the yellow spot on the white ground, were not visible to most subjects at 5 m. The colors on the white card were very rarely visible at the end of the line. On the black card the red and green could be distingaished by a number of subjects. The results of these tests bearing on the threshold for the perception of the spots appear in Table X. About all that can be gathered from this table is that there are more men than women with weak left eyes. The records for the blue on the black ground, and for the yellow on the white ground, do, however, afford some means jaf judging of the status of those who, in the other combinations, fall beyond the limits of the test, i. e., $ra. In these two instances, the right- eye test shows the men somewhat better than the women, and the left-eye test shows them very slightly inferior. The results bearing on the threshold for the recog- nition of the colors of the spots are shown in Table XI. In this table the combinations, black on a white back- ground and white on a black background, do not appear, because for them the threshold of perception was the only one obtainable. The difference between the sexes is more marked in the recognition of color than in the perception of the spots. In the latter respect the right eye is superior among the men ; in the recognition of color it is superior among the women. There are but two instances, blue and yellow on white, in which it is superior in the men. In two more, green on white, and yellow on black. VISION »S TABLE X. Keenness of vision. Thresholds of perception for the several spots, i. e., distances at which the spots were perceived. Distance of Subject prom Card (Decimeters) . 45 Women, £ \ Women. g t Men... *; 5 Women, »!j ( Men . . . 19 19 23 22 23 23 20 8 12 8 II 20 19 23 19 ■i j ii Women Men . . . Women, Men . . . 21 23 23 19 20 19 23 19 21 20 22 l8 20 19 23 19 21 22 23 19 86 THE MENTAL TRAITS OF SEX TABLE XI. Keenness of vision. Thresholds of recognition for the various spots, i. e., distances at which the color of the spots was recognized. Distance or Subject from Card (Decimktebs) . o 5 2 3 ID 2 3 '5 2 4 20 6 4 25 4 2 3° 4 4 35 4 3 Men... I 2 4 6 S 3 I 2 ■d ;S ( Womin. 14 8 I 2 S Men . . . r *: Women. ■2 ( Men... 3 5 II 12 i6 4 9 I 6 2 2 I S Women. '& 1 Men . J y Women. I I I I I 2 4 I I 4 2 X I 2 3 3 2 6 7 6 9 8 i o n >2 ( Men... 2 4 2 2 3 2 7 n a Women. « f Men . . . *; \ Women. •^ (.Men... I I I 2 S 3 4 S 6 8 3 6 s s 9 5 2 I 2 I I I 3 I I "S ^ \ Women. I 2 3 7 10 2 ( Men ... J \ Women. I I I 2 3 2 4 13 IS 1- m ■2 ( Men... I I 4 I 2 3 13 iio ■g \ Women. .if i « / Men... ^ \ Women. 2 2 2 2 3 I 6 S S .4 5 3 4 4 7 2 3 3 2 2 2 I I 1 I I n •^ ( Men... 3 3 3 4 6 I 2 I 2 ■s ^ \ Women. I 2 2 3 4 I I s 3 3 11^ S ? Men... u \ Women. I 3 S 3 I 3 I 4 3 3 3 2 2 I 4 7 3 1 >< m •^ ( Men... I 2 3 3 I 2 6 6 ^ Women, tu ■ S ( Men ... « \ Women. 10 8 6 8 4 9 6 8 6 I 3 I 4 •■ I n •^ ( Men... 10 I 8 4 I VISION 87 it is practically the same for both, and in the other four combinations it is better in the women. The left eye has a better record among the women in all colors except yellow, in which it is somewhat better in the men. The superiority of the women is more marked in the recognition of red and green than in the recognition of blue and yellow. Yellow is the only color for which the men's record is better than the women's. The general conclusion is that the men's eyes are possibly somewhat keener than the women's in the detection of the presence of an object, but quite surely less keen in the recognition of its color. The former statement is qualified because the test was not well devised for determining that point, and the data on which it is based are meager. D. DISCRIMINATION OF COLOR. The test regarding the discrimination of color was made with the larger series of Holgrem worsteds for testing color-blindness. The worsteds were given to the subject heaped upon a gray cloth. He was given a sample to serve as a standard, and was told to select all the worsteds in the pile which were of the same color as the sample. It was carefully explained that the worsteds might differ in shade from the sample, but must not differ in hue. When the required worsteds were selected, he was told to arrange them in order from lightest to darkest. The samples were given in the order — green, blue, red, and yellow. After each series was selected it was mixed into the pile before the selection of the next one began. The subject was marked "color-blind" only in undoubted cases, where decided oranges were 88 THE MENTAL TRAITS OF SEX placed with yellows, lavenders with blue, or browns and grays in the color series. When bad mistakes were made, but not bad enough to rank the subject as unquestionably color-blind, he was marked "poor" in color discrimination. The series in which the mistakes were very slight were graded as "medium," and those which were perfect were recorded as "excellent." The curve for the discrim- ination of color (Fig. 47) , h 1 ,1 + shows a strikingly better color *M ' discrimmation in the women „. . . . ' ' •, than in the men. The men pre- Discnmination of color. . . / Abscissas — grades of dis- dominate in the "color-blind" crimination. ^nd "poor" Sections, and the Ordinates — number of sub- . ^, ,, ,. ,, , jects. women in the "medium and ----•women; men. "excellent." E. DISCRIMINATION OF VISUAL AREAS. For the tests on discrimination of visual areas a series of small white squares mounted on large black cardboard squares was used. The size of the black squares, and the position of the white squares on them, were identical throughout the series. The standard square measured 20 mm. on a side. Those for com- parison were 19.5, 19, 18.5, and 18 mm. The subject sat at a table facing a black screen. The experimenter stood behind the screen and placed the two squares to be compared in front of the screen successively. The directions were to report which of the two squares VISION 89 shown was the larger. The larger differences and worked down to the smaller. The point at which three-fourths of twelve judgments were correct was taken as the limit of discrimination. The curves for the dis- crimination of visual area (Fig. 48) are very similar for the men and the women. What difference there is is in favor of the men. They are somewhat more numer- ous in the region of finest discrimination (19.5 and 19.5 mm. + ). series began with the Its- II lis Fig. 48. Discrimination of visual area. Standard square, 20 mm. Abscissas — size of squares just discriminable from the standard. Ordinates — number of sub- jects. women ; men. SUMMARY OF OTHER EXPERIMENTAL WORK ON VISION There are no tests to compare with the present series on the absolute sensitiveness of the retina to light or on the discriminative sensibility for grays, and none exactly comparable with the test on keenness of vision. Those which are on record employed the method of reading type or numerals. Pearson (69) reports a series of measurements on men and women at Cam- bridge, in which the average is slightly higher for the men with the right eye and for the women with the left eye. The Columbia University tests (82), in which the same method was used, revealed no differ- ence in sight. The present test happens to coincide with the Cambridge results in showing the right eye 90 THE MENTAL TRAITS OF SEX slightly better among the men, and the left eye among the women. In both cases, however, the differences are very slight. Krauskopf (43) found a greater percentage of eye defects among girls than among boys. The total mass of results does not warrant us in postulating any sex difference in keenness of vision. Three distinct problems in color vision have been the objects of previous investigations : the absolute sensitiveness of the eye to color ; the discriminative sensibility for color ; and the presence of color-blind- ness. The first of these was investigated by Nichols (62). He prepared series of mixtures of white pow- der with colored pigments for the four colors, red, green, blue, and yellow. The series varied in intensity from mixtures indistinguishable from white, to clearly colored mixtures. The series for the four colors were placed in glass bottles, and the bottles were indis- criminately mixed. The subject was required to sort them according to hue and shade. Nichols found that men were able to distinguish smaller amounts of pigment than women in all colors except blue, in which women excelled. This result is not in accord with that of the present series of tests, which finds women more sensitive than men to all colors except yellow. With regard to the second problem — the ability to discriminate shades of a single color — all ob- servers agree with our result, i. e., that women are superior to men. Lombroso (51, chap, iii) reports that women are three times as keen as men in distin- guishing colors with the Holgrem worsteds, a differ- ence which he attributes to their practice in embroid- ery. Nichols, in the test reported above, finds that VISION 91 women are better than men in arranging the series of colors according to intensity. Gilbert (30) and Mac- Donald (55, p. 1 106) both report that among school children girls are better than boys in distinguishing the shades of a single color. Luckey (53) seems to be alone in his doubt about a sexual difference in this respect. He reports experiments on a good many children and a few adults, and says that he finds the color range and the power of discrimination in the primary colors equal for the two sexes. The investigations which have been made regard- ing the third problem — the presence of color-blind- ness — may be said to have established without ques- tion the fact that this defect is more frequent among men than among women, Jeffries (40, 41, 42) re- ports tests on large numbers of persons both in this country and in Europe which show a decidedly larger percentage of color-blindness among males than among females. Mullen (59) collected the reports on tests for color-blindness made in the United States, France, England, Denmark, Sweden, Russia, Austria, China, and Japan between the years 1880 and 1897. In all of these reports in which a comparison of sex was made, the percentage of color-blindness was much higher among men than among women, Wissler (82) corroborates these findings in his report of the tests on Columbia University students, and it holds for the present series of tests on University of Chicago students. No comparative test (other than that of the present series) on the judgment of visual areas is on record, MacDonald (55, p. 1104) reports a test on school children in the estimation of the length of a line. 92 THE MENTAL TRAITS OF SEX In that, as in the present test on judgment of area, the males were somewhat more accurate than the females. GENERAL SUMMARY OF EXPERIMENTS ON VISION. The generalization suggested by the experiments on vision is that on the whole men are somewhat better than women in brightness vision, while women are better than men in color vision. Although no difference between the two in keenness of vision has been established, men's eyes are shown to be abso- lutely more sensitive to light than women's, and they make finer discriminations of grays. The results as to the absolute sensitiveness of the eye to color are contradictory. .Nichols finds it greater in men, and the present test shows it greater in women. There is general agreement, however, that women discriminate color better than men, and are less subject to color- blindness. The tests on visual discrimination of area and on estimation of length show that in this faculty males are somewhat superior to females. CHAPTER VII. INTELLECTUAL FACULTIES. The investigation of the intellectual faculties cov- ered four different fields: A. Memory. B. Association. C. Ingenuity. D. General information. A. MEMORY. The memory factors investigated were the rate of memorizing, retentiveness, and the nature of the imagery employed. The material to be memorized consisted of two series of nonsense syllables, each series containing ten syllables. The first series (" mon, yit, zev, yer, zam, kig, sef, gav, cim, nis") was read aloud, and the second (" hue, cir, suv, nif, fom, mep, yom, fim, zok, seb" ) presented visually. In both cases the syllables were given at the rate of one per second. To avoid rhythm and secure a con- stant rate of presentation for all subjects, they were timed by a metronome. The auditory series was read aloud as distinctly as possible, the visual series was placed on a stroboscopic drum and displayed syllable by syllable behind an opening in a black screen. The auditory series was learned first in each case, and the visual series immediately afterward at the same sitting. The subject was given no directions about the way 93 94 THE MENTAL TRAITS OF SEX he should do the memorizing. He was merely told that the series of syllables would be given him as many times as he needed it to learn it correctly. A pause of from twelve to fifteen seconds intervened between successive presentations. As soon as the subject thought he knew the series, he began to say it aloud in the interval between presentations. If it were not correctly said, the readings con- tinued until it was. Memory. Rate of memorizing. Audi- After it was learned tory series. i . • Abscissas — number of repetitions. the subject was asked Ordinates — number ^of subjects. tO describe accurately - - - - women; men. ^^e type of imagery he had used in memorizing, to tell whether or not he had learned the series by means of associations, and to report any tendency to group the syllables in learning them. Retentiveness was measured by the number of repe- titions required to memorize the same series just one week after the first memorizing. The subject was not told that he would be required to memorize them a second time ; the hours were merely