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Chicago 
 Public Sclioois 
 
 
 ; 3 S p> cial Report 
 of the Department of 
 
 CHILD STUDY 
 
 AND 
 
 PE DAGOGI C 
 INVeSTIGATION 
 
 ON 
 
 Children Attending 
 the Public Day-Schools 
 for the Deaf in Chicago 
 
 D. P. MacMILLAN, Ph. D., 
 Director 
 
 r. C. BRUNER, Ph. D., 
 AssUlant 
 
 0fac 
 
 OMI0A4O NCWBFAPSR UNION, OHIOAttO 
 
 An Enlarged and Revised EdKIon of a Preliminary 
 
 Report Submitted to the Board of Education and 
 
 Printed on Nay 25, 1906 
 
Cornell University 
 Library 
 
 3ji 
 
 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/cu31924013873777 
 
CHICAGO 
 PUBLIC SCHOOLS 
 
 A SPECIAL REPORT OF 
 THE DEPARTMENT OF 
 
 Child Study and Pedagogic 
 Investigation 
 
 ON 
 
 CHILDREN ATTENDING THE 
 PUBLIC DAY-SCHOOLS FOR 
 THE DEAF IN CHICAGO 
 
 D. P. MAG MILLAN, Ph. D. 
 
 Director 
 
 F. G. BRUNER, Ph. D., 
 
 Assistant 
 
 An Enlarged and Revised Edition of a Preliminary 
 Report Submitted to the Board of Educa;tion and 
 Printed on May 25, 1906. 
 
^S3 
 
 HI ^1d 
 
TABLE OF CONTENTS. 
 
 Page. 
 
 Letter of Transmittal 3 
 
 Introduction 7 
 
 Hearing 9 
 
 Classification 11 
 
 Speech 16 
 
 Visual Acuity 21 
 
 PHYSICAL CONDITION: 
 
 Stature 25 
 
 Weight 28 
 
 Head Measurements 28 
 
 Lung Capacity 32 
 
 Strength of Grip 36 
 
 Grip Index 38 
 
 Motor Ability 41 
 
 Motor Index 45 
 
 MENTALITY: 
 
 Imitation and Suggestibility 48 
 
 Perception 49 
 
 "A" Test ' 49 
 
 Shot-sizing Test 57 
 
 Lifted Weights 64 
 
 Memory 70 
 
 Amenability to Training 72 
 
 SUMMARY AND SUGGESTIONS 74 
 
LETTER OF TRANSMITTAL. 
 
 Chicago, October 12, 1908. 
 Mr. E. G. Cooley, Superintendent of Schools — 
 
 Dear Sir: I submit herewith a report on the deaf children 
 of the pubHc schools of Chicago, and ask that a sufficient num- 
 ber of copies be printed at the earliest convenience. The subject- 
 matter has been on our hands now for a long time, and on ac- 
 count of the large number of requests for the information col- 
 lected by us, as well as the intrinsic interest and value of this 
 data for our teachers in service, I believe the whole subject ought 
 to be put in available form for use. 
 
 An account of our dealings with the special study of the deaf 
 children is given in a formal way in this letter of transmittal to 
 you. 
 
 The attention of the Department of Child Study and Peda- 
 gogic Investigation was first officially drawn to deaf children in 
 the public schools of Chicago by action of the Board of Educa- 
 tion at the opening of school in September, 1902. At this time 
 the Superintendent of Schools placed the matter before the 
 Committee on School Management, and on September 3, 1902, 
 the minutes of the Board indicate the following course of 
 action : 
 
 "The Committee on School Management reports that there 
 are in the School for the Deaf Mutes quite a number of children 
 who might be more properly taken care of in the schools for the 
 feeble-minded. As the task of separating the feeble-minded 
 from the normal children in these schools is a delicate one, the 
 committee recommends that the Superintendent be authorized to 
 employ the teachers in the Child Study Department to aid him 
 in determining whether they should be excluded from the public 
 schools or not." (Proc. 1902, Page 70.) 
 
 A report on these children was submitted to the committee 
 on October 2, 1902, which showed that a psycho-physical ex- 
 amination had been given to 160 pupils in the rooms for deaf 
 children, among whom were found 16 children who were notice- 
 ably or markedly subnormal in mentality and were accordingly 
 
4 LETTER OF TRANSMITTAL 
 
 recommended for exclusion from the public schools. Since that 
 time it has been the policy to have each child undergo a psycho- 
 physical examination by the Department of Child Study, as soon 
 as the parents of the child make application for his admittance 
 to these rooms for deaf children. In two or three instances the 
 Supervisor had been prevailed upon to admit to these rooms, 
 when the classes were exceptionally small, certain children who 
 were practically deaf for ordinary school exercises and afflicted 
 with speech defects, for the reason that they would gain excep- 
 tional benefit from the kind of training which the teachers of 
 these children alone could give. 
 
 On account of the time-worn contention among parents of 
 deaf children as to the relative superiority of the lip-reading or 
 oral and the manual methods of teaching the deaf, and especially 
 as to the alleged non-adaptability of the oral method to any 
 children except those of more than ordinary brightness, and to 
 those with some p»ower of hearing, it so happened that the whole 
 matter was again brought before the Committee on School Man- 
 agement at the beginning of the school year 1904-1905. No 
 definite action was taken by the Board until the following 
 communication was received October 26, 1904, from one of its 
 members which finally was effective in bringing about the more 
 comprehensive and formal report herein embodied. 
 
 "... Since the last meeting I have visited several deaf and 
 dumb schools, and I found them very much neglected. In one 
 case I found two children who were not deaf or dumb, and had 
 no right to be placed with these children. I also found at least 
 thirty or forty per cent of the children under normal, as well as 
 deaf and dumb, and was informed that teaching these children 
 the oral system was a waste of time on account of their impaired 
 mental condition. I also found teachers with classes so large 
 that it is impossible for one teacher to make progress with all 
 the children — naturally more attention was given to the brighter 
 children and the others were neglected. Therefore I think it 
 the duty of this Board to thoroughly investigate the entire mat- 
 ter and where there are children who cannot learn the oral sys- 
 tem, the combined alphabet or the sign system should be taught 
 in special rooms in schools other than where the oral system is 
 
LETTER OF TRANSMITTAL 5 
 
 taught. I also think more time should be given to the teaching 
 of reading, writing and arithmetic, as these studies seem to me 
 to be the most essential to a deaf and dumb person. . . I trust 
 your honorable body will give the matter the most thorough con- 
 sideration and investigation, as this department of the public 
 school system is much neglected and should have a thorough 
 reorganization, better rooms, more teachers and more attention 
 in general given to the children afflicted by the loss of hearing 
 and speech." 
 
 On January i8, 1905, a committee consisting of the Super- 
 intendent of Schools, the Director of the Child Study Depart- 
 ment and three medical inspectors was appointed to investigate 
 the whole matter and to report its findings to the Board of Edu- 
 cation. In accordance with the usual routine of such matters 
 the whole inquiry was referred by the Superintendent of Schools 
 to the Department of Child Study and Pedagogic Investigation, 
 and on April 12, 1905, a brief summary of the results was sub- 
 mitted in a preliminary report. The only action taken on the 
 matter at this time was to refer it back to the investigators with 
 instructions to present the data in detail. The final report herein 
 submitted was placed in the hands of the Superintendent of 
 Schools, subject to call from the Committee on School Manage- 
 ment, which demand finally was made on May 25, 1906, where- 
 upon it was ordered printed at once, and copies distributed 
 among the members of the Board of Education and educators of 
 the city. 
 
 The original form in which it was printed by the Secretary 
 of the Board was, in certain features, abbreviated and popular- 
 ized and as such it fulfilled a temporary and local service, but 
 owing to the large number of requests for copies and inquiries 
 from school boards of other places, from educational governing 
 bodies and from professional and general libraries in this and 
 other countries, as well as the desirability of placing our re- 
 sults in permanent form for our teachers, it seems highly advis- 
 able to print the whole subject-matter in a form which will more 
 adequately meet the larger demand. 
 
 Very respectfully yours, 
 
 D. P. MAC MILLAN, Director. 
 
EXPERIMENTAL STUDIES OF DEAF 
 CHILDREN. 
 
 It is doubtful if more than a very small minority of persons 
 who have not had intimate dealings with deaf children are 
 familiar with the characteristics which differentiate this special 
 group from hearing children. One meets with all sorts of opin- 
 ions and notions concerning their capabilities or incapacities. 
 It is held by some that the senses of deaf children, other than 
 hearing, are exceptionally acute, and again the assertion is made 
 that children who are defective in one sense are deficient in all 
 the senses and for this reason they speak of the mind of the deaf 
 child as of a distinctly lower type. 
 
 This study is not, indeed, concerned with all the deaf child- 
 ren in Chicago, nor with all deaf children of school age. It 
 deals with deaf children attending the public day schools whom 
 this department considered of high enough grade of mentality 
 to be educable by the special class methods of the public schools 
 for the deaf. These deaf children have been admitted into these 
 special rooms of instruction upon recommendation, after being 
 subjected to a careful psycho-physical examination to determine 
 their mental status and the degree of hearing power which they 
 possessed. The feeble-minded and those of extreme sub-normal 
 mentality are not incorporated in our results. It was, then, our 
 object to carefully examine and estimate the comparative physi- 
 cal and mental status and to make an extended study of the 
 progress and school conditions of the deaf children in the public 
 day schools of Chicago. 
 
 Some three months were devoted to this study. Children 
 were taken in groups of two or three in a private room in which 
 conditions were similar to those of the classroom, and in all 
 about one or two hours was given to each child. This length 
 of time was found necessary on account of the difficulty of get- 
 ting responses from this class of children, who are naturally so 
 excessively timid and hesitant in manner. This it is natural to 
 
8 EXPERIMENTAL STUDIES 
 
 expect on account of the difference in their social life, which 
 is usually confined to intercourse with parents, teachers or 
 children similarly afflicted. Experience has shown that one must 
 have at least a half-hour's intimate association with any child 
 before he can be reasonably sure that the responses secured are 
 anything at all like normal, and that the estimate made of the 
 child's mental efficiency is not totally erroneous. If this be true 
 of children in general, it is so true as to be axiomatic when deaf 
 children are the subjects of examination. To estimate the men- 
 tal status or educational possibilities of the deaf child requires 
 not only special knowledge of their habits and characteristics, 
 but also considerable intimacy with their environment and social 
 conditions. A cursory examination will very frequently lead one 
 to adjudge a child as of sub-normal mentality, whereas a greater 
 familiarity with the disparities and mental traits of this class of 
 children will enable one to secure surprising results. It was 
 found advantageous, in order to overcome the reticence of these 
 children, to make the first examination brief and preliminary, 
 so that the children might become personally acquainted with the 
 examiners and confident in all their modes of expression. 
 
 In order to investigate the hearing and speech possibilities 
 and progress of deaf children, it is indispensable that we have 
 some knowledge of the sensory, nervous and bodily conditions 
 which are intimately related to both hearing and speech. Thus, 
 it is necessary to know something of the sight, as good vision 
 is necessary to good lip-reading. It is necessary to know 
 whether the defect in hearing is local or whether it is due to gen- 
 eral lack of sensitiveness. Likewise it is of value to know 
 whether the deaf child is less or more sensitive to impressions 
 of touch, weight, etc. In case these senses are obtuse, one might 
 well conclude that the deficiency in aural acuity is primarily due 
 to general dullness of the whole psychical system. If the other 
 senses are acute, the defect is probably due to the organ of 
 hearing and not to obtuse mentality. To acquire speech it is of 
 the first importance to have good organs of speech. The nose 
 and throat must be open and free. The naso-pharyngeal cavity 
 must be examined for enlarged tonsils and adenoid growths. 
 Something must be known of the hard and soft palate in their 
 
DEAF CHILDREN 9 
 
 relation to middle-ear deafness and breathing power, as well as 
 the condition of the tongue, both as to structure and mobility. 
 The general nervous condition of children very markedly in- 
 fluences their speech and mental ability. The same nervous con- 
 ditions which induce such defects as stammering, stuttering, hes- 
 itancy, lisping and lalling are as likely to occur in deaf children 
 as in hearing children. Then, too, there are such nervous affec- 
 tions as chorea, nervous inertia and general incoordinations. 
 These especially influence mentality and speech.^ 
 
 The report of the Child Study Department for the year 1899- 
 1900 showed that those children who were larger, stronger 
 quicker and better nourished were mentally superior to those 
 who were not so well developed. The same conditions which 
 favor physical superiority are found to have a like or comparable 
 influence on the mental side. It therefore to a degree not only 
 affords a convenient but a serviceable cue to the mental status, 
 to know how deaf children compare in size, strength, quickness, 
 sensory and motor defects with hearing children of the same 
 age. In the case of a child having no language, it is difficult to 
 gain much information directly of his mental ability. It is, how- 
 ever, possible to measure his efficiency in such simple processes 
 as perception, and, in case a child possesses a few symbols, it is 
 possible to learn something of his immediate sense memory. It 
 was our aim to employ only simple tests to study all these various 
 phases of the sensory, physical, nervous and higher mental life 
 of these children, in order to sec-jre cumulative evidence of 
 the exact nature of their hearing defects and of their mental 
 and physical conditions as these are related to the acquiring of 
 speech and school training. 
 
 HEARING. 
 
 METHOD OF CONDUCTING THE TESTS. 
 
 Three instruments were used in the examination of hearing 
 power : 
 
 First: The Audiometer. The instrument used was an 
 ordinary Seashore audiometer. This is, in brief, a simple elec- 
 trical apparatus for producing a measurable noise which is 
 brought about by the making and breaking of a secondary cur- 
 rent. This noise is transmitted to the ear of the person tested 
 
lO EXPERIMENTAL STUDIES 
 
 by a telephone receiver held tightly against the ear. The child 
 is tested with his back to the examiner and with eyes closed. 
 The instrument was devised for testing differences in aural 
 acuity of persons not ordinarily considered defective in hearing. 
 In many cases its range is too limited for grading hearing power 
 when this power is not of sufificient acuity to detect speaking 
 tones of the human voice. The hearing power of children can be 
 conveniently graded according to the norms for hearing acuity, 
 worked out with normal children and already reported on. (See 
 Report No. 2, Department of Child Study and Pedagogical In- 
 vestigation.) 
 
 Second: "Snapper." This little instrument when snapped 
 between the forefinger and thumb, makes a mechanical 
 snap of sufficient loudness to be heard by the human ear 
 of average acuity in a quiet medium at a distance of about 500 
 feet. It is held by the experimenter slightly behind the ear of 
 the child examined, out of range of vision either direct or lateral, 
 and the child is asked to count the clicks, or in case of the 
 younger children, the starting of the body entire, and the super- 
 ficial reflexes, especially the conjunctival, are observed. By 
 this means the hearing power of certain children could be gauged 
 who could not be reached by the more delicate instrument. 
 
 Third: Differential Tube. This piece of apparatus consists 
 of a tube of soft rubber whose internal diameter is 4 mm. and 
 whose length is 100 cm., fitted with hard rubber ear pieces to 
 be inserted into the ears, one end into the child's ear and the 
 other into the ear of the examiner. This ear piece was held 
 firmly between the first, finger and the thumb, and care was taken 
 that the stimulation was not communicated through the sense of 
 touch. A tuning fork of pitch "a" was struck on a hard sub- 
 stance and its base applied to the tube. First, in order to famil- 
 iarize the child with the sound, the fork was struck briskly on a 
 hard object and its base placed on the child's front teeth. Only 
 after the child becatae somewhat familiar with the sound thus 
 conducted, was recourse had to air conduction. This instrument 
 proved adaptable for testing hearing power of even lower grade 
 than the snapper, owing largely to the fact that the stimulus 
 had a greater duration, thus affording a better opportunity for 
 the element of attention to enter. 
 
DEAK CHILDREN II 
 
 This work with instruments was further supplemented by 
 tests made with the human voice in ordinary speaking tones and 
 in shouting, taking care when within close range that the child 
 was made as nearly as possible dependent upon the sense of 
 hearing. 
 
 CLASSIFICATION. 
 
 The hearing ability of this group of children somewhat con- 
 veniently is divided into five classes. This division is purely 
 conventional and practical inasmuch as it is formulated wholly 
 on the basis of school room efficiency and the value which must 
 be attributed to the power of hearing in its relation to the acqui- 
 sition of oral speech. 
 
 In the first column, Class i, are shown the pupils who are 
 totally deaf — insensitive to the strongest sound vibrations which 
 we had any means of employing. 
 
 In the second column. Class 2, are presented those who are 
 practically deaf, i. e., only sounds which are continuous and most 
 intense can be heard. It is very probable that their hearing can 
 never be developed sufficiently to hear the human voice even with 
 the assistance of mechanical devices. 
 
 In column three, Qass 3, is given the number of those child- 
 ren who possess a degree of hearing power — they hear loud 
 sounds, but yet they have not sufficient sensitivity and control 
 of hearing to understand vocal speech. The children of this 
 class offer hope that with the assistance of mechanical devices 
 for intensifying the voice, their hearing power may be developed 
 so that advantage may be taken of this normal means of ac- 
 quiring spoken language. 
 
 Qass 4. Those pupils who are deaf for ordinary school 
 conditions, are placed in column four of the table. In general, 
 the pupils of this class hear only words spoken loudly and close 
 to the ear and are therefore to be considered as deaf from the 
 point of view of conditions that ordinarily prevail in the school- 
 room. They do, however, possess sufficient hearing to assist 
 them in acquiring speech when appeal is made to their under- 
 standing through this sense avenue. 
 
 In column five, Class 5, is listed a certain small number of 
 hearing children who were temporarily in the rooms for the 
 
12 
 
 EXPERIMENTAL STUDIES 
 
 •deaf and who are greatly in need of the training in articulation 
 which it is not possible for them to get in our school system, 
 €xcept from teachers who have had special training in the rudi- 
 ments of voice culture. 
 
 TABLE I. 
 
 POWER OF HBABINO. 
 
 Schools 
 
 Class 1. 
 
 Totally 
 
 Deaf 
 
 Class 2. 
 Practically 
 Deaf. Hear 
 only most in- 
 tense continu- 
 ous sounds 
 
 Class 3. 
 
 Hear loud 
 noises but can- 
 not hear speech 
 
 Class 4. 
 
 Deaf for ordi- 
 nary school 
 purposes 
 
 Class S. 
 
 Hearingr chil- 
 dren. In deaf 
 rooms for speech 
 training 
 
 Holden 
 
 2 
 2 
 5 
 2 
 10 
 1 
 4 
 3 
 
 ? 
 
 4 
 11 
 
 1 
 
 1 
 2 
 4 
 2 
 1 
 2 
 1 
 1 
 8 
 2 
 8 
 
 2 
 
 7 
 4 
 8 
 
 
 3 
 4 
 3 
 5 
 
 17 
 
 5 
 1 
 2 
 1 
 3 
 6 
 1 
 
 
 1 
 
 1 
 5 
 
 
 
 2 
 
 2 
 1 
 
 
 
 
 
 1 
 
 
 
 2 
 
 Beidler 
 
 
 Darwin 
 
 Froebel 
 
 Hammond 
 
 Kozminski 
 
 Normal 
 
 Seward 
 
 Yale 
 
 
 Totals 
 
 55 
 
 33 
 
 53 
 
 25 
 
 8 
 
 Total number examined 174 
 
 Although thus classified, it must not be assumed that these 
 children will always retain the exact relative order here pre- 
 sented. With some the hearing power deteriorates, while the 
 hearing power of others will show marked improvement owing 
 to their general mental training in giving attention and in 
 attaching significance to excitations of this sense organ. Even 
 among those congenitally defective in hearing it must not be 
 assumed that the hearing power will always remain stationary. 
 Some children were in the deaf rooms who were regarded as born 
 absolutely deaf and now at the age of fifteen or sixteen are 
 able to hear conversation. This improvement usually accom- 
 panies the great growth changes at the periods of second denti- 
 tion and of puberty. There are certain children with varying 
 degrees of deafness whose hearing has gradually improved ; there 
 are other cases of deafness in which there is apparently no 
 improvement. The congenitally deaf, however, form, as far as 
 we are able to determine, only about 50 per cent of the total 
 number, but it is difficult to draw a hard-and-fast line of de- 
 markation between congenital cases and deafness as one of the 
 
DEAF CHILDREN IJ 
 
 sequelae of disease. Many parents assign very insignificant causes 
 for this affliction. In many other cases it is impossible to deter- 
 mine just when dfeafness did occur, especially since scarlet fever, 
 spinal meningitis and other febrile diseases sometimes are ex- 
 perienced during the first year of the child's life before speech 
 develops, and deafness is attributed to these, whereas as a 
 matter of fact, it antedated than. The two most frequent 
 maladies which leave deafness as one of the sequelae in their 
 wake, as suggested above, are scarlet fever and spinal menin- 
 gitis. The significance of this is manifold in that very frequently 
 some tendency to mental aberration is also present, together with 
 nervous disturbances and inco-ordinations. Although not feeble- 
 minded always, these children so afflicted would be far below 
 the normal in mentality even were their hearing normal. It is 
 a matter of observation that deafness which occurs as a result 
 of disease is as frequently attributed to some catarrhal condi- 
 tion of the middle ear, atrophy of the ossicles of this region, 
 or degeneration of the typmanic membrane, as to some internal 
 ear trouble or lesion of the brain. Sometimes these diseases 
 cause absolute loss of hearing. In other cases there is but slight 
 diminution in auditory acuity. In every case it is very desir- 
 able to know just where the defect lies, as well as the degree of 
 deafness, in order to classify the child and suit his school train- 
 ing not only to his present status but also to his future needs. 
 Reference to Table I will show the relative proportion of 
 children in each of the five classes. In the first class there are 
 55 ; in the second, 33 ; in the third, 53 ; in the fourth, 25. Were 
 the number examined very large, extending into the thousands 
 instead of 178, we might reasonably expect to find an equal 
 number of children in each class ; that is, experimental evidence 
 goes to show that there are varying degrees of deafness, rang- 
 ing all the way from slight and temporary impairment 
 of hearing due to a cold, to the stage of absolute and permanent 
 silence. This, of course, necessitates some practical standard by 
 which one must judge whether a child's hearing is sufficiently 
 poor to justify his being assigned to the the rooms for the deaf. 
 Where the recommendation has been made by the Child Study 
 Department, the criterion has been a practical one, based not 
 
14 EXPERIMENTAL STUDIES 
 
 alone upon the child's absolute power to hear, but also upon 
 his inability to carry on the work successfully in the rooms with 
 hearing children. However deaf a child might be, he was never 
 recommended for the deaf classes as long as his progress in the 
 rooms with hearing pupils was satisfactory. Likewise in those 
 cases where the defect was more largely one of mentality in- 
 stead of defective hearing it has been the policy of the Child 
 Study Department to recommend that the child be excluded from 
 the rooms for the deaf. The above criterion seems the only one 
 usable in actual practice. 
 
