- FIRST SERIES NO. 108 MAY 1, 1926 Sn UNIVERSITY OF IOWA STUDIES a a STUDIES IN CHILD WELFARE VOLUME III NUMBER 4 THE DEVELOPMENT OF MOTOR CO-ORDINATION IN YOUNG CHILDREN » An Experimental Study in the Control of Hand and Arm Movements by Betu WELLMAN, PH.D. PUBLISHED BY THE UNIVERSITY, IOWA CITY Issued semi-mo pity ure ughout the yea Entered at the postoffice at Iowa City, Iowa, cond class matter under the a of October 8, 1917 “LBNOS i 164 v. 3: 4 Cee ae < ta UNIVERSITY OF IOWA STUDIES IN CHILD ;“* WELFARE Proressor Birp T. Baupwin, PH.D., Editor FROM THE IOWA CHILD WELFARE RESEARCH STATION VOLUME Ill NUMBER 4 THE DEVELOPMENT OF MOTOR CO-ORDINATION IN YOUNG CHILDREN An Experimental Study in the Control of Hand and Arm Movements by Beto Wewtuiman, Pu.D. PUBLISHED BY THE UNIVERSITY, IOWA CITY, IOWA FOREWORD A detailed analysis of the psychological and physiological factors in motor control of the hand and arm furnishes the problem for this investigation in the motor coordination of young children. Dr. Wellman has adapted the. tracing board for laboratory use with young children and has devised a practical tracing path for labora- tory use with children and adults. Her data include approximately 8,000 individual records on eight selected directions of movement, by 186 little children. The method is experimental and analytical, with significant results with regard to individual differences, handedness, age, and the influence of direction of movement, suggestion, and prac- tice. No apparent sex differences are found, apparently no transfer from one direction to another, and no close relationship between intelligence and these special motor abilities. The bibli- ography furnishes valuable references in the field of motor control, and the conclusions from the study have a direct bearing on motor development and training of little children in motor codrdination. This study was accepted as a partial fulfillment of the require- ments for the degree of doctor of philosophy in child psychology. Other investigations of the grosser movements of the legs, arms, hands, and fingers in manual play and physical activities are also being pursued in our Preschool Psychological Laboratories with a view to making a comprehensive study of motor development dur- ing the first six years of childhood. Birp T. BALDWIN Office of the Director Iowa Child Welfare Research Station State University of Iowa May 1, 1926 CONTENTS CHAPTER FOREWORD I STATEMENT OF THE PROBLEM II PusBuisHED EXPERIMENTS IN Moror Co-ORDINATION Experiments with Young Children Experiments with Children Less than Five vitae of Age Experiments atin Guitrert of nee aie ae veer of Age Experiments with ne eens Board Experimental Analyses of Writing Movements III Procepure or EXPERIMENTS Tracing Board Experiment Materials Method of Gonductine Eenenmenti Method of Scoring Response of Children Tracing Path Experiment Materials Method of Gendron: Menerinent Method of Scoring Response of Children TV QUANTITATIVE ANALYSIS OF EXPERIMENTAL RESULTS Reliability of Tests Age Differences Sex Differences Performance with Right om ‘Left rede Practice Effects and Transfer of Training Relative Difficulties of the Eight Directions Tracing Board Experiment Tracing Path Experiment . Accuracy and Time of Each Trial Correlations between Times and between Gs on Separate Trials 6 CONTENTS CHAPTER VI Vil Correlations between Scores and Times on Sepa- rate Traits : Significant Diverenees) in Mean Correlations between Scores on Three Trials. Deviations from Straight Line Relation between Coodrdinations in eenecnmenie ath Tracing Board and Tracing Path PSYCHOPHYSIOLOGICAL KLEMENTS OF MOVEMENTS IN Ex- PERIMENT WITH TRACING PATH Mechanics of Movements Indications of Pressure Time Factors in Movements Freeline Movements Motor Co-oRDINATION, PHysicAL GROWTH, AND INTELLI- GENCE Motor Geaeaneen ate Broteal Gros Motor Coodrdination and Intelligence Motor Coordination according to Various MoRetres SUMMARY AND CONCLUSIONS REFERENCES . PAGE 57 oT 61 61 63 65 Gon 74 75 76 81 81 81 82 85 89 CHAPTER I STATEMENT OF THE PROBLEM In almost every aspect of the young child’s life, demands are being made upon his ability to codrdinate his movements. In build- ing blocks, in stringing beads, in buttoning his coat, in lacing his shoes, in eating, in scribbling or writing, fine coordinations of the hand and arm are required. Observation of young children con- vinees one that there are differences in the ability of different children to make these adjustments. Just what the differences are, how to measure them, and how they are related to other phases of the child’s development are questions around which little experi- mental work has been centered. The present investigation represents an approach to the study of some phases of the development of motor codrdination in young children. The main specific objectives were (1) to make an an- alysis of the influence of direction of movement on control of the hand and arm in young children; (2) to analyze the muscular and psychological factors involved in such control; (3) to note age, sex, and individual differences; and (4) to determine the relative de- velopment and control of right and left hands. It was hoped ultimately to contribute to the problem of what constitutes motor control, of whether it is possible to establish a motor index, and of what place motor ability takes in the child’s developing abilities. Two experiments were planned with these objectives in mind. The apparatus for the first experiment is an adaptation of the Stoelting tracing board for use with very young children. The materials for the second experiment consist of sheets of paper on which are printed two lines with a space between of the same dimensions as the tracing board path; between these lines the child attempts to draw a line with a pencil. The experiments are described in detail later in the study. 