arranged so that he came to the laboratory just a week after the first memorizing. In almost all cases the subjects said that they had made no effort to repeat the syllables since the first memorizing. A few had tried it simply out of curiosity, and one of the men suspected that he would be asked to memorize them a second time and had made a special effort to remember them. There were two women and two men who failed to appear at INTELLECTUAL FACULTIES 95 Memory. Rate of memorizing. Vis- ual series. Abscissas — number of presentations. Ordinates — number of subjects. women ; men. the hour when the second memorizing should have taken place. In these instances the interval was from one to three days over a week. The abnormally slow second learnings do not, however, coincide with these longer periods According to the well-known psycho- logical law of forgetting, ^i there is very little differ- ence, so far as memory is concerned, between a pe- riod of seven days and one of nine or ten. Aside from this consideration, however, the exceeding of the regular period by these four subjects may be disregarded in com- paring the men's retentiveness with the women's, be- cause two of them were men and two women. Figs. 49 and 50 are the curves for the first memo- rizing of the two series. The auditory series has a total average considerably greater than that of the visual series. No subject learned the auditory series in less than eight repetitions, while a number learned the visual in six. Not more than thirty-five repeti- tions were required in any case for the visual series, while the auditory series has fifty-five as its upper limit. There are two factors which are adequate to explain this difference. The first, and by far the most important, is that the habit of memorizing by means of printed symbols is universal, while very few, if any, of the subjects had ever formed the habit of learning material that is read aloud. Moreover, the visual symbols are more easily grasped in the first instance 96 THE MENTAL TRAITS OF SEX than the auditory. The second factor which might tend to shorten the time of the visual series is that it was learned second in each case, and therefore had the benefit of the practice obtained in learning the auditory series. Since nonsense syllables were com- pletely unfamiliar ma- terial for memorizing, the first series presented the additional difficulty of getting accustomed to a new subject-matter. -y^^ ,/ y In both the auditory li and the visual series the women show distinctly greater power of mem- orizing than the men. Here, again, we find both men and women at both both cases more women 1 J, b i II 11. li Fig. 51. Memory. Retentiveness. Auditory series. * Abscissas — number of repetitions. Ordinates — number of subjects. women ; • men. extremes, but there are in than men who memorized quickly. Retentiveness was found to be practically the same for both the men and the women (Figs. 51 and 52). In the auditory series the curves for retentiveness correspond very closely. In the visual the women are slightly better, but the difference is too small to be of any significance. Since the women are thus shown to have a greater power to memorize nonsense syllables than, the men and an equal power to retain the memory, they may be said to have, on the whole, better memories for such syllables than have men. The question arises whether this fact justifies a general statement that women are superior to men in the faculty of memory. INTELLECTUAL FACULTIES 97 Fig. 52. Retentiveness. Visual If what we wish to measure is mere power of memory, isolated as far as possible from the factors of reason and association, nonsense syllables are universally conceded to be the best material. The results would justify us, therefore, in the statement that memory in its purest form is better 7j among women than i among men. A record was also made of the type of im- agery used by each per- son in memorizing the syllables. The difficulty of making exact and adequate observations of one's own imagery is great even for individ- uals with special train- ing, and is still greater for the unpracticed. The results in the present case were made as trustworthy as possible by questioning each subject at once and carefully as to the exact nature of his mental proce- dure. The great variety of combinations of imagery used makes their tabulation in significant form difficult. The scheme which has been followed in the present case is to classify all the cases in which imagery of the same sort predominates together. For instance, all the cases in which auditory imagery is predominant are put together. Among these are some in which only auditory imagery was used, and some in which visual, or motor, or both, were secondary to the audi- tory. Where two or three types of imagery were used so equally that no one could be called predominant, Memory. series. Abscissas — number of repetitions Ordinates — number of subjects. women ; men. /o 98 THE MENTAL TRAITS OF SEX the case is classified according to the components, as auditory-motor, visual-motor, etc. It is of course impossible to assert that the type of imagery used in this particular piece of memorizing is characteristic for the thinking of an individual, but habit must play a large part in determining the imagery to be used in dealing with novel material, such as nonsense syl- lables. TABLE XII. Types of imagery used in memorizing.' B s 1 1| ■2(5 > i a ■| 4^ 1 .SS- ..«>. i^-AAbscissas — time in minutes. ' ' I, Ordinates — number of subjects. - - - - women ; men. complicated process of reasoning for its solution — a problem in which it was easy to become confused unless all the factors were sharply separated and clearly grasped. The problem was handed written to the subject. He was told that it involved no diffi- cult computations. The process was timed from the moment the problem had been read through. A fail- ure was recorded only in cases in which the subject had worked from forty-five minutes to an hour, and was completely hopeless of getting any solution. The problem was the following: "A man swimming in a river finds that he can swim three times as fast down stream as up stream. The river flows at the rate of a mile an hour. Find his rate of swimming in still 114 THE MENTAL TRAITS OF SEX water." Any solution which could be explained was accepted. A mere stumbling upon the correct answer was not called a solution. The curves of results for the second test (Fig. 67) show no marked difference between the men and the women in quickness of calculation. On an average the men have somewhat the advantage. Two of the men n 10 • Fig. 67. Ingenuity. Second test. time in minutes. number of subjects. Abscissas- Ordinates women ; with very good records had been teaching mathematics within a year, while none of the women were primarily concerned with it. Taking this fact into considera- tion, the difference between the two curves is insig- nificant. The third problem involved to some extent both perceptual quickness and reasoning. The apparatus consisted of a checker-board, composed of red and yellow squares, and eight men. The board had eight squares, four of each color on each side, like an ordi- nary checker-board. The problem was to place the eight men on the board in such a way that no two were on the same straight line of squares, either perpendicu- larly, horizontally, or diagonally. Both red and yellow INTELLECTUAL FACULTIES US Ingenuity. Third test. Abscissas — time in minutes. Ordinates — number of subjects. women ; men. squares could be used. The problem is far too com- plicated to be solved by inspection, nor can it be reasoned out in detail. The process in solving it con- sisted in adopting some general method, and trying it, modifying it if necessary, until the proper combination was hit upon. There was one method which gave a logical certainty of some solution, but only one or two sub- jects discovered it. Most of them pro- ceeded by starting at some part of the board and trying to work systematically from that point. If that failed, another portion was taken as starting-point and the trial made again. Some few placed all eight men in a row along one side of the board, and worked by moving seven of them out from this position, varying the placing until the conditions were fulfilled. In almost all cases the subject felt that the solution, when obtained, was largely a matter of chance. He had simply stumbled upon the right combination, rather than really solved a problem. Very few of them could have reproduced the solution after the men were removed from the board. However, the problem certainly required original method, quickness in seeing complicated forms, and perseverance. In this test the men show themselves decidedly superior to the women (Fig. 68) . There were two women who were quicker than any of the men, but there ii6 THE MENTAL TRAITS OF SEX were also two more women than men who failed. The superiority of the men is shown in the great majority of them in the region from fifteen to thirty minutes. It is very difficult to evaluate this difference, because of the indefinite nature of the problem. Most of the women expressed a great distaste for all such problems, because they were uninteresting. Many of them were so uninterested that they did not really work at it. Whether the men found it equally uninteresting, but forced themselves to work in spite of lack of interest, or whether the problem appealed to them as more interesting, it is difficult to say. From the voluntary comments of the subjects the latter hypothesis seems more probable, but in this case we are confronted by the further question why such a problem should have more interest for men than for women. The test may point to a greater interest on the part of men in a prob- lem, merely as a problem, regardless of any possible usefulness, or any further application. The fourth trial of ingenuity was a mechanical prob- lem. The subject was required to find out the method of operating the apparatus used for determining the light threshold described above on p. 76. The test was always made shortly after the deter- mination of the light threshold, when there was usually ■ a spontaneous interest in the apparatus. The neces- sity for uniformity in the time of the stimulus was explained, and the subject was told that his problem was to find out, first, how a constant length for all ex- posures of light was secured automatically, and second, how the absolute intensity of the light was varied. He was told that he might do anything he pleased with the apparatus, except take out screws, which would not be necessary to discover its workings. INTELLECTUAL FACULTIES 117 The apparatus was particularly favorable for a com- parative test, because it was so entirely unfamiliar to all the subjects. The mechanical principles involved in it were all very elementary. The difficulty was to find out how the various parts worked together. Since the apparatus was so unique, acquaintance with other mechanisms was of as little assistance as possible, although unquestionably a knowledge of mechanics in general is of assistance in solving any particular mechanical problem, however unlike previous ones it may be. Two difficulties were experienced by all the subjects in this problem. The first was in making the connec- tion between the metal ball and the inclined trough. The ball was not found in the trough, but lying on the table by the apparatus, either in an open box or in the stop at the foot of the padded incline. The second difficulty, which was still more serious, was to discover that the ball could be released and the screen opened by a single movement. The fact that the ball would close the screen was found out very quickly. The method of regulating the absolute intensity of the light gave but little trouble. Only twenty-one women and twenty-two men are recorded in the curves for this test, because it was not given to the first subjects on whom the experiments were performed. The apparatus was explained to them at their request. When later the decision to use it for an ingenuity test was made it was of course im- possible to apply the test to these subjects. In the fourth test the men have a somewhat better record on the whole than the women (Fig. 69), al- though the difference is not marked. There is a consider- able majority of the men in the region under fifteen Fig. 69. Ingenuity. Fourth test. Abscissas — time in minutes. 118 THE MENTAL TRAITS OF SEX minutes, but they are also somewhat in excess at the other end of the curve. None of the women failed to get a solution in an hour, while two men worked from an hour and a quarter to an hour and a half and failed. The fifth ingenuity experiment was also the solu- tion of a mechanical problem. The subject was given a wooden model of a very simple ^, .