 Among normal hearing children, speech is an instinctive ac- 
 quisition which shows itself at a relatively definite time in mental 
 ripening. The activities and speech of all persons in the home 
 are a constant appeal to the young and yearning listener, and 
 so there come to be set up mental associations between his acts 
 of hearing and his vocal responses. The activities of seeing, 
 hearing, touching, etc., which at first operate somewhat inde- 
 pendently of each other, come to be firmly and constantly con- 
 nected, so that one sense organ-act stands for the activity of 
 another sense-process or group of such processes. Seeing, comes 
 to stand for touching. Hearing means doing or going to do. 
 The child hears his own prattle as well as the speech of others 
 about him. Others attribute meaning to his spontaneous bab- 
 blings and his special acts, and, in the initial steps at least, his 
 acts are named for him. These activities in which he indulges 
 and to which others give specific values and names, are at first 
 gross and inchoate, with meanings as vague, but gradually become 
 with his growth of consciousness, more definite and precise. In 
 this way a certain word or name heard is associated with some 
 object reacted upon and the child's natural babblings are made 
 to conform to the word heard. Thus the child, through his 
 own hearing and with very small effort, catches the cues which 
 lead to his articulation of the words he has heard spoken by 
 those about him. But with the deaf child, the process of acquir- 
 ing speech is by no means so simple. No sounds are heard, or 
 if sensed at all, are heard very indistinctly, so that the procedtire 
 becomes one in which intense and concentrated attention is nec- 
 essary to succeed at all. 
 
DEAF CHILDREN 1 5 
 
 The most direct inherited associations are between speech 
 and hearing, and not between speech and sight, as must be the 
 procedure in the case of those whose power of hearing is ab- 
 sent or very defective. It is always very difficult to divert na- 
 ture's course, but this does not imply that it is never advisable 
 as exigencies arise to modify her laws or methods of procedure. 
 When limitations have been set to one group of associations, it 
 is absolutely indispensable to form a new set of associations if 
 training of any part is to take place, and this re-direction of an 
 instinctive procedure is not accomplished without considerable 
 effort. Intercourse between individuals is possible only by some 
 language medium, and a language medium implies some sort 
 of symbols which refer directly to objects, activities or events, 
 and it further implies that the symbols used have a common 
 meaning to all using them. 
 
 All articulatory symbols of intercourse are relatively arbi- 
 trary and conventional, and their expression must occur either, 
 as is commonly the case, by the natural way of imitating with 
 the vocal mechanism what is received through the auditory appa- 
 ratus — in which case the symbols are expressed spontaneously — 
 or the meaning of these symbols must be consciously acquired 
 and their expression laboriously worked out, as in the case of 
 the deaf. In the latter there must occur a definite adjustment 
 of mouth-parts and chest activity on the one hand, or the 
 manipulation of the hands on the other, according as the vocal 
 or manual language is used. One must be learned as well as 
 the other. The selection and preference of one method over 
 another, must be decided on other than psychological grounds, 
 inasmuch as psychology properly defined, deals with a descrip- 
 tion and explanation of all mental processes, and so every men- 
 tal reaction, the true and serviceable as well as the false and 
 trivial, must have its history as to its origin, characteristics and 
 function. Both utility in social relations and facility or ease 
 of acquirement must largely determine whether one or the 
 other method of training the deaf shall be used in the school- 
 room. 
 
 There is the further question as to whether the manual 
 method has certain limitations as compared with the oral in 
 
l6 EXPERIMENTAU STUDIES 
 
 developing the mind. But this is a question that must be de- 
 cided, for the present at least, on theoretical and philosophical 
 grounds. Thus far there have been no scientific investigations 
 on adults, trained by these two methods, which might tend to 
 show that the range of expressive thought is greater or less in 
 one method than the other. The philosophical problem is one 
 that does not concern us here, 'for it leads to nothing more than 
 the expression of an opinion, and offers no hope for the solution 
 
 of the question. 
 
 SPEECH. 
 
 There are found in the rooms for the deaf, children who had 
 no speech when deafness occurred. There are others who had 
 learned to speak a little, and again, there are a few others whose 
 deafness appeared after five years of age and who possessed con- 
 siderable power of speech. It obviously would not be just to 
 group all these together. Therefore the children are distrib- 
 uted into three groups on the basis of their capacity for appre- 
 ciating and using speech, taking into account the time they have 
 been receiving instruction. We have then as a mater of fact 
 the following groups: (i) those whose speech is normal or 
 nearly so; (2) those whose speech is defective either in the 
 quality of tone of the vocal sounds or in the articulation of the 
 consonants, nasals, labials, sibilants, etc.; and (3) those who have 
 no speech or are incapable of uttering intelligently at least fifty 
 words. Of course all children who had lost their hearing be- 
 fore they had learned to talk would be in group 3 on first en- 
 tering school. 
 
 The problem, then, is that of determining the character 
 of the speech that has been acquired for the different periods 
 that the children have been in school. In keeping with this, 
 the children in the various rooms have been distributed accord- 
 ing to their efficiency in speech after they have been in school 
 three, five, seven and ten years. It must be borne in mind that 
 these groups do not include all the children in the rooms for 
 the deaf, since obviously there is a large number of them who 
 for various reasons have not been in school for as long a period 
 as three years. Furthermore, not only must the length of time 
 the pupil has been in school be considered but also his condition 
 
DEAF CHILDREN 1 7 
 
 on entrance into school. Under those three groups, therefore, 
 of children whose speech is nonnal, whose speech is defective, 
 and those whose speech is practically wanting, it was thought 
 advisable to indicate the following ( See Table II, p. 19) : 
 
 I. Children w'ho have sufficient hearing to assist them in 
 acquiring speech. 
 
 II. Pupils whose hearing was lost after the age of five 
 years — i. e., after quite a degree of facility in speech had been 
 gained before deafness occurred. 
 
 III. Pupils who lost hearing before five years of age — i. e., 
 where an opportunity had been afforded for the loss of auditory 
 imagery and the fading of muscular habits associated with 
 articulation and phonation. 
 
 IV. Those born deaf, or those in whom the loss of hearing 
 occurred so early in life that speech had never been acquired. 
 
 THREE YEARS IN SCHOOL. 
 
 Of deaf children who have had speech training for no longer 
 than three years, we can make the following summary : 
 
 24, speech normal, or nearly so. 
 
 23, speech more or less defective — i. e., have considerable 
 speech, but the articulation or tonal quality of the voice is more 
 or less defective. 
 
 7, speech wanting — i. e., from the practical standpoint, little 
 or no speech. 
 
 It must be understood that where speech is herein spoken 
 of as more or less defective, the child can usually be easily un- 
 derstood by almost everybody, and in all cases can be under- 
 stood by those who are accustomed to associate with him, though 
 his voice, to be sure, is unpleasant and unnatural. 
 
 Oi these twenty-four whose speech was found to be normal, 
 it is interesting to learn that six children possessed some usable 
 remnants of hearing, while 18 were deaf. Of the 18 deaf at 
 least ID had lost their hearing after the age of five years, leav- 
 ing only 6 who were afflicted with deafness before the age, of 
 five and 2 congenitally deaf. That is, we may say, that normal 
 speech had been taught to 8 of the 54 children by the indirect 
 method during the brief period of three years. 
 
 Turning to the 23, w'liose speech was understandable but 
 
l8 EXPERIMENTAL STUDIES 
 
 somewhat defective, the data show, that 3 had some hearing 
 and 3 had lost their hearing after the age of five, 9 deaf chil- 
 dren had lost their hearing earlier than the age of five and 8 
 were born deaf. 
 
 Of the 7 who possessed little or no speech ability after 
 three years in school, none had ever had hearing to be of any 
 service in the acquisition of an articulatory language, 4 having 
 been congenitally deaf and 3 having lost their hearing early in 
 life. 
 
 To summarize then if we exclude from consideration first, 
 those who have sufficient hearing to assist them in acquiring 
 speech and those who lost their hearing after five years of 
 age, which two groups obviously form a separate class, we have 
 remaining those who lost their hearing before the age of five and 
 those who were born deaf. Of these we find : 
 
 8, normal speech. 
 
 17, speech more or less defective. 
 
 7, speech wanting. 
 
 FIVE OR SIX YEARS IN SCHOOL. 
 
 Turning now to the children who have been in school five 
 or six years, we find the cases distributed as follows : 
 
 13, speech normal. 
 
 14, speech more or less defective, 
 o, speech wanting. 
 
 Considerable interest attaches to a comparison of the make 
 up of the children of these three groups with those of three year 
 school instruction. (See Table II.) Whereas, among the lat- 
 ter but 8 of 24 with normal speech had lost their hearing earlier 
 than five years, or were congenitally deaf, of those with 5 or 6 
 years of school instruction, 10 of the 13 belonged to this class; 
 all of those with somewhat defective speech had lost their hear- 
 ing early in life ; and no child of 5 and 6 years' school instruction 
 was found without speech sufficient to communicate his simpler 
 needs. 
 
 Again to summarize the results, excluding as above, that 
 special class comprising those who have some hearing and those 
 'who lost their hearing later than the age of five, we have those 
 
DEAF CHILDREN 
 
 19 
 
 classified as born deaf and having lost their hearing before the 
 age of five — of these there are: 
 
 10, speech normal. 
 
 14, speech more or less defective, 
 o, speech wanting. 
 
 SEVEN OR MORE YEARS IN SCHOOL. 
 
 Taking up those children who have been in school seven or 
 more years, we find the following distribution. (See Table II.) 
 13, Speech normal. 
 9, Speech more or less defective, 
 o, Speech wanting. 
 One boy among those with normal speech had hearing and 
 was temporarily given a place in the rooms for the deaf to rem- 
 edy his very defective articulation. Of the remaining 12, only 
 2 had lost their hearing later than five years, 2 were deprived of 
 their hearing before the age of 5 and 8 were congenital cases. 
 
 One only of the 9 with somewhat defective speech had lost 
 his hearing later than 5, 3 before tlie age of 5 and 5 had been 
 deaf from birth. 
 
 TABLE II. 
 
 ABILITY TO USE SPOKEN LANGUAGE. 
 
 Table showing the power of speech possessed by children of different degrees 
 of deafness, who have received speech training for three, five, seven, and ten 
 years respectively. 
 
 Character of 
 speech 
 
 Time in 
 school 
 
 Hearm? 
 sufficient 
 to aid in 
 acquiriner 
 speech. 
 
 Deaf 
 
 Hearintr 
 lost after 
 the age of 
 five years 
 
 Hearingr 
 lost before 
 the ape of 
 five years 
 
 Congren- 
 itally 
 deaf 
 
 
 
 6 
 3 
 
 
 1 
 
 10 
 
 2 
 
 
 6 
 
 7 
 2 
 
 
 2 
 3 
 5 
 3 
 
 Speech normal, or 
 nearly so. 
 
 5 or 6 years 
 
 10 years or more. . . 
 
 Speech somewhat 
 
 defective, either in 
 
 quality of tone or 
 
 articulation of sounds. 
 
 
 3 
 
 
 
 
 3 
 
 1 
 
 
 9 
 4 
 3 
 
 
 8 
 10 
 5 
 
 
 5 or 6 years 
 
 10 years or more. .. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 Speech wantmg-, 
 or less than 
 
 S or 6 years 
 
 
 
 SO words 
 
 10 years or more... 
 
 
 
 Totals 
 
 13 
 
 16 
 
 34 
 
 40 
 
 
 
 
 Taking into consideration then the acquirement of speech as 
 it is related to time of instruction, we find of the whole number 
 of 103 children who had had at least three years school training. 
 
20 EXPERIMENTAL STUDIES 
 
 that 96 succeeded in acquiring oral speech, of whom 50 possessed 
 normal speech and 46 were able to interpret oral language, but 
 to speak albeit with difficulty or slight defect. It will be seen, 
 moreover, that of this whole number there are 13 children who 
 possessed sufficient hearing to enable them to be materially as- 
 sisted in acquiring speech under schoolroom conditions. Of the 
 children who must be classed as deaf, 16 lost their hearing after 
 the age of 5 years ; 34 were deprived of their hearing before the 
 age of 5 years, while there are 40 whose parents gave evidence 
 regarding their early lives which indicated that in all probability 
 these children were born deaf. 
 
 Although 7 children were found whose speech was wanting 
 after a period of training of 3 years, there were none after a 
 school period of 5 or more years who were not able to express 
 themselves more or less intelligibly. 
 
 Not considering those who lost their hearing later than the 
 age of s, and those who have considerable hearing, 23 had voices 
 which were unpleasant and unnatural after three years of school 
 training, 14 after five years and 9 after seven, or more years. 
 These comparisons are made with reference to the voice of the 
 normal child as a standard and are obviously unfair to a child 
 working under the limitations of the deaf. It would no doubt be 
 better to use a criterion of practical utility rather than one of 
 esthetic value, but it is impossible in the case of the former to 
 arrive at any norm for comparison, and hence we are forced to 
 the use of the apparently less practical standard of reference, 
 which, nevertheless, has, as a matter of fact, considerable signifi- 
 cance. 
 
 The time that a child has been in school is not the only nor 
 is it the most important, factor in effecting speech efficiency. 
 The natural endowment of the child is an extremely important 
 consideration. Next stands the environment, some of the most 
 important factors of which are the character of the food which 
 the child receives, and the regulation of his rest and exercise. 
 It is further of significance whether the parents speak the lan- 
 guage of the school and are thus able to give the child some 
 drill in the exercise of his speech outside of school hours, or 
 in case the parents do speak the language of the school, whether 
 they have the time and inclination to thus co-operate with the 
 
DEAF CHILDREN 
 
 2r 
 
 teachers. An attempt was made to evaluate all these factors in 
 the study of the condition of each child, and formed part of the 
 "basis for the specific recommendations which were given to the 
 child's teacher at the time he was examined with reference to 
 his school possibilities and the best line of treatment adapted to 
 his particular needs. 
 
 VISUAL ACUITY. 
 
 TABLE ni. 
 
 VISUAL ACniTT. 
 
 Tables showing the distribution of deaf and hearing children, respectively, 
 as regardSi the visual acuity o£ both eyes, whether the vision of the two eyes 
 Is the same or different. 
 
 DEAF CHILDREX. 
 
 Vision 
 
 1.00 or 
 better. Nor- 
 mal 
 
 0.67 of nor- 
 mal. 20-30 
 
 0.50 of nor- 
 mal. 20-40 
 
 0.40 of nor- 
 mal. 20-50 
 or less 
 
 Blind 
 
 The vision of both eyesbeiipr 
 The vision of one eye belns 
 
 1.00. the other 
 
 The vision of one eye beinff 
 
 0.67. the other 
 
 The vision of one eye being 
 
 0.50. the other 
 
 225 
 
 35 
 22 
 
 21 
 
 9 
 11 
 
 Total number examined, 353. 
 
 
 HEAItlNQ 
 
 childre; 
 
 «. 
 
 
 
 
 Vision 
 
 l.COor 
 better. 
 Normal 
 
 0.67 of 
 
 normal. 
 
 20-30 
 
 O.SOof 
 
 normal, 
 
 20-40 
 
 0.40 of 
 
 normal, 
 
 20-50 
 
 0.29 of 
 normal, 
 
 20-70 
 orle s 
 
 Blind or 
 
 nearly 
 
 so 
 
 The vision of both eyes beinjr. . 
 
 The vision of one eye beinsr 
 
 1.00 the other 
 
 972 
 
 82 
 119 
 
 11 
 
 8 
 31 
 
 27 
 11 
 18 
 11 
 
 69 
 21 
 20 
 7 
 24 
 
 
 
 4 
 
 The vision of one eye bein^ 
 
 
 
 The vision of one eye beinp 
 SO 1 he other 
 
 
 
 
 
 The vision of one eye beingr 
 
 
 
 
 
 
 
 
 
 
 
 Total number examined, 1,436. 
 
 The oral method of training the deaf implies not only the 
 utterance of speech, but also speech-reading. With normal hear- 
 ing children this is done through the medium of the ear, where- 
 by even the slightest variation of tones and inflections are in- 
 terpreted naturally and without effort, yet each carrying with it 
 a significance that differentiates a shade of meaning. 
 
 Though the eyes are always used in discerning the attitude 
 
 of the speaker by the hearing child, the use of these organs plays 
 
 a subordinate role. Not so with the deaf child. Every idea 
 
 • communicated to him, except the few he gets through touch, taste 
 
22 EXPERIMENTAL STUDIES 
 
 and smell, must reach him through his eyes. In interpreting 
 speech he must observe the most minute movements of the mouth- 
 parts, the eyes and facial muscles, to interpret their significance, 
 translate them into ideas and observe shades of meaning by 
 the slightest variations in muscular adjustments and movements. 
 Hence the condition of the deaf child's vision becomes a very im- 
 portant consideration. While there are many opportunities for 
 relaxation of the eyes of the normal child, these opportunities 
 are obviously less frequent in the case of those children who 
 have to depend on their vision almost entirely. Defective vision,^ 
 therefore, tends to produce greater limitations among the latter 
 than the former. 
 
 In Table III are given the distributions of deaf children and 
 of normal hearing children, from comparable social environments 
 and home surroundings, as regards visual acuity. In this the 
 emphasis is laid on the function of vision as a determining factor 
 in acquiring school information. It is well known that a child 
 may have very defective vision in one eye and yet because the 
 other eye functions normally, the child may not be seriously 
 handicapped in receiving impressions from his surroundings. 
 Accordingly the acuity of each eye is registered separately and 
 the number of children is recorded who have good vision with 
 both eyes as well as the number of those who are visually acute 
 with one eye and defective in the other, or indeed, those who 
 have poor vision with both eyes. 
 
 In the upper half of the table is recorded the distribution of 
 353 deaf children and in the lower half a similar distribution 
 of 1,436 hearing children. Looking at the upper half of the 
 table for a moment (the part referring to deaf children) it is 
 seen that in the first line, beginning at the left, are tabulated; 
 first the number of children with normal vision in both eyes 
 (225) ; then the number whose vision for both eyes is 0.67 nor- 
 mal (35) ; 0.50 normal (21) ; and 0.40 normal (2), respectively. 
 In the second line is shown the number of deaf children whose 
 vision for one eye only is normal, while that of the other is 0.67 
 normal (22) ; 0.50 normal (9) ; 0.40 normal (3) ; and where 
 the vision of one eye is wholly wanting (5). Then in the third 
 hne follows the number whose vision in one eye is 0.67 normal 
 
DEAF CHILDREN 23 
 
 as registered from the vision chart, while that of the other eye 
 is 0.50 normal (ii) ; 0.40 normal (4) ; and vision entirely want- 
 ing (o). This will suffice to make the whole table easy of in- 
 terpretation. 
 
 From the distributions in the table it is thus seen that of the 
 total number of deaf children from whom we have visual acuity 
 records (353) there are 225 or 63.7 per cent whose vision 
 is normal as judged by the standards of the optician or occulist. 
 Two hundred and sixty-four of the 353 or nearly 75 per cent 
 have vision of at least one eye normal according to the same 
 standards, and nearly 90 (88.9) per cent have at least one eye 
 whose visual acuity is 0.67 normal. 
 
 It is of interest and significance to compare the visual acuity 
 of deaf children with that of the 1,436 hearing children in the 
 lower half of the table. About 3 per cent fewer of the deaf 
 have the vision of both eyes normal. Four per cent fewer have 
 vision of at least one e3'c normal, but almost 2 per cent more of 
 the deaf have a visual acuity of both eyes 0.67 normal or bet- 
 ter, as compared with their hearing companions. Certainly of 
 considerable pedagogical significance is the fact, moreover, that 
 the per cent of hearing children whose vision is very poor — 0.50 
 normal or lower for one or both eyes — is nearly one-half greater 
 than in the case of deaf children. Accordingly, it is clear that 
 deaf children are not handicapped by visual defects, to any 
 greater extent than are those children not afflicted with loss 
 of hearing. By way of accounting for the relatively poor show- 
 ing of deaf children among those whose vision is normal or 
 nearly so, it is probable that resort must be made to some psycho- 
 logical explanation induced by the deaf child's inability to react 
 to the test as efficiently as do hearing children. And owing to 
 the paucity of numbers too much weight must not be attached 
 to the apparently better showing of deaf children when com- 
 paring those whose vision is very poor. As much as can be 
 asserted with confidence is that it is extremely probable in the 
 light of the experimental data exhibited in Table III, that deaf 
 and hearing children, on the whole do not dififer as regards vis- 
 ion. A summary of the comparisons just made will perhaps 
 show what has been said to better advantage. 
 
24 
 
 EXPERIMENTAL STUDIES 
 
 Wiole number of children : Deaf, 353 ; hearing children, 1,436. 
 
 Vision, 1.00 (20-20) or better. Both ( Deaf 
 
 eyes ( Hearing* child. . 
 
 Vision, 1.00 (20-20) or better. One! Deaf 
 
 eye at least 1 Hearlner child.. 
 
 Vision, 0.67 (20-30) or tietter. Both ( Deaf, 
 
 eyes 1 Hearing child.. 
 
 Vision, 0.67 (20-30) or better. One J Deaf 
 
 eye at least 1 Hearing diild.. 
 
 Vision, O.SO (20^40) or less. Both J Deaf 
 
 eyes 1 Hearing child. . 
 
 Number. 
 