8 IOWA STUDIES IN CHILD WELFARE Motor coordination of the hand and arm was studied in each experiment by means of movement in eight directions: Direction 1 ( | ), down Direction 2 (—), left to right Direction 3 ( ft ), up Direction 4 (<), right to left Direction 5 (/ ), right to left down Direction 6 (\,), left to right down Direction 7 (7), left to right up Direction 8 (X\ ) For the last four movements the tracing board and the paper with the printed path were placed at an angle of 45 degrees to the base line of the table. The laboratory conditions were especially favorable for carrying on intensive investigations with young children. Children from two to five years of age were in regular daily attendance at the Preschool Laboratory and Junior Primary Group of the Iowa Child Welfare Research Station, and the six-year-old children were in attendance in the first grade of the University of Iowa Elementary School. All were present for from one and one-half to three hours each morning and could be taken to special examining rooms for individual work at any time during the morning. All of the chil- dren were acquainted with the examiner and with the conditions of the laboratories before the experiments were begun. For the main experiments, 136 children served as subjects; many of the children were subjects for repeated tests or special experi- ments. Their attitude toward the experiments expressed good cooperation, curiosity in regard to the working of the tracing board, and interest in good performance. right to left up CHAPTER II PUBLISHED EXPERIMENTS IN MOTOR CO-ORDINATION Motor coordination may be studied from a number of angles, de- pending upon whether the movements are voluntary or involuntary and upon the particular characteristic or characteristics of move- ment involved. When voluntary movements have been studied, the rate, accuracy, precision, force, and extent of movement have been the subjects of investigation. When involuntary movements have been studied, the chief concern has been the extent of move- ment. Since the force of movement involves structural growth to a greater degree and actual control to a less degree than the other characteristics do, it is not considered in the following discussion of the published findings relating to motor cdordination. EXPERIMENTS WITH YOUNG CHILDREN Experiments with Children Less Than Fie Years of Age Since 1923 a few significant and extensive experiments have been published on the growth of motor ecodrdination in children below school age. Prior to that date, preschool children were studied only as they were more or less incidentally included in groups with older children, when the concern was largely in differentiating older and younger children rather than in differentiating the younger children themselves. Gates and Taylor,*® in 1923, studied the acquisition of motor control in writing by forty-five preschool children. Two groups were taught to write, one by tracing letters and the other by copy- ing them. A series of five letters was first practiced for several days, then another series of five letters. The scores made by the eroup who traced were higher than those made by the group who 1. Of the earlier experiments mention should be made of the reports of Kelly,57 who tested tapping rate and the extent of the least possible move- ment of the shoulder and finger in children as young as four years; of Wyczolkowska,112 who classified the spontaneous scribblings of some children (the number is not stated) from two to six years of age; and of the maze tests by Cunningham,?3 Shaw,%3 Porteus,8° and Young.115 9 10 IOWA STUDIES IN CHILD WELFARE wrote, but their ability to write letters at the end of the experiment was considerably less, that is, there was little transfer from the tracing situation to an actual writing situation. The first comprehensive investigation on motor codrdination in preschool children was that of Baldwin and Stecher,® who gave a large number of tests to 105 children from two to six years of age. They included several tests that involve motor control in combina- tion with form perception, as well as six tests of more strictly motor coordination. These six tests were the tracing path, Porteus maze, three hole, perforation (in which the child punches holes in a paper), walking board, and a test with seven Montessori dressing frames. Correlations of the tests with each other and of the motor tests with tests of mental ability were given, together with partial correlations when mental age was constant and when chrono- logical age was constant. The correlations among the motor tests that remained highest after the effects of mental age and chronological age had been eliminated were the tracing path with maze and three hole, maze with three hole, and three hole with per- foration. The raw correlations of the motor tests with Stanford- Binet and Detroit kindergarten tests were high, and were still positive when chronological age was held constant, the partial co- efficients being largest for the three hole and Porteus maze. Sex differences were slight. This report was followed closely by the works of Gesell®® and of Johnson.** Gesell tested 500 children from birth to six years of age, including for the very young infant such abilities as holding up the head, creeping, walking, and picking up an object. The tests at the older levels included writing movements, maze tests, a steadiness test, in which the child catches a cardboard fish by put- ting a stick through its eye, and drawing a picture. Gesell com- bined his tests into tentative norms for diagnostic purposes, but gave no discussion of the interrelations of the various tests, and his system of scoring makes comparisons with the results of others rather difficult. Johnson** used four motor tests with 260 children from three and one-half to thirteen and one-half years of age. These tests were tapping, steadiness, throwing a dart at a target, and maze tracing. Johnson found an increase in score with chronological age for each of the tests, the increase being least marked for steadiness. The MOTOR CO-ORDINATION IN YOUNG CHILDREN 11 maze coordination test was found to be a good measure at four, five, and six years of age. In tapping, girls excelled boys at every age except four years. No consistent sex differences were found for steadiness. Correlations between tapping and steadiness and the weight-height index were insignificant. Experiments with Children of Five and Six Years of Age Tests have been used more extensively with children of five and Six years than with younger children, undoubtedly because of the greater accessibility of children in the schools. Tapping, steadiness of the hands, arms or body, plunger, aiming, or target tests, maze tests, tracing board, walking board, writing movements, crossing out dots, string games, balancing coins, threading needles, tying string, interlacing slats, moving one hand in a circle while patting the head with the other, and thumb and finger opposition are tests that have been reported by various investigators for these ages.? In general, the results of these investigations showed a marked increase of motor control with age, a positive relationship with general mental ability, and an indication of superior performance by children from superior environment. Findings in regard to sex differences were contradictory. EXPERIMENTS WITH THE TRACING BOARD The tracing board was first invented and used by Bryan,** in 1892. His tracing board differed from the commercial instrument now used in that it utilized tin foil and that the two strips came to- gether at one end of the path. Little use has been made of the tracing board with children since the time of Bryan, and his com- plicated system of scoring has been discarded. The tracing board has been found to give a good index of handed- ness in children. Better results have been obtained with the positive instruction ‘‘Go down the middle of the groove’’ than with the negative instruction ‘‘Do not touch the sides.’’ For both children and adults the scores have been higher for movements that are 2. The investigators who have used one or more of these tests are: Bee- ley,7 Berry and Porteus,’ Bickersteth,9 Bolton,12 Bryan,13 Burt,16 Carlisle,19 Conway,2°, Foote,27 Freeland,28 Freeman,3° Gesell,39 Gilbert,4°,41 Hancock,47 Hunt, Johnson, and Lincoln,5® Johnson,51,53 Kirkpatrick,58 Lamprey,&1! Mead,66 New York State Board of Charities,7° Ream,87 Rogers,9° Smedley,%5 Starch,97 Tow,102 and Town.103 3. The test has been included in a series of tests with children by Bolton,12 Beeley,? and Town.103 With adults it has been used by Thompson,99 Lang- feld,62 Gates,35 Link,63 Perrin,75 and Rudisill.91 12 IOWA STUDIES IN CHILD WELFARE toward the body than for movements that are away from it. No correlation has been found with other motor tests nor with tests of intelligence for adults. Sex findings have been contradictory. EXPERIMENTAL ANALYSES OF WRITING MOVEMENTS Analysis of the conditions affecting the muscular codrdinations required for handwriting and similar movements has been a sub- ject of some interest to experimenters. Reference has already been made to the work with preschool children by Gates and by Gesell. ‘Seripture and Lyman,°*? in 1892, tested the ability of ten boys about thirteen years of age to draw lines in four different directions. Smaller amounts of deviation from a true straight line were found for the two vertical and horizontal lines than for the two angle move- ments. The most nearly accurate line was down and the least nearly accurate line was the angle movement from the left down. Speed and pressure changes in writing were investigated with children and adults by Freeman,?**13? and with adults by Binet and Courtier.*° Differences in speed changes and in pressure were found between good and poor writers and between children and adults. There was retardation in speed at turns, or changes in direction, the retardation being less for children than for adults. Good writers used a looser grasp of the pen than poor writers. Rhythm in handwriting was studied by Nutt’? and by West,?°° who found that children were low in rhythm. Speed in making vertical marks was reported by Kirkpatrick®® and the slope of letters by MacMillan.® Although the Porteus maze tests were intended by their author to measure mental alertness, prudence, forethought, and the power of sustained attention, they have been used by other investigators for determining motor control in young children, since success for the young child depends largely upon his ability to make the re- quired codrdinations. The movements involved are closely related to writing movements.4 4. The investigators who have used maze tests with young children are Norsworthy,72,73 Mead,66 Cunningham,23 Shaw,93 Porteus,78,80,82 Berry and Porteus,$ Burt,16 Town,103 Morgenthau,68 Baldwin and Stecher,5 and Gesell.39 A variation worked out in the Johns Hopkins University laboratories has been used with young children by Johnson.53 The maze as a motor learning problem with young children has been reported by Young.115 CHAPTER III PROCEDURE OF EXPERIMENTS Two experiments were planned for the study of the young child’s ability to codrdinate his movements in eight fundamental directions. In the preliminary experiment the apparatus used was a modifica- tion of the Stoelting tracing board. Fifty-four children from three to six years of age acted as subjects. As an outgrowth of this pre- liminary experiment, a tracing path test was originated, which served as the basis for the main experiment and for the special experiments on the factors contributing to control of movement. In the experiments with the tracing path 186 children from three to six years of age were subjects. This number included the fifty- four children of the tracing board experiment. Many of the chil- dren served as subjects for repeated tests and in a series of special experiments. TRACING BOARD EXPERIMENT Materials The Stoelting tracing board, commonly used, consists of a wooden block upon which is set a glass path 25 em. long, 5 mm. wide at the top, and 1 mm. wide at the bottom, with brass strips and a raised rule on either side of the glass. The subject attempts to proceed down the glass path with a metal stylus without coming into contact with the brass strips. As soon as contact is made, there is a sound of an electric buzzer or bell, which is wired in circuit with the tracing board. The distance the subject has traversed when he makes the first contact is noted from the rule and is usually recorded as the score. It was believed that the noise of the buzzer might prove so at- tractive to little children when they are subjects that their delight in hearing the buzzer might invalidate the results. To safeguard against this, a tracing board was designed for this experiment in which the metal and glass parts are reversed from the Stoelting model so that the buzzer sounds continuously while the stylus is on the path. A paper rule was placed under the glass and all parts were sunk into the wooden background, so that a smooth surface 13 14 IOWA STUDIES IN CHILD WELFARE is presented, over which the stylus glides easily from brass to glass instead of being blocked by the rule, as in the Stoelting model. A short binding post that would interfere as little as possible with a free range of movement over the whole board was used. A special stylus with a point considerably shorter than the regulation point of the Stoelting stylus was made of aluminum in order to avoid scratching the brass and glass (Figure 1). Method of Conducting Experiment The child stood before a low table on which the apparatus rested. The height of the table was adjusted to the child’s height so that he naturally took a position with the elbow flexed at right angles and the forearm resting on the table. Eight positions of the tracing board for the different directions of movement were used. Four directions, three trials in each direction, constituted one day’s per- formance for a child. The sequence of directions was as follows: First day, directions 1 ( J ), 2 (—->), 3 (ft ), 4 (<), right hand Second day, directions 1, 2, 8, and 4, left hand Third day, directions 5 (/),6 (\), Ta) 0) ONS rrigitenand Fourth day, directions 5, 6, 7, and 8, left hand This sequence was kept the same for all children. For a study of the influence of the difficulty of particular directions on scores, it is desirable to use different sequences of directions with equated eroups. However, development is so rapid at the ages concerned in this investigation that if further subdivision were attempted, the