^ combination lock. He ^' *' " " /"^was told that it was a model of an object with the use of which he was Ordinates— number of subjects. perfectly familiar, al- women; men. though the form waS unusual, and that he was to find out what it was and how it worked He was told whether or not he was correct when he thought he knew its use. Most of the subjects could tell what it was before they discov- ered how it worked, although in a few cases the reverse was true. A diagram of the lock is given in Fig. 70. The inside of the lock is shown in its locked position, i. e.,. with the bolt A out. The bolt was held in place by a rod at B, which passed through a long, narrow open- ing, leaving the bolt free to move back and forth the distance of the opening, and also up and down about the rod as axis, from the top of the lock to the bottom. A spring, C, passed from the inner end of the bolt A to a rod fastened to the wall of the lock at D. E and F represent pegs which moved freely about their axes. Handles from these pegs projected about one inch through the wall of the lock. To unlock it, the peg INTELLECTUAL FACULTIES [19 Fig. 70. Ingenuity. Apparatus used in fifth test. E was first turned so as to raise the bolt toward F. When the bolt was at its highest point the catch, G, was opposite the peg F. When F was then turned so that its thin edge pointed to the back of the lock, it carried the bolt with it, and braced it inside of the lock so that none of it projected. The lock was then unlocked. To lock it, it was only necessary to turn the peg F back to the posi- tion shown in the fig- ure, when the bolt, through the action of the spring C, at once flew back to its original position. The lock was always given to the subject in its locked position as shown in the sketch. The chief difficulty experienced in this test was in discovering that the bolt would move in and out, as well as up and down. The up-and-down motion was apparent as soon as the pegs were moved, but the opening in the bolt on which it moved in and out was so far back that it could not be seen by looking in at the open end of the lock, and the subjects were not allowed to take it apart. In some cases the in-and- out movement was discovered by an accidental press- ing on the bolt, sometimes it occurred to the subject to try that movement purposely, and sometimes it was found by experimenting with the peg F and its relation to the catch G. After the in-and-Qut motion was once discovered the solution usually came quickly. At first most of the subjects explained it on I20 THE MENTAL TRAITS OF SEX the basis of the up-and-down movement as a latch, and worked out the other solution only when they were told that it was not a latch. The results show a very evident advantage on the side of the men. The majority of them solved the problem in less than twelve minutes, while the majority of the women took more than twelve minutes. jTjg _j Two women failed en- Ingenuity. Fifth test. tirely, while, all the Abscissas — time in minutes. men worked OUt the Ordinates — number of subjects. solution in forty-five women ; men. . mmutes or less. The difference was no doubt partly due to the fact that most of the men were familiar with the construction of locks in general (although none of them knew exactly this form), while the women had had much less experience with locks of any sort. To sum up the results of the ingenuity tests, they show that, on the whole, the men have a decided ad- vantage. They were much superior to the women in two tests (the third and the fifth), somewhat superior in one (the fourth), equal in one (the second), and inferior in one (the first). There are several indica- tions that special education plays some part in these results. Two of the problems in solving which the men proved superior to the women, viz.j those of the lock and the visual apparatus, were in the realm of mechanics, with which men are by education more familiar than women. In the lock problem the men's superiority is marked, while in the visual-apparatus INTELLECTUAL FACULTIES 121 problem it is only slight. The latter problem, dealing as it did with a unique machine, was one in which previous experience with mechanical contrivances would be of comparatively little assistance. Experi- ence with locks, however, would assist materially in solving the lock problem, though the form of the lock was unfamiliar. Of the three non-mechanical prob- lems, the women were better in one, the men were better in one, and they were equal in one. D. GENERAL INFORMATION. The questions to test general information were selected as a test for college students, not,as a- repre- sentative set of questions for intelligent people in general. The correct answers were facts that a col- lege student of the third or fourth year could fairly be expected to know. The majority of them were facts that the average college student must have known at some time during his career. It was sought to make the questions perfectly fair and representa- tive ; there were no catch questions. In order to make the evaluation of the results as exact as possible, questions of fact only were asked. The answers are definitely either right or wrong ; they can be marked with very little variation due to the personal equation. An exact evaluation of questions of theory or opinion is much more difficult. The questions were handed to the subject written, and he was given all the time he wished to answer them. They were as follows : Name two writers of English who wrote before Shake- speare ; give the title of one work of each, and tell whether it was poetry or prose. /' THE MENTAL TRAITS OF SEX Give approximately the dates of the period during which Shakespeare wrote. To what nation and what period does each of the follow- ing writers belong : Pope, Racine, Schiller, Coleridge, Balzac, Dryden, Petrarch, Heine, Browning, Ibsen ? Name one work of each of the following writers : Tolstoi, Charlotte Brontd, Macaulay, Victor Hugo, Nathaniel Haw- thorne. Who wrote the following works : Tom. Jones, Cyrano de Bergerac, Two Gentlemen of Verona, The Excursion, Pride and Prejudice, Richard Feverel, Childe Harold, dam Bede, The Vicar of Wakefield, The Newcomes ? 6. Name the great subdivisions of the Aryan race. 7. Name the nations occupying the Tigris and Euphrates valley previous to the time of the Roman empire. ■ 8. Name (a) two famous lawgivers of ancient Greece, and {b) three Grecian cities which, at different times, held supremacy over Greece. 9. (a) When did the French Revolution occur ? {!>) Name three men who were prominent in French poli- tics during the five years subsequent to the beginning of the Revolution. I o. {a) When did the Roman republic cease ? [i) What form of government followed the republic ? (c) Who brought about the change ? 11. {a) What was the Missouri Compromise ? (J)) What is its date, approximately ? 12. Is hypnotism an established scientific fact, or is it fraud and superstition ? 1 3. How does the binomial theorem lessen labor in mathe- matics ? ■ _ „ 14. Solve this equation for jr: 5:1:* — 21^=2. . 15. What is (a) a sine ? (Ji) a tangent ? 16. (a) What are the fundamental laws of motion ? (*) Who first formulated them ? 17. What does it mean to say that the specific gravity of a body is four ? 18. What is the principle on which the telephone works ? 19. Is the energy furnished by an electric battery created in the battery ? If not, where does it come from ? INTELLECTUAL FACULTIES 123 ■20. Give the chemical formula for water, and explain its meaning. ^21. What happens to the substance of a piece of wood when it is burned ? Is any of it destroyed ? '^. Are there any cases of spontaneous generation among living organisms ? If so, where ? y 23. What is the nature of the simplest type of animal known ? 24. Name the departments of biology, and the other branches which have contributed most to establish the truth of the theory of evolution. ,25. For what were the following men noted, and in what century did they live : Weissmann, Socrates, Esterhazy, John Stuart Mill, Baclu Charlemagne, NebucAiadnezzar, Kant, Pericles, Bacon, /Rameses II., Goethe, Alfred the Great, Dante, Alexander, Kepler, Richelieu, Edmund Spenser, Galileo, Herbert Spencer ? Even in questions as definite as these some diffi- culties arise in grading. For instance, where approxi- mate dates are asked for, how close an approximation shall be demanded ? In each of these cases a more or less arbitrary standard was adopted. For instancej if the dates given for the period during which Shake- speare's plays were written included the greater part of the correct period, the answer was given full credit ; if they included a small part only, part credit was allowed. If they fell entirely out of the correct pe- riod, no credit was given. Answers to the third ques- tion were considered correct as to date if the correct century was given for each of the writers named. The latter part of the eighteenth century was con- sidered a correct answer as to the date of the French Revolution. Dates within fifty years, on either side, of the end of the Roman republic and within ten years of the Missouri Compromise were called correct answers as to those events. The last question was 124 THE MENTAL TRAITS OF SEX ■ J,U / considered correctly answered as to dates if the cen- tury given for each man mentioned were within one hundred years, on either side, of the correct period, except in the case of men who lived in the eighteenth or nineteenth century, where the correct century was required in the answer. In the very early dates, still more leeway than a century was given. Before giving the re- sults of this test, one very evident source of error must be men- tioned, which was also met with in the ingenu- ity tests. The same set of questions was used for the entire series of subjects, and there was always the possibility that later subjects had been told some of the questions by previ- ous ones. Each subject was requested not to talk about the questions to other students, because the same set of questions was to be used for all. Each subject was asked before he was given the questions whether or not he had been told anything about them. Aside from these precautions, there was nothing to be done except trust to the honesty of the subject. Any accu- rate evaluation of the test would have been impossible if different sets of questions had been used, because no two sets of questions of exactly equal difficulty could be made out. Just how large a part a previous knowledge of the questions really played in the results, it is of course impossible to say. The impression of Fig. 72. General information. Entire series of questions. Highest possible grade, 250. Abscissas — grade of the papers. Ordinates — number of subjects. women ; men. INTELLECTUAL FACULTIES 125 the experimenter was that it was very small. There were only one or two cases where there was even a suspicion of such knowledge. The twenty-five questions fall into the following classes : English literature ( five questions). History (six questions). Physics (four questions). Mathematics (three questions). Biology (three questions). Chemistry (two questions). Psychology (one question). General (one question). The results of the tests will be given both for the entire series and for the separate divisions. The answers were graded on a basis of lO for each ques- tion. The highest possible grade for the entire series is therefore 250 ; that for jj each division is given be- low the appropriate dia- gram of results. The two curves for the total examination (Fig. 72), although different, do not differ in such a way that we may call one bet- ter than the other. Both the extreme records, 100 and 220, are those of women ; but on the other hand the men are more numerous than the women at both extremes. There are six men and only two women under 120, and also * ■ 2f }'$■ if St Fig. 73. General information. Questions on English literature. High- est possible grade, 50. Abscissas — grade of the papers. Ordinates — number of subjects, women : men. 126 THE MENTAL TRAITS OF SEX ^t> f/> ID 20 30 Fig. 74. General information. Questions on his- tory. Highest possible grade, 6o, Abscissas — grade of the papers. Ordinates — number of subjects. - - - - women ; men. 10 six men and two women over i8o. The curves, on the whole, coincide remarkably. Both center around i6o, where each stands at three. Each one has twelve "below and ten above i6o. The curves repre- senting the grades in English literature (Fig. 73) show a decided ad- vantage on the side of the women. From thirty- five down the curve for the men is above, while from thirty-five up, that of the women is above. The results of the examination on history appear in Fig. 74. What differ- ence there is between the two curves is in favor of the men, although it is not very great. In physics (Fig. 75) the men have a decided advantage. The ex- tremes of the two curves are the same, and the women are slightly more numerous in the region of the best records ; but the general course of the men's curve is better than that of the women's. The majority of the women fall below fifteen, the majority of the men above. 10 30 Fig. 75. General information. Questions on physics. Highest possible grade, 40. Abscissas — grade of the papers. Ordinates — number of subjects. - — women ; men. *t INTELLECTUAL FACULTIES 127 The two curves for the examination on mathe- matics (Fig. 76) correspond closely. What differ- ence there is, is in favor of the women. There are more men than women in the lower ranges, and more women than men in the upper. In biology (Fig. 