 Per cent 
 
 225 
 972 
 
 63.7 
 66.9 
 
 264 
 1153 
 
 74.8 
 79.0 
 
 282 
 1123 
 
 79.9 
 
 78.2 
 
 314 
 1287 
 
 88.9 
 89.6 
 
 33 
 188 
 
 . 9.3 
 13. 1 
 
 In the foregoing statements of results and comparisons 
 nothing has been said as to what constitutes defective vision. 
 Of course it is well understood that defective vision from the 
 educator's standpoint is quite a different consideration from 
 visual defects as an oculist understands the matter. For in- 
 stance, a child may have normal vision (20/20) in one eye, and 
 the other may be only two-thirds, two-fourths, two-fifths, two- 
 sevenths or even less in visual acuity. It will readily be granted 
 even by oculists that if a child possesses sufficiently acute vision 
 to be able to carry on his school work well he must be placed in 
 a different category from those whose vision seriously impede 
 their school labors. Very unfortunately the minimum degree of 
 visual acuity that must be possessed to insure against eye strains, 
 inefficient book- and black-board work, and certain physical ills 
 which attend the functioning of weak visual organs, has not yet 
 been determined. Indeed it is improbable that any hard and 
 fast line can ever be set to mark off the functionally efficient 
 from the inefficient eyes, and particularly not in terms of visual 
 acuity alone. One frequently finds instances where the dioptric 
 defect is seemingly grave, and yet the individual appears to see 
 well and experiences no ill effects from the use of his eyes, 
 and on the contrary a very slight irregularity in the organ of 
 vision itself is frequently attended by very serious pains and 
 strains. In the latter the trouble is induced by bodily or nervous 
 depletion, primarily, and only secondarily is it to be attributed 
 to irregularity in the structure of the dioptric media. 
 
PHYSICAL CONDITION. 
 
 Besides the foregoing data on the comparative sensitivity of 
 the sight and hearing of deaf children, and their acquired power 
 of speech after definite periods of school instruction, it is of im- 
 portance to gain some definite idea of their general physical con- 
 dition. 
 
 Here again it is to be observed that so-called practical obser- 
 vations and verbal descriptions of differences between this group 
 of children and normal children have always led to exaggerated 
 accounts and unwise statements regarding the deaf, sometimes 
 to their advantage, but more often to their disparagement. There- 
 fore the more positive and precise are the statements and the 
 greater variety of aspects of the physical make-up investigated, 
 the greater is the hope of our understanding the exact condi- 
 tions that must be encountered in attempting to educate these 
 children into citizenship. It is on this account highly desirable 
 to present certain quantitative statements of the physical status 
 and deficiencies of deaf children as are evidenced in the two 
 more or less, closely related aspects of physical growth, viz., 
 size ov bulk and movement or control. 
 
 In pursuance of this end, in the following tables are given 
 the comparative stature, height-sitting, weight, lung capacity, 
 maximum length and breadth of head, strength of hand-grip 
 and voluntary motor ability, distributed according to age and 
 sex throughout. (The greater number of cases (293) recorded 
 in some of these tables is brought about by the fact that they in- 
 clude measurements other than these made during the period of 
 this special investigation.) 
 
 STATURE. 
 
 The stature records represent the net heights expressed in 
 millimeters. (See Table IV.) 
 
 It will be seen that deaf boys are not so tall on the average 
 as normal hearing boys at any age with the exception of those 
 at the age of 10 years, at which time a slight difference is in 
 favor of the deaf boys. This exception may be accounted for by 
 
26 EXPERIMENTAL STUDIES 
 
 a class of boys who had been receiving instruction and unusual 
 physical training since their kindergarten days and who pos- 
 sessed especially favorable home surroundings. 
 
 The deaf girls before the age of lo years are noticeably 
 shorter than hearing girls and the differences are greater than 
 the inferiority of deaf boys for their corresponding age — ^norms ; 
 but after this age the deaf girls are almost uniformly taller than 
 their hearing companions. To be sure the numbers are small 
 and the cases (75) of those years of apparent superiority may 
 be exceptional in this respect, but the fact is indicative at least 
 that for the deaf girls the disabilities which they experience in 
 hearing or the causes of their affliction have not, during this span 
 of years, impaired their growth as measured by their stature. 
 
 The height-sitting measurements show (Table V) that deaf 
 boys are uniformly inferior throughout the years represented. 
 The girls on the other hand are inferior up to the age of 11 
 years; at the ages 11, 12 and 13 they are taller sitting; at 14, 
 15 and 16 years they are again inferior, and thereafter the four 
 cases show excess over the hearing girls. 
 
 Taking the deaf children as a whole and comparing them 
 with hearing children with regard to stature it is found that only 
 seventy-seven out of one hundred and seventy-seven, or 43.5 
 per cent, of deaf boys are equal to or above the average stature 
 of hearing boys for equal age as against eighty-eight that would 
 be found with the same normal hearing boys, and in height-sit- 
 ting only sixty out of one hundred and sixty-seven boys, or 
 35.9 per cent, are equal to or above the average of normal hear- 
 ing boys, instead of a possible eighty-three or eighty-four out of 
 one hundred and sixty-seven in a normal group. Again we find 
 only fifty-two out of one hundred and twelve deaf girls, or 46.4 
 per cent who are equal to or above the average statures for the 
 normal hearing girls of their respective ages, and in height-sit- 
 ting only forty-three out one hundred and ten, or 39.1 per cent, 
 are equal to or above the average of hearing girls for the same 
 ages represented. Both deaf boys and girls, consequently, it is 
 learned, are not quite so tall as are hearing children of corre- 
 sponding ages, and the deaf of both sexes have shorter bodies 
 than do their hearing companions. 
 
DEAF CHILDREN 
 
 H O > 
 
 
 "-* -^ th o i-~ c- e 
 
 ■ U"; VTj ir, ir. \fi 
 
 SSSKS^Sss 
 
 p 
 
 
 
 
 w 
 
 
 ^ bt u 
 2-5 2 
 
 o y c 
 
 ■^rr-t^niHoorHirjo^ooro 
 
 n-j-^h-r-roror-(r-r-<©o 
 
 
 cr irjTj- r-rir- oo ■- 
 
 incooono^cc- 
 
 ^ i-H M M M ro ^ -)- If , O -c -2 f- 
 
 o(MOMonu^Oi-(i-ir-no 
 
 OQ 1- XT) i-H »r* o h* cr c- oc m ri c~^ 
 r5 "* >f J u"* u-j o iTi o -D .o I- fo o 
 
 nriTj-r-iTtorjo-rHmc^no 
 
 ) "* iTj Uj O »0 nO 
 
 ■ifSiHni-Hr-IWT-ltHr 
 
 O'^iOOO^O^O OO'-O^O'OO 
 
 •or-MC>o»-<r-»<^'^u'jor-oo 
 
:28 EXPERIMENTAL STUDIES 
 
 WEIGHT. 
 
 With reference to weight (See Table VI) it may be said 
 that the deaf boys on the average are almost uniformly lighter 
 than the hearing boys, and although there are exceptions to this 
 at ages 7, 15 and 18, the numbers and the average deviations at 
 these ages make the data non-significant. In the case of the 
 girls there is greater irregularity in the data. This does not 
 become evident, however, until after the age of 10 years. The 
 girls are, still, at no age, where the numbers are at all significant 
 as inferior to the norms for their hearing sisters as are the boys. 
 
 Again comparing the deaf children as a group with hearing 
 children, it is found that in weight, there are only forty out of 
 eighty-five boys, or 47 per cent, who are equal to, or above, the 
 averages for hearing boys for the same ages, and with girls we 
 find thirty-two out of a total of fifty-three girls of all ages, or 
 60.4 per cent, who are equal to or above the average of normal 
 ■girls for their ages. While deaf boys are, on the whole, there- 
 fore, slightly lighter than hearing boys, deaf girls are consider- 
 ably heavier on the average than are hearing girls of compar- 
 able ages. 
 
 HEAD MEASUREMENTS.* 
 
 In Table VII are recorded the head measurements of the 
 ■deaf children, boys and girls by ages; the average maximum 
 length and breadth of head of deaf children with the average 
 deviation for each age group placed side by side with the corre- 
 sponding figures for hearing boys and girls. (Note — See p 88.) 
 
 It will readily be seen that almost uniformly the deaf boys 
 have shorter heads than the hearing, and that in breadth of 
 liead the deaf boys are almost as uniformly wider than the aver- 
 age of our norms from hearing children. Deaf girls show the 
 same tendencies in head measurements as the deaf boys. The 
 average maximum length of head of the deaf girls is less, while 
 the average greatest breadth is greater, although indeed there 
 are exceptions in breadth at ages 9, 11, 16 and 17. 
 
 *The Smedley cephalometer was employed to make these meas- 
 urements. The details and methods with reference to the head meas- 
 urements conform with those of our best American and German anthro- 
 pologists. 
 
DEAF CHILDREN 
 
 B 
 
 
 PS 
 ■S 2'^2 
 
 
 
 IX 
 
 
 
 
 
 
 S 
 
 1 
 
 
 
 
 ';;l 
 
 
 M 
 
 •u 
 
 
 
 a 
 
 t 
 
 
 
 o w%ofOir)»H^oDMNomoooco 
 
 
 ■(or^r-oor^a-oonr-ooo 
 
 88 
 
 riO"*r«»HOt-oooooi-<f^>OM'* 
 
 •Si? 
 h is 
 
 ItcS 
 .in 
 
 I a 
 
 W"" 
 
 ■* coM^n•onoo^■* ooi^-* ^o 
 
 
 
 1,5 b 
 t3 !^"Si3 
 
 ■g 
 
 at 
 
 § S 
 
 
 
 82 
 
 3sa 
 
 ■oooM^mi-tnoTfi- 
 
 ^O ^ ^O O ^ '•O ^£ ^ o o o ^ ^ ^ ^ 
 
 ID OI—OOCO^^firOTl-ii^'^t— 00^ 
 
30 EXPERIMENTAL STUDIES 
 
 In addition to average lengths and breadths are given the 
 averages of the products of length and breadth of the head of 
 each child of both the deaf and the hearing children of the sev- 
 eral ages (Table VII). By consulting the columns of the table 
 which represent products it will be seen that in the case of the 
 ■boys, the deaf are uniformly inferior to the hearing children, 
 and this comparative status likewise obtains throughout with 
 the girls with the exception of the age of 12, where the nine 
 cases measured show a superiority on the side of the deaf. 
 
 In these measurements again let us consider the deaf as a 
 group and compare them with normal hearing children of com- 
 parable ages. In length of head only sixty-seven cases out of a 
 total of two hundred and seven, 32.3 per cent, are equal to or 
 in excess of the average hearing child for each age group. In 
 breadth, however, there are one hundred and twenty-four of the 
 whole number of two hundred and seven boys whose heads are 
 as broad or broader than the average — 59.9 per cent. 
 
 Practically the same ratio obtains in the same measurements 
 with the girls. Only thirty-seven out of a total number of one 
 hundred and twenty-seven girls, or 29.1 per cent, are equal or 
 greater in length of head than the averages of our normal group 
 and in breadth there are eighty-seven out of the whole number 
 of girls, one hundred and twenty-seven, or 68.5 per cent, whose 
 heads are as wide or wider in greatest breadth than the av*age 
 of the normals for their ages of hearing children.f 
 
 Deaf children have, as a whole, therefore, smaller heads 
 than do hearing children, taking as a criterion the length, breadth 
 product,* and they are more brachiocephlic, broad-headed. 
 
 fXliese norms of head measurements have been taken from the 
 Statistics on Growth by Franz Boas, published in Report of Com- 
 missioner of Education, Chapter II, 1904. It Is found in consulting 
 the records of this Department that with reference to this particular 
 physical measurement our cases are so largely atypical, that it is 
 thought unsafe to adopt them in a comparative study of this character, 
 and on this account recourse is had to the careful record of indi^'idual 
 measurements in the report of Professor Boas. The standard devia- 
 tions recorded in his tables are translated into the average deviation 
 by using the formula A. D.^.79796. 
 
 *It would have .been better, no doubt, to have rendered a comparison 
 of head size based on the three head dimensions, employing as the 
 height measurement the maximum height of the head above the floor 
 of the auditory meati, but it was Impossible for us to get satisfactory 
 records of the last named measurement. 
 
DEAF CHILDREN 
 
 
 > — 
 
 00 IT) 00 f*) O O M n -Mr, f 1 i~I 
 
 O 00 o 
 
 So ("I .-^ o f r- vr, .-< o> 00 .H 
 r^ n (V( -t ri -f m o r- iZ ir* 
 n n ri ri r< i~< ri r-i ^ ?*i ro f^ 
 
 sO I- o -o rr o -M^ '-I c- 
 
 Hnoxo-Dca-nr-i-i 
 
 IT, -t-^r-i/innr-rou 
 
 
 o o ■* oc o ir J -r 
 
 vf i c- IT, -c -r •-' 30 
 -n- ir> i o 1^ I- 
 
 sC ifj rj >f J m ro -s f^j 
 
 X cr ^ i-i rirt-t- II, 
 
 ^j fo i/i r* I/, f » u. fo u7 o -* &. ^ rt 
 N r4 r-j ri rj N 1-1 rt M n rH 
 
 o o I"! rr ri o r- r-i 'n o -x o o i- 
 
 -l-.-tCO'+OrHa'f-'-frHX.-lr-IC 
 
 o '-T -r r- r 
 1- irj u-j ir; ^ 
 
 lOcr-r-i^Tooxui^nrir-iri^ 
 
 
 -Or-000'0»Hr'irT«*-li-)'Ot-XC C r-i-r 
 t-l tH ^ i-( iH iH tH 1-1 rH t-< r-< n ri 
 
32 EXPEEIMENTAL STUDIES 
 
 LUNG CAPACITY. 
 
 The measurement of the lung capacity was taken by means 
 of the ordinary wet spirometer (Narragansett) and simply in- 
 dicates the greatest amount of air that can be expelled from the 
 lungs after a forced inspiration. This is after everything is 
 considered, perhaps also the best test of the amount of air that 
 is available for use. It may not give a direct index of the actual 
 or possible size of the lungs, but it affords in a way a convenient, 
 safe and valuable criterion of the degree of activity to which 
 the vocal apparatus has been subjected, or is capable of exercis- 
 ing at the time the test is made, as well as the extent of the 
 child's general physical activity. It is on this account quite 
 natural that we should find that the deaf children are markedly 
 inferior in lung capacity to normal hearing children, and this 
 palpable inferiority, even in the case of those deaf children who 
 were given special physical and speech training, gives us an in- 
 dication of the immense amount of physical exercise other than 
 speech that normal hearing children naturally indulge in and 
 from which the deaf are barred by reason of their sensory handi- 
 caps. The intimate relation which exists between middle ear 
 infirmities, high and narrow bone-palate formation with all the 
 accompaniments and causes of obstructed breathing and dimin- 
 ished lung capacity has doubtless been observed by every careful 
 investigator of normal children with merely defective hearing. 
 It has likewise been pretty well recognized that the amount 
 of usable air in the lungs of normal adults varies, within 
 limits, with the degree of general physical activity. But besides 
 suffering the consequences of inertness during early years, the 
 deaf children do not give their lungs anything like the same de- 
 gree of exercise that normal hearing children indulge in, since 
 indeed they vocalize so little, and hence the cumulative effects 
 of this double handicap becomes palpable and hard to overcome 
 even with persistent exercise. In no other particular are the 
 deaf children so uniformly or markedly inferior to the hearing 
 normal children as in lung capacity. This is seen clearly by 
 reference to Table VIII. 
 
 The deaf boys are inferior at every age. This inferiority, to 
 be sure, is not so pronounced at ages ii and 12 years, or at 
 
DEAF CHILDREN 
 
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34 EXPERIMENTAL STUDIES 
 
 the particular epoch in their lives at which we notice that some 
 of the other measusements showed an equality or even superior- 
 ity to the norms for hearing children. The same inferiority is 
 apparent in the case of the deaf girls, and here again the great- 
 est inferiority is shown at those years, lo, ii and 12 years, at 
 which we previously saw a lack of uniformity. 
 
 Here again it should be noted that because of the relatively 
 small number of children examined at each age it is probably 
 a safer criterion to take the total number of deaf children whose 
 lung capacity is equal to or above the average for hearing child- 
 ren of the same age. In counting over the cases with this object 
 in mind we find among the one hundred and forty-seven deaf 
 boys, of all ages examined, that only eighteen, or 12.2 per cent, 
 are equal to or above the average for hearing boys, and that in 
 the case of the deaf girls thirty-two out of a total of ninety-five 
 of all ages, or 33.9 per cent, are equal to or above the average 
 for hearing girls, instead of 50 per cent, which figure would 
 indicate them as normal. 
 
 It is interesting to note the position of deaf children with 
 reference to lung capacity in the per centile group of hearing 
 children.* 
 
 These are shown in Table IX, in which is indicated the per 
 centile group of hearing children into which the average of the 
 records of the deaf of each age fall. In a parallel column is 
 given also the average for each age, of the ratios which the in- 
 dividual lung capacity records of deaf children make with the 
 average lung capacity of hearing children of the same age. Thus 
 it is seen that the average lung capacity of deaf boys, and girls 
 as well, of the mean age of six and one-half years, falls in the 
 
 *For an explanation of these percentile grouplnps, see Report of 
 tlie Child Study Department, Public Schools, Chicago, 1901, p. 13. In 
 brief, the method of procedure was as follows : the four or five liun- 
 dred records secured for the children at each age were distributed 
 according to ranli. The minimum measurement gives the zero per- 
 centile for the whole gi-oup. To determine the ten percentile, ten per 
 cent of the nnmiber of cards is removed, beginning with the minimal 
 record, and the highest measiu-ement on the card so removed is re- 
 corded as the maximal limit of the ten percentile group. A similar 
 placing and selecting of the next highest ten per cent of records with 
 their minimal and maximal limits gives us the twenty percentile group 
 and so on, for the others. 
 
DEAF CHILDREN 
 
 
 
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36 
 
 EXPERIMENTAL STUDIES 
 
 TABLE IX. 
 
 LUNG CAPACITY. 
 
 Boys 
 
 Girls 
 
 Aee. 
 
 Percentile Group 
 
 Average of the 
 
 Percantiie Group 
 
 Average of the 
 
 
 ratios of 
 
 of Normals m 
 
 ratios of 
 
 Yrs. Mos. 
 
 which deaf 
 
 deaf children to 
 
 which deaf 
 
 deaf children to 
 
 children fall 
 
 normal hearing: 
 
 children fall 
 
 normal hearing 
 
 5 .5 
 
 
 
 0-10 
 0-10 
 
 .74 
 
 6. ...6 
 
 0-10 
 
 .81 
 
 .62 
 
 7. ...6 
 
 10-20 
 
 .82 
 
 0-10 
 
 .77 
 
 8. ...6 
 
 10^20 
 
 .83 
 
 20-30 
 
 .83 
 
 9. ...6 
 
 30-00 
 
 .90 
 
 10-20 
 
 .82 
 
 10. ...6 
 
 20-30 
 
 .88 
 
 40-50 
 
 .96 
 
 11. ...6 
 
 20-30 
 
 .91 
 
 60-70 
 
 1.03 
 
 12. ...6 
 
 10-20 
 
 .85 
 
 10-20 
 
 .85 
 
 13. ...6 
 
 10-20 
 
 .81 
 
 20-30 
 
 .88 
 
 14. ...6 
 
 10-20 
 
 .77 
 
 10-20 
 
 .84 
 
 15. ...5 
 
 10-20 
 
 .75 
 
 40 
 
 .96 
 
 16. ...6 
 
 10-20 
 
 .79 
 
 40-50 
 
 ■ 98 
 
 17. ...6 
 
 0-10 
 
 .63 
 
 40-50 
 
 .98 
 
 
 Below limits of 
 normals 
 
 .48 
 
 
 
 
 
 
 19 6 
 
 
 
 30-40 
 
 .95 
 
 
 
 
 
 ten per centile group of hearing boys and girls of that age, and 
 on the average, deaf boys have a lung capacity .8i as large as 
 hearing boys, and deaf girls .74 as large as hearing girls, at 
 this age. 
 
 The table presents the data so clearly that further comment 
 is unnecessary. The striking inferiority of deaf children of both 
 sexes at all ages, almost uniformly, stands out in this table even 
 more convincingly than in Table VIII. 
 
 STRENGTH OF GRIP. 
 
 To determine to what degree the strength of the grip of 
 deaf children is inferior or superior to normal children of the 
 same age and school conditions, an adjustable grip dynamometer 
 was used, which registers the strength of grip in kilos (i kilo= 
 2.2 lbs.). The gross results of these tests are given in Table X. 
 The ages, number of pupils of each age tested, grip of 
 right and left hand are given in parallel columns for boys 
 and girls respectively, and the norms of the grip of normal 
 children (taken from Child Study Report No. 2, 1899-1900),. 
 placed in columns adjoining for ready comparison. 
 
 By consulting Table X we find that the deaf boys are slight- 
 ly superior in right hand at ages 7, 8, 9 and 11. After the age 
 of 12 years they are uniformly inferior, and this inferiority in- 
 creases with age. The strength of left hand is superior with 
 
DEAF CHILDREN 
 
 37 
 
 TABLE X. 
 
 STKENGTB Off GEIP. DEAP BOYS. 
 
 Right Hand 
 
 Left Hand 
 
 Age 
 lYrs. Mos. 
 
 No. of 
 cases 
 
 Deaf 
 children, 
 average 
 
 grip, 
 
 legs. 
 
 A. D. 
 
 Hearing 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 Deaf 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 A. D. 
 
 Hearing 
 children, 
 Average, 
 
 grip, 
 
 kgs. 
 