groups at any one stage of development would necessarily be too small for reliable conclusions. The possibility of changes in difficulties of directions with increasing age made it inadvisable to equate the groups irrespective of the range of ages. In view of these considerations and the fact that considerable labor was in- volved in the mere mechanics of keeping groups equated for in- dividual tests extending over a period of three years, it seemed best to maintain the same sequence of directions for all the children used in this investigation, and to interpret the data accordingly. The sequence of specific directions was decided upon from an a priort standpoint of possible difficulties, practice effects, and transfer of training. Care was taken to include only positive suggestion in the in- MOTOR CO-ORDINATION IN YOUNG CHILDREN 15 structions and in the supplementary remarks that were sometimes necessary, such as to finish the trial, to go slowly, or to assume a correct position, since Langfeld® found with his adult subjects with the tracing board test that much better results were obtained when the subject was instructed, ‘‘Go down the middle of the groove’’ than when he was told, ‘‘Do not touch the sides.’’ The instructions were: ‘‘See this pencil. I’m going to go right down this path [pointing] with the pencil. As long as I keep on the path the buzzer over here [indicating] will make a noise. Now watch me. [The experimenter demonstrated by going the entire leneth in fifteen seconds, saying at the same time, ‘‘I’m going to try to keep going down the path all the time.’’] Now you do it.”’ The child was then given the stylus in his right hand and shown how to hold it in the ordinary writing position, with the body erect and both feet firmly on the floor. For directions 2, 3, and 4, the instructions were, ‘‘Now we want to begin here and go this way.’’ When the child came the second day, the instructions were shortened to, ‘‘You remember this game, don’t you? Try to keep in the path all the time.’’ Generally after the first day’s performance no fur- ther instructions were needed as to the direction the movement was to take. When the child seemed uncertain, or hesitated, the ex: perimenter said, ‘‘Begin here and go down (or up) this way.’’ The child was not instructed to stop at the first contact, as is the usual method with the tracing board test, but finished the entire length of the path each time. This change was made in order to get a record of the entire movement, to avoid interruptions, which are irritating to the child, and to prevent confusion in the child’s mind as to what was desired. Method of Scoring All points of contact during the entire course of the movement and the amounts off path at each contact were recorded in half centimeters and the time for each trial was taken with a stop watch. Two methods of scoring the results were thus possible: The first score was the point of first contact or distance that the child had gone when he first went from the brass to the glass, and the second score was the percentage of the total path, 25 em., that the stylus was on the path. In calculating the percentage on the path each contact was counted as 0.5 em. off path. The average of three trials was used in each method. 16 IOWA STUDIES IN CHILD WELFARE Response of Children Good interest and careful effort were maintamed throughout the course of the experiment, with, of course, certain daily fluctuations. The children did not seem to lose their interest in the test with the repeated performance; in fact, they often clamored for a chance - o ‘‘play’’ with the examiner when it was not their turn, and were much pleased at playing a familiar game. It was extremely difficult. to know at times whether the child’s interest and attention were lagging in a poor trial, or whether the difficulty lay in his inability to control the movement. Frequently these two factors seemed to go together, that is, if the child could do well, his interest was main- tained, while if he was deficient in control, he lost interest. It is, of course, difficult to secure from preschool children any systematic introspective observations on a test. If a leading ques- tion was asked, the child became reticent and no help was forth-. coming. When he felt that the experimenter was in sympathy with him, he might volunteer significant remarks on the test, which helped to give an insight into his problems and his understanding of the task. Some children, for example, indicated that they perceived a difference between the wider and narrower ends of the path by such remarks as, ‘‘It’s upside down,’’ when the apparatus was turned for the movement away from the body, ‘‘Kind of hard to get from down here up to here, that little part,’’ or ‘‘That end’s so little, I can’t hardly do it that good,’’ and by beginning at the wider end without indication from the experimenter as to where to begin. At times the experimenter waited to see where the child would begin if not directed; the child usually began properly, but was unable to give a reason for so doing. With some children the remark that as long as they kept the stylus on the path the buzzer would sound did not convey the idea that the sound would cease when the stylus went off the path. If they seemed puzzled or remarked on this fact, they were told to come back on the path and the buzzer would sound. This usually was sufficient explanation to relieve the situation. In only two in- stances was the buzzer a noticeable distraction, and in these two cases each child watched it during only one trial. If the child showed a tendency to pronounceedly accelerated speed with successive trials he was cautioned between trials to 20 slowly. In a few cases the caution to go slowly had no noticeable effect ; “SSOUISNG SNOLIIS B St Sout] ey} UssMjoq suidvsy “e “SLT ‘yqged oy wo snpA4s 043 dooy SC ‘yurod YLoys B sBIL supxys djoy 0} otnsserd sory [ALS 9f9ITT SIT, Zs Sty UL ‘Ssve~s of} YIM Ysung jos st pue [epou st yjed oy} pavoq Sumer, styy up "TL “Sry MOTOR CO-ORDINATION IN YOUNG CHILDREN 17 in most cases, however, the result was a slowing down for the next following trial, but a speeding up again with the subsequent trial. The concept of slowness seems to be fairly well defined with these children, although a caution to go slowly is not kept in mind for more than one trial. TRACING PATH EXPERIMENT Materials Some deficiencies in the use of the tracing board experiment as a means for detailed analysis of motor control soon became appar- ent: (1) A permanent record of the course of movement was not obtained. Such a record was desired for a detailed analysis of the types of lines made and the factors influencing these different types of performance. (2) The recording of the contacts on the tracing board required such close attention and concentration on