'j'j') we find the men in excess at both the good and bad extremes. The general course of the curves, however, shows a somewhat higher average in the women's record. The questions in chemistry were both so simple that the answers were almost all correct. Eighteen women and seventeen men were graded at ten on both questions. In the question on hyp- notism the men have a better record than the women. The men all answered correctly. Four women failed on the question. The results of the exami- Fig. 76. General information. Ques- tions on mathematics. Highest possible grade, 30. Abscissas — grade of the papers. Ordinates — number of sub- jects. - - - - women ; men. nation on question 25 appear in Fig. 78. Here again the men are in excess at both extremes. It is impossible to call either curve better, on the whole. To assist further in the analysis of the results of i» 10 Fig. 77. General information. Ques- tions on biology. High- est possible grade, 30. Abscissas — grade of papers, Ordinates — number of sub- jects. - - - - women ; men. 128 THE MENTAL TRAITS OF SEX ) Jl T i 7 S 9 ' Fig. 78. General information. Question 25. Highest possible grade, 10. Abscissas — grade of papers. Ordinates — number of subjects. women ; men. the general-information tests, the grades in English literature and history, as the literary subjects, and those in physics, mathematics, biology, and chemistry, as the scientific subjects, were summed. The two summations are shown in Figs. 79 and 80. In the diagram for the lit- erary subjects the men are more numerous in the middle ranges and the women in the higher, while in the diagram for the scientific subjects the reverse is the case. The results of the series of tests on general infor- mation may be summed (, up as follows : In aver- age grade on the entire series of questions there ■^ is no difference between 3 the men and the women. There is, however, a dif- ference in grouping. The men are more numerous • at both good and bad ex- tremes than the women, and the women more nu- merous than the men in the middle ranges. The women stand better than the men in the literary subjects, and not so well in the scientific. This does not mean that the women 70 Fig. 79. General information. Summation of grades in the literary subjects. Highest possible grade, no. Abscissas — grade of papers. Ordinates — number of subjects. women ; men. INTELLECTUAL FACULTIES 1 29 were superior in both the literary subjects nor that the men were superior in all the scientific. The relation of the sexes in the separate subjects was as follows : English literature : women much superior. History ; men a little superior. Physics : men much superior. Mathematics : women very slightly superior. Biology : women a little superior. Chemistry : both sexes equal. In the results of the tests on general information, as in those on ingenuity, special training is unquestion- ably a factor. As appears from Table XXVII, far more women than men were in- terested in English litera- ture. Although the women were as interested in sci- ence as the men, probably the stress of their work had fallen more on literary than on scientific studies. Many of the women were preparing to be teachers, and had, therefore, from practical considerations devoted themselves pri- marily to those subjects in which the openings for women are most numerous, viz., literary subjects. Many of the men, on the other hand, intended to be physicians, and hence were laying the stress of their work on scientific studies. The slight superiority of the men in history is probably due to the presence of several students who were preparing for a law course. io to Fig. 80. General information. Summation of grades in the scientific subjects. Highest possible grade, 120. Abscissas — grade of papers. Ordinates — number of subjects. women ; men. I30 THE MENTAL TRAITS OF SEX SUMMARY OF OTHER EXPERIMENTAL WORK ON INTEL- LECTUAL PROCESSES. There have been a number of researches on the comparative memory of the sexes, although none of the others have required memorizing or measured retentiveness. The other tests have all followed the method of making a single presentation of some series of stimuli and requiring the subject to reproduce it. The power of memory was then measured by the accuracy of the reproduction. Tests on university students have been made at Columbia University (82) and at the University of Wisconsin, the latter by Jas- trow (35). At Columbia University visual, auditory, and logical memory were tested ; the first two by pre- senting series of numerals through the eye and the ear, and the last by reading aloud a passage to be re- produced. The result was to show that women had a decided advantage in visual memory, men a doubtful advantage in auditory memory, while there was no difference in logical memory. Jastrow's method was to display a series of words one by one, requiring the subject to write the first association which occurred to him. Two days later the subject was asked to write the original list again from memory. In this test women made a better record than men. It was after- •ward performed on high-school students with the same result. Stern (76a) has made a few tests tend- ing to show that the memory of women for the details of pictures is completer than that of men, but that they add in recollection more of imaginary material than do men. Bolton (9) tested auditory memory in school children, both in the high school and in the grade schools, by the method of reading INTELLECTUAL FACULTIES 131 aloud a series of numerals, which were then repro- duced. He finds the girls decidedly better than the boys. Shaw (75) employed the method of requiring school children to reproduce a story which had been read to them, and again the girls made the better record. Netschajeff (60) experimented on school children of St. Petersburg, varying from nine to eighteen years in age. He tested memory for objects, sounds, numbers, and various kinds of words. His general result is that, with slight exceptions, girls excel boys in power to recall. Very much the same series of tests was performed by Lobsien (48) on school children of Kiel between the ages of nine and fourteen and a half. His results are formulated with reference both to the number of impressions reproduced and to the correctness of the order in which they were reproduced. He finds that the girls excel the boys in both respects. Ebbing- haus (22) used memory as one of his methods of testing mental ability. He stands alone in finding girls inferior to boys up to the age of eleven or twelve years. The fact that the boys and girls he tested were being educated in different kinds of schools (^Gymnasium and Madchenschule') may account for this discrepancy. The results of former experiments thus agree almost unanimously with the present series in showing better memory in females than in males. Two investigations other than the present are on record in which the attempt has been made to obtain a statement of the comparative rapidity of the asso- ciation process in men and women. Jastrow (34) took the time required to write one hundred words as rapidly as possible. He found no difference in the 132 THE MENTAL TRAITS OF SEX time required by men and women ; but as he himself says, his method of measurement was rough. The second association test referred to was made at Co- lumbia University (82). It consisted in requiring the subject to write the first association to each of nine words. The words were given the subject printed on a card. The entire time of the process was taken. The men proved to be more rapid than the women. Neither of these results accords with those of the pres- ent test, which show the women to be somewhat more rapid. If what is sought is a measurement of the normal rapidity in passing from one idea to the next when the process is made as natural as possible, the form of test employed in this series seems better fit- ted to give the i;pquired value than the two just de- scribed. The process of merely observing and noting down the thought sequence as it occurs from a given starting-point seems less artificial than that of writing down one hundred different words, or of writing the first association to a given word. The writer is there- fore inclined to put more faith in the results of this test than in those of the others. Qualitative, as distinguished from quantitative, comparisons of the association faculty in men and women have been made experimentally by Jastrow '(34i 35> 36, 37) and by Miss Calkins (13) and her students (61): Two methods were employed by each. The first was to require the subject to write one hundred different words as rapidly as possible. Jastrow finds that men furnish a greater variety of words and a greater number of unique ones than women. Miss Calkins, on the contrary, finds the va- riety of words furnished by women about equal to INTELLECTUAL FACULTIES 133 that of men, and their number of unique words greater than that of men. The second method consisted in requiring the first association to each of a list of given words. Neither investigator discovered any differ- ence by this method. They agree in finding some classes of words mentioned more frequently by one sex than by the other, such as food-stuffs by women. But as both Miss Calkins (13) and Miss Tanner (79) have pointed out, this fact points not to original sex- ual difference in type of mental activity, but to dif- ference of training and surroundings from childhood on. There are no previous tests on ingenuity and gen- eral information with which those above recorded may be compared. It is well known that in school work girls have better records on the whole than boys (55, p. 1045). ^ut the general average of school work is not comparable to the results of our test on general information. The former takes account of the way in which the lessons assigned are learned, the latter of the amount of definite information which the individual has at hand when it is suddenly called for. There are a few other investigations which have a more or less remote bearing on the intellectual tests. Lindley (47) , investigating puzzle interests, says that he discovered no difference in the age at which the various puzzle interests develop in the two sexes. He attributes this failure to the small number of indi- viduals investigated. Dearborn (19), studying the imagination by means of ink blots, found no difference between the sexes. Minot (58), found greater uni- formity in women's diagrams than in men's. Miss Cal- kins (12), investigating the mathematical consciousness. 134 THE MENTAL TRAITS OF SEX found from answers to a questionnaire that men are more likely to reason out a mathematical demonstra- tion, and less likely to memorize it, than are women. This is not in agreement with the present tests, which show that the women as a whole have an equal capacity with the men for furnishing an original solution of a mathematical problem when it is called for unexpect- edly. Ebbinghaus (22), and Bellei (8), both made tests on school children which were intended to measure intellectual ability. The former used the methods of mental arithmetic, memory, and what he calls a combination method, which consisted in requir- ing the child to fill in the omissions in a text which had been prepared with some syllables or letters omitted. The rapidity and accuracy with which this could be done was regarded as a measure of mental ability. The latter used the first and third of the methods just described. Ebbinghaus found the boys superior to the girls up to the age of fifteen, when the girls were somewhat superior. Bellei's results do not agree with Ebbinghaus's. His experiments were con- fined to children of a single class in school having an average age of eleven years. He finds the girls supe- rior to the boys. GENERAL SUMMARY OF EXPERIMENTS ON INTELLECTUAL FACULTIES. It is well established that women have better memories than men ; they memorize more quickly and retain as well. The results of the various experiments on association do not agree as to either quantitative or qualitative differences of sex. The most trustworthy evidence goes to show that the process of association INTELLECTUAL FACULTIES 135 is somewhat more rapid in women than in men. As to qualitative differences, none of the methods employed seems to have thrown, or to be capable of throwing, any real light on this question. The experi- ments which have been performed to determine com- parative ingenuity show the men superior to the women. There are indications, however, that mechani- cal training, which boys unquestionably receive to a greater extent than do girls, is an important factor in this result. The question whether the more extensive mechanical education of boys is not to be accounted for by their greater natural ingenuity will be discussed later. In total amount of general information there is no difference between men and women who have taken the same course of education. The women are somewhat the better informed in literary and the men in scientific subjects, but this is probably due to selec- tion of studies and not to sex. CHAPTER VIII. AFFECTIVE PROCESSES. The affective processes were investigated from two points of view : A. The physiological expression of affective processes as re- vealed in circulation and respiration. B. The introspective account of affective processes given in re- sponse to questions on personality of the following classes : 1 . Questions on age, health, and nationality. 2. Questions on sensory experiences. 3. Questions on methods of rest and recreation. 4. Questions on the individual aspects of personality. 5. Questions on the social aspects of personality. 6. Questions on intellectual interests, methods of work, and beliefs. A. THE PHYSIOLOGICAL EXPRESSION OF AFFECTIVE PROCESSES AS REVEALED IN CIRCULATION AND RESPIRATION. For investigating the changes in circulation and breathing in response to the affective processes Hallion and Comte's air plethysmograph (32) and Bert's rubber-capped metal respirator were used re- spectively. These instruments were used simulta- neously, writing side by side on a smoked drum. The object of the experiment was not explained to the subject. He was directed to sit still and keep his eyes shut. A normal curve was first taken to show the characteristic reaction of the individual in a state of repose. When this had been obtained vari- 136 AFFECTIVE PROCESSES '37 ous stimuli were applied. Agreeable and disagree- able odors were given him to smell ; he was touched on the face with a piece of cold metal ; a loud sound was produced by dropping a heavy object on the floor; his hand was pricked with a pin; and to show the effect of mental application he was given problems in addition and multiplication to solve. The curve was watched constantly, and if any marked changes occured in it during the interval between stimula- tions, the subject was told to remember what he was thinking about at that time and report later. In the belief that the significant features of the changes in pulse and breathing were to be sought rather in the amount of the change than in its form or direction (2) the results were formulated on the basis of the violence of the changes inr the plethys- mograph and the respirator curves, due either to spontaneous emotion, or to the stimuli applied. Table XIV gives the results : TABLE XIV. Degree of change in respiration and circulation in response to affec- tive changes. Changbs. Slight. Medium, Violent. II 7 8 6 6 Men ' 10 The table shows a greater proportion of men than women with violent physiological changes, and a greater proportion of women than men with slight ' But twenty-three men appear in this table because two records were accidentally destroyed. 