 5. ...6 
 
 2 
 
 7 
 
 28 
 
 24 
 
 20 
 
 23 
 
 17 
 
 18 
 
 18 
 
 14 
 
 14 
 
 11 
 
 6 
 
 4 
 
 6.5 
 97 
 12.7 
 15.8 
 16.4 
 19.5 
 21.7 
 21.7 
 23.4 
 28.9 
 28.1 
 38. 6 
 37.7 
 355 
 
 .5 
 1.9 
 2.7 
 2.5 
 2-4 
 2-8 
 3.5 
 2.8 
 3.0 
 81 
 4.9 
 7.2 
 2.3 
 70 
 
 
 5.5 
 8.7 
 11. 7 
 14.6 
 15.6 
 17.8 
 19.5 
 20.7 
 211 
 28.5 
 26.3 
 37.2 
 37-4 
 37.5 
 
 .5 
 1.7 
 2.0 
 2.8 
 3.0 
 21 
 2-4 
 3.0 
 2.2 
 65 
 6.3 
 6.7 
 1.6 
 10.0 
 
 7. 12 
 
 6. ...6 
 
 7. ...6 
 
 8. ...6 
 
 9. ...6 
 
 10.. ..6 
 
 11. ...6 
 
 12. .6 
 
 13. ...6 
 
 14. ...6 
 
 15. ...6 
 
 16. ...5 
 
 17. ...6 
 
 18. ...6 
 
 19 .... 6 
 
 9.97 
 11-51 
 13.31 
 15.37 
 17. 67 
 20. 03 
 22.45 
 26. 43 
 30.40 
 36.38 
 42.35 
 47.14 
 51.43 
 
 9.29 
 10.92 
 12-43 
 14.51 
 16.66 
 18.80 
 20.62 
 24.40 
 28.40 
 33.73 
 39.40 
 42.87 
 47-16 
 
 20. ...6 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 STRENGTH OF GRIP. DEAP GIRLS. 
 
 Right Hand 
 
 Left Hand 
 
 Age 
 Yrs. Mos. 
 
 No. of 
 cases 
 
 Deaf 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 A. D. 
 
 Hearing 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 Deaf 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 A. D. 
 
 Hearing 
 children, 
 average 
 
 grip, 
 
 kgs. 
 
 6 6 
 
 7 6 
 
 8 6 
 
 9 6 
 
 10 6 
 
 11 6 
 
 12 6 
 
 13 6 
 
 14 6 
 
 15 6 
 
 16 6 
 
 17 6 
 
 18 6 
 
 10 
 7 
 14 
 11 
 13 
 11 
 9 
 12 
 10 
 14 
 5 
 7 
 1 
 4 
 
 8.8 
 12.9 
 11.1 
 12.6 
 15-4 
 16-8 
 19.3 
 24.2 
 23.7 
 27.5 
 35-2 
 32-0 
 33.0 
 39.0 
 
 2-2 
 1.9 
 23 
 1.6 
 1.7 
 3.3 
 2-3 
 4.2 
 3.5 
 3-8 
 3-4 
 3-1 
 
 "iio 
 
 9.12 
 10.65 
 11.67 
 13-88 
 15-43 
 17-65 
 20-19 
 23-49 
 26-10 
 27.91 
 29-50 
 29-63 
 29.87 
 
 8-10 
 9.80 
 10.60 
 12-20 
 14.70 
 15.60 
 16-70 
 22-90 
 22-40 
 25.40 
 30.10 
 29.00 
 28.00 
 32.25 
 
 2.10 
 2.50 
 2.00 
 1-10 
 2.30 
 3.10 
 270 
 4-58 
 3.12 
 4.07 
 2-80 
 2-85 
 
 "s.is" 
 
 8.49 
 9.99 
 10.96 
 12.99 
 14.46 
 16.58 
 18.97 
 21.80 
 24.03 
 25.80 
 27.31 
 27.55 
 27,77 
 
 20 6 
 
 
 
 
 1 
 
 
 
 
 
 the deaf boys at ages 7, 10, 11, 12 and 14 years and inferior at 
 ages 6, 8, 9, 12, 13, 15, 16, 17 and 18. 
 
 The deaf girls are weaker in right hand grip than the norms 
 for hearing girls at ages 6, 8, 9, 10, 11, 12, 14, 15 and slightly 
 stronger at ages 7, 13, 16, 17 and 18. Practically the same com- 
 parative status obtains in grip of left hand of these deaf girls. 
 
 Again because the number of cases of the deaf is so small» 
 a comparative estimate of the children as a whole may better be 
 
38 EXPERIMENTAL STUDIES 
 
 made from the number of children of the group who are equal to 
 or superior to the average of our normal children in this test of 
 strength. In actual numbers it is found that ninety boys out of 
 two hundred and four, or 44.1 per cent, are equal to or superior 
 to the averages for hearing children. With the left hand, as a 
 group, the deaf boys stand higher than with the right hand, in- 
 -Bsmuch as one hundred out of two hundred and four, or 49.7 
 per cent, are equal or superior to the average of children of the 
 ages included in the norms. 
 
 In the case of the deaf girls there are fifty-five both left and 
 right hand out of the total number of one hundred and twenty- 
 four, or 44.4 per cent, who stand equal to or superior to the 
 norms of hearing children for the ages represented. It appears, 
 therefore, that the deaf boys as a group more nearly approach 
 the norms of their hearing companions than the girls with the 
 left hand, while the advantage is slightly in the favor of deaf 
 girls as a group in respect to the right hand. 
 
 GRIP INDEX. 
 
 The observation has quite frequently been noted * that left- 
 handedness is found more frequently among deaf children than 
 among the hearing. Various reasons have been assigned for 
 this peculiarity, although all agree, however, in supposing that 
 there is some intimate connection between speech and this dif- 
 ferentiation in hand power or selectiveness in manipulation. 
 
 In Report No. 2 (1900) of this Department, the data with 
 reference to changes in growth of hand strength of normal 
 children were presented. Moreover, it will be remembered that 
 in Prof. J. Mark Baldwin's studies of his two children ** there 
 was an account of a noticeable preference for one hand over 
 another in grasping for attractive objects which made its initial 
 appearance about the time of speech beginnings. This apparent 
 correlation of the two modes of expression at the time of their 
 origin seems to be again in evidence at the time of the great 
 
 **Mental Development in the Child and the Race, 1896, chap. I. 
 *Hartmann, Ueber Taubstumme, Deutsch med. Wochenschr, III, 
 1877. 
 
 Deaf -Mutism — (trans. Cassell), 1S80. J. Kerr Love; Deaf- 
 Mutism, Ohap. I, Glasgow, 1896. St. Hilalre; La Surdi-ilutite, p. 251, 
 Paris, 1900. 
 
DEAF CHILDREN 
 
 39 
 
 transformations of life. An instance of this occurs during the 
 pubertal epoch. In the reports of .this department attention was 
 called to the fact that the greatest difference between the 
 strength of the hands occurred at early adolescence contempo- 
 raneously with the greatest changes of voice. Another group of 
 facts somewhat akin in import relates to speech defects. It was 
 found in our work that by far the greatest number of minor 
 speech defects was discovered among children who were pro- 
 nouncedly left-handed or who acquired ambidexterity by reason 
 of the teacher's persistence and the parents' training. This 
 whole line of reasoning may be merely a matter of coincidence. 
 It seems much more reasonable to suggest that all cases of minor 
 speech defects correlate directly with inferior intelligence, as 
 
 TABLE XI. 
 
 MANUAL INDEX.* 
 GRIP. 
 
 Boys 
 
 Girls 
 
 
 Deaf 
 
 Hearing: 
 
 Deaf 
 
 Hearing 
 
 Age 
 Yrs. Mos. 
 
 
 
 
 
 
 No. of 
 
 Index 
 
 No. of 
 
 Index 
 
 No. of 
 
 Index 
 
 No. of 
 
 Index 
 
 
 cases 
 
 per cent 
 
 cases 
 
 per cent 
 
 cases 
 
 per cent 
 
 cases 
 
 per cent 
 
 6....5 
 7. ...6 
 
 7 
 28 
 
 88.8 
 90.0 
 
 
 
 
 
 
 
 8 
 
 93.1 
 
 7 
 
 85-0 
 
 9 
 
 90.0 
 
 8. ...6 
 
 24 
 
 87.0 
 
 29 
 
 92.0 
 
 14 
 
 93.0 
 
 28 
 
 92-9 
 
 9. ...6 
 
 19 
 
 86.0 
 
 44 
 
 93.1 
 
 12 
 
 91. 
 
 39 
 
 91.5 
 
 10. ...6 
 
 23 
 
 89.0 
 
 42 
 
 93.04 
 
 13 
 
 920 
 
 41 
 
 91. 7 
 
 11 .... 6 
 
 16 
 
 94.0 
 
 44 
 
 95-4 
 
 11 
 
 94.0 
 
 45 
 
 921 
 
 12. ...6 
 
 18 
 
 92-0 
 
 40 
 
 91.6 
 
 9 
 
 86-0 
 
 47 
 
 92-4 
 
 13. ...6 
 
 18 
 
 91.0 
 
 48 
 
 91.1 
 
 12 
 
 95.0 
 
 45 
 
 93.6 
 
 14....6 
 
 14 
 
 94. 
 
 36 
 
 91.8 
 
 8 
 
 92.6 
 
 64 
 
 93. 1 
 
 15. ...6 
 
 14 
 
 93.0 
 
 31 
 
 92.5 
 
 14 
 
 91.0 
 
 47 
 
 91.7 
 
 15. ...6 
 
 11 
 
 93.0 
 
 20 
 
 90-9 
 
 6 
 
 93.16 
 
 39 
 
 90.6 
 
 17. ...6 
 
 5 
 
 94-2 
 
 90 
 
 91.8 
 
 7 
 
 90.85 
 
 51 
 
 89.9 
 
 18. ...6 
 
 4 
 
 93.2 
 
 37 
 
 89.4 
 
 4 
 
 83.0 
 
 75 
 
 89.9 
 
 
 
 
 
 
 
 
 •Note. — The measure of the Index is In each case, the -per cent which the 
 wealier hand Is of the stronger. The degree of right- or left-handedness Is 
 not therefore indicated. 
 
 indeed our work with subnormal pupils would seem to indicate, 
 and that ambidexterity is one of the marks of inferior mental- 
 ity instead of the converse, as further work with reform school 
 boys gave evidence of. (See General Reports II and III). This 
 feature of the whole matter is held in reserve for another series 
 of studies. 
 
 It must not be forgotten, however, that this matter of the 
 
40 EXPERIMENTAL STUDIES 
 
 number of deaf children who are left-handed is a relatively sec- 
 ondary problem in comparison with the larger aspects of growth 
 in hand strength which center about the differences in hand 
 power between the right and left hands of deaf children through- 
 out the years of growth. 
 
 This growth in specialization is indicated in Table XI, in 
 terms of manual index. The measure of the manual index is in 
 each instance the per cent which the weaker hand is of the 
 stronger, and for convenient comparison the index of normal 
 hearing children is placed in adjoining columns, both for boys 
 and girls. 
 
 There seems to be greater difference — that is, the manual in- 
 dex is less — between the strength of grip of the hands of deaf 
 boys as compared with hearing boys at the ages 7, 8, 9, 10 and 
 II years. Beginning with the age of 12 years and from 12 to 
 18 years, both inclusive, there is less difference in the strength 
 of the hands of deaf boys as compared with their hearing mates 
 of corresponding ages. In comparing the younger deaf boys 
 with those older in years it is found that, in general, the differ- 
 ence between the strength of the hands tends to diminish, that 
 is, whereas, in the early years the manual index is less than 
 ninety, it goes up to ninety-three or ninety-four in the older 
 years. As the deaf boys increase in age there is less and less 
 difference between the strength of their hands, less specialization 
 or selectiveness in manual power. This is the direct opposite of 
 what we find among hearing boys, among whom we find that the 
 strength of hands is more equal in the early years, and that the 
 difference between the hands increases perceptibly as they grow 
 older.* This may be only another indication that deaf boys are 
 later in maturing than hearing boys, or that the lack of activity 
 of all sorts and especially of constructive manipulation of ma- 
 terials is so great an environmental handicap as to practically 
 make the deaf boys a species by themselves. There is by no 
 means so great uniformity found in the differences of hand 
 power of deaf girls as compared with their hearing companions 
 of equal ages. There is less difference between the strength of 
 
 ♦Compare Binet Quotation from Dr. St. HUaire, "that grip of left 
 hand differs less from right hand than normals." Also, Kilian. 
 
DEAF CHILDREN 4I 
 
 the hand of deaf girls at ages 8, lo, ii, 13, 16 and 17 years; 
 and greater difference between the hands of deaf girls than in 
 the case of hearing girls at ages 7, 9, 12, 14, 15 and 18 years 
 respectively. The general tendency, however, so far as this can 
 be read from the data at hand, seems to show that up to the age 
 of 12 years there is less difference between the strength of hands 
 of deaf girls than hearing girls of equal ages — the direct oppo- 
 site of the relation that was found to obtain in the case of 
 deaf boys. 
 
 In comparing the younger deaf girls with those of older 
 years we find that the differences between the hands increase as 
 they grow older, the opposite of what we found prevailing 
 among deaf boys, and more in line with the trend of develop- 
 ment of normal hearing girls. Again this may be largely due 
 to the fact that the difference in activity which is found between 
 deaf and hearing girls is not so great as the difference between 
 deaf and hearing boys. 
 
 To summarize, the nature of the data is such as to make it 
 unwarrantable to assert that any differences exist in relative 
 strength of the two hands of deaf girls as compared with their 
 hearing sisters, but with reference to deaf boys the data seem to 
 indicate that for younger years, during pre-adolescence, more 
 differentiation in the strength of the two hands, respectively, ob- 
 tains than among the hearing, and for the adolescent years, less 
 differentiation prevails than among children with normal hear- 
 ing — that is, the deaf are more ambidexterous. 
 
 MOTOR ABILITY. 
 
 In examining the voluntary output of energy one should take 
 into account not only the gross and spasmodic total result of 
 effort usually called strength and represented in one instance as 
 hand-grip (Table X), but also the factor of the quickness or 
 speed of voluntary movement. This factor of voluntary motor 
 ability is recorded herein as simple tapping-time, and in our tests 
 registers the number of taps that can be made with an electric 
 tapper during thirty seconds. The two most important elements 
 in a test, namely, precision of movement and constancy in effort 
 and execution unfortunately we shall have to ignore entirely, 
 and hence there is presented only the total number of taps made 
 during thirty seconds. 
 
42 
 
 EXPERIMENTAL STUDIES 
 
 TABLE XII. 
 
 MOTOn ABILITY DEAF BOYS. 
 
 Riffht Hand 
 
 Left Hand 
 
 A ere 
 Yrs.Mos. 
 
 No. of 
 cases 
 
 Deaf 
 
 children, 
 
 averasre no. 
 
 of taps, 
 
 30 sees. 
 
 A. D. 
 
 Hearing 
 children, 
 average no. 
 of taps, 
 30 sees. 
 
 Deaf 
 
 children, 
 
 average no. 
 
 of taps, 
 
 30 sees. 
 
 A. D. 
 
 Hearing 
 children, 
 average no. 
 of taps, 
 30 sees. 
 
 5. ...5 
 6. ...6 
 7. ...6 
 8. ...6 
 9. ...5 
 10. ...6 
 11. ...6 
 12. ...5 
 13. ...6 
 14. ...6 
 IS. ...6 
 16. ...5 
 17. ...6 
 18. ...6 
 19 . 6 
 
 2 
 
 7 
 
 20 
 
 22 
 
 22 
 
 22 
 
 17 
 
 18 
 
 17 
 
 14 
 
 17 
 
 12 
 
 7 
 
 4 
 
 76.1 . 
 117.8 
 120.1 
 129.2 
 137.9 
 138.0 
 146.8 
 163.3 
 165.3 
 174.0 
 176.4 
 1820 
 162.4 
 164.5 
 
 15.0 
 19.5 
 13.5 
 18.6 
 10.8 
 19.5 
 16.1 
 15.5 
 16.9 
 21.5 
 26.4 
 21.5 
 9.9 
 12.5. 
 
 
 72.0 
 100.5 
 
 97.7 
 105.8 
 115.0 
 114-6 
 124.1 
 141.2 
 145.0 
 145.4 
 152-8 
 159.5 
 146.3 
 150-6 
 
 12.0 
 2.6 
 13.8 
 22.6 
 12. 3 
 19.0 
 16.1 
 14.4 
 
 20. 
 IS. 7 
 16.6 
 
 20. 1 
 18.6 
 25.7 
 
 
 
 
 
 
 147 
 151 
 161 
 169 
 170 
 184 
 184 
 191 
 196 
 196 
 197 
 
 117 
 127 
 132 
 141 
 145 
 156 
 155 
 159 
 170 
 174 
 183 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 MOTOB ABILITY DEAF GIBLS. 
 
 Right hand 
 
 Left hand 
 
 Age 
 Yrs. Mos. 
 
 No. of 
 cases 
 
 Deaf 
 
 childen, 
 
 average no. 
 
 of taps, 
 
 30 sees. 
 
 A. D. 
 
 Hearing 
 children, 
 average no. 
 of taps 
 30 sees. 
 
 Deaf 
 
 children, 
 
 average no. 
 
 of taps, 
 
 30 sees. 
 
 A. D. 
 
 Hearing 
 children, 
 average no. 
 of taps, 
 30 sees. 
 
 5....5 
 
 6....6 
 
 7....6 
 
 8.. ..6 
 
 9. ...5 
 
 10. ...5 
 
 11. ...5 
 
 12. ...6 
 
 I3.---6 
 
 14---. 6 
 
 15. ...6 
 
 15. ---6 
 
 17. ...6 
 
 18. ...6 
 
 19----6 
 
 20-. .-5 
 
 1 
 
 8 
 13 
 14 
 10 
 13 
 10 
 9 
 12 
 7 
 12 
 6 
 7 
 1 
 3 
 
 115.0 
 112.9 
 109.9 
 
 122.5 
 134.9 
 141-5 
 148-2 
 153.7 
 155.9 
 157-7 
 174.0 
 177.1 
 175.7 
 178.0 
 188.0 
 
 
 
 105.0 
 95.1 
 103.7 
 93.8 
 115.5 
 128.2 
 132.2 
 131-4 
 137-1 
 133.3 
 158.7 
 161.1 
 163-4 
 159.0 
 171.0 
 
 
 
 11.1 
 14.5 
 12-2 
 14-5 
 17-2 
 22-4 
 20-6 
 18.1 
 21.1 
 24-1 
 12-8 
 14.9 
 
 "is.o" 
 
 
 25.0 
 21.3 
 17.0 
 13.8 
 12. 1 
 13.0 
 20.2 
 25.9 
 14.0 
 21.0 
 10.5 
 11.9 
 
 "■9.'3" 
 
 
 
 
 145 
 149 
 157 
 169 
 159 
 178 
 181 
 181 
 188 
 184 
 193 
 
 117 
 118 
 U9 
 139 
 140 
 153 
 157 
 159 
 167 
 162 
 169 
 
 
 
 
 
 
 In Table XII are given in parallel columns the following: 
 
 (a) The number of children tested at each age. 
 
 (b) The average number of taps made in thirty seconds by 
 the children. 
 
 (c) The average deviation of the records from the average. 
 For ready comparison the averages for normal children for cor- 
 responding ages are placed beside those of the deaf. The rec- 
 ords are given for both boys and girls for the right and left 
 hands. 
 
DEAF CHILDREN 43 
 
 By going over thife table somewhat in detail one sees that 
 the deaf boys are with the right hand notably and uniformly 
 slower than normal hearing boys, and that although not so quick 
 at any age with the left hand, they are not in this case so in- 
 ferior, and at the age of twelve years almost equal to the hear- 
 ing boys. Moreover, this relative slowness seems to increase as 
 they grow older. 
 
 In the case of the girls we find that they too are much 
 slower at all ages with the right hand, and with the left, though 
 slower than hearing girls, they are at no age as much slower 
 relatively as with the right hand. Indeed, at the ages fifteen 
 to seventeen, they are almost equal in quickness to hearing 
 girls with the left hand, and at the age of seventeen years they 
 are actually quicker on the average. Moreover, the inferiority 
 of the girls, unlike that of the boys, appears to decrease with age, 
 and this may be only another indication of the increased degree 
 of general physical activity in which they come to indulge, as 
 well as of other environmental factors. 
 
 Again on account of the paucity of numbers at each age it 
 is advantageous to take the deaf boys and girls as a group and 
 compare them in quickness directly with the hearing boys and 
 girls for the corresponding ages represented in each deaf group. 
 It is thus found that of all deaf boys examined, only forty-one 
 out of one hundred and seventy-two, or 23.8 per cent, are as 
 fast or faster than the averages for hearing boys of their ages 
 with right or left hand, and that only twenty-nine of a total of 
 one hundred and one, 23.8 per cent, deaf girls are, with the 
 right hand, equal to or above the average for normal hearing 
 girls of corresponding ages, while only thirty-four out of ninety- 
 nine cases, 37.3 per cent, recorded for quickness of left hand, 
 equal or surpass the averages of hearing girls for the same ages. 
 
 The relative standing of the deaf, all in all, when compared 
 with hearing children in the cases of both boys and girls, is 
 therefore found to be, even less favorable, when rapidity of 
 movement is involved, than was found in the measurements of 
 stature and weight, and only slightly better than the relative 
 standing of the deaf in lung capacity. 
 
 The facts are diagramatically exemplified in the accompany- 
 
44 
 
 EXPERIMENTAL STUDIES 
 
 ing figure, which indicates the positions occupied on a per centile 
 scale drawn from a large number of hearing children of each 
 age, the average standing of deaf boys and girls of correspond- 
 ing ages. From this it is seen for example, that the average 
 standing of seven year old deaf girls is lowfer than the average of 
 the lowest lo per cent of the records selected from the 
 performances of hearing girls. In one instance, only, 12 year 
 old deaf girls, does their average tapping rate exceed the aver- 
 
 n 
 
 TAPPIBS ABILITISS- Rieht Hana . 
 
 A 
 
 / 
 
 // /7 /7 /9 
 
 ^Z 
 
 THE HOBIZOUTAL NDMEEALS BEPKESENT THE AGES OF THE BESPECTIVE GKOtTPS 
 
 THE PEBCENTS ON THE VEBTICAL LINE SHOW THE BATINQS OF THE n EAF BOTB 
 AND GIBLS FOB THE DIFFEBENT TEABS. 
 
 age of hearing girls, and in the averages for three age groups 
 only among boys do their performances equal the average of 
 hearing children. 
 
 Further, in the tests of motor ability as with the hand- 
 strength there is an advantage and interest in giving the manual 
 index. This index of manual quickness (See Table XIII) 
 measures in each instance the fraction which the slower hand 
 
DEAF CHILDREN 
 
 45 
 
 is of the faster. In comparing then the manual index, as deter- 
 mined by relative quickness of movement, of deaf boys with 
 hearing boys, it is seen that there is practically no difference 
 observable until after the age of eleven and one-half years. 
 After this age, however, the manual index is higher among the 
 deaf boys, showing that the difference in motor control of the 
 right and left hand is not so great as among hearing boys of 
 the same ages, or that specialization in this method of ex- 
 pression has not attained as high a degree among the deaf as 
 the hearing, that is, the deaf tend more to ambidexterity than do 
 ordinary hearing children. 
 