the part of the experimenter that little opportunity was left for observation of the numerous other reactions of the child. (3) It was practically impossible to obtain an accurate score for the child whose move- ments were very rapid or very irregular. The tracing path test was designed to meet these deficiencies and still be as comparable as possible to the tracing board test. Two lines were printed on a sheet of paper with the area between them the same as the area of the brass path of the tracing board (25 cm. long, 5 mm. wide at one end, and 1 mm. wide at the other end). The other conditions of the two experiments were as nearly identical as possible. A permanent and accurate record was obtained, and the scoring demanded of the experimenter while the experiment was in progress only the recording of the time for each trial. Method of Conducting Experiment The sheets of paper were fastened by thumb tacks to a piece of beaverboard the size of the table top. The sheets for the three trials in any one direction were fastened in a row along one edge of the board and when one direction was completed, the board was turned, bringing the sheets for the next direction into place. Each time, the child moved to a position directly in front of the sheet. The directions of movement and the order of giving them were the same as for the tracing board test. For those children in this study who were subjects for both the tracing board and the tracing path ex- periments the two tests were alternated, the tracing path following the tracing board, in this order: 18 IOWA STUDIES IN CHILD WELFARE First day, directions 1, 2, 3, 4, tracing board Second day, directions 1, 2, 3, 4, tracing path Third day, directions 5, 6, 7, 8, tracing board Fourth day, directions 5, 6, 7, 8, tracing path The instructions to the child were: ‘See this pencil. I want you to make a mark right down the path with the pencil. [Experimenter demonstrated how to follow the path by drawing an imaginary line from 0 to 25.] Keep right in the path all the time.”’ Method of Scoring Examination of the records showed that there were wide ranges of difference in the amount of excursion of the lines made by the children. The best method of scoring, therefore, seemed to be one that would take into account the total length of line and the relation of the part of the line within the path to the part that was out of the path. It was surprising to find that no accurate instrument was available for measuring the length of a crooked line. Chart- ometers on the market are graduated only in centimeters, which are too coarse units for the purpose, or they are graduated in the English system in eighths of an inch. Consequently various meth- ods were tried out. Fine wire or thread bent to conform to the contour of the line and later straightened to be measured was im- practicable because of the inaccuracy due to expansion and con- traction on bending and unbending and because of the laboriousness of the task of measuring. Freeman,** in his handwriting experi- ments, in which the areas were much smaller, used fine pointed dividers with a ruler, or millimeter paper bent to conform to the line, but these methods also were laborious and impracticable for our purposes. An aluminum wheel, 20 em. in cireumference and graduated in millimeters, with the edge milled to avoid slipping upon the paper, was finally constructed. For measuring the length of a line within the path the wheel was set down at zero and moved along the line until an intersection of the printed line was reached. The reading was noted, the wheel lifted and set down again at the point where the pencil line again intersected the printed line, and the measuring continued to the next intersection. This method gave the cumula- tive length of the line within the path and did away with the neces- sity for computation. Similarly, the length of the line outside the path was found. MOTOR CO-ORDINATION IN YOUNG CHILDREN = 19 Three checks were made to determine the accuracy of the meas- urements: (1) The total length of the line was measured and checked against the amount in path plus the amount off path. (2) Straight lines were measured and the measurements found to be exact. (3) One typical record was measured twenty times. The mean deviation was found to be 0.24 mm. and the range 2 mm., with fifteen of the twenty trials measuring exactly the same. One of the most difficult records to measure was then selected and measured five times, and the error was found to be not greater than for the typical record. A check was also made by remeasuring some records independently after several days’ interval and comparing the re- sults with those originally obtained. In no case was the difference greater than 2 mm. The score for this test was obtained by dividing the length of the line in the path by the total length of the line.5 Response of Children In an attempt to get the child’s judgment on his product and his attitude toward his accomplishment, the experimenter asked, ‘Which of these do you think is best?’’ indicating the last three trials, and when the choice was made, ‘‘Why do you think that is best??? The three and four-year-old children selected a trial, but could seldom give any plausible reason for the selection, saying that they did not know or ‘‘ Both are best,’’ ‘‘They’re all best,’’ or “Because I writed them nice.’’ The five-year-old children, although their selections did not always agree with the experimenter’s judg- 5. When detailed analysis of the lines is not desired, a quicker method of scoring that will give practically the same percentage within the path may be used. The score is obtained by measuring with a rule the number of millimeters of the guideline opposite the parts of the child’s line that are within the path and dividing this number by the number of millimeters of the guideline oppo- site the child’s total line. This rule method was tried out and the scores checked against the scores by the wheel method for 359 cases (average of three trials each). In 61.8 per cent of the cases the results showed no difference in scores by the two methods; in 31.2 per cent there was a difference of 1 point; and in only one case was there a difference as large as 4 points: Difference in Number of scores, in points cases 0 222 (61.8 per cent of 359) 1 112 (31.2 per cent of 359) 2 14 ( 3.9 per cent of 359) 3 10 ( 2.8 per cent of 359) 4 1 ( 0.3 per cent of 359) — 359 20 IOWA STUDIES IN CHILD WELFARE ment, gave good reasons for their choice, such as, ‘‘ Because it’s the straightest line,’’ ‘‘Because it’s more straighter,’’ ‘‘Doesn’t have as many bumps in it,’’ and ‘‘ Because I went out of the path in the others. See.’’ One child gave as his reason, ‘‘Because it’s the last.’? When asked if the last is always the best, he replied, ‘‘ Yes, because I have practiced on the others.’’ It will be noted that al- though the instructions merely said to keep within the path, many children interpreted them to mean that they were to make as straight a line as possible. CHAPTER IV QUANTITATIVE ANALYSIS OF EXPERIMENTAL RESULTS The results of the tracing board and tracing path tests on the control of hand and arm movements were studied with reference to reliability and to the influence on scores of age, sex, hand used, practice, and direction of movement. The relation of scores made on the two tests was also considered. RELIABILITY OF TESTS The reliability of the tracing board test was found by correlating the scores on one half of the directions against the scores on the other half. The groupings used were directions 1 ()), 4 (<), 6 (\,), and 7 ( 7) against directions 2 (—>),3(7T),5 (7), and 8 (\). These groupings were arrived at from two stand- points, the best pairing according to the order in which the tests were given, and the best pairing according to naturalness of move- ment from an adult a priori standpoint. The coefficient of correla- tion obtained by the product-moment method with these groupings for the fifty-four children from three to six years of age was 82 + .04. When the Spearman-Brown prophecy formula® was applied for two tests, the reliability coefficient for the whole test became .90 + .O1. The reliability of the tracing path test was computed by using the groupings of directions used with the tracing board. The cor- relation obtained by the product-moment method for ninety-four children from three to six years of age was .969 + .004. When the Spearman-Brown prophecy formula was applied, the reliability co- efficient for the whole test became .984 + .002. This correlation was, of course, influenced by the range of ages included. In order to de- termine what the reliability would be within an age group, correla- tions were worked out by the rank method for three age groups and Nr COR 2 ee, are ee e soy aN pret BP McCall, W. A. How to Experiment in Education. New York: Macmillan, 1923. Pp. 281 (p. 111). 21 22 IOWA STUDIES IN CHILD WELFARE the values transmuted into r. The reliability coefficients thus ob- tained were: r Prophecy r At three years 785 = .05 .876 At five years 908 += .02 951 At six years 875 + .04 933 The correlations between the various directions are discussed in connection with the relative difficulties of the eight directions. AGE DIFFERENCES Tables 1, 2, 3, and 4 give the points of first contact on the tracing board for each subject (average of the three trials), with the average and standard deviation for each direction separately for right and left hand performances. The average point of first contact for the eight directions for each child is also given. It will be noted from these tables that while the differences in averages are small, each age group ranks higher than the preceding age group for each direction, except that the six-year group does not gain over the five-year group. Whether or not these differences with age are significant may be determined by finding the probable error of the difference of the means.7 It is found that the difference between the means for the children of three and five years is more than three times the probable error of the difference, and therefore significant, for each direction with the right hand, but that with the left hand the difference is not significant for any direction of movement except direction 7 ( / ). The actual differences between the means and the probable errors of the differences for these two groups are as follows: Right hand Left hand Actual P.E. of Actual P.E. of Direction difference difference difference difference Gls 4.3 93 1.6 .79 Lea (pam 5.9 .76 Pid .48 Fe “y ) 4.0 95 +5 87 He Ce) 4.7 46 1.1 .78 a ¢ Pie 4.3 1.08 0.2 92 6 ( ~ ) 5.0 1.06 1.5 .90 7 (J) 5.0 1.43 ay § W138 8 ( RK ) 6.5 1.74 0.2 .76 (Ct Oe EVA aoe: +P Ey 1 McCall, W. A. How to Experiment in Education. New York: Macmillan, 1923. Pp. 281 (p. 151). MOTOR CO-ORDINATION IN YOUNG CHILDREN ~— 23 For the left hand, the scores for the four age groups are so close that the actual difference in the average of the eight directions be- tween the three-year group and the six-year group is less than the difference between the three-year and four-year groups for the right hand. The left hand scores are at a lower level throughout than the right hand scores, the scores for all groups with the left hand approximating the scores for the three-year group with the right hand. This means that the disparity between right and left hand became increasingly greater with the increase in age. The correlation of the average point of first contact on all direc- tions with age was .88 + .03 for boys and .53 + .09 for girls from three to six years of age, indicating that the older child tended to go a longer distance than the younger child before making a contact. Comparison of the averages with the results of Town? shows that the fifteen four-year-old children in this study are equal to and probably ahead of Town’s forty-two five and six-year-old chil- dren. Her average point of first contact for direction 2 (— ) with the right hand was 6.47, P.E. 2.48. Her records show a number of zero scores, which did not oceur with the children in this ex- periment. The two tracing boards and methods of experiment were somewhat different, however, and for that reason the scores are not directly comparable. The distance the child kept on the path, expressed in terms of percentage of the total length of the path, was used as another method of scoring the results. This method does not penalize un- duly the child who goes off path early in his course but keeps on the path the rest of the way, as does the method of recording only the point of first contact. Tables 5, 6, 7, and 8 give these percentages for the individual children, with averages and standard deviations for the age groups. In general, the results show the same tendencies as those for the point of first contact, that is, an increasingly higher score with age, and an increasingly greater difference between right and left hands. The individual scores on the tracing path test with the right hand are given in Tables 9 to 15, with the averages and standard de- viations for each half-year group. It will be scen from these tables that the scores of the six-year group are nearly double those of the three-year group, and that there is a general increase in scores from any half year to the next. This increase is greatest between three 24 IOWA STUDIES IN CHILD WELFARE mM 4 hres ip ix (ji ee K OBBLIOAV jes dicdOeged ist seoSadnes 2 2 se A arti Panes sect AOC ERT art att pee tie re Oo NOOK KMS OA tS os 00 a 4 ard meet gen re ar A ON lh Re a ae ° RR [wa BOG sw aia Ho 18 8 ~ i = » SNSCS HOM ON Shee = ie eyes a AMON iwntHt AN oud 6 ot s o pales SHAS | IQR KS is: | 12 \y NN OMtM CSINM MA an tbe: oS + J ee TAS Doar tied a hee a eres aay Sr Rae } a AN HOH ArN HAMA nA fat) o ri = 6 = S mo CNM COM AMROMNONM as HILM@T~lSis BAN BOW aAwwdsd dics oO p= = os A eH MMOH WSChm HNNMNMEE 0 a T AM OAAR RIOH NAHIOAe HH! a w~ 4 -y{SR2RSSCH BOM WOOMMOh S) = SoNncote POM Weridnisnke ~~ oO 3S a=) ag ofe10A WRINODOOCMONMHNAROOCNMON Ho V iis oc isr non dsinniscntn a ome mH cra wo Yih 22SS Som SQ aQeQ ee Cl ad od Smo aso wan ° = A Parl wie aen cg hace ot AAC Te Cet arte os mR it arasS adi wisad wea Py ~ q A TREN ROPES ea el age aa me ai o |o See TH WINN ONM ANM FAN a o a ~ “o = Bs pt oe era ° Pin tare, BS RAVE eaaee Set Romer ase ee ne Go eta - |S| g ON\|oi Vides End cicidi Wales oy Ol a, 7 oe @ |A| © a TAs pacbrerererigt nica) heli rs ie a AMAATHOr-MONAHMOM mH = 6 Ps a | nc |RPESHSERRSSSHEONQ MO z | WDiDHSHAWASSOSSIHASM WS ) = = on = 5 —BOMGIMN HH MQOSHENRQ on - a T IDM NO AOMIOMr~HAAMOO HH as ES Aria barteri ark: Se are pees oe 8 Bey B a DH HAASCOSCAANDS OMG HOS Pah ° D MOOT | Ore a ete 1 peaeta erat aperenan & |i sieox | OGY Gl al GY c9 69 9 9 9 9 9 Od 09 4 60 69 8 = tT! Ei m AM pO _ kod oo A _ 19 § ONHAM 0 a oI HAS RAR AGRO oo S) Fa ee i MOTOR CO-ORDINATION IN YOUNG CHILDREN TABLE 2 Individual Scores (Average of Three Trials) on Point of First Contact on the Tracing Board by Children of Four Years 1 lmmanaooaoe Hid 62 O © | 00 Zenblpeos Gres Ged wi xis | wi 0 |/ hor Piet eariere eo en catia riod NO rid | xia ae ere ce ee ety oe Ki] raed aia rit jisa r= Ren ROM Dry | wD s a oJ Maa aida na | or oS oO iS REE MOO io #3 10 \, 7 yee A er ait a = ota AKO tO oD | b H HIS ~ | mMaomn moO INhmmoo /nHr a SHH oa =H 00D HAN | eS cS © SHmOnoKnRNSO MOONY HA HLM Hla didtdines Sodio | we = mMONDOOON Qh mer | 0% a tT EOE ED Ay S COI AES OO | Id + /2RIMOCONA SSCOCOM | +4 a MAIG MH AAA oS id 1d 06 © Hi od mMOTASOARKACHRHAANDH | BIOA Mf ) esBI0AV IDSSOPEAWGGOrSISS ~ a 1 YY | PRROM YAS on | He Dae pe barb ge eo | os ae 4 grigrlar tarde ta he: par G crs be Je mR i ditidaork kok aSSira a YY ro| & Sebi ad (pe Reh oer ee Prise. aod Al ¢ COAlaABaANN AGO Id | oO fas} 2 am. (ome | = »| SeOhEHh eS Oo [19 © af q jo Ny B= 00 60. Op Os S371 19 00 | CO fe} A Ee RCC ae ae BO Er Se OG SO ChE 4 00 a |~ MMras AToadnssessoanly ° o aor o ae © BE SSNS O26 O09 09 Tet 3 A 69 < Jad FS Hi AES OS OID Wid 00 wi os bos S Re Rae pene ea en Sees Saw ea Pe Lee) Oks ow WANOOAMWDIORDODONOMND | ON rm = re Sag GE EP ape react Nis Marl al aah MB 8 ee et ae aw _ —— 25 26 IOWA STUDIES IN CHILD WELFARE ‘ee moOnNaqadogriddto | 3 OBBIOAYV ID co HOE OHE OO | 10 o a ro) ° So Meare |i. aa Sor aa las 5 ONO OK |innN Gy “4 oo 6 ~ On =) ~ A ee SS Son = Ne = wm teis Sx [o) ~ ce) = a ex) ine) mQnooeeo Hon mis] S/S Ala i Wess Gis Jide B | 4) § ; aq ein tu bas ° op te | “in 2 + g NG 10 al ater a lina ssa Pe ac ah By = MrOMOSCCONN |ON faa 5 wf OACNHHOK HIS |iddg on oN te q © SEEKER MNROMM | Oo S A OT SHadcradiod OS on g fa qf a mMOONNROCOCOMNS |OQ = a tT ASSHSAHHOO ld apa a MOOR ANMONRN|AN AF wide oi © os aS ri oO & = S WOMMMDOHHHO | A Gas) QSVIOAY PS LI GR aR eee es req ro = os Lond 3 TM o| sqyuoyPyT by B= 00 00 ry OT 69 19:19 (eal ra of | 3 |<] sox |4bddh ddd | g ° fas] tH . : = HO ~ 5A . (=r) ODS + t~ 0 5 fa = ame taotin sini | GP D Beene see MOTOR CO-ORDINATION IN YOUNG CHILDREN TABLE 4 Individual Scores (Average of Three Trials) on Point of First Contact on the Tracing Board by Children of Six Years Left hand Right hand IDHININAM OOdtola esBIOAV WOHtoOoOmAH Wein | Oo A etter Cpe Sak: rior har eae CHM SO War | od x PP et eke Sh o9 | 19 RR [bar saos WSodrlon re ~~ = MOMOMO COrROC|AN = CAD) |Sascsidn Oisanis jaca © > S) ES a See rae he Cae oe = ION | oid S 09 aAScon linn Hy Ss IHGOMAN SNe lida “3 5 mMrmeomMo SONGS! Ho HIMH—lsaswonm eXisac | oa A NOMNMOSOM COST /|ONH a tT AMMONIA WDiIAO | wMN ,/2@eehre mame lan re MADOC A Hooded | Ha INT MOMDNHNDOH|aA OSBIOAV SMOWSSSCSOKIBNHA OK |S oq Andean Ae a oYf|rSheRre mmralna mHHOnMSD eS CO oD RopisadSisti SsSau|ou a ES Be tees SMHrEMmrMNMm MMOM | AO = J \SBAGBES Hiaotdl| as 5 Ssaestere = = 5 hShWMS SHANA; RS g ON | SbtiSra onno|as oa sede + ey ey hens ee ie a ODMm~Or~r~HOAMH | oN de bs SOOSOMMOOHNMOS |ON H/T oer Kr adddawdsd jr a 27 IOWA STUDIES IN CHILD WELFARE 28 OFL TFL g'e9 G99 389 | 69 82 Sik dee l6e uL8 g99 | 69 39 0°€9 G99 969 | FG #9 FOL | BL &8 e6p | Fr GG ge eas hae) O80 1° On. “ASL gsr | OF FF Te9 | 99 9g COOL 259. aes el Sofes Met ged ord F'0S 3G | Le 8F > Nore a gay © oo i jo} @ OLT GOTT 939 LéL 69 LL 16 =¥6 Si Beetle L9Pre69 69 62 Le =6Tg £9 GL OL L Tr 89 G8 GL LL &6 ref Poet 94 6& Lg Neat 9 G JUOMLGAOW FO WOTPOITIG pusy 4J0"] OSI FIT Sel SIT S09 F6S L6G 69 SP HU SG eho) O83: 2s Gi. 29 ade fine gee Orie ea tha 1) £9 S19 OG GL 19s Tee 269° 08 Ola 6Ger 200 69 co. se 79 ¢é¢ G02 89 1G) 6g sg OF 09 G6 G8 G0 5 S27 Ge ATES Ger ¥e5 Gi 09 eOh GL Pe =AG Tea, CG o80 EES €9 $2 #9 0S ee ee ees eres dco GOL: OGL G&L OFT T89 639 839 €89 L6G 89 FS9 8'L9 LL 06 GL - 66 694.19. 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Oss 8'F9 CP aC hint «ECL LO P'S9 GQ =9S 2°69 = S9 8°€8 egc ROIS het Be ag: P39 dee Nope x Tope gs Pel LE LOL ROE, AeGs Cs aie ised Pees FA aes ctf) E'LG Causa pe ico ees ware > IAN 4 aap ers ae re} vw oO pusy yysty ‘a's OSBIOAY —€ —¢ Cm NA MH 60 HIN 19 10 | oD LTA OTL LIW ct ell Gol ThA 6ouL Ol TTIW SW LW Li 9W cal oN oN Ta SIvdX doy, JO UoIp[tyO Aq prvog Suroe1y, oy} UO Ye UIY}IA oUrT FO odsvyuooIeg UO (s[VIY, 9olYT, JO osvIOAW) sSoLodg [VNPLATpUyT ¢ a1avi, 29 MOTOR CO-ORDINATION IN YOUNG CHILDREN TRCSP Pia Ger. cl Gi-00 Sioned oles LL PPL. 60T2 108 s8'Sl 20 ce FOL 0 OL LoL ‘a's 919 9°89 699 G6L B89 969 869 OSL BC) iE Gh FOO NG Cha GC Om Lene, ciel OSBIOAV 6°08 CO AmeTee SOs = Rh ORCAS Cae OL e688 O68 1625987) 96 M2862 082-228 228k 685 | ee ced 8°99 Tne ee P05 es SS Loe Ol eee Lal apie GQ 9-5 60 Oh, 2 8 ae bee OO eG olay real €8h Coren) OL 2 PL ae eOL GG2) #18. "26S. 208. | soser CS 0°08 Te Gera Oeo- eo hes 00 O92 66) 2 O82. 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EL, see eieie 61 GPL PLES L ABO EG Len Gae asin as OS I'¥8 GL 388 "29h SG" ATR ONS SSS ies eee Sil PSL OR ARL Gres Lia ep Oe LG 4 OO fo ahh om CL 0°69 LB SO RO OL 99 CG ar Gs the ees OSI €L9 Fo 69 OL = 92 6°SL Th 8h (9S) Sha G0) Atha Bier eet oe STI Fee ee EG Ne el een Tl Pe | Ns, ae nee ee emma ge © TERPS AG Sct ie Beant aloe t Oe Nee ees & 2 re tego! hans eis tame oe | Re Bo} | 8 | 4 | PITMO o2 JUSMIOAOT FO WOTLIOITIC. oe JUOMIOAOM FO UOTIOIIG puey 4yo'T puey yyqsty ooV S189 INO,T FO WoiptyH Aq prvog Suroviy, oy} UO YB UIY}IM OUITT Fo oseJUOdIOg WO (S[VIL, voIYY, JO esvioOAY) Sol00g [VNPTAtpuy 9 TGV, IOWA STUDIES IN CHILD WELFARE 30 Pol 89 V6S 068 96h Ve 3) p> SIVIA GALT FO UoIppIyO Aq pxrvog Surovay, oy} UO Ye UIY}IM OUT FO osvzUdIog WO (S[VILy, oo1Y, FO osB1VAV) SoLoog [eNpIArpuy UGt ey MO lee OL kee bee EOL 609 TV9 GOL ScL TrL 60L SY oOU se e095 585 ES 68 SS PE NU ais deen eee A) ei JUOULIAOUL JO WOTJIOIIG puey 4yo'T 68 T&L 9'F8 LFS 636 | 66 66 126 | 148 86 66i| cL 8 TT3 | OL #6 g's | 98 ¢9 C'I6 Gigs | sg #8 £06 8°58 ses | 06 99 b> Sis 5 oieaee) 3 (jo) oO L @Iavy GE 2 1G See St For ne O Petre Lo8 698 9T8 L06 L88 G68 L8 $6" 216 £6 76" _-.88 L6;2— 2G38 SOS es SL oe S16.) 