138 THE MENTAL TRAITS OF SEX changes. If, as is supposed, the amount of change in the curve runs parallel with the degree of emotion- al disturbance, the result means that the men had slightly more intense affective experiences than the women — a conclusion decidedly opposed to the popular opinion on this subject. B. THE INTROSPECTIVE ACCOUNT OF AFFECTIVE PRO- CESSES GIVEN IN RESPONSE TO QUESTIONS ON PERSONALITY. The series of questions^on personality was designed to cover all questions of interest with regard to an individual which do not lend themselves to experi- mental treatment, or at least which could not be treated experimentally in the present series of tests. The questions cenjered chiefly upon the affective con- sciousness — upon temperament and disposition, likes and dislikes, and interest. They included also what- ever questions of fact with regard to the individual's history seemed important. The evaluation of the answers to the questions which dealt merely with facts of individual history presents no serious difficulty. The answers to ques- tions on the nature of the individual's affective con- sciousness, on the other hand, are extremely difficult to evaluate. The difficulty is the one involved in all questionnaires. There are at least two important sources of error which the experimenter has no means of con- trolling or measuring. The first is the fact that many individuals have not the skill to interpret carefully and accurately if they will ; the second is the fact that many individuals will not be, or cannot be, perfectly honest in answering questions on personality. What we are sure of getting in answer to such questions, is AFFECTIVE PROCESSES 139 not so much true statements with regard to the per- sonality of the individual, as the individual's reaction toward the question asked. The answer will approach the truth in proportion as the individual is skilled in introspection and honestly endeavors to tell the truth. How far these conditions were fulfilled in the present case it is impossible to say; but it may be said that the conditions of the present questionnaire were as favorable as possible for their fulfilment. The indi- viduals questioned had all had some training in psy- chology and were therefore more skilled than average persons in introspection. They had all voluntarily lent themselves to the test out of interest in it, and would for that reason be likely to endeavor to be honest. Their judgment was entirely unbiased by any knowledge of the ultimate purpose of the test. The questions were asked one by one by the experi- menter and answered orally by the subject. Each question could thus be explained whenever necessary, and the answer discussed. The general impression of the experimenter was that the subjects were really interested in the questions and tried to give honest answers. The questions asked dealt with the following sub- jects : (i) age, health, and nationality; (2) sensory experiences; ( 3) methods of rest and recreation ; (4) individual aspects of personality; (5) social aspects of personality; and (6) intellectual interests, methods of work, and beliefs. I . Questions on age, health, and nationality. — The first set of questions on personality was designed to bring out the degree of homogeneity of the material for this investigation. The questions were as follows : 140 THE MENTAL TRAITS OF SEX 1. What is your age ? 2. What is the state of your health, poor, medium, good, or excellent ? 3. Are there any physical abnormalities of your sense organs of which you are aware ? 4. Do you consider yourself of a nervous temperament ? 5. What is your own nationality and that of your parents ? Of what nationality were your ancestors ? The ages of the subjects are represented in the curves of Fig. 81. The age curves for men and women coincide very closely, twenty-two of each falling between the limits of nineteen and twenty-three years. Three of each sex were twenty-five years old or more. Both curves cul- minate at twenty-one years. The answers to the question on health are represented i n Table XV, which shows four more women than men in the poor and medium sections, and four more men than women in the good and excellent sections. There were, however, more women than men who graded TABLE XV. Health of the subjects. 23 If n Fig. 81. Age of the subjects. Abscissas — ages. Ordinates — number of subjects. - - - - women ; men. Poor. Medium. Good. Excellent. 3 4 3 4 12 14 Men AFFECTIVE PROCESSES 141 themselves as having exceptionally good health. We find the women therefore more numerous at both ex- tremes of health and the men more numerous in the middle range. The total balance would incline toward better health for the men. The number of physical abnormalities of the sense organs reported is summed in Table XVI. The records of the two sexes coincide almost exactly. TABLE XVI. Physical abnormalities of the sense organs of the subjects. Eye. Ear. Nose. None. 6 5 4 4 3 3 IS IS Men Table XVII shows the way in which the question on nervousness was answered. Here again the records of the two sexes coincide too closely to indicate any difference between them in this respect. TABLE XVII Degree of nervousness of the subjects. No. Slightly. Yes. Women 9 10 7 S 9 Men 10 All of the subjects were of American birth. Two of the men were Canadians, but all of the other sub- jects were born in the United States. The men showed a larger percentage of foreign parentage than the women. Both parents were natives of the United 142 THE MENTAL TRAITS OF SEX States in the case of twenty of the women and sixteen of the men. The birthplace of the parents in the remaining cases is shown in Table XVIII. TABLE XVIII. Nativity of the parents of the subjects. a V Nativity of Parents. 1 S 20 I6 Both parents born in United States. 2 One parent bom in United States, the other in England. One parent born in United States, the other in Ireland. One parent born in United States, the other in the West Indies. Both parents born in Canada. One parent born in England, the other in Canada. One parent bom in England, the other in Wales. Both parents born in Germany. Both parents born in German Poland. One parent born in Germany, the other in Switzerland. Both parents born in Austria. Both parents born in Russia. The nationality of the subjects' ancestors appears in Table XIX. One man and one woman did not know anything about their ancestors previous to their settle- ment in America, and hence could not answer the question as to their nationality. Many of the other subjects seemed doubtful on this question. The report is therefore incomplete and probably incorrect in some respects. Still, it serves as some indication of the races most largely represented. It appears from the table that the ancestry of the great majority of the subjects, both men and women, was English, Welsh, Scotch, or Irish. After the Brit- ish nationalities, in order of representation in the table, AFFECTIVE PROCESSES TABLE XIX. Ancestry of the subjects. 143 i "Ha 1 i 4 I j 6 < 1 1 1—1 M g 5( i H 1 1 •-> 14 12 9 10 5 s 4 2 s 7 8 7 I I 3 I I I I I Men I comes the German, and after that the French. Other nationalities are represented only in scattered instances. The general result of the questions on age, health, and nationality was to show a high degree of uniform- ity in these respects among all the subjects. Since these are all factors which might, if they differed widely, be held accountable for differences discovered between the sexes, the fact that in respect to them the records of the men and the women examined coincide so closely indicates that the material selected was really homogeneous and a fair basis for a comparison of the sexes. 2. Questions on sensory experiences. — The ques- tions on sensory experiences were as follows : 1 . Is any one of your senses notably keen or notably dull ? 2. Are you particularly sensitive to impressions derived from any one sense ? 3. Do you derive special pain or pleasure from the sense- impressions of any one sense-organ ? 4. Have any of your sense-organs bad special training ? 5. Do musical tones suggest colors to you ? 6. Are letters, words, or names colored to you ? 7. Have you any color associations with smells or tastes ? The answers to the first four questions are em- bodied in Table XX. The number of subjects who had received special training of the senses is so 144 THE MENTAL TRAITS OF SEX TABLE XX. Answers to questions 1-4 on sensory experiences. E e5 1 e3 1 1 1 :! Senses notably keen ( Women I Men . . . I 3 3 5 4 4 4 12 IS Senses notably dull. Women Men . . . I 2 2 I I 4 3 18 18 Senses particularly prominent in con- sciousness. ( Women (Men... ■• 4 2 6 5 3 7 12 13 Senses a source of special pleasur^ C Women (Men... I I 3 2 10 6 5 8 9 10 Senses a source of special pain. ( Women I Men . . . I 3 I 4 I S 7 14 15 Senses specially trained. ( Women ( Men . . . •■ 4 2 9 10 IS IS nearly identical for the two sexes that training cannot be held responsible for the sense-differences shown by this series of experiments. Fifteen subjects of each sex were without any training, and ten subjects of each sex had been trained. Of the ten women, three had been trained in both sight and hearing, one in sight alone, and six in hearing alone. All of the ten men had been trained in hearing and two of them in both sight and hearing. The table shows that sensory experiences were on the whole somewhat more prominent in the women than in the men. There were more women than men who reported AFFECTIVE PROCESSES H5 special keenness of sense, who had some special sense more prominent in consciousness than the others, and who derived special pain and pleasure from simple sensory experiences. The preponder- ance of women is very small in each case, but is constant. The senses reported particularly keen or dull are almost the same for both sexes. In promi- nence in consciousness and power to give pleasure or pain we find vision predominating in the women and hearing in the men — results which may be cor- related with the women's use of visual imagery and the men's use of auditory imagery, as shown in the memory test (see chap, vii, sec. A). Pseudo-chromaesthesias proved to be much more frequent among the women than among the men ; there were only twelve women who reported none, while there were twenty such men. Among the thirteen women who reported pseudo-chromaesthesias the color association was made in nine cases with musical tones, in four with letters or words, in two with tastes, and in four with odors. None of the color associations of the men were at all fully devel- oped. Of the five who reported them one said it was a discarded habit of which he had not been conscious for several years. Among the other four there were two cases of color association with tones, one with letters, two with taste, and one with smell. Here again we find evidence that visual experience is more important in the consciousness of women than in that of men. 3. Questions on methods of rest and recreation. — The questions on methods of rest and recreation were as follows : 146 THE MENTAL TRAITS OF SEX I. What way of resting after intellectual work do you prefer ? 2. Arrange the following employments in the order in which they give you the most pure pleasure : reading, the theater, the opera, concerts, lectures, social gatherings, outdoor sports, indoor games. The answers to question i are presented in Table XXI. In cases where two or more methods of rest- ing were equally enjoyed by the same subject, all were counted. The difference between the sexes is most apparent in the relative numbers of men and women who preferred sleep and outdoor exercise. The other methods of rest named in the table were about equally prized by men and women. TABLE XXI. Answers to questions on preferred methods of resting after intellec- tual work. Modes of Resting. Sleep. Light reading. Outdoor exercise. Social inter- course. Tlie theater. Revery. Women Men 12 8 5 5 10 14 4" s 2 I I The answers to question 2 are formulated in Table XXII. The number of men or women who assigned to a given amusement a given place in the order of their preference is placed under the name of the amusement and opposite the number in the col- umn headed "Order" which indicates the place assigned. Thus, the number of women who assigned the sixth place in the order of their preference to con- certs is found under " Concerts," and opposite the 6 in AFFECTIVE PROCESSES TABLE XXII. 147 Order of preference assigned by the subjects to eight amuse- ments. 