 TABLE XIII. 
 
 MANUAL INDEX.* MOTOE ABILITT. 
 
 Boys 
 
 Girls 
 
 
 Deaf 
 
 Hearingr 
 
 Deaf 
 
 Hearingr 
 
 Age 
 
 
 
 
 
 
 Yrs.Mos. 
 
 No. of 
 cases 
 
 Index 
 
 No. of 
 cases 
 
 Index 
 
 No. of 
 cases 
 
 Index 
 
 No. of 
 cases 
 
 Index 
 
 6. 6 
 
 (y 
 
 79 3 
 
 
 
 g 
 
 85.5 
 83-9 
 
 
 
 7. ...6 
 
 25 
 
 79. 9 
 
 8 
 
 79 
 
 
 
 12 
 
 11 
 
 80.1 
 
 8. ...6 
 
 22 
 
 81. 18 
 
 33 
 
 81 
 
 4 
 
 14 
 
 79.0 
 
 8 
 
 80.32 
 
 9. ...6 
 
 21 
 
 83-7 
 
 60 
 
 82 
 
 6 
 
 10 
 
 83.6 
 
 44 
 
 79.4 
 
 10. ...6 
 
 22 
 
 81-9 
 
 47 
 
 « 
 
 3 
 
 12 
 
 860 
 
 48 
 
 82-4 
 
 11.. ..5 
 
 17 
 
 82.5 
 
 49 
 
 83 
 
 
 
 10 
 
 88-2 
 
 46 
 
 83.1 
 
 12. ...6 
 
 18 
 
 87.1 
 
 44 
 
 82 
 
 5 
 
 9 
 
 86.1 
 
 49 
 
 80.7 
 
 13.. ..5 
 
 17 
 
 85.5 
 
 50 
 
 84 
 
 6 
 
 11 
 
 85.5 
 
 44 
 
 86.7 
 
 14.... 6 
 
 14 
 
 83.2 
 
 40 
 
 82 
 
 08 
 
 7 
 
 85-1 
 
 68 
 
 86.1 
 
 15-. ..6 
 
 16 
 
 861 
 
 35 
 
 86 
 
 6 
 
 11 
 
 87.2 
 
 48 
 
 86.7 
 
 16. ...6 
 
 11 
 
 91.7 
 
 21 
 
 87 
 
 1 
 
 6 
 
 91.1 
 
 40 
 
 88.0 
 
 17. ...6 
 
 7 
 
 88-9 
 
 13 
 
 88 
 
 7 
 
 7 
 
 92-1 
 
 51 
 
 88.1 
 
 18. ...6 
 
 3 
 
 86-2 
 
 3 
 
 93-3 
 
 1 
 
 89. 
 
 24 
 
 90. 9 
 
 *<NoTE. — The measure of the Index Is In each Instance the per cent which 
 the slower hand Is of the faster. 
 
 Again in running our eye over the data in each column to 
 determine differences due to age among deaf boys, it will readily 
 be seen that in general there is not so great a difference between 
 the younger and the older deaf boys as is found to obtain in 
 the case of the younger noiTnal hearing boys and the older hear- 
 ing boys. 
 
 With respect to the manual index of deaf girls it is seen that 
 at nearly every age there is not so great a difference in 
 the control of the hands as is found to prevail among the hear- 
 ing girls of comparable ages. This difference between the deaf 
 and hearing girls is very pronounced at some ages, notably at 
 
46 EXPERIMENTAL STUDIES 
 
 ages, seven, nine, ten, eleven, twelve, fifteen, sixteen, and seven- 
 teen years and not so marked or even slightly less at ages, eight, 
 thirteen, fourteen, and eighteen years. It appears safe to w^ar- 
 rant the statement, however, that there is less pronounced dif- 
 ferentiation or selectiveness in motor manipulation among deaf 
 girls than is found in the case of their hearing sisters. 
 
 One fact stands out prominently in the tests of motor abil- 
 ity, notably that both deaf boys and deaf girls of 12 years and 
 older more nearly approach the standing of hearing children than 
 do those of the younger years. That is, as deaf children 
 increase in age, they become more nearly like normal hearing 
 children. There seems to be no other casual factor to which 
 this relative increase in efficiency with age can be attributed ex- 
 cept that lack of definite motor control is intimately related to 
 mental maturity. Since in their early years, deaf children have 
 had few experiences as compared with hearing children, this 
 increase in motor ability would be more rapid with mental train- 
 ing than is that of th.e hearing child. This suggestion of the 
 very close correlation between mentality and the development 
 of the nervous mechanism is likewise illustrated and exempli- 
 fied by work which has been done on primitive people. These 
 show that while not greatly inferior to the normal average white 
 people of civilization in strength for their stature, there is a 
 marked inferiority in their quickness of response. This diflfer- 
 ence in moving time is apparent even in the doing of things with 
 little or no meaning, as well as in the performance of acts that 
 require a more complex mental factor to initiate and control 
 them. It may be said that responses are the result of stimula- 
 tion, and that the nervous mechanism, subject to the more 
 varied and greater number of sensations appreciated, other 
 things being equal, will respond the more rapidly. This cor- 
 relation suggests the ver" interesting psychological problem of 
 the inverse influence of "the psychical on the efficiency of the 
 motor mechanism. The question of the influence of bodily move- 
 ments in giving rise to mental content has long been recognized. 
 The influence of the psychical on the physical mears that an 
 unused mind, no matter from what caused, is accompanied by 
 sluggish bodily action. It suggests also, the influence which 
 school training of the purely mental type has in aflfecting an in- 
 crease in manual productivity. 
 
MENTALITY. 
 
 The problem of determining the mental status of deaf chil- 
 dren is infinitely more complicated than that of estimating the 
 psychical efficiency of hearing children. This is to be attributed 
 in no small measure to the fact that their symbols for express- 
 ing themselves and making known to us the contents of their 
 minds are few and inadequate. 
 
 On account of the paucity of symbols, too, it becomes exceed- 
 ingly difficult to devise any tests which may be used with the 
 same degree of facility and certitude on the deaf and hearing 
 children alike, and thus make a quantitative statement of the 
 differences of mentality between a deaf and hearing child. This 
 does not mean, of course, that the mental condition of a deaf 
 child cannot be determined with a fair degree of certainty by 
 one who has had special training and has acquired special skill 
 in bringing out and interpreting responses which are indicative 
 of the deaf child's mental power. In testing the mentality the 
 aim was more specifically that of examining definite functions 
 rather than of evaluating proficiency in any particular line of 
 school training. 
 
 Proceeding from the simplest to the more complex processes, 
 simple tests were given to determine the following functions 
 of the child: 
 
 (a) Imitative ability ; 
 
 (b) Suggestibility; i. e., his ability to follow directions; 
 
 (c) Perceptive ability; i. e., the child's efficiency or 
 skill in discriminating sense differences in degree and kind. 
 
 (d) Capability in reproducing immediately (at once) a con- 
 text which is relatively without connection with other meanings, 
 i. e., the immediate sense memory. (With the deaf children 
 the reproduction of things heard is eliminated.) 
 
 (e) Ability to think, i. e., to intelligently use such con- 
 cepts as cause and effect, part and whole, and the Hke. 
 
 With reference to the general power of thinking, it should 
 be stated that in speaking of such a highly complex mental activ- 
 
48 EXPERIMENTAL STUDIES 
 
 ity as the power of forming good judgments, it is always 
 necessary to tell in advance the particular field in which this 
 activity is operative. It is a common observation that persons 
 may exercise good judgment in dealing with one phase of human 
 life, and yet show exceptionally poor judgment with another 
 group of facts. A man, for instance, may be sound in science 
 but most eccentric and unsafe in business and religion. Hence 
 it is unwise to use any arbitrary tests for general comparison 
 of individuals or groups, who may happen to have had diverse 
 interests and different training. In this test of the deaf chil- 
 dren, an estimate was made merely of each child's ability to 
 size up situations and in general to interpret and communicate 
 meanings. 
 
 In addition it should be noted that the simpler tests were 
 used for diagnostic purposes, and no effort was made to state 
 them in quantitative terms. The question of primary import- 
 ance was: Has the child a mind which is well balanced or 
 sane, and susceptible of training, or is he feeble-minded? 
 
 Imitation. 
 To determine whether the child had sufficient mental abil- 
 ity to imitate, the following tests were employed: The child 
 was placed at a distance of four or five feet facing the experi- 
 menter. He was encouraged to observe attentively and execute 
 the same acts which the experimenter performed, such as (i) 
 placing the feet together, heels and toes ; (2) standing erect, 
 with head and shoulders thrown back; (3) raising one or both 
 hands to a horizontal position at the side, and in front or per- 
 pendicularly above the shoulders; (4) with the hands extended 
 horizontally in front, the child spread apart his fingers, follow- 
 ing the experimenter, holding now one, and now two, together. 
 
 Suggestibility. 
 
 To determine the child's suggestibility, two tests were em- 
 ployed. In the first the child performed certain acts which he 
 had just seen the experimenter execute. He made three, four 
 or five, or any number of steps, after watching the experimenter 
 perform the same, or he tapped a certain number of times in 
 response to the same number performed by the experimenter. 
 This implies that an idea or image of the performance or end to 
 
DEAF CHILDREN 49 
 
 be attained exists in the mind of the child, and that he has the 
 ability to work out the meaning of the image or idea in some 
 definite act or series of acts. There is also involved in a sug- 
 gestion test the concept or translation from one sense to an- 
 other. In order for the child to take three steps as a result of 
 having seen three hand movements, it is necessary that he have 
 definitely formed the concept of three, and this is by no means a 
 simple function. 
 
 In the second test for suggestibility packs of specially pre- 
 pared cards were used, and the child was required to sort them 
 in groups of their likes and unlikes. Three of such packs were 
 employed, each containing forty cards. On the cards of the first 
 series were pasted small circles of eight elementary colors. After 
 the cards had been thoroughly mixed the child was requested to 
 sort them into piles, according to color. On the cards in the 
 second series were pictures of familiar objects instead of colors; 
 in the third simple geometrical forms. The procedure in all 
 three parts of the series was practically identical. How- 
 ever simple and elementary these tests for imitation and suggest- 
 ibility may seem, experience with large numbers of children in 
 the Child Study laboratory has shown that feeble-minded chil- 
 dren are unable to execute even such simple operations. 
 
 Perception. 
 
 As tests which largely involve simple perception three were 
 employed; one calling for sense discrimination by sight, the sec- 
 ond by the sense of touch and the third bringing into play the 
 muscular sense. 
 
 To test the first function — sense discrimination by sight — 
 use was made of a special form of what is customarily known 
 as the "A" Test. (See form of this test, pp. 50 and 51.) The 
 test is one which has done service in the Child Study Laboratory 
 of the Chicago Public Schools for a number of years, and was 
 invented and devised largely for diagnostic purposes. As is seen, 
 the test is composed of two parts. In the first, one hundred 
 "a's" (18 point size) are arranged symmetrically in rows, so as 
 to involve the perceptive factor to a negligible degree, in mark- 
 ing them out, while in the second half of the test the one hund- 
 red "a's" are scattered promiscuously among the remaining let- 
 
so EXPERIMENTAL STUDIES 
 
 a ^ d a d 
 
 cs « cs °* ^ 
 
 ^ CS c3 C3 ^ 
 
 C8 ee c8 * * 
 
 * C8 C8 ce C3 
 
 ^ & d ^ ^ 
 
 53 C8 S 03 * 
 
 86 C3 c3 ^ ^ 
 
 * CS c3 c8 03 
 
 ^ C3 ^ ^ 03 
 
 * C3 c8 cS 53 
 
 C8 ^ 53 rt OS 
 
 ^ a as a ^ 
 
 o3 c3 08 ^ fi 
 03 iS OS c3 * 
 
 2S 03 rt ^ ce 
 
 ^ ti C8 C3 ^ 
 
 * as rt C3 C8 
 
 ^ C8 rt 88 C5 
 
 ^ S S3 ^ 03 
 

 
 H 
 
 ■ 
 
 H 
 
 H 
 
 
 
 
 O 
 
 P 
 
 
 o 
 
 W 
 
 c5 
 
 A 
 •< 
 
 R 
 
 p 
 ft 
 
 cfi 
 
 n 
 
 s 
 
 
 cs 
 
 cs 
 
 _M pi? 
 
 as M 
 
 o 
 
 N ^ S 
 
 be 
 
 
 C8 o 
 C8 C^ 
 
 bo 
 
 be 
 
 03 
 S3 
 o 
 
 03 
 
 CS 
 C6 
 
 CO 
 
 08 
 esi 
 
 c8 
 
 03 
 
 O 
 
 biD 
 
 CQ 
 
 C8 
 
 03 
 On 
 
 03 
 
 B 
 
 03 
 
 03 
 
 k» 
 
 o 
 
 C8 
 
 03 
 
 03 ^ R 
 
 fl k o 
 
 o 
 
 03 
 
 CS 
 
 ESS 
 
 ^ 03 
 
 bJD 
 
 OS 
 
 es3 
 
 03 
 
 cs 
 ^ cs 
 
 I a 
 
 CS 
 
 S s^ 5S 
 
 CS 
 
 O * 
 
 cS 
 
 bc 
 
 cs 
 
 03 
 
 OS 
 
 i3 
 
 
 a 
 
 N 
 
 ^ 
 
 M 
 
 
 ■«-3 
 
 o 
 
 03 
 
 
 pQ 
 
 03 
 
 a 
 
 03 
 
 E3 
 
 03 
 P^ 
 
 03 OS 
 
 — t>- ^ 
 
 be o^ -S 
 
 CS OQ O^ 
 
 O 
 X 
 
 OS 
 
 cs 
 
 be 
 
 03 
 
 be « 
 
 O oj 
 
 be K 
 
 cs 
 
 t-i 03 
 
 • pH 
 
 O 
 
 03 
 
 SI 
 
 O 
 
 ^ CS P-^ ^ ^ 
 
 X 
 
 cs 
 
 OS 
 
 N 
 
 03 
 >^ 
 
 it 
 
 PS 3 
 
 P« cs 
 
 I §- 
 
 08 
 
 o 
 
 pO 
 
 03 
 
 X 
 
 C8 
 
 
 be 
 
 pfi 
 
 Is 
 
 03 
 
 be 
 
 o 
 
 C8 
 
 be 
 
 ■§ 
 
 oe 
 •i-t 
 
 QC 
 
 N 
 
 cr 
 
 08 ($ 
 
 ^ -^ 
 
 CS 
 
 03 
 
 GC 
 
 CS 
 
 
 -^ 
 
 • p-l 
 
 ^ 
 
 pTS 
 
 cs 
 
 
 o 
 
 CS 
 
 
 
 § I 
 
 I— H 'W 
 
 N 
 OS 
 
 a a 
 
 po 
 
 o 
 
 cs 
 X 
 
 m 
 
 03 
 
 cs 
 
 a 
 
 03 
 X 
 
 ;^ X 
 
 & be 
 
 a^ OS 
 
 cs &« 
 
52 EXPERIMENTAL STUDIES 
 
 ters of the alphabet, so as to form one hundred groups of letters 
 of five each. 
 
 The first part of the "A" test was designed with two ob- 
 jects in view. By taking the time required by the chifd to place 
 a stroke with a pencil through each of the one hundred "a's" 
 when he has been requested to do it as rapidly as possible, a 
 measure is afforded of a certain type of motor ability. But in 
 addition to this there is also afforded, which is more particularly 
 to the purpose of the test in hand, a measure of the physiological, 
 or motor time consumed in marking one hundred "a's." After 
 completing part one, the child was instructed to place a stroke 
 through the a's in the page print (see p. 51), as quickly as 
 possible, being sure to mark out every "a"; the instructions be- 
 ing uniformity as given above for deaf and hearing children 
 alike. A measure of the time required to perform this test was 
 also taken and a record made of the number of "a's" not marked. 
 
 It is readily apparent that at least two factors enter into 
 the selection and marking of "a's" as called for in this test; the 
 one a mental factor concerned in the several acts of discrimina- 
 tion in finding the "a's," and the second, physiological, having 
 to do with the motor task of making the marks. To disinte- 
 grate these factors and arrive at a measure of the purely men- 
 tal time actually involved in perception, is the point of chief 
 moment, to make the test of value in stating quantitative differ- 
 ences between individuals and groups. And this is acomplished 
 approximately . by subtracting the motor time gotten in the first 
 part of the test from the total time required to perform the sec- 
 ond part. This latter we shall call the "Perception Time" (P. 
 T.) in the discussions and tables. 
 
 There is one factor in connection with the "A-Test" which 
 makes the results awkward to handle. If every child marked out 
 all the "a's," differences in perception might be stated directly 
 in terms of the perception time. The fact is, however, that many 
 children fail to find all the a's, there being sometimes as many 
 as forty that the child does not see and mark out. Here, con- 
 sequently, are two variables, which thus far there has been found 
 no satisfactory way of equating in terms of each other. Thus 
 
DEAF CHILDREN 
 
 
 rt jj g 
 < 
 
 
 
 
 
 
 n 
 
 < 
 
 00 ■* 00 N in •* 00 p* t- o 
 
 
 
 
 1 
 
 XI 
 
 i a 
 
 Sis 
 
 
 
 
 
 a 
 
 < 
 
 o>lnc^-opHo6oo^ou^o 
 
 
 
 
 ll 
 
 a ^ 
 
 o'rt •-• >o m t- ^ (*i fH o 
 
 
 
 
 
 
 ■"SRRSSRSS" 
 
 
 
 
 
 
 lno.H.-^^o-u■iOOT^'J••>*■lrt^- 
 
 
 
 o sO 00 o 1^ r- Tf n n r» u^ ir, -* 
 
 
 
 < 
 
 oo-OrH{*)r-'*Tf-Moorouir- 
 
 
 
 isssasssssss"-- 
 
 
 s 
 
 ■Li 
 
 oxnuir»M-»-oa>r-NOooi/>M 
 
 Ui 
 
 1 
 
 
 -* * o r« 00 o r< ■* o* 00 in 00 r^ 
 
 
 S3 
 
 o-ooo'*NDooi-«t-ooo«r- 
 
 
 S 
 
 is 
 
 O'fH-OTrr-^^a'.HMOc 
 
 I- 
 
 
 gg&gssKSSffis^ 
 
 ^ 
 
 
 
 o-sOuiNpinc^ r-o*OMWiinn 
 
 
 
 sOO-OOOOj3-00£iOOO 
 
 
 
 
 
 
 
 
 
 
 
 
 r-orjo- o.-iriro-tu'ivot- 
 
 or 
 
 o- 
 
 
54 EXPERIMENTAL STUDIES 
 
 it is impossible to say, exactly, whether a child who has marked 
 out all the a's and whose perception time is 60 seconds, has bet- 
 ter or poorer ability, as regards this test, than the child whose 
 perception time is, say one-half as great — 30 seconds — but who 
 has failed to mark out ten or fifteen of the a's. A probable de- 
 termination of the efficiency of children in the test, however, 
 was secured by calculating from the time required to mark out 
 the a's in each case, the estimated time that would be required 
 to mark out 100 a's. That is, in the event that it took 170 sec- 
 onds to pick out 85 per cent of the a's, it was estimated that 
 200 seconds would be required to pick out all the a's. No cor- 
 rection, however, was made for a's overlooked in those cases 
 where at least 96 per cent had been marked. For the most part 
 the children were tested one at a time, and in no case were 
 there more than three children given the test together. 
 
 All the data from the "A-Test" available for statistical pre- 
 sentation will be found in the accompanying tables. (See Tables 
 XIV and XV.) The tables are sufficiently self-explanatory 
 to require little direction in reading off the data and their sig- 
 nificance. To facilitate comparisons with hearing children the 
 data from this group are placed in parallel columns with those 
 from the deaf. It is seen that there are indicated for each age: 
 (i) the number of children examined, (2) the average motor 
 time, and (3) the average perception-time (total time less motor 
 time), together with the average deviation of the individual rec- 
 ords from the mean or average of each group; also the number 
 of a's on the average not discerned. 
 
 Table XIV exhibits the data so as to show the relative num- 
 ber and per cent of deaf children of each age whose records 
 fall below the average or mean performance of hearing children 
 of corresponding ages. It is, indeed, the more telling of the two 
 tables, too, inasmuch as the influence of the small number of rec- 
 ords which make up the average of each group, and the skewing 
 tendencies of extreme records, loose their undue weight. 
 Motor Time — 
 
 We are not concerned particularly, with the question of 
 motor proficiency in the present instance, but it is worth while 
 in passing to note the comparative standing of deaf and hear- 
 
DEAF CHILDREN 55 
 
 ing children, respectively, in motor time as measured by the 
 first part of this test — a form of motor-ability test. The rela- 
 tive motor inferiority of deaf children stands out most clearly 
 during the earlier years, but it is by no means lacking for any 
 of the ages considered in these comparative measurements, since 
 at no age is the average motor time for deaf children as low as 
 for their normal hearing companions. Table XV shows the 
 relative motor inefficiency of deaf children, if anything, even 
 more conclusively. We find that at the age of seven the rec- 
 ords of all deaf children are poorer than the average for hearing- 
 children. At eight years of age, ii of i6, or 69 per cent of the 
 deaf make poorer records; at nine years, 9 of 15, or 60 per 
 cent; at ten years 20 of 26, or yj per cent, and when children 
 of eleven years are compared, again all rank lower than the 
 average for hearing children of the same age. Of the total 
 number of deaf children who performed this part of the test, 
 148 in all, 122 or 82.4 per cent, stood lower in motor efficiency 
 than the averages of the records for children with normal hear- 
 ing of comparable ages. The numbers are too few to warrant 
 closer mathematical treatment, and indeed such treatment is 
 unnecessary in the face of the data just offered. The reasons 
 for this manifest motor inferiority have already been com- 
 mented upon, and nothing requires to be added in this place. 
 Perception Time — 
 
 Again looking at Table XIV, in the columns headed "Per- 
 ception Time," differences between the two classes of children, 
 more pronounced than those shown in the 'Motor Time," are 
 observed. The time required by deaf children to pick out the 
 one hundred a's, on the average, ranges from almost twice that 
 required by hearing children at the age of seven, to more than 
 a third longer for the later years, fourteen and fifteen. For 
 none of the age groups is the average perception time of chil- 
 dren who have no hearing anything like as small as for chil- 
 dren who hear normally, though the difference between the two 
 groups progressively diminishes with increasing years. 
 