206 GL 55. £a0- Roo Gol ere 1S | 68 SOS Looe as saahee tee 92 GZ OS, 4595 sSG>. 216 68-9020 ics ae [8° «G8 308>~ °c6: 5 ars a6 G25 71S6~ By6.c66 LS > oe $8 &8 C8: 68" “soL- 788 7- S66 oaeG NOU ae ae age am 9 q v 6 G L JUOWOIAOW JO UOTPOLIG puvy yysyy ‘a's OSBIOAY ee ine Paaliam belts a: Sou Loo PP TSH OF 6S OFA SF PEW 6oul PIEYO ee 31 MOTOR CO-ORDINATION IN YOUNG CHILDREN eles Oye Oley Lie S Oe--020 WAFS 66 So Li cG Sacp sce Citar Guest seer.) ‘a's SoL 808 819 SPL VOL T8L B8L WEL G8 G68 €F8 S68 FLL Y9I8 998 Ls OSVIOAV Cimss Ulm aL Soar 0. 2 0G Sie LD = 09 VEL 9L LL oe SS 608 Soe L0. 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Sls SLi Shae lo eGR aie cee STIL pe eee, chet) Piel Nw ate Ne ay te ee 8 L 9 G P ¢ 2 T g 8 3 9 c 7 ¢ 3 if =I e prt JUOWUIIOAOW FO WOTJOIIG 09 {UOMIOAOW FO WOTJIOIICGT puey 4yzory sie bg migegal ah | tet ae bom me oa ne PILRY CVALO ETT et aae eases ane CR ee Pe SIB9K XIG JO UoIp[IyO Aq prvog SuToViy, oy} UO YIV_ UIY}IM ouryz Fo oseyUooIOg UO (s[BIL], cooly], JO osvIOAV) Soloog [VNptATpuy 8 Fav, 32 IOWA STUDIES IN CHILD WELFARE TABLE 9 Individual Scores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Three Years Direction of movement mM Child: (ee ee ee eee 3 E eet ee Cea 6 ie AMC mit ees WN M1 SGP a7 ors Midd LO AG) 40 Onde eds ae Oe M2 th ae lee ec eeeh 43.3 M3 Sai0 oe 37 831 684 k8F 150 LBS eos ade oe r4 SHO 1-66) 23 4S eb n88 1) He SS eevee 70 Ree M4 oT | 39 7-93. 407) 46 35.2 F5 SAL el 965.25 (6385047 ed Oe OT Sot ese M5 941 7 | BaV O58 R91 tod BT ont ben od al eo F6 041 155. 45 55.38 69 S6ur45 961 | -BgO M6 911-0 1°47 37 36) 39-0146 Reena ebOL F7 30 |{87 00) 40 2yoS3 2087 Se MME BGM E40 Te 47eNl eae M7 aca’ dy 58 Re 81 72.3 Msg 37 1 58 49 28656.58.) 87) ae es0 so eae M9 sg et Ogmmegs ahd CetaT 85.8 F8 3-4 BL 4B. O7 BGS 70 0 Se a6 eae ee F9 oyu ee Pio ty i eT ye ee M10 3\'9 4.43! 49 Unay: 46°98 87 57a oe mene Mil gg. |-43 939149 bb 54 B70 eo F10 3-9 515 49 SF 33 ibs 46s eB bie bs. 4s 45.4 Average 50.4 42.7 41.9 45.0 50.6 44.9 48.1 47.1 S.D. 16.9 15.4 144 14.6 11.3 11.3 14.6 12.8 and four years of age and least between five and one-half and six years, where the scores near perfection. The variability of the scores, aS measured by the standard deviations, is greater for the younger children than for the older children. Only the superior children less than two years and nine months of age in. this group understood the task sufficiently well to make scores. There were three such girls, aged two years and three months, two years and seven months, and two years and seven months, respectively, who succeeded; the third one of these had previously failed at two years and three months. Four other chil- dren less than three years of age failed to make scores. Their ages were as follows: Boy, 2 years, 3 months: failure again at 2 years, 6 months Boy, 2 years, 6 months: no second attempt Girl, 2 years, 7 months: success at 2 years, 11 months Boy, 2 years, 10 months: suecess at 3 years, 2 months The coefficient of correlation between age and the average score on the eight directions on the tracing path for the entire group of MOTOR CO-ORDINATION IN YOUNG CHILDREN ~ 33 TABLE 10 Individual Seores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Three and One-Half Years ee Direction of movement Chil K = A at a & ‘lee en tee 0 grea, ee Semeur a Mie et ee ENE OK M12 3- 3 40 20 45 57 54 45 a7 5S 46.4 Fil 3- 3 47 70 fies 54 AT 61 55 46 56.6 F12 3- 3 60 47 31 50 a 61 54 65 52.6 F13 3- 3 52 42 OL 58 55 54 5 59 Doo M13 3- 4 69 73 62 50 63.5 M14 3- 4 61 46 oF 22 41 24 27 40 ot. F14 3- 4 60: 52 46 59 54.3 M15 3-— 5 76 69 70 63 Au yas 47 59 65.8 M16 3- 5 36 26 31 40 33.2 F15 3- 5 30 68 oo 44 39 17 72 48 51.6 M17 3- 5 49 41 ot 56 69 69 AT 72 55.0 F16 3- 5 65 59 36 50 56 56 hi fee 58.5 F17 3-— 5 80 62 78 69 70 59 61 73 69.0 M18 3- 6 80 49 61 67 64.3 M19 3-— 6 42 51 48 ay! 49.5 M20 3- 6 49 38 he 56 67 76 72 79 64.3 F18 3-— 6 89 78 81 65 43 61 oF 43 62.1 F19 3- 7 61 62 66 42 32 40 Do 42 50.0 M21 3-— 7 42 27 27 21 54 60 47 63 42.6 F20 3-— 7 74. 76 70 61 62 62 48 83 67.0 F21 3— 7 70 48 52 31 85 61 63 56 58.3 F22 3-— 7 84 90 ta 87 83.5 F24 3- 8 75 ti 43 44 72 46 40 65 52.8 F23 3- 8 65 38 36 35 43.5 F25 3- 8 54 46 65 60 83 51 58 59 59.5 M23 3- 8 86 80 io 49 67.5 M22 3- 8 83 90 95 79 83 89 69 80 83.5 M24 3- 8 69 53 O1 57 80 62 fa 63 64.3 Average 02.4 7°54;9: "55.17 503.0 “60.8 59.3 55.2... 61.2 S.D. 1GAe (Sidon 1 7. 7ecld 7 1 15.0» 1842 children was .81 -+ .03 for boys and .82 + .03 for girls, indicating that the older child made a higher score than the younger child. SEX DIFFERENCES For determining any possible differences in scores on the tracing board that might be due to sex, the averages of the scores with the right hand and the standard deviations were calculated for all boys and for all girls for each direction of movement, since the number of children was too small for subdivision of the age groups by sexes. Table 16, which gives these average scores and standard deviations, shows that by either method of scoring there are no differences in scores that can be attributed to sex. Neither does it appear from o4 IOWA STUDIES IN CHILD WELFARE TABLE 11 Individual Scores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Four Years Age AY Direction of movement Child 2 mn aE MOLE els Sse eRe in Tks ROL) : a E Lee gy a Re kT ee 6 Ue Jue 4 Wickes aed Wht an IA at F26 3-80 B5 ASO G7. ord 76.3 M25 589 G1 1870 Pe7d eos ae ob va70. 71 BE 69.4 M26 5-30 55. A Five we De CBSe 74 Bo Ba 55.8 F27 Sau 4h NAS 1 RATE BOS il COG) et GO ae 53.4 F28 3-10 GA. OD aNT Aime) . 85.8 M27 3-10 foe GA SEO re eto 61.5 F29 3-10 Soe Rds) 6S 6G 69.0 M28 4— 0 85 63 74 62 71.0 M29 4 0 78 78° AT N51 63.5 F30 ria | TO) STO GOO. PSl eT alae es cee ey 80.0 F31 4-1 O4n e011 BOs ess 91.3 M30 4 2 86 82 95 68 82.8 Average 77.0 71.6 70.1 62.7 66.8 75.5 66.8 65.0 S.D. 145 217.8" 180014 Suey ol lie ee TABLE 12 Individual Seores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Four and One-Half Years Age : ¢ Direction of movement Child a: A a ; s E Ree CMe? Me one eee ee Tees Ke eo el Pie ee 2 ey aN te Ve F32 Aone Sa Ta Pe OT RTE OO errs TA ae 81.8 F33 Whe OF 79.) 77> O76 80.5 F34 4— 3 64.5) 38.00 GS a ebOty Ly] abo OA meee 57.4 M31 ya 1 Wes Ours OS aes 90.5 F35 AarA 87. 884 -B6™ (OR vO4ieo 7 Biers aeemR 85.9 F36 4— 5 89. 00) a7 Gia Od ses ad) mee 86.8 M32 4— 6 95 0 189°. 487 Ea7S ESS WOT aunts. bez 81.4 M33 4— 6 RO. Soa TT AO OB er G oer a eerie 76.0 F37 4— 7 03 (5 RR re iAe AeA 89.8 F38 4— 7 Rei 84 gerd | Ch eT) re BO eee 75.6 F39 a S00) erg Grey gs eda 61 GS RT 67.9 M34 