6 1 i a u § 1^ 5 1" Q U w. M. W. M. w. M. w. M. W. M. w. M. W. M. w. M. I 2 3 4 I 7 4 5 4 3 2 5 7 8 2 I 2 3 8 4 4 5 2 ' 2 S 5 2 2 3 3 3 2 3 2 4 s 5 6 3 2 1 4 4 7 3 2 2 12 6 2 I z I I 7 6 10 X I 2 3 6 2 8 2 I 3 3 5 5 2 4 4 S 2 i 2 I 2 9 2 6 4 2 z z X X I 4 IS 3 3 X 3 2 column headed "Order." That number is 6. Incase a subject placed two amusements in the same grade of esteem they were tabulated accordingly ; and the amusement which the subject placed next after these two was tabulated, not as in the next lowest grade, but as in the next lowest but one. If, e. g., a subject placed reading highest, concerts and the opera next, and social gatherings next, reading would be tabu- lated as his first chdice, concerts and the opera as his second, and social gatherings as his fourth. It appears from Table XXII that the men's tastes were more evenly distributed than the women's. The women's columns show more large groups and more zeros than the men's. The order in which the women as a whole and the men as a whole esteemed the amusements in question is given in Table XXIII. From this table it appears that the amusements fall into two groups, each of which was held in the same relative esteem by both the men and the women, though the order of the 148 THE MENTAL TRAITS OF SEX TABLE XXIII. Summation of Table XXII. Order in which the eight amuse- ments were esteemed by the women as a whole and the men as a. whole. Order. Women. Men. I 2 3 4 5 6 7 8 Opera Reading Theater Outdoor sports Concerts Social gatherings Lectures Indoor games Outdoor sports Theater Reading Opera Social gatherings Concerts Indoor games Lectures amusements within the group differs for the two sexes. The first group consists of reading, the theater, the opera, and outdoor sports ; the second of social gath- erings, concerts, lectures, and indoor games. The only marked difference in the order of amusements in the two columns of Table XXIII is in the places assigned to the opera and to outdoor sports, which stand respectively first and fourth in the women's list and fourth and first in the men's. It is surprising that social gatherings are placed so low in both scales and that the men gave them a higher preference than did the women. 4. Questions on the individual aspects of personality. — The questions on the individual aspects of personality were as follows : 1 . Do you consider yourself very emotional ? 2. Is your instinct to express emotions or to repress and hide them ? 3. What sort of physical expression do violent emotions have? 4. Are you very introspective ? 5. Do you do much day-dreaming .? AFFECTIVE PROCESSES 149 6. Do you ever have illusions, hallucinations, or presenti- ments ? 7. Are you of the impulsive or of the reflective type in action ? 8. Do you always give reasons to yourself for your judg- ments and decisions at the time when you make them, or are they frequently intuitive ? Q. Are you very active physically ? ID. Are you mechanical? i. e., do you enjoy working with your hands ? 11. Have you executive ability? 2". e., do you enjoy manag- ing and taking responsibility, and do you succeed when you do ? 1 2. Have you a contented disposition, on the whole ? 13. Are you inclined to brood and worry over things which go wrong ? 14. Is your impulse to blame yourself if possible, or others if possible, or fate, when things go wrong ? 15. Are you very conscientious? 16. Do ethical or aesthetic or religious ideas play the largest part in controlling your acts ? The answers to these questions, with the excep- tion of question 3, are summarized in Table XXIV. The only difference in emotional nature indicated by the answers to the first two questions is a somewhat greater tendency on the part of the women to repress emotions, while the men reported themselves more disposed to express their emotions. In answer to the third question both the men and the women reported trembling as the commonest physical effect of emotion and a tendency to weep as the next commonest. The next in order were rigidity of the muscles and aimless movements in the case of the men, and faintness and weakening in the case of the women. The women mentioned on an average more physical effects of emotion than the men. Whether this fact is due to greater accuracy and completeness on the part of the ISO THE MENTAL TRAITS OF SEX TABLK XXIV. Answers to questions on individual aspects of personality. Women. Men. 10. Emotionality : Great Medium None Expression or repression of emotion : Expression predominant Repression predominant Neither predominant Introspectiveness : Great Medium None Disposition to day-dreaming : Great at present Great formerly Some None ^ Illusions, hallucinations, and presentiments Illusions Hallucinations Presentiments None of the three Impulsiveness or reflectiveness in action : Impulsive Reflective Neither, primarily Character of judgments and decisions : Reasoned Intuitive Neither, primarily Physical activity : Great Small Taste for mechanics : Great Some None Executive ability : Marked Slight None Habitual contentment: Marked Slight None 10 S 10 6 i8 I 13 6 6 10 S 7 3 13 12 7 i6 2 17 7 I 13 12 10 2 '3 13 4 8 13 3 9 10 5 10 10 IS 13 6 6 8 5 10 4 2 2 8 17 9 IS I i6 8 I i6 9 6 3 l6 II 10 4 i8 2 s AFFECTIVE PROCESSES TABLE XXIV— Co»ft«Kf59 TABLE XXVn-Conttnued. Studies found easiest — Continued: Women. Men. 5. Mathematics. 4. Mathematics. 2. History. 2. Sociology. 2. Philosophy. I. Philosophy. I. Economics. I. Sociology. 3. All equally easy. 3. All equally easy. Studies found hardest : Women. Men. 6. Mathematics. 12. Mathematics. 6. History. 4. Science. S. English. 3. Ancient languages. 5. Philosophy. 3. Modem languages. 4. Ancient languages. 3. Philosophy. 3. Science. 2. Economics. 2. Modem languages. I. History. I. Economics, I. English. 3. All equally hard. 2. All equally hard. Studies in which best work had been done : Women. Men. 11. Ancient languages. 7. Modern languages. 10. Modern languages. 4. Ancient languages. 5. Mathematics. 4. Philosophy. 5. Science. 4. English. 4. English. 4. History. 3. History. 3. Science. 2. Philosophy. 3. Sociology. I. Economics. 2. Mathematics. 2. Economics. 2. Work equally good in all. 2. Work equally good in all. Studies adopted as specialties : Women. Men. 5. Modem languages. 5. Economics. 4. Ancient languages. 3. Science. 4. Science. 3. Philosophy. 4. Philosophy. 2. Modern languages. I. English. I. History. I. Economics. I. Sociology. I. Sociology. 10. None. II. None. i6o THE MENTAL TRAITS OF SEX The answers to the first five questions are summarized in Table XXVII. The number before the name of each study indicates the number of times the study was men- tioned in the answers as most interesting, easiest, etc. The most striking thing about this table is the general uniformity in the answers. Both the men and the women reported philosophy and science as the subjects of greatest interest, languages as the easiest and the one in which best work had been done, and mathematics as the hardest. Science, philosophy, and languages occupy closely corresponding positions in the tables of the men and women throughout. The only marked difference in the amount of interest in the various studies reported by the two appears in the greater interest of the women in English. Mathe- matics was reported as the hardest subject by twice as many men as women, while more of the women than of the men found it easy and reported good work in it. History, while equally interesting to both sexes, appears easier for the men. It is interesting to note that in both cases the subjects which were easiest were also those in which best work was being done. This correspondence is somewhat closer in the case of the women. The studies found easiest by the greatest number of women were also those in which the great- est number of them were specializing — a statement which is not true of the men. The number who had done no specializing was about the same in both sexes. The outcome of these questions is interesting in its bearing on the test for general information (chap, vii, sec. D). It goes to show that the individuals used for that test were really comparable in amount of training and in interests. AFFECTIVE PROCESSES i6i The answers to the remaining questions under the present head are summarized in Table XXVIII. TABLE XXVIII. Answers to questions on methods of work and beliefs. Women. Men. 6. Number-forms and diagrams for days and months : Present Absent 7, Character of mental imagery : Visual Motor Auditory Visual-motor Auditory-motor Visual -auditory Visual-motor-auditory 8. Use of a schedule of daily work : Rigid Flexible None 9, Proportion of time given to study ; All More than half Half Less than half. 10. Manner in which study is regarded : As a pleasure As drudgery Partly as a pleasure, partly as drudgery. . . . 1 1 . Career selected : Practical Intellectual Practical and intellectual None yet selected 12. Religious beliefs : Strong Some None 13. Adherence to church creeds : Some creed adhered to None adhered to 1 4a. Attitude toward spiritualism: Belief Neutrality Disbelief 7 4 18 21 14 IS 4 I 2 3 I 3 2 2 3 10 8 3 6 12 II 7 8 7 9 6 2 S 6 13 II 4 II 8 3 I 2 14 8 4 13 6 2 16 10 5 4 4 II 9 8 16 17 I 4 5 5 19 16 l62 THE MENTAL TRAITS OF SEX TABLE XXVm—Cctitinued. Answers to questions on methods of work and beliefs. Women. Men, 14*. Attitude toward telepathy: Belief Neutrality Disbelief 14^. Attitude toward Christian science : Belief Neutrality Disbelief 15. Influence of omens and presentiments: Some None 16. Superstitions : Some None 10 IS 10 4 5 6 2 3 2 I 21 21 9 6 16 19 9 7 16 18 Number-forms and diagrams for the days of the week and the months of the year are shown by the table to be more numerous among the women than among the men, although the difference is much less marked than it was in the case of the pseudo- chromaesthesias. This again points to the greater prominence of visual experience in women. The answers to the question on the general type of mental imagery, however, do not accord with the previous evidence on the subject. There are more men than women who report that visual or visual-motor imagery predominates in their thinking. The memory test and the questions on sensory experience would have led us to expect auditory imagery to be more com- mon among the men than among the women, but the answers to the question on imagery do not bear out this expectation. Since a general question on the type of imagery is so difficult for those comparatively unskilled in introspection to answer accurately, per- AFFECTIVE PROCESSES 163 haps in this case the special pieces of evidence are more to be trusted than the general answer. The only marked sex-difference revealed by the questions on methods of study (8-10) is that the women on the whole derive more pleasure from the study itself, while to the men it is more likely to be a means to an end. They seem about equally inclined to be systematic in the disposition of time. There is a slight predominance of women with rigid schedules, and of men with flexible schedules. The men report a somewhat larger proportion of free time spent in study than the women — a result which is contrary to the popular opinion on the subject. The answers regarding the selection of a career indicate chiefly the fact that over half of the women were planning to teach — an occupation which they classed as intellectual — while about the same number of men were preparing for courses in either law or medicine — professions which are classified as intellectual and practical. There were none who expected to devote themselves to art in any form. The questions on beliefs (12-16) revealed a some- what greater tendency on the part of the women to have strong religious beliefs and to be affected by omens and superstitions ; and, on the part of the men, a more marked tendency to believe in spiritualism, telepathy, and Christian science. SUMMARY OF OTHER EXPERIMENTAL WORK ON AFFECTIVE PROCESSES. Before bringing together what little experimental material there is on the subject of the affective aspect of consciousness as it appears in men and women, it 1 64 THE MENTAL TRAITS OF SEX may be well to emphasize still further the extremely unsatisfactory nature of both methods of investigating affective processes employed in the present work. One of them — the questionnaire — is only semi-scien- tific, while the other — the method of expression — has as yet developed no standard for evaluating the results. The mere personal answer to a question about matters of temperament and disposition, or even about intellectual characteristics, is far from approaching the value of a scientific fact. In fact, such personal esti- mates are peculiarly liable to perversion for obvious reasons. The method of expression, while it holds forth some hope that it may some day lead to the dis- covery of a constant correlation between affective states and certain involuntary movements — particu- larly those of circulation — has not as yet given us any trustworthy criterion for interpreting results. Recognizing fully the serious criticisms to be passed on the methods employed, the results are given not as scientifically determined facts, but as constituting the only indication of probabilities which we have at present. The few previous experiments on record regarding the affective processes which have any bearing on the present series relate, first, to synaesthesia ; second, to one of the individual aspects of personality ; third, to the relative use of visual imagery by men and women ; and, fourth, to beliefs. I. Several experiments on synaesthesia of various forms agree in showing this experience to be more fre- quent among women than among men. Galton (26) found that number-forms were twice as numerous among women as among men. Chalmers (17) finds number-forms more frequent among female students AFFECTIVE PROCESSES 165 than among male. Krohn (44) says that the greater number of his cases of pseudo-chromaesthesia were among women. Miss Calkins (14, 15) found that a very high percentage (50) of the women she examined had synaesthesias, but she furnishes no data for a com- parison with men. 2. In the data collected at Wellesley College from Wellesley and Harvard students (45) it appeared that a larger proportion of the women examined were inclined to day-dreaming than of the men. This fact accords with the results of question 5 of sec. 4, above. 