 Judging from this tendency of the difference in perception 
 time of the two classes to become less with age, it is not un- 
 
56 
 
 EXPERIMENTAL STUDIES 
 
 likely that were deaf adults and those with hearing examined 
 and compared little difference would be discovered. 
 
 Considerable variability is exhibited by the average devia- 
 tions of both groups, and a much greater amount of variability 
 among the performances of the deaf than of hearing children. 
 That the differences brought out by the averages of the two 
 groups, however, is real, is conclusively shown by the charac- 
 ter of the data shown in Table XV, where the number and per 
 cent of deaf children whose standings are inferior to the aver- 
 ages of hearing children of comparable ages are given. Thus 
 it is seen that at the age of seven years all deaf children pos- 
 sess a lower standing than the average for children who hear ; at 
 
 TABDE XV. 
 
 TEST PERCEPTION. 
 
 SUMMABY OF TABLE XIT. 
 
 Relative number and per cent of Deaf cMldren whose records stand lower 
 than the averages for their respective ages of Hearing children. 
 
 Motor time 
 
 Perception time 
 
 Age 
 
 Number 
 
 Number 
 
 Per cent 
 
 Number 
 
 Number 
 
 Per cent 
 
 examined 
 
 lower 
 
 
 examined 
 
 Lower 
 
 
 7 
 
 9 
 
 9 
 
 100 
 
 7 
 
 7 
 
 100 
 
 8 
 
 15 
 
 11 
 
 59 
 
 14 
 
 12 
 
 85 
 
 9 
 
 15 
 
 9 
 
 60 
 
 15 
 
 12 
 
 80 
 
 10 
 
 25 
 
 20 
 
 77 
 
 25 
 
 23 
 
 88.4 
 
 11 
 
 15 
 
 15 
 
 100 
 
 IS 
 
 11 
 
 73.2 
 
 12 
 
 9 
 
 9 
 
 100 
 
 9 
 
 9 
 
 100 
 
 13 
 
 17 
 
 12 
 
 70 
 
 16 
 
 12 
 
 75 
 
 14 
 
 9 
 
 7 
 
 78 
 
 9 
 
 9 
 
 100 
 
 15 
 
 20 
 
 18 
 
 90 
 
 20 
 
 15 
 
 75 
 
 16 
 
 12 
 
 12 
 
 100 
 
 12 
 
 8 
 
 66.7 
 
 All 
 
 
 
 
 
 
 
 agres 
 
 148 
 
 122 
 
 82-4 
 
 143 
 
 118 
 
 82.5 
 
 eight, 12 of 14, or 86 per cent; at nine, 12 of 15, or 80 per 
 cent; at ten, 23 of 26, or 88.4 per cent of the deaf require a 
 longer time to pick out from among four hundred other letters 
 the one hundred "a's" than the averages of their hearing com- 
 panions for comparable age-groups. Concerning deaf children 
 of all ages grouped together, we discover that 82.5 per cent, 
 118 of the whole 143 examined, have a longer perception-time 
 than the averages of children of the same ages not thus af- 
 fTicted. 
 
 When the number of "a's" not marked is taken into account 
 
DEAF CHILDREN 57 
 
 the results are in all essential respects comparable to those 
 above. (See Table XIV). Deaf children not only require a 
 longer time on the average to discriminate between the "a's" and 
 the remaining letters of the alphabet when they are intermin- 
 gled, as in the "A" Test, but they are also able to discriminate 
 less accurately than children whose ears function normally, as 
 is indicated by the greater number of errors, — "a's" overlooked, 
 — and this deficiency likewise extends to all ages. Indeed, if 
 we follow closely the results of the test, we are forced to say 
 that deaf boys and girls from twelve to fourteen show rela- 
 tively less discriminability than do those of the younger years. 
 The data regarding the A-Test are strikingly conclusive. 
 Deaf children,' on the average, are from two to three years less 
 mature than hearing children of the same ages in the kind of 
 ability that is called for in this test. And certainly this can not 
 be attributed to the fact that a certain kind of skill is called 
 for in the test, that the lack of school training from which deaf 
 children suffer would fully account for. On the contrary, it is 
 difficult to see how ordinary school exercises would conduce to 
 rapid and accurate symbol discrimination, except in the gen- 
 eral sense of leading the child to be more keen and alert in 
 meeting any general and unfamiliar situation. From other tests 
 and measurements, as well as from intimate association and 
 observation, we are forced to conclude that a relative imma- 
 turity of from two to three years, as compared with hearing 
 children, extends to all phases of the mental life of the deaf, 
 and no doubt, too, its cause is to be found in the natural alien- 
 ation which the minds of these children suffer by reason of the 
 sensory barriers that have been set against their intermingling 
 in the mental and social life of the communities in which they 
 were born and are maturing. 
 
 Perception of Size. 
 Shot Test — 
 
 The second test, which deals primarily with perception, had 
 for its object, as stated above, the determination of a child's 
 sensitivity as measured by the ability shown in discriminating 
 the sizes of small objects by the active exercise of the sense of 
 
58 EXPERIMENTAL STUDIES 
 
 touch. This end was brought about by using a series of light 
 canvas bags containing ordinary commercial shot of the fol- 
 lowing sizes: Nos. BB, B, i, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 
 12, dust shot. 
 
 The test had, like the foregoing test, grown out of the daily 
 duties and needs of the Department of Child Study, and had 
 been effectively used almost daily for four or five years, in the 
 regular series of tests and measurements given to normal and 
 abnormal children in the laboratory. 
 
 In conducting the test a child was first given a bag con- 
 taining the median-size of the series, or shot number 6, at the 
 same time another bag containing a size shot so large that 
 ordinarily little difficulty would be encountered in perceiving 
 the actual size-differences, after the child had rolled the shot- 
 bag between the forefingers and thumb. 
 
 It was found that in the case of very young deaf children 
 these ideas of comparison, "greater than," "less than," are 
 rather late in developing, and teachers of the manual alphabet 
 assert that such relational ideas are probably of all ideas the 
 most difficult to appreciate and express in communicable sym- 
 bols. With young children, especially those who had practically 
 no language, considerable patience and perseverance was found 
 necessary in order to have them get this conception of greater 
 and less associated with or abstracted from the objects or quali- 
 ties compared. Hence the necessity of using large differences 
 at the beginning of the test. These considerations are equally 
 pertinent to those perceptional tests dealing with the attempts 
 to determine and express differences of weights, which are con- 
 sidered later on. 
 
 As soon as a degree of familiarity was gained by the child 
 with the test and method of procedure, bags containing shot- 
 sizes of smaller differences from the median-size, number 6, 
 were presented and compared by him each in turn with the 
 standard, until each size, both larger and smaller than the me- 
 dian, was tested and a judgment expressed on the sensed differ- 
 ence. In each instance great care was exercised by the exam- 
 iner that there be no marks of identification on the bags examined, 
 nor acquaintance with any particular way in presenting the bags. 
 
DEAF CHILDREN 59 
 
 nor any other means or measure of the child's devising or dis- 
 covery which could interfere with the end desired, viz. : to deter- 
 mine the least difference, greater or less, than the median size, 
 number 6 shot, that might be accurately sensed under controlled 
 conditions. 
 
 Whether indeed the sizes of shot used in the series are 
 graded uniformly or not, is a question which need not concern 
 us, since it would be impossible to state, even though the actual 
 differences between the variously numbered shot were equal, 
 that the qualitative results obtained in the tests have absolute 
 significance, e. g., that one child has twice or three times the 
 sensitivity to tactual perception of size that another child pos- 
 sesses. 
 
 Below are given such measurements of the shot in diame- 
 ters, in both the English and metric systems, as are actually 
 necessary for a speedy application of the test: 
 
 It is admitted that this test is in itself a very complex proc- 
 ess, involving not only the ordinary skin sensations of touch, 
 but also calling into exercise the muscular and articular sensa- 
 tions. But this variety of sensory data, as well as further dif- 
 ferentiations due to individual variations, such as differences in 
 the thickness of the cuticle, and again lack of uniformity among 
 the subjects who were examined in relying upon the compo- 
 nent factors in the actual test of sizing — such, as for example, 
 may be brought about by one person's dependence in the test 
 upon pressing the shots between the fingers and thumb, while 
 another relies upon lightly rolling the contents of the bags — 
 will enter only remotely into the test from the point of view 
 herein taken, which is to determine whether deaf children, on 
 
 Size 2 
 
 3.70 mm. 
 
 0.146 inches 
 
 Size 3 
 
 3.15 mm. 
 
 0.128 inches 
 
 Size 4 
 
 2.99 mm. 
 
 0.1 18 inches 
 
 Size 5 
 
 2.89 mm. 
 
 0.1 14 inches 
 
 Size 6 
 
 2.79 mm. 
 
 0.1 10 inches 
 
 Size 7 
 
 2.66 mm. 
 
 0.104 inches 
 
 Size 8 
 
 2.36 mm. 
 
 0.093 inches 
 
 Size 9 
 
 1.83 mm. 
 
 0.076 inches 
 
 Size lo 
 
 1.75 mm. 
 
 0.069 inches 
 
 Size II 
 
 1.52 mm. 
 
 0.060 inches 
 
6o tXPERIMENTAL STUDIES 
 
 the average rank higher or lower than hearing children in this 
 very primitive and still in our day substantial mode of gaining 
 information. 
 
 The results of this test are presented in Table XVI. In this 
 the deaf children are compared directly with the hearing chil- 
 dren of their respective ages. The table is divided into two 
 main divisions, or parts. The main division on the left, for 
 both deaf and hearing, indicates the portion of the experiment 
 in which the standard is compared with shot of a smaller size, 
 and the other main division has reference to that part in which 
 the shot compared is larger than the standard. The sizes of the 
 shot sensed are given at the top of each column from I to XII, 
 and the results of comparative sensitivity under these headings 
 show the per cent of children who are able to sense one, two 
 and three size-dififerences. 
 
 As already indicated, differences in sensitivity of subjects 
 do not always run parallel to objective differences, but it is, 
 however, quite natural to make the inference that actual dif- 
 ferences in the sizes of shot discriminated measure to a degree 
 subjective differences in the sizing sensitivity of individuals, so 
 that a child who can discriminate size 6 from size 7, or size 6 
 from size 5, has a keener sense of touch than a child who can 
 only sense differences between two, three or more sizes. 
 
 Owing to the small number of cases, the girls and the boys, 
 respectively, are divided into three groups; first, those chil- 
 dren from 6 to 8 years; second, those from 9 to 12 years; 
 third, those between the ages of 13 and 18 years. The ages of 
 the groups are given in the first column of Table XVI, and in 
 the second column is presented the number of cases examined 
 in each group. For ready reference the recorded per cent of 
 correct answers in each instance is marked by Roman numerals. 
 Thus, in the third column, marked I, is recorded the per cent 
 number of children who correctly sensed a difference between 
 the sizes 6 and 7. In comparing, therefore, the deaf children 
 with the hearing of like ages, in this particular test, we exam- 
 ine columns I and IV, VII and X, for records of their re- 
 spective abilities in dealing. with one size; columns II and V, 
 VIII and XI, for differences of two sizes; and columns III 
 
DEAF CHILDREN 
 
 
 n 
 
 
 u 
 
 
 p 
 
 
 s 
 
 
 Eei 
 
 
 o 
 
 
 H 
 
 
 m 
 
 
 ^, 
 
 
 M 
 
 > 
 
 09 
 
 kj 
 
 tH 
 
 § 
 
 
 M 
 
 N 
 
 ■< 
 
 03 
 
 y 
 
 b 
 
 
 O 
 
 
 !? 
 
 
 O 
 
 *fl*-S 
 
 «ie 
 
 m-^i 
 
 
 CO** to « 
 
 *^C0^ to 0) 
 
 M^ tc V 
 
 4sa 
 
 
 
 S3K 
 
 
 
 
 
 
 CO eo S 
 
 ?ss 
 
 SSr 
 
 t-op6 
 
 
 <5i 
 
 
 
 ?SS 
 
^2 EXPERIMENTAL STUDIES 
 
 and VI, IX and XII, for the results secured when the test in- 
 volved actual differences of three sizes. 
 
 It is readily seen that at no age-group do so many deaf 
 children accurately sense small differences as their hearing 
 mates. Thus, in the 6 to 8 age-group of boys, 23.5 per cent 
 only of the deaf children gave correct answers in attempting 
 to sense a difference between sizes 6 and 7, whereas 60 per 
 cent of the hearing children of corresponding ages were able to 
 answer correctly (See columns I and IV), and in comparing 
 sizes 6 with size 5, the deaf and hearing children stand, re- 
 spectively, 21 and 80 per cents (columns VII and X). 
 
 Owing to the nature of the data in this Table, it is unnec- 
 cessary to discuss any more than the recorded abilities of the 
 children in dealing with differences of one size. (Columns I, 
 IV, VII, X). It is interesting, nevertheless, to note that where- 
 as 15.4 per cent of all deaf boys, in the age-group 9 to 12 
 years, are recorded as being able to perceive no smaller differ- 
 ences than three sizes (column III), there were no hearing 
 boys of the same age who were unable to detect size differences of 
 at least two. 
 
 It is, moreover, apparent that while sensitivity in this test 
 increases with age, there is a much greater increase observed 
 among the deaf boys and girls than among the hearing chil- 
 dren of comparable ages, for we see that the per cent stands, 
 respectively 23.5-42.3-56.2 and 21. -37. 7-56.2 for the deaf boys, 
 as against 60.-60.-78. and 80.-73.-67. for hearing boys (columns 
 I, VII, IV, X), and 40. -61. "1-60.7 on one-half of the Table, and 
 40-55.6-71.4 on the other half for deaf girls, as against 67.58.3- 
 70.6 and 44.-54.-83. for hearing girls (columns I, VII, IV, X). 
 
 Besides a discussion of the differences due to increased ages 
 of the deaf and hearing children, it is interesting to not* 
 whether our tables show any sex differences in this particular 
 test of sensitivity. It is apparent, to speak in general terms, 
 that deaf girls are more sensitive in this test than deaf boys, 
 while, on the other hand, among the hearing children, the ad- 
 vantage in sensitivity Hes with the boys. (See especially age- 
 group 9 to 12 years, for deaf and hearing boys and girls). The 
 reasons for this are, however, difficult to point out. It may, 
 
DEAF CHILDREN 
 
 63 
 
 indeed, be due to some fundamental difference between deaf and 
 hearing children; again differences of training and daily ex- 
 periences may affect their skill in reacting in this test, or we 
 may have to fall back on the observation that the number of 
 deaf children in each age-group is so small as to preclude 
 positive statements on this score. 
 
 For the very reasons, however, that the number of cases is 
 so comparatively small, and the data of the sizing-test are pre- 
 sented in terms of ranks of individuals, it is of some interest 
 to turn to the additional data subjoined, which show the num- 
 ber and per cent of children who are able to size differences as 
 
 TABLE XVIL 
 
 SIZING TEST (ACTIVE TOUCH). 
 
 Showing the number and the per cent of children who are able to sense 
 differences as indicated, the children being grouped without reference to age. 
 
 Deaf boys, all 
 
 Deaf etItIs, all 
 aees 
 
 Boys and eirls- 
 
 Heariner boys, 
 all aeres 
 
 Hearlner fflrls, 
 all ayes 
 
 Boys and firirls. 
 
 No. 
 
 of 
 
 cases 
 
 75 
 
 56 
 131 
 
 51 
 105 
 
 I. 
 Size 6 
 from 
 size 7 
 
 33, or 4456 
 
 32, or 57?i 
 65, or 50% 
 
 35, or 65?6 
 
 32, or 63JS 
 67, or 63.85S 
 
 II. 
 Size 6 
 from 
 size 8 
 
 38, or Sl% 
 
 21. or yj% 
 59, or 45* 
 
 19, or 35Ji 
 
 18, or 359i 
 37. or 35.236 
 
 III. 
 Size 6 
 from 
 size 9 
 
 4, or S% 
 
 3, or b% 
 7, or S% 
 
 1, or 2% 
 1, or 1% 
 
 IV. 
 Size 6 
 from 
 size 5 
 
 32, or 43% 
 
 34. or 61?i 
 66, or 50Ji 
 
 40, or 7436 
 
 32, or 6336 
 72, or 68-536 
 
 V. 
 Size 6 
 from 
 size 4 
 
 35, or 4736 
 
 19, or 3436 
 54, or 4136 
 
 12. or ■22% 
 
 18, or 3556 
 30, or 2836 
 
 VI. 
 Size 6 
 from 
 size 3 
 
 8, or 1036 
 
 3, or 536 
 
 11, or 936 
 
 2, or 436 
 
 1, or 236 
 
 3, or 336 
 
 indicated in Table XVII, where the children are grouped with- 
 out reference to age. In this Table XVII it is more than 
 ever apparent that deaf children, as a group, are not so sen- 
 sitive as hearing children. Giving exact statement, it is seen 
 that only 50 per cent of the 'deaf children sensed the smaller 
 size differences (See columns I and IV of Table XVII), where- 
 as 68.5 per cent, or at least 63.8 per cent of the hearing boys 
 and girls, accurately detected a difference of one size. Of 
 course, the qualification should be made that the number of 
 children in the different age-groups are not equal. However, 
 because there are more children in the older age-groups than in 
 the younger, and again since sensitivity is observed to increase 
 with age, whatever advantage there is, lies with the deaf chil- 
 dren. 
 
 Again, by reason of the further groupings of children 
 
64 EXPERIMENTAL STUDIES 
 
 which this table makes, the sex differences of the deaf and 
 hearing children, already alluded to, become more significant. 
 Taking the deaf first in order, it will be seen that 44 per cent 
 of the boys gave correct answers to the test on one side, below 
 size 6, and again 43 per cent of the whole group were correct 
 for a difference of one size above size 6, whereas the deaf 
 girls gave 57 and 61 per cent, respectively, correct. The deaf 
 girls, as a group, although inferior to their hearing sisters in 
 sensitivity, are not so much below as the deaf boys in this par- 
 ticular. The hearing boys stand 65 and 74 per cent for one 
 point's discrimination, while 63 per cent of the hearing girls, 
 as a group, show ability to perceive differences of one size above 
 or below the standard. Moreover, from internal evidence in the 
 table, the deaf and hearing boys seem more variable in abilities 
 than the hearing and deaf girls. 
 
 Least Noticeable Differences in Lifted Weights. 
 
 Turning now to the third perception test, we come to con- 
 sider the child's power to discriminate small differences in lifted 
 weights, where the lifting or hefting is done by a free, full-arm 
 movement, such as occurs when a child passes alternately from 
 one weight to the other in lifting them from a table, upon 
 which they have been placed. 
 
 For the test series small wooden bottles of uniform size and 
 dimensions were employed. So far as external appearances 
 go, they could not be easily distinguished the one from the 
 other. The bottles were loaded to the required weight with a 
 filling of shot. They were then packed with paraffin and cotton, 
 so as to prevent any movement of the contents within, after 
 which they were carefully sealed. The series ran at intervals 
 of two grams from a weight of 8 grams to one of 32 grams. In 
 order it stood, 8, 10, 12, 14, .16, 18, 20, 22, 24, 26, 28, 30, 32 
 grams. With the 16 gram weight, which was used as a point 
 of departure, or standard, weights heavier and lighter were com- 
 pared; the 16 gram weight and the one heavier or lighter than 
 it, having been placed upon a table before the child, and he 
 asked to heft them, one after the other, and to indicate which of 
 the two was the heavier. Care was taken, however, to keep the 
 
DEAF CHILDREN 65 
 
 child dependent upon actually sensed factors in hefting, and to 
 guard against his identification of the standard weight by extra- 
 neous signs. A comparable method of procedure was followed, 
 sometimes with weights heavier, sometimes with those lighter 
 than the standard, in irregular order, until the experimenter, 
 after several determinations around the standard weight, had 
 satisfied himself of the least noticeable difference in weight, 
 both lighter and heavier than the standard, that the child could 
 sense. 
 
 In recording the data it seemed best in indicate simply which 
 weights the child could discriminate, accurately and invariably, 
 from the standard, or i6 gram weight. 
 
 Consequently the tables, showing the comparative sensitivity 
 of deaf children for weight, like the preceding tables for siz- 
 ing, give the results in terms of the number and per cent of 
 boys and girls who were able to distinguish between (i) a 
 weight of 16 grams and one of i8 grams, (2) one of 16 grams 
 and one of 20 grams, (3) one of 16 and one of 22 grams on the 
 one side of the standard, and between (4) weights of 16 and 14 
 grams, (5) 16 and 12 grams, and (6) 16 and 10 grams, re- 
 spectively, on the other. 
 
 Such data as we were able to collect are recorded in Table 
 XVIII, arranged so as to show sex differences, and the com- 
 parative standing of deaf and hearing children, respectively, of 
 comparable ages. As in the preceding test, because of the pau- 
 city of numbers, it was deemed advisable to somewhat arbi- 
 trarily group the records according to age. Thus, in the first 
 group, we placed the records of the boys and girls ranging in 
 ages between 6 and 8, inclusively; in the second, the preadoles- 
 ents (9 to 12 years), while the last group is composed, for the 
 most part, of children beyond the age of puberty (13 to 18 
 years, inclusively). 
 
 Inasmuch as the primary interest in comparing hearing and 
 deaf children, with respect to this test, centers about the least 
 perceptible difference in weight, which, on the whole, the 
 groups, respectively, are able to sense, it is with the 
 parts of the data which indicate the number and per cent of 
 children making the smaller discriminations, that we are chiefly 
 
66 EXPERIMENTAL STUDIES 
 
 concerned. Indeed, since the figures are, for the most part, 
 mutually exclusive, in casting up age, sex and group compar- 
 isons, we need consider only the data found in the columns in- 
 dicated by the Roman numerals I, IV, VII and X. 
 
 Examining critically now the data in the columns indicated, 
 it is to be noted that for the younger years (6 to 8) deaf boys 
 are rather strikingly inferior to their hearing mates in this 
 sense, while the converse holds in the case of the girls. In the 
 i6 and i8 gram set, 66.7 per cent of deaf boys were able to 
 make the discrimination invariably, as against 80 per cent of 
 the hearing boys. The figures for deaf and hearing girls are 
 66.7 per cent and 44.4 per cent, respectively. In the 16 and 14 
 gram set again 66.7 per cent of the deaf boys always rendered 
 correct judgments, while 100 per cent of the hearing boys were 
 able to do. so. For deaf girls the figure is 71.4 per cent, against 
 66.7 per cent for hearing girls. The number of hearing chil- 
 dren, especially at these ages, is unfortunately small, so that 
 too much weight cannot be attached to the results. 
 
 In the next age-group (9 to 12 years) the numbers are lar- 
 ger, and the conclusions consequently a little more reliable. 
 Deaf boys now rank in muscular sensitivity above hearing boys, 
 the per cents being, for the 16-18 gram pair 88.4 and 74, re- 
 spectively, for the deaf and hearing boys, and for the 16-14 
 gram pair, 77.3 and 72, respectively, for the groups considered. 
 Between deaf and hearing girls of this age-group, the differ- 
 ences are discovered to be inconsequential. The figures for the 
 16-18 gram pair are 53.3 and 54.0 per cent, respectively, and 
 for the 16-14 gram pair of weights, 64.2 and 58.3, per cent. 
 
 The groups of adolescents (13 to 18 years) are not so large; 
 but differences between the groups in the mental attitude in 
 which the test would be approached, ought to be less signifi- 
 cant than for the younger ages. (If this factor actually enters 
 into the test.) So far as the results go, no significant differ- 
 ences in muscular sensitivity between deaf and hearing boys 
 or deaf and hearing girls stand out. Deaf boys rank lower in 
 the 16-18 gram set than hearing boys, as is shown by the rela- 
 five per cents who invariably rendered correct judgments, 60 
 per cent of the deaf and 66.7 per cent of the hearing boys, but this 
 
DEAF CHILDREN 
 
 67 
 
 > a 
 
 n o 
 
 •3 
 .s 
 
 u 
 
 XII. 
 16 firms. 
 
 from 
 10 s^ms., 
 per cent 
 
 
 ■ in 
 
 
 
 
 
 
 
 
 
 rot--* 
 
 
 000 
 
 
 1 
 
 p 
 
 2 - "^c 
 
 3^ 
 
 
 
 
 
 VIII. 
 16 enms. 
 
 from 
 12 firms., 
 per cent 
 
 orto 
 
 >O00rt 
 
 ^ -H ft 
 
 t-rjo 
 
 
 1 
 
 =3 
 
 ■3 
 
 .S 
 
 H 
 
 2 - « fl 
 
 i 
 
 
 
 2 rj 
 
 5 -^ 
 
 
 
 2 - « S 
 
 OOro 
 
 ■*©■* 
 
 5^a 
 
 2 - « « 
 
 
 *0^0 
 
 OS 
 
 as 
 
 ""S^S 
 
 =^SS 
 
 •3 
 1 
 
 
 
 ; -+ 
 
 
 
 
 
 
 MOO 
 
 sis 
 
 2 - " ^ 
 
 SS8S 
 
 t-fon 
 
 s 
 ^3 
 
 ^?3S 
 
 ''"IhS 
 
 
 1 
 
 oc 
 
 
 
 oc 
 
 
 
 
 
68 EXPERIMENTAL STUDIES 
 
 inferiority is compensated for in the 16-14 gram pair of weights, 
 where the per cent of deaf who sensed a difference was 64 as 
 against 61 for the boys with hearing. In the case of the girls, 
 the deaf have a slight advantage in the 16-18 gram pair, 78.3 
 per cent making correct judgments, as opposed to 70.6 per cent 
 of the hearing girls, but with the 16-14 gram set 69.6 per cent 
 of the deaf girls invariably gave correct replies and 70.6 per 
 cent of the hearing girls. 
 
 Looking for differences between the boys and girls as re- 
 gards sensitivity for lifted weights, among deaf children it is 
 discovered that for the younger years, the sexes do not differ 
 very significantly, the same per cent of boys and girls sensing 
 a weight difference between 16 and 18 grams, and only a slight 
 advantage being shown in favor of the girls in the 16-14 gram 
 set. Among hearing children of the same ages, on the con- 
 trary, the boys show up markedly better than the girls, 80 per 
 cent sensing the difference in the 18-16 gram set, and icx3 per 
 cent in the 16-14 gram set, as against 44.4 per cent and 66.7 per 
 cent, respectively, for the two sets, in the case of the girls. 
 
 Comparing the sexes in the second age-group (9 to 12 years 
 old), we find the boys uniformly better both as regards deaf 
 and hearing children. The figures run as follows : 
 
 Deaf. Hearing. 
 
 
 16-18 set. 
 
 16-14 set. 
 
 16-18 set. 
 
 16-14 set. 
 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 Per cent. 
 
 Boys 
 
 , ... 88.4 
 
 77-3 
 
 74.0 
 
 72.0 
 
 Girls 
 
 53-3 
 
 64.2 
 
 54-0 
 
 58.3 
 
 Conditions are reversed when we turn to the older group 
 of boys and girls, those between the ages of 13 and 18 years, as 
 may be seen from the following summary: 
 
 Deaf. Hearing. 
 
 16-18 set. 16-14 set. 16-18 set. 16-14 set. 
 Per cent. Per cent. 
 
 Boys 60 64 
 
 Girls 78.3 69.6 
 
 Thus, although some sex differences were discovered, when 
 age groups were considered separately, taken all together the 
 group tendencies counteract one another, so as to obliterate any 
 
 Per cent. 
 
 Per cent. 
 
 66.7 
 
 61.0 
 
 70.6 
 
 70.6 
 
DEAF CHILDREN 
 
 69 
 
 conclusive evidences of such tendencies in one direction or an- 
 other. 
 
 Looking for differences in sensitivity that might come with 
 increased age, the data also offer nothing very promising. The 
 16-18 set does show such a tendency in the case of the hearing 
 girls, but the exact converse is shown, with both this weight set 
 and the 16-14 gram set in the case of the hearing boys; The 
 data for the deaf are altogether too irregularly distributed to 
 warrant any general conclusion. A larger representation in each 
 age-group, however, might bring out some decided evidence of 
 improvement in the weight sensitivity with age, but it is equally 
 likely that the responsible factor is the elementary nature of the 
 test. 
 
 PHRiCBPTION OP WEIGHT (ACTIVE). 
 
 BKIEF SnMMABY OF TABLE XTIII. 
 
 Deaf boys, fill ages- . ■ 
 Deaf srirls. all apes . ■ ■ 
 Soys and ?irls (deaf) ■ 
 
 No. of 
 cases 
 
 62 
 47 
 109 
 
 16 8TS. from 
 
 18 gTS., 
 
 per cent 
 
 71 
 
 68.1 
 
 69.7 
 
 16 £rrs. from 
 14 arrs., 
 per cent 
 
 69.3 
 68.1 
 68.8 
 
 Eearin? boys, all ases . . 
 Hearing ?irls, all aeres - 
 Boys and girls (hearingr) 
 
 55 
 50 
 105 
 
 72.9 
 58.0 
 65.7 
 
 70.9 
 64.0 
 67.6 
 
 In the foregoing discussion, because the numbers at each 
 age are so small, the children were placed in three groups, and, 
 to a degree, the disadvantages due to small numbers were over- 
 Come, though, to be sure, not wholly obviated. There are sev- 
 eral advantages, therefore, in comparing the deaf boys and girls 
 as a whole, irrespective of age, with hearing boys and girls 
 under like conditions, as well as to compare our deaf children 
 as a whole, with their hearing companions. The results of such 
 groupings are presented in Table XVIII (Summary), and we 
 accordingly see that, in sensing a difference of two grams be- 
 tween two lifted weights, 71 per cent and again 69 per cent of 
 the deaf boys gave correct responses, as against 73 per cent and 
 71 per cent of the number of hearing boys examined. Further, 
 68 per cent and again 68 per cent of all deaf girls correctly 
 sensed a difference of two grams, whereas only 58 per cent and 
 64 per cent of the hearing girls were equally sensitive. Finally, 
 
70 EXPERIMENTAL STUDIES 
 
 in the group representing boys and girls, we see in comparing 
 the deaf children with hearing children in this test that 70 per 
 cent in one instance and 69 per cent in the other case, of all the 
 deaf girls examined, accurately sensed the actual differences of 
 two grams in the weights presented, whereas 66 per cent and 
 again 68 per cent of the whole number of hearing girls ex- 
 amined, were able to note the same differences. Deaf girls, 
 therefore, as a whole, irrespective of age, rank better than their 
 hearing sisters, but, on the contrary, deaf boys rank more poor- 
 ly, and, taking boys and girls together, irrespective of age, 
 while the advantage lies slightly with the deaf, their superiority 
 over their hearing companions is not sufficiently marked, con- 
 sidering the paucity of numbers, to warrant us in asserting that 
 the difference is real. 
 
 Memory. 
 
 Among the different materials employed for testing the im- 
 mediate sense-memory, the ordinary Arabic numerals must be 
 considered among the best, both from the point of view of con- 
 venience and reliability of results. Numerals are symbols used 
 in our civilization, and inasmuch as they are in themselves rel- 
 atively non-significant, they can be employed readily in making 
 a comparative study of one kind of memory. A numeral is not 
 liable to have more associations with one individual than with 
 another. To test the visual sense-memory, cards on which were 
 placed in rows the ordinary Arabic numerals were held before 
 the child, after which the cards were removed and the child 
 was required to reproduce the numerals which were seen, in the 
 exact order in which they appeared on the cards, either orally 
 or in writing. In order to avoid groupings the child read the 
 numerals from right to left, and the greatest number which he 
 could accurately reproduce was considered a measure of his vis- 
 ual sense-memory. In the second part of the test the numerals 
 were repeated to the child by the experimenter, care being taken 
 that there should be no rhythm which could induce groupings; 
 and the child reproduced the numerals as before. 
 
 The test thus consisted of the two parts (i) pure visual 
 sense-memory, (2) indirect visual-memory, read from the lips 
 of the experimenter. This latter also afforded a test of the 
 
DEAF CHILDREN 
 
 71 
 
 child's ability to read unrelated word-symbols from the lips of 
 the speaker. 
 
 TABLE XIX. 
 
 MEMORY SPAN. 
 
 Afire 
 
 Number 
 
 Visual 
 
 Lip readiaff 
 
 Yrs. Mos. 
 
 Deaf 
 
 Normal 
 
 Deaf 
 
 7 6 
 
 8 6 
 
 9 5 
 
 10 6 
 
 11 6 
 
 12 6 
 
 13 6 
 
 14 6 
 
 IS b 
 
 16 6 
 
 17 6 
 
 18 6 
 
 19 6 
 
 10 
 13 
 
 13 
 
 17 
 
 12 
 
 7 
 
 12 
 
 12 
 
 17 
 
 6 
 
 4 
 
 2 
 
 3.3 
 3-3 
 3.7 
 4.1 
 4.4 
 4.7 
 48 
 5.2 
 4.9 
 5.7 
 5.5 
 5.0 
 5 
 
 5 
 5 
 6 
 6 
 6 
 
 8 
 
 3.2 
 3.0 
 3.1 
 3.7 
 4.0 
 4.4 
 4.2 
 4.7 
 4.3 
 4.3 
 4.7 
 4.0 
 5-0 
 
 In Table XIX are given the memory spans of deaf and nor- 
 mal hearing children in parallel columns. It is seen that where- 
 as the hearing child of from seven to eight years has, on the 
 average, a memory span of five numerals, the deaf child has 
 a memory span of but three numerals, and while the hearing 
 children from 12 to 19 years of age have, on the average, a 
 memory span of seven numerals, the deaf children can remem- 
 ber but four or five. It is further seen that there is but a slight 
 superiority when the numerals are directly seen in comparison 
 with the indirect reading, or reading from the lips. This offers 
 a suggestion that lip-reading has kept pace with the child's 
 general development. 
 
 Taking all these tests and observations together for the 
 purpose of estimating the mental status of the deaf children, we 
 see that it is possible to get a general view of their compara- 
 tive abilities with respect to particular mental powers. But when 
 these mental functions are all taken together they do not ex- 
 haust the content of such a highly complex thing as mentality. 
 It is necessary always to bear in mind what we really mean in 
 everyday life by mental capability or mentality. Is it the abil- 
 ity to speak, to read, to write, to follow directions, carry on or- 
 dinary functions of life without assistance, or does it mean 
 the capacity an individual has to improve by training and prac- 
 tice and the relative facility with which training can be accom- 
 
72 EXPERIMENTAL STUDIES 
 
 plished? With the deaf child we necessarily must place more 
 emphasis on the latter, i. e., the teachableness of the individual. 
 Sometimes he cannot speak, read, write or follow directions as 
 given by us, because he lacks the symbols — language, the me- 
 dium by which we, as hearing individuals, indicate directions. 
 And until he learns the symbols and the meanings attached to 
 them it is impossible to test him by such standards. Such a pro- 
 cedure would be as unfair as to give the unclassified man direc- 
 tions in Greek, and then classify him as mentally deficient be- 
 cause he was unable to follow them. 
 
 Therefore, the chief criterion used in testing the mentality 
 of the children in the deaf rooms was their amenability to train- 
 ing. The question put to ourselves was this: Has the child 
 sufficient mentality so that, with the training he shall receive in 
 school, he will be partially or wholly self-supporting when he has 
 reached maturity, or will he likely become a ward of the State? 
 
 Such a criterion naturally gives us three somewhat distinct 
 classes, which may be called: 
 
 1. Mentally Normal: Those who will be wholly self-sup- 
 
 porting at maturity. 
 
 2. Slightly Sub-Normal: Those who will not be, in all proba- 
 
 bility, wholly self-supporting when they attain to man- 
 hood and womanhood, but may require some external 
 direction in any occupation which they may take up, or 
 in the general conduct of life. 
 
 3. Those who will probably require direction and care, and 
 
 hence must be regarded as wards of the State. 
 We find, then, that as thus classified, the deaf children are 
 distributed in the following order, and these ratings are made 
 partly on the basis of the personal judgment of the examiner — 
 being the result of an hour's careful inspection of the child's 
 work — but more particularly based on the child's performance 
 in the mental tests given : 
 
 Number of Normal Mentality 173 
 
 Number Slightly Retarded or Sub-Normal 11 
 
 Number Mentally Defective, or of those who do not give 
 promise of being at least partially self-supporting at 
 maturity o 
 
 Total number examined 184 
 
DEAF CHILDREN "J^ 
 
 It is thus seen that of the total number of 184 children in 
 attendance at the deaf schools, only 11, or 6 per cent, are so 
 backward mentally that they do not give hope of being able to 
 support themselves independently after they have reached the 
 ages of manhood and womanhood, and further, there is not a 
 single individual whom it seems the State will have to take 
 over as a ward.* It may be noted that this number, 6 per cent, 
 of the group of deaf children who are accounted as Sub-Nor- 
 mal, is considerably higher than we find among all school chil- 
 dren, among whom 5 or 6 per thousand are regarded as dis- 
 tinctly Sub-Normal in the very technical use of the word. This 
 rather large number is doubtless intimately related to, if not, 
 indeed, caused by, the diseases and disorders that bring about 
 impairment of hearing in such a large number of the deaf chil- 
 dren. 
 
 ♦This does not mean tbat tbere are no mentally-defective and 
 feeble-minded children among the deaf In Chicago, but that in the pre- 
 liminary examination of deaf children, toy this Department, for admis- 
 sion to the rooms for the instnietion of the deaf, the parents of those 
 who were too low a grade of mentality to profit by such instruction as 
 the public schools afford, were advised to send their (Jhildren to institu- 
 tions where special province is the care of such cases. In no case were 
 feeble-minded childi'en permitted to enroll in the classes for the deaf. 
 
SUMMARY AND SUGGESTIONS. 
 
 In making a brief resume of the study heretofore presented 
 in detail, the attempt will be to give the results in barest out- 
 line only and then add the suggestions which come to mind as 
 a consequence of these results. 
 
 It was pointed out that the intimate relation between the 
 mental and physical life of children made it necessary, if the 
 study should be full and complete, that these aspects of the 
 child's life should receive careful consideration. Further, by 
 way of introduction, it was indicated that owing to the extreme 
 timidity and narrow social life of deaf children, time, patience 
 and skill were required in order to elicit any responses which 
 would be indicative and characteristic of this type of children. 
 
 The hearing ability of the deaf was found to vary by degrees 
 from absolute silence and insensibility to any sounds whatever, 
 to a condition of semi-deficiency where the auditory acuity was 
 too defective for the child to carry on his work in the grades 
 with hearing children, i. e., it was found that deaf children do 
 not form a distinct group. There are all grades of hearing 
 power and the classification night better be based on the use 
 which the power of hearing serves in social communication. 
 
 It was found that only thirty-two per cent of the whole num- 
 ber of deaf children were totally deaf ; nineteen per cent were 
 found to be practically deaf, that is, they gave no hope of ever 
 being able to hear the human voice, even with the aid of mechan- 
 ical instruments. There were thirty per cent who were unable 
 to hear speech, but could hear loud noises. This and the next 
 group, which contains fourteen per cent, who could hear loud 
 speech, form a class which may for certain purposes be grouped 
 together. In comparing the intensity of the noise which some 
 of these children are able to hear, with that which some adults, 
 whose hearing became impaired after maturity, are capable of 
 appreciating and responding to intelligently, it is found that 
 there are deaf children who hear no speech at all whose absolute 
 hearing power is superior to that of some of those who hear and 
 
DEAF CHILDREN 75 
 
 depend on speech. This diiference in speech-hearing abihty 
 seems to be due entirely to the absence of the habit of attention 
 to the significance of sound-sensations on the part of deaf chiU 
 dren. These considerations oiler the suggestion that if some 
 means were employed of intensifying speech-sounds and in this 
 way create the habit of attending to sound sensations of speech, 
 in many cases the hearing of the deaf children might be so im- 
 proved that to a considerable extent they could be made depend- 
 ent on hearing in carrying on social intercourse. Of course, such 
 a habit could not be developed short of many months of training 
 and for this reason we found it impracticable to make the test of 
 the value of any apparatus on the market for this purpose. Differ- 
 ent devices of hearing apparatus are very highly recommended, 
 but we are not aware that any of these have been extensively 
 tried anywhere in Chicago. Not having given any apparatus 
 for developing the power of hearing a careful and crucial test, 
 the Child Study Department does not therefore feel justified in 
 recommending any particular form or device, but we do think 
 that some apparatus should be given a trial, especially since 
 twenty per cent of all children in attendance at different rooms 
 for deaf children give the hope of having their hearing sufficient- 
 ly improved to hear conversation. 
 
 Passing to the part of the investigation relating to the speech 
 and speech-reading of the deaf, the main consideration in rela- 
 tion to the time that had been spent in acquiring it, was the 
 character of the speech. Necessarily the character of the deaf 
 child's speech depends on the amount of training he has received. 
 This aggregate of training, in a great majority of cases, can be 
 measured by the time the child has been in school. Waiving all 
 consideration of those children who possess sufficient hearing to 
 enable them to speak in the natural way and those who lost their 
 hearing after they had learned to speak, thus limiting ourselves 
 to those who are born deaf and to those who lost their hearing 
 early in life, we find that after a period of three years in school, 
 twenty-five per cent have speech which is normal, or nearly so; 
 there are fifty-three per cent whose speech is defective and twen- 
 ty-two per cent in whom speech is practically wanting, i. e., less 
 than fifty words. 
 
76 EXPERIMENTAL STUDIES 
 
 To repeat here, for the sake of clearness, a statement made 
 in the body of the report, when we speak of a deaf child's speech 
 as normal, we mean that his articulation and tonal quality are 
 good, but not that his range of vocabulary is equal to that of a 
 hearing child of the same age. A latitude in this particular 
 must be allowed of from three to five years. After a school 
 period of five years we find that forty-two per cent of those 
 born deaf or those who lost their hearing early in life, have 
 speech which is normal or nearly so, fifty-eight per cent have 
 speech which is more or less defective and not a single indi- 
 vidual was found who could not intelligently talk at least fifty 
 words. At the end of seven years of school training forty-seven 
 per cent were found to have normal speech and fifty-three per 
 cent with speech somewhat defective. Only four individuals 
 had been in school as long as ten years. Of these one had some 
 hearing; the other three, congenital cases, were found to have 
 speech which was normal. 
 
 From the foregoing it appears that at least where conditions 
 ■obtain as they do in our day schools for deaf children, more than 
 three years of training is necessary in order that the average 
 deaf child shall acquire speech, but that almost every child (so 
 far as our results indicate) is able to learn the use of speech 
 and speech-reading after a school period of five years. 
 
 It is unfortunate that the school has no control of the home 
 and social conditions of children and especially the deaf. If it 
 were possible to control, in a measure, the food, rest, exercise 
 and language environment of the deaf child, and if it were pos- 
 sible to enlist the co-operation of parents in employing school 
 tnethods of communicating with their children, whatever these 
 methods may be, the acquirement of any language would be 
 greatly facilitated. In fact, it is found to be so with the method 
 ■now in use, in those homes where parents are eager to learn and 
 adopt the school room practices. Children from better homes, 
 it was observed, were from two to four years in advance of those 
 who came from less favored homes. However, it is doubtful 
 whether many consider the time element as after all the factor 
 of paramount importance. Probably the most vital consideration 
 is whether the great majority of deaf children or all deaf chil- 
 
DEAF CHILDREN "JJ 
 
 dren can acquire speech even after ten years of training, and if 
 (as shown by the results of our investigations) all children, after 
 they have been in school from five to ten years, do gain a suffi- 
 cient mastery of speech to carry on intercourse with hearing, 
 people, then the question arises whether the oral method be of 
 more service to them than the manual in the succeeding forty 
 or fifty years, while they are earning a livelihood and are getting 
 the most out of life that it has to offer. But as before men- 
 tioned, the problem of the relative value of oral or manual lan- 
 guage as a means and medium of intercourse in the social and 
 industrial world is one which it was impossible for us to evaluate 
 and on this account we prefer to leave it untouched. 
 