3. The Columbia University tests (82) included a question as to the kind of mental imagery chiefly employed by each subject. This question, like the same one in the present series (question 7 of sec. 6), revealed no greater use of visual imagery by the women as against the men. Likewise Miss Calkins (12) found practically no difference between men and women in the tendency to visualize numerals. On the other hand Galton (26) came to the conclusion that women have more vivid visual imagery than men. Since his subjects were gathered miscellaneously, they were not as comparable in this respect as university students. 4. Sumner {yj) using a questionnaire on belief, found belief in presentiments, omens, and supersti- tions more prominent among women than among men — a result in agreement with that of questions 1 5 and 16 of sec, 6, above. GENERAL SUMMARY OF EXPERIMENTS ON AFFECTIVE PROCESSES. The physiological expression of affective processes, as shown in the experiments on circulation and respi- ration, is more intense in men than in women. As to 1 66 THE MENTAL TRAITS OF SEX the character of the affective processes themselves, the most striking thing revealed by the above ques- tions on personality is their close coincidence in both sexes. The realm of feeling is one of those upon which chief stress is laid by those who believe that there are important psychological differences of sex, and yet we find a series of men and a series of women reacting toward questions about the life of feeling in wonderfully similar ways. Nevertheless, a few differ- ences are revealed, some of which confirm certain conclusions suggested by previous experiments of the present series. Sensory experience in general seems to be some- what more prominent in the consciousness of women than in that of men. Other investigators agree that synaesthesias occur more frequently in women than in men, and in the present investigation they were found (grouping all forms together) in fifteen women and eight men. This fuller sensory experience of women may be correlated with the fact that their senses as a whole are more highly developed. The greater promi- nence of visual consciousness among women is especially marked. That women's visual conscious- ness held this relative position was suggested by their better-developed sense of color, their more frequent use of visual images in memorizing, and their greater readiness in solving a problem depending on quick- ness of visual perception. This suggestion receives further confirmation from the fact that a greater number of women than of men report vision as the sensory field which attracts attention most readily, and as the one from which most pleasure and pain are derived. Pseudo-chromaesthesias, number-forms AFFECTIVE PROCESSES 167 and diagrams for the days of the week and months of the year are also more numerous among women than among men. The pseudo-chromaesthesias may be correlated with the more highly developed color sense of women. The greater motor ability of men, which was shown by the experiments recorded in chap, ii, may be correlated with the answers to the questions on methods of rest and recreation and the question as to physical activity. More men than women prefer outdoor exer- cise as a method of resting after mental work. Men class outdoor sports much higher than do women as a form of amusement. Physical activity is greater among men than among women. Social consciousness seems to be more prominent in men than in women. Social gatherings are ranked higher, as a form of amusement, by men, and their immediate relations to their fellows seem to be of greater importance to men than to women. The religious consciousness is more prominent among women than among men. More women than men have strong religious beliefs and regulate their actions by religious standards. Belief in omens, pre- sentiments, and superstitions is also somewhat more prominent among women. As far as the strength of the emotional nature, the form of its expression, and the degree of impulsive- ness in action are concerned, the answers coincide very , closely for the sexes. The only difference is that women seem to have a greater tendency to inhibit the expression of emotion and to act from reason rather than from impulse. The tendency to introspection is the same for both sexes. It is somewhat more apt to 1 68 THE MENTAL TRAITS OF SEX take the form of day-dreaming among women. The reports on conscientiousness are the same for both. Men are more frank than women, and women are more easily embarrassed than men. In intellectual interests, easiest and hardest branches of study, and methods of work, there are only trifling divergences. Women derive more pleasure from study than men, while men devote somewhat more time to it than women. CHAPTER IX. CONCLUSION. In the previous chapters the separate divisions of conscious processes, motor ability, the various sensory fields, intellectual faculties, and the affective processes have been considered singly with reference to their comparative development in men and women. We may now bring together the results obtained from the various fields, and ascertain whether or not any broad generalizations with reference to the psychological norms of men and women which can be regarded as of fundamental importance have been reached. / It has been found that motor abil ity in most of its forms is better developed in men than in women. In strength, rapidit y of mo vement, and rate of Jatigue, they have a very decided advantage, and in precision of movement a slight advantage. These four forms of superiority are probably all expressions of one and the same fact — the greater_muscular strength of men. In fthe formation of a new co-ordination women are I superior to men. The greater muscular strength of men is a universally accepted fact. There has been more or less dispute as to which sex displays greater manual dexterity. According to the present results, manual dexterity which consists in the ability to make very delicate and minutely controlled movements is slightly greater in men ; that which consists in the ability to co-ordinate movements rapidly to unforeseen stimuli is clearly greater in women. 169 I70 THE MENTAL TRAITS OF SEX There have been two opposing views on the general subject of the sensibility of the .sexes ; one assigning the keener senses to men, and the other to women. They have been based either on inadequate experiment in a few fields of sensibility or on general theoretical considerations. The present investigation of the total field of sensibility has resulted in the following con- clusions regarding thresholds and discriminative sen- sibility : ^ Thresholds. — ^Women have lower thresholds in the recognition of two points on the skin; in touch; in sweet, salt, sour, and bitter taste ; in smell ; in color; and in pain through pressure. ! Men and women are alike in respect to the upper and lower limits of pitch. Men have a Ipwer threshold in the perception of light. Discriminative sensibility. — Women have finer dis- crimination in pitch and in color. Men and women have equal discrimination in temperature, in odor, and in passive pressure. Men have finer discrimination in lifted weights ; in sweet, sour, and bitter taste ; in shades of gray ; probably in areas on the skin (the test on this subject does not warrant certainty); and in visual areas. The number of cases in which the advantage is on the side of the women is greater than the number of ' cases in which it is on the side of the men. The thresholds are on the whole lower in women ; discrimi- native sensibility is on the whole better in men. Those sensory judgments into which sensations of movement enter directly, such as the discrimination of lifted weights and of visual lines and areas are somewhat oetter in men. All these differences, however, are slight. CONCLUSION 171 As for the intellectual faculties, women are decid- edly superior to men in memory, and possibly more rapid in associative ^thinking. Men are probably superior in ingenuity. In general jnformation and intellectual interests there is no difference character- istic of sex. The data on the life of feeling indicate that there is little, if any, sexual difference in the degree of dominatiga.iy. feOlPtion, and that socjal consciousness is more prominent in men and religious consciousness in women. Let us now turn to the question how well or how ill these results accord with the prevailing bioloj[ical view of the mental differences between the sexes. It is perhaps not fair to speak of a prevailing view in a question regarding which dispute is so rife ; but the view which seems to command the adherence of most scientists at present is that advanced by Geddes and Thomson (29). It is worked out in some detail on the psychological side by Fouillee (25); Brooks (10) and Patrick (68) represent the same tendency. The view is not altogether free from contradictions, nor entirely satisfactory in so far as it pretends to be a theory of the evolution of sex. Leaving these points aside, its general tenets are that the differentiation between the sexes in the course of evolution has been in the direction of a sort of division of labor, the male assuming the processes of nutrition and the female those of reproduction, which has made women more anabolic and men more catabolic in physiological structure. This difference is displayed in its most elementary form by the two sexual cells. The female is large and immobile. It represents stored nutrition. 172 THE MENTAL TRAITS OF SEX The male cell is small and agile. It represents ex- penditure of energy. From these fundamental char- acteristics the social and psychological differences can be deduced. The female represents the conserva- tion of the species — the preservation of past gains made by the race. Her characteristics are continuity, patience, and stability. Her mental life is dominated by integration. She is skilled in particular ideas and in the application of generalizations already obtained, but not in abstraction or the formation of new con- cepts. Since woman is receptive, she possesses keener senses and more intense reflexes than man. Her tendency to accumulate nutrition brings about a greater development of the viscera, and, since emotions are reflex w|ives from the viscera, woman is more emotional than man. The male, on the other hand, represents the introduction of new elements. Males are more variable than females throughout the animal kingdom. Everywhere we find the male sex adven- turous and inventive. Its variety of ideas and senti- ments is greater. Its activities are characterized everywhere by impulsiveness and intensity, rather than by patience and continuity. Men are more capable of intense and prolonged concentration of attention than women. They are less influenced by feeling than women. They have greater powers of abstraction and generalization. It is evident that, on the surface at least, the results at which we have arrived accord very well with this theory. Men did prove in our experiments to have better-developed motor ability and more ingenuity. Women did have somewhat keener senses and better memory. The assertion that the influence of emotion CONCLUSION 173 is greater in the life of women found no confirmation. Their greater tendency toward religious faith, however, and the greater number of superstitions among them, point toward their conservative nature — their function of preserving established beliefs and institutions. But before we accept the theory advanced as the correct interpretation of the facts, it would be well to examine a little more closely the evidence on which it rests, and consider whether or not there is any other possible interpretation with equal claims to a hearing. In the first place, this theory, in so far as its deduc- y/tions about mental characteristics are derived as neces- { sary conclusions from the nature of the genital cells, 1 1 seems to rest on somewhat far-fetched analogies only. The sets of characteristics deduced for the sexes may be correct, but the method of deriving them is not very convincing, nor is the set of characteristics derived for each sex entirely consistent. Women are said to represent concentration, patience, and stability in emotional life. One might logically conclude that prolonged concentration of attention and unbiased generalization would be their intellectual character- istics. But these are the very characteristics assigned to men. Women, though more stable in their emo- tions, are more influenced by them, and, although they represent patience and concentration, they are incapa- ble of prolonged efforts of attention. Men, whose activity is essentially intermittent, and whose emotions are greater in variety and more unstable, are charac- terized by prolonged strains of attention and unbiased judgment. It may be true, but the proof for it does not appeal to one as very cogent. In fact, after read- ing the several expositions of this theory, one is left 174 THE MENTAL TRAITS OF SEX with a strong impression that, if the authors' views as to the mental differences of sex had been different, they might as easily have derived a very different set of characteristics. There is truth as well as humor in Lourbet's (52, chap, vi) suggestion that, if the nature of the genital cells were reversed, it would be a little easier for this school of evolutionists to derive the characteristics of sex with which they finally come out. In that case, the female cell, smaller and more agile than the male, would represent woman with her smaller size, her excitable nervous system, and her incapacity for sustained effort of attention; while the male cell, large, calm, and self-contained, would image the size and strength, the impartial reason, and the easy con- centration of attention of men. The fact which is put forward to prove the greater natural ingenuity and inventiveness of man is his greater variability. Lombrpso, without more ado, asserts that the male is everywhere, and in all respects, more vari- able than the female, and that this fact alone is sufificient to prove his greater creative ability. The doctrine has been unquestioningly adopted by all the advocates of this theory. It is called upon to explain the occurrence of more individuals of unusual mental capacity, both above and below the norm, as well as to account for the greater versatility and inventiveness of the male mind. Unfortunately for the theory, the latest researches on the question of variability have failed to sustain it. Pfiarspn (69) subjects the previous methods of meas- uring variability to criticism, and finds them very faulty. He insists that pathological variations are not a fair test of average variability in the sexes, because many CONCLUSION 175 1*1 diseases have a tendency to attack one sex rather ^than the other. The true measure of the variability which must be regarded as important in evolution is, he says, the amount of normal variation found in organs or characteristics not of a secondary sexual character. The variation, however, of any organ must be judged by its relative departure from its mean, not, as has for- merly been done, by its absolute variation, or by its variation relatively to some other organ. Taking all (' the available physical measurements of human beings ) as a basis for his calculation, Pearson finds the total ) trend of his observations to be toward a somewhat ' greater tendency to variation in women than in men. He concludes that "the principle that man is more variable than woman must be put aside as a pseudo- scientific superstition until it has been demonstrated in a more scientific manner than has hitherto been attempted." While it may still prove true that men are intellec- tually more variable than women, it cannot be deduced directly from the universally greater variability of man. The fact is often held to be proved from the greater prevalence of both genius and imbecility among men, but, as Pearson points out, these are both forms of abnormal variation. It is perfectly conceivable that the class which presented the greatest number of abnor- malities in a character might not be the class which displayed the widest normal variations of that char- acter. But even though it could be shown that men are ' intellectually more variable than women, it is still difficult to see why this would give a basis for the statement that inventiveness and ability to arrive at 176 THE MENTAL TRAITS OF SEX new generalizations are characteristic of the male mind as opposed to the female. It would, if true, lead us to expect a greater number of intellectu- ally inferior and of intellectually superior individuals belonging to the male sex. In so far as great origi- nality is characteristic of exceptional mental ability, it would lead us to expect that the greatest discover- ies and inventions should come from these excep- tional individuals. But that is not at all the same thing as saying that originality and inventiveness are characteristic of the male mind as a whole, in opposi- tion to the female mind, as a whole. This statement assumes not merely greater variability of mind in general, but the presence of a variation in a given direction. The biological theory of psychological differences of sex is not in a condition to compel assent. While it is true, therefore, that the present investigation tends to support the theory, it is just as true that the uncertain basis of the theory itself leaves room for other explanations of the facts, if there are other sat- isfactory ways of explaining them. In considering the question whether or not there is any other explanation for the facts in the case, it is , important to remember that the make-up of any adult individual cannot be attributed entirely to inherited tendency. The old question of the relative impor- tance of heredity and environment in the final out- come of the individual must be taken into considera- tion. Although the timeworn controversy is far from satisfactory settlement, the results of recent observa- tion on individual development have tended to empha- size more and more the extreme importance of envi- CONCLUSION 177 ronment. The sociological experiments in which very young children from the criminal classes have been placed in good surroundings, with no knowledge of their antecedents, have shown that such children usu- ally develop into good members of society. The entire practical movement of sociology is based on the firm conviction that an individual is very vitally molded by his surroundings, and that even slight modi- fications may produce important changes in character. /The suggestion that the observed psychological differences of sex may be due to difference in environ- ment has often been met with derision, but it seems at least worthy of unbiased consideration. The fact that very genuine and impoirtant differences of envi- ronment do exist can be denied only by the most superficial observer. Even in our own country, where boys and girls are allowed to go to the same schools and to play together to some extent, the social atmos- phere is different, from the cradle. Different toys are given them, different occupations and games are taught them, different ideals of conduct are held up before them. The question for the moment is not at all whether or not these differences in education are right and proper and necessary, but merely whether or not, as a matter of fact, they exist, and, if so, what effect they have on the individuals who are subjected to them. The difference in physical, training is very evident. Boys are encouraged in all forms of exercise and in out-of-door life, while girls are restricted in physical exercise at a very early age. Only a few forms of exercise are considered lady-like. Rough games and violent exercise of all sorts are discouraged. Girls 178 THE MENTAL TRAITS OF SEX are kept in the house and taught household occupa- tions. The development of physical strength is not held up to girls as an ideal, while it is made one of the chief ambitions of boys. While it is improbable that all the difference of the sexes with regard to physical strength can be attrib- uted to persistent difference in training, it is certain that a large part of the difference is explicable on this ground. The great strength of savage women and the rapid increase in strength in civilized women, wherever systematic physical training has been intro- duced, both show the importance of this factor. When we consider other forms of motor ability than mere muscular force, such as quickness of reaction and accuracy of co-ordination, it seems very probable that mere differences of physical training are ample to account for these differences of sex. While it seems to be true that slower rates of movement and decreased accuracy of co-ordination do result from greatly infe- rior physical strength it is not true that the correlation is quantitatively a close one. Even with wide differ- ences in muscular force, the difference in motor abil- ity is comparatively slight. Where the differences in strength are slight, we have no reason to expect differ- ences in motor ability on that ground. When we consider the other important respect in which men are supposed to be superior to women — ingenuity or inventiveness — we find equally impor- tant differences in social surroundings which would tend to bring about this result. Boys are encouraged to individuality. They are trained to be independent in thought and action. This is the ideal of manliness held up before them. They are expected to under- CONCLUSION '79 stand the use of tools and machinery, and encouraged to experiment and make things for themselves. Girls are taught obedience, dependence, and defer- ence. They are made to feel that too much independ- ence of opinion or action is a drawback to them — not becoming or womanly. A boy is made to feel that his success in life, his place in the world, will depend upon his ability to go ahead with his chosen occupation on his own responsibility, and to accom- plish something new and valuable. No such social spur is applied to girls. Royce (73) in his article on the psychology of invention says : Only heredity can account for the very wide differences between clever men and stupid men, or explain why men of genius exist at all. But the minor and still important invent- iveness of the men of talent, the men of the second grade, is somehow due to a social stimulation which sets their habits varying in different directions. And this stimulation is of the type which abounds in periods of individualism For once more, the primary character of the social influences to which we are exposed is that, within limits, they set us to imitating models; they tend to make us creatures of social routine, slaves of the mob, or obedient servants of the world about us Inventions thus seem to be the results of the encouragement of individuality. If one applies these words to the question of the relative inventiveness of the sexesi, and realizes the wide differences in social influence which still exist even in a community where women have more free- dom and more education than anywhere else in the world, it seems rash to assume that the observed dif- ference in inventiveness represents a genuine and fundamental sexual difference of mind. The fact that the difference revealed by experiment is so slight in men and women whose educations have been as nearly i8o THE MENTAL TRAITS OF SEX alike as those of students in a co-educational univer- sity, tends to throw further doubt on the fundamental ' importance of this distinction. The very brief period in which women have been given any systematic edu- cation, or any freedom of choice in occupation, makes it impossible to decide the question on the basis of previous achievement. The same social influences which have tended to retard the development of motor ability and of invent- (iveness in women would tend to develop keenness of ; sense and the more reproductive mental processes, such as memory. The question is largely one of the distribu- tion of attention. A large part of a boy's attention goes toward his activities — the learning of new move- ments, the, manipulating of tools, the making of contrivances of various sorts. A girl's less active exist- ence must be filled with some other sort of conscious process. The only possibility is that sensory and per- ceptual processes should be more prominent. In some cases the special training of girls tends directly toward i the development of a special sense. This is notably i true in color, and perhaps has some influence in taste. On the more purely intellectual level, it is only natural that in the absence of a sufRcient social spur toward originality and inventiveness, they should depend more ; upon memory for their supply of ideas. It is easier for any individual to learn some one else's ideas than to think out his own. Every teacher has to struggle against the tendency to memorize merely, and to endeavor in every way to stimulate original thought and help pupils to form the habit of doing their own thinking. It is no great matter for surprise that in the absence of social stimulus toward originality of CONCLUSION j8i thought, women should have tended, from inertia, to stay in the realm of reproductive thinking. It will probably be said that this view of the case puts the cart before the horse — that the training and social surroundings of the sexes are different because their natural characteristics are different. It will be said that a boy is encouraged to activity because he is natu- rally active — that he is given tools instead of a doll be- cause he is naturally more interested in tools than in dolls. But there are many indications that these very [interests are socially stimulated. A small boy with an I older sister and no brothers is very sure to display an ambition to have dolls. It is in most cases quenched early by ridicule, but it is evident that a boy must be taught what occupations are suited to boys. The sor- rows of a small girl with brothers because she is not allowed to run and race with the boys and take part in their sports and games have frequently been recounted. If it were really a fundamental difference of instincts and characteristics which determined the difference of training to which the sexes are subjected, it would not be necessary to spend so much effort in making boys and girls follow the lines of conduct proper to their sex. The more probable interpretation of the facts is that the necessities of social organization have in the past brought about a division of labor between the sexes, the usefulness of which is evident. Social ideals have been developed in connection with this economic necessity, and still persist. This is not the place to discuss the question whether or not the conditions of social organization still demand the same division of labor, and make the preservation of the traditional ideals for the sexes i8z THE MENTAL TRAITS OF SEX necessary to the good of society. If such is the case, there is no doubt that the present state of affairs will persist. There are, as everyone must recognize, signs of a radical change in the socXal_j.deals of sex. The point to be emphasized as the outcome of this study is that, according to our present light, the psychological differences of sex seem to be largely due, not to dif- ference of average capacity, nor to difference in type of mental activity, but to differences in the social influences brought to bear on the developing individ- ual from early infancy to adult years. The question of the future development of the intellectual life of women is one of social necessities and ideals, rather than of the inborn psychological characteristics of sex. 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