 There are, however, certain suggestions that refer more spe- 
 cifically to those who are engaged in teaching the deaf, which 
 we feel ought to be made.. Where oral speech is to be taught, 
 it is undoubtedly the part of wisdom to take cues from nature's 
 ways of dealing with normal hearing children. Every effort 
 should be made to ascertain as early as possible in the life of 
 these children the nature and degree of deafness, together with 
 the causes which brought about the defect, so that perchance 
 something may be done to remedy or improve the conditions. 
 In the case of the congenital deaf and those who lost their hear- 
 ing before the middle of the second year, the ideal procedure 
 would be to have instruction begin as nearly as possible after 
 the time that speech tendencies normally develop.* It is one of 
 the laws of instinctive behavior that if tendencies to activity are 
 not utilized at the time they appear in nature's program, they 
 fade and the activity must be developed anew at the expense of 
 considerable effort, and there is no reason why this does not 
 apply to speech as well as to other human activities. Whether 
 kindergartens should form a part of the public school system of 
 education for the deaf is a matter pertaining wholly to public 
 policy and administration, but certain it is that those few chil- 
 dren now in the deaf schools who have had the advantage of 
 early instruction are far in advance of the less favored chil- 
 dren in their power to adjust themselves to the educational force* 
 at work in our social life. 
 
 •Of. Kerr Archives of Crtol. 33 : 129. 
 
78 EXPERIMENTAL STUDIES 
 
 The important part which hearing plays in the acquiring of 
 speech is another element that cannot be too much emphasized. 
 By all means advantage should be taken of the hearing, power 
 which the child has, however little this may be. Especially im- 
 portant is this in the case of those children whose hearing be- 
 came impaired through disease after speech had been acquired. 
 Unless the hearing factor is utilized, there is a tendency for con- 
 fusion to result from the inability of the child to distinguish the 
 hearing images from the imperfectly formed visual images. (Of 
 course reference is here made only to language images.) 
 
 In the matter of sight, which is so overwhelmingly impor- 
 tant in the life of the deaf child instructed in the oral method, 
 who must depend on this sense almost entirely, the investigation 
 showed very happily that the visual acuity of the deaf is on the 
 whole as good as that of the hearing children. Nor is the rela- 
 tive number of those suffering from decidedly defective vision 
 greater in the former group than it is in the latter. The sug- 
 gestion is pertinent here that the eyes of the deaf children should 
 receive frequent testing so as to obviate any permanent impair- 
 ment of vision which may result in consequence of eye strains. 
 
 In comparing the stature of the deaf with that of hearing 
 children, it was discovered that both deaf boys and deaf girls 
 were, on the whole, shorter in stature for corresponding years, 
 and both sexes among the deaf have shorter bodies in proportion 
 to the total height, than hearing boys and girls. With respect to 
 weight, deaf boys were slightly lighter, on the whole, than their 
 hearing fellows, but on the other hand, deaf girls were slightly 
 heavier, age for age, than hearing girls. Deaf children in gen- 
 eral, of both sexes, were found to have smaller heads than nor- 
 mal hearing children, when as a criterion of size, the length- 
 breadth product is employed. On the average, too, they were 
 more brachiocephalic (broader headed.) 
 
 The most striking comparative inferiority of the deaf was 
 fwinted out in connection with the data on lung capacity. Deaf 
 boys as a group, it was seen, stood about on a par with the 
 twenty-five percentile group of hearing boys ; and the deaf girls 
 had about the same rank as the thirty-five percentiles of their 
 hearing sisters. In general average, deaf boys and girls rank 
 
DEAF CHILDREN 79 
 
 seventy-five and eighty-five per cent, respectively, of the norms 
 for hearing children of their respective sexes. It is thus seen 
 that the efifect of sedentary life is especially marked in diminish- 
 ing the vital capacity of the deaf. Of course, speech normally 
 has a tendency to develop lung power, but the deaf child suffers 
 from the deprivation of this as well as from the deficiency of 
 physical exercises, so that his blood is insufficiently aerated and 
 oxydized, giving rise to anaemic conditions with all their attend- 
 ant evils. 
 
 Taking as a measure of strength, the ability to compress an 
 adjustable dynamometer, with each hand separately, it was found 
 that deaf boys, although slightly stronger than hearing boys 
 during their younger years, with the on-coming of adolescence, 
 showed a marked inferiority, and this was equally palpable in the 
 case of the less used and stronger hands. Between deaf and 
 hearing girls no significant difference stood out, and this, as 
 previously intimated, is but natural to expect. Hearing girls 
 are much less given to activity, as a whole, than hearing boys, 
 but that between hearing and deaf girls is probably not such as 
 to carry significant weight. Further, in the way of indicating 
 strength differences between the two groups of children, may 
 also be employed the grip indices, i. e., the fraction which the 
 weaker hand is of the stronger in each individual case, on the 
 average. Here again, there was found to be no significant dif- 
 ference between the grip indices of deaf arid hearing girls; on 
 the contrary, deaf boys were found to be less ambidexterous, 
 during the pre-adolesent years, but more ambidexterous after 
 the age of maturing, than hearing boys. 
 
 Taking as another measure of bodily efficiency, the quickness 
 with which a child is able to perform voluntary co-ordinated 
 movements as determined by the number of taps which can be 
 made in thirty seconds, it was found that at no age was the 
 average for deaf boys equal to the average of hearing boys, 
 with the right hand, and with the left hand the difference in 
 motor ability in favor of the hearing boys is still more apparent. 
 Deaf girls in the case of both hands, were found strikingly in- 
 ferior to hearing girls, and at no age is the average performance 
 of the deaf significantly higher than that of their hearing sis- 
 
8o EXPERIMENTAL STUDIES 
 
 ters. It was further noted that both deaf boys and deaf girls 
 of 12 years and older more nearly approached the standings of 
 hearing children in tests of motor ability than the deaf of young- 
 er years. Furthermore, while the grip indices showed deaf boys 
 approaching maturity only, to be more ambidexterous than hear- 
 ing boys, the motor ability indices showed that the deaf of both 
 sexes, at all ages, are more ambidexterous on the average than 
 their hearing companions. It may be added, too, that this latter 
 index is, all in all, a better criterion of manual selectiveness than 
 that of grip. The relative standing then, of deaf children as a 
 class, in comparison with hearing children, was found to be even 
 less favorable, where rapidity of movement is involved, than was 
 apparent in the measurements of stature and weight, and only 
 slightly better than their relative standing in lung capacity. 
 
 By way of accounting for the more favorable showing of 
 the deaf children of more mature years, it was pointed out that 
 there seemed to be some intimate relation between an increased 
 variety of mental content and growth in motility, that is, accord- 
 ing to this view we should expect, with increased mental train- 
 ing, a greater degree of motor activity. By this indirect means, 
 therefore, the outflow of significant motor energy is enhanced. 
 But the problem of increasing bodily efficiencies should be at- 
 tacked directly. Certain provisions should be made to develop 
 the bodies of the deaf children. Their tendencies to be inert and 
 inactive should be counteracted or overcome. Considerable en- 
 couragement or stimulation is necessary to bring about continual 
 increase in bodily activity in order that their movements may ap- 
 proach that free and unstrained type of the normal hearing chil- 
 dren in their plays and home life. These large, free and easy 
 movements have, besides the advantage of developing and main- 
 taining the physical tone, the added value of furnishing stimula- 
 tion to mental growth. On this account, deaf children should be 
 encouraged to participate in the spontaneous out-of-door games 
 of hearing children as far as they are able, i. e., the plays of 
 the door-yard and of the street. Likewise, the periods of desk 
 work in the schools, especially for children under 12 years of age 
 should be as short as possible and the emphasis should be placed 
 
DEAF CHILDREN 8l 
 
 upon the gross physical activities which are called into play in 
 their marches, games and constructive arts. 
 
 In turning to the more distinctly mental features of the in- 
 vestigation, the results show the deaf to be equal to normal hear- 
 ing children in the more elementary functions, such as imitation 
 and suggestibility, which are, to be sure, extremely elementary 
 and fundamental in character, but in the higher functions they 
 were found to be generally inferior. In the first test, for which 
 measurements were received — the "A-Test" — deaf boys as well as 
 deaf girls of all ages, are found to rank from three to four years 
 below hearing children, both as regards the time of discrimina- 
 tion and accuracy, in selecting one symbol from others of its 
 kind in a page of printed matter. A smaller per cent of deaf 
 children of both sexes than hearing children were found to be 
 able to discriminate the smallest differences in size, and in heft- 
 ing or sensing small differences in weight, probably no differences 
 obtain between the two classes of children. Deaf boys were 
 found to be slightly inferior to hearing boys in general, whereas 
 deaf girls were discovered to be generally superior to the hear- 
 ing. Discriminations made in the latter test (weight) are based 
 on shocks of differences into which a comparison with a con- 
 scious standard weight-image is not thought to enter, in spite of 
 many contentions to the contrary, that is, the sensory data are 
 relatively less complicated than are those which enter into the 
 sizing test, and hence the weight test, like those of imitation and 
 sensibility, would be less liable to indicate individual differences 
 than the test calling for discrimination of size. 
 
 With regard to immediate sense-memory, which was the 
 only aspect of that important function which it was found prac- 
 ticable to employ on these children, it was pointed out that at 
 all ages, the memory span of the deaf averages about two nu- 
 merals less that that for hearing children, about the same rela- 
 tive inferiority that was observed in the case of the "A-Test." 
 This inferiority of the deaf on the mental side perhaps means 
 no more than that the child is from three to four years less 
 mature than the hearing child of his age, and that his date of 
 maturing will be correspondingly delayed. It does not neces- 
 sarily mean that adult deaf individuals will be much inferior in 
 
82 EXPERIMENTAL STUDIES 
 
 mental comprehension and initiative to hearing adults. Indeed, 
 this mental retardation may be due to conditions in training, 
 and were the deaf child's instruction begun in infancy instead 
 of at six years, the difference might be reduced or even elimi- 
 nated. 
 
 The problem of determining the number of deaf children 
 who are sub-normal, using a relatively pure mental standard, pre- 
 sents difficulties which we find it impossible to meet. One can 
 never determine just how much training, a deaf child has had. 
 It is found much more feasible and practicable to employ as a 
 criterion the individual's susceptibility to training. On this ba- 
 sis the investigation showed that there are but 6 per cent of 
 those in the rooms for deaf children who do not give promise 
 of being able to at least support themselves on reaching ma- 
 turity. And even these 6 per cent of the total number, will be 
 at least partially self-supporting; that is, able to earn a live- 
 lihood under direction. Further, not one was found whom it 
 would seem that the State must eventually take over as a ward. 
 
 The question of grading the deaf children is one that merits 
 consideration, and it seems highly desirable to have the chil- 
 dren well classified. Although individual instruction undoubt- 
 edly has many advantages over class work, nevertheless the 
 stimulus that comes from companionship with their mates in 
 a class exercise has a decided educational value. This associa- 
 tion without doubt goes far to incite, continue and cultivate 
 tendencies to express and communicate ideas. It would also 
 tend to prevent the too close dependence of children upon the 
 teacher's initiative, and to avoid the narrowing effects ensuing 
 from their fitting responses only to that which is expected or 
 demanded of them. In day schools where the children are dis- 
 persed over the city, proper classification is of course a puzzling 
 problem. 
 
 Commendable efforts have already been made in the public 
 day schools for the teaching of the deaf in Chicago, in estab- 
 lishing within certain districts of the city centers where a con- 
 siderable number of deaf children are collected, making it possi- 
 ble to grade and classify children according to age. natural apti- 
 tude and school experience. But there is the additional desid- 
 
DEAF CHILDREN 83 
 
 eratum of a proper Course of Study for the deaf. As in the 
 case of instruction of hearing children, there should be pro- 
 vided for deaf children, adapted to different years of their 
 school training, a certain definite body of information with 
 which teachers should be expected to make the children con- 
 versant. This is especially important in view of the fact that 
 it becomes necessary sometimes to transfer a deaf child from a 
 school in one part of the city to another. It thus ought to be 
 possible to have a certain repertoire of words and activities 
 which all deaf children should acquire during their first year 
 of school life, and in the same way for the following three or 
 four years. The saving of the teacher's time and energy in 
 duplicating work already done, in discovering the amount and 
 character of the previous training of the child, would be con- 
 siderable, and a decided step in advance would have been taken 
 in the direction of a proper grading of the deaf. 
 
 In offering the above experimental study of the compara- 
 tive physical and mental life of the deaf there are, of course, 
 many psychological and educational problems which have not 
 been touched upon. The foregoing is, however, presented with 
 the hope that it will throw considerable new light uf>on a prob- 
 lem which has hitherto been approached only from the stand- 
 point of theory and personal experience. 
 
APPENDIX. 
 
 HISTORICAL NOTES. 
 
 So far as the Department of Child Study is aware, no 
 scientific study has ever been undertaken with the same object 
 in view, similar methods of procedure and with comparable 
 groups of children. Reference should, however, be made to Dr. 
 Love's studies * of fifty-four deaf children of the Glasgow In- 
 stitution in 1896, and their reported standing as compared with 
 boys of corresponding ages in the public schools of that city. 
 The statistics on the physical characteristics of the children 
 (grouped at ages 15, 13, 11 and 9 years respectively), relating to 
 height, weight, circumstances of head and chest, seem to show 
 that they compare favorably with the normal hearing children 
 of corresponding ages, but the numbers are so small as to render 
 it very unsafe to generalize the findings on this special group 
 or to compare the results obtained with those of other workers. 
 The same is true in referring to the mental qualities of the deaf 
 children, with the added stricture that no ultra-school tests were 
 given. Classifications of mental status were based on observa- 
 tions and estimates of the teachers and no check is presented to 
 us of the personal equation of the observers whereby compari- 
 sons can be made between the mentality of these children and 
 any other selected group of deaf children. 
 
 Again one must note Binet's work ** on the head measure- 
 ments of deaf children at the National Institute of Asnieres, 
 France, in 1901. To these cephalic measurements should be 
 added, as indeed they were incorporated by the author, the sta- 
 tistics previously published by the attending physician to the in- 
 stitution. Dr. St. Hilaire *** on height, weight, lung capacity, 
 thoracic perimeter, strength of hand grip, circumference of head, 
 in every item of which the deaf children are recorded as in- 
 
 *J. Kerr Liove, Deaf Mutism, 1896. 
 
 **Alfred Binet, Les Proportion du Crane chez Sourds-Meuts 
 L'Annee Psychologlque, VIII, 3901 ; 385. 
 
 *«*Etlenne SaJnt-Hllaire, La Surdl-Mutitfi, fitude Medicale, 1900. 
 
86 APPENDIX 
 
 ferior to the normal hearing children of the same ages. The spe- 
 cific object of this study was to note cephalic changes in a com- 
 parison of the three groups according to age of the children ex- 
 amined. The shape of the heads of deaf children between five 
 and seven years was compared with the group nine to eleven 
 years, at which time the transformations evidenced by the vari- 
 ous diameters were; pronounced, and these two groups were, in 
 turn, compared with the older groups, ranging in age from fifteen 
 to seventeen years. The comparative status of the deaf and 
 hearing children in these French institutions will be referred to 
 on a later page of this study. Any attempt to draw direct com- 
 parisons between groups of children must always be open to 
 certain reservations, but in this case it may be noted at once that 
 the deaf children attending the public day schools of Chicago 
 are a specially selected group, due to the preliminary entrance 
 examinations to these rooms which are given by this depart- 
 ment. 
 
 Dr. Ferrai, in 1902, made some comparative psychological 
 experiments * on twenty- four deaf children and twenty-two 
 normal orphaned children from socially comparable institu- 
 tions in Rome. The recorded results of the mental tests which 
 dealt, it should be noted, only with simple and complex memory, 
 ought to be of the greatest importance, but unfortunately they 
 are not of such a character as, to show anything more than dif- 
 ferences due to training and environment. The general conclu- 
 sions exhibit pretty much what might be expected from the ma- 
 terial presented — that the deaf-mutes have a memory much in- 
 ferior to hearing children, and give evidence of much greater 
 improvement and progress during a definite period, because in- 
 deed, there is greater possibility of rapid improvement in their 
 case before the psychological limits are reached with the subject 
 matter at hand. 
 
 The study made by Schaefer and Mahner (**) of four 
 deaf, four blind and four normal hearing children is likewise 
 of interest, mainly for the attempt to establish direct compari- 
 sons between these special and variant groups of children. The 
 
 *I>r. Carlo Ferrai, Recerchl comparative Psicologia ^)erimentale 
 sui sordo multl. Intern. Archiv fur Schulhygiene. Band I. heft 4. 
 **Ztsch. f. Psych., 38; 1905, pp. 1-23, 
 
APPENDIX 87 
 
 results are, however, vitiated by the fact that none of the deafs 
 were congenital, but became afflicted between the ages of 2 to 
 9 years. Furthermore, the attempt to make comparisons be- 
 tween the deaf children at each age and the normal hearing chil- 
 dren two years younger may have seemed suggestive for the 
 special group of institutions investigated, but certainly cannot 
 be supposed to yield results susceptible of very general applica- 
 tion. 
 
 The somewhat intensive study of Dr. Decroly and Mme. 
 Degand on visual memory of seven deaf children is in a 
 measure deserving of special mention for its insistence upon 
 specifically psychological methods of attacking the problem of 
 the development of the deaf. The deaf children who were com- 
 pared with normal hearing children are reported as not of equal 
 ages in each instance, and consequently no true index of the rate 
 of natural mental maturing is given us. 
 
 Such an important investigation as Dr. F. Danzieger's 
 of the 286 deaf mutes of the institution at Ratibor, Germany, deals 
 as the title shows, specifically with malformations of palate and 
 its relation to nose, eye and ear defects, but in general it can- 
 vasses the characteristics of the family medium into which deaf 
 children are born — the prevalence of deafness in the blood rela- 
 tions and the diffused neuropathic tendencies of the near-of-kin. 
 It may be described as a study which is largely taken up with a 
 discussion and comparison of groups of deaf children with one 
 another and not of deaf children with hearing children. These 
 groups are divided on the basis of the casual factors of deafness 
 and also more or less upon the time of appearance of the afflic- 
 tion. 
 
 •L'Annee Ps.vehol. (3906), Vol. 13; p. 128. 
 **Dr. P. Danzieger, "Die ilissbilclungen des Gaumensi nnd ihr 
 Zusammeuhang mit Nase, Auge, n. Ohr," Wiesbaden, 1900, 
 
APPENDIX 
 
 A COMPAEISON OF DEAP AND HEAEINO BOYS OP CHICAGO AND PAEIS. 
 
 
 
 10 years 
 
 12 years 
 
 14 years 
 
 Features 
 examined 
 
 Deaf 
 
 Hear- 
 ing 
 
 Per 
 cent 
 which 
 deaf 
 is of 
 hearing 
 
 Deaf 
 
 Hear- 
 ing 
 
 Per 
 cent 
 which 
 deaf 
 is of 
 hearing 
 
 Deaf 
 
 Hear- 
 ing 
 
 Per 
 cent 
 which 
 deaf 
 is of 
 hearing 
 
 Height 
 
 Chicago . . . 
 Paris 
 
 mm. 
 
 1335.4 
 1243.0 
 
 mm. 
 1330.3 
 1340.0 
 
 100.4 
 92.7 
 
 mm. 
 1370.2 
 1310.0 
 
 mm. 
 1418.9 
 1370.0 
 
 96.5 
 94.9 
 
 mm. 
 
 1528.1 
 1430.0 
 
 mm. 
 1547.4 
 1510.0 
 
 98. 9 
 
 94.7 
 
 Weight 
 
 Chicago . . . 
 Paris 
 
 kgs. 
 28.18 
 27.47 
 
 kgs. 
 29.3 
 31.00 
 
 95.8 
 88.6 
 
 kgs. 
 
 30.4 
 
 32.24 
 
 kgs. 
 
 35.6 
 33.0 
 
 85.3 
 97.9 
 
 kgs. 
 40.09 
 39.17 
 
 kgs. 
 44.7 
 41.0 
 
 89.5 
 95.5 
 
 Luner 
 capacity 
 
 Chicago . . . 
 Paris 
 
 cu. 
 cm. 
 1466 
 1000 
 
 cu. 
 cm. 
 1659 
 1670 
 
 88.3 
 59.8 
 
 cu. 
 
 cm. 
 1704 
 1190 
 
 cu. 
 cm. 
 1956 
 1800 
 
 87.1 
 66.1 
 
 cu. 
 cm. 
 2171 
 1741 
 
 cu. 
 cm. 
 
 2527 
 2030 
 
 85.9 
 85.7 
 
 Circum. 
 of 
 
 CUcago . . . 
 Paris 
 
 mm. 
 527 
 508 
 
 
 
 521.2 
 519.0 
 
 
 
 539.3 
 529.0 
 
 
 
 Head 
 
 521 
 
 97.3 
 
 533 
 
 97.3 
 
 533 
 
 99. 2 
 
 Hand I 
 erip 1 
 
 Chicago 
 
 R. H... 
 
 L. H... 
 Paris 
 
 R. H... 
 
 L. H... 
 
 kgs. 
 19.5 
 17.8 
 
 12.87 
 13.37 
 
 kgs. 
 17.7 
 16.6 
 
 17.5 
 17.0 
 
 108.0 
 107.0 
 
 73.5 
 78.6 
 
 kgs. 
 21.7 
 20.7 
 
 17.5 
 16.6 
 
 kgs. 
 22.4 
 20.6 
 
 21.12 
 19.5 
 
 92.4 
 100.0 
 
 82.8 
 85.1 
 
 kgs. 
 28.9 
 28.5 
 
 23.66 
 23.0 
 
 kgs. 
 30.4 
 28.04 
 
 25.45 
 21. 18 
 
 95.0 
 101-8 
 
 92.9 
 95.4 
 
 The direct comparison of the Deaf and Hearing Boys; of Chicago and Paris, 
 as well as the relatiye standing of the Deaf as compared with the Hearing can 
 be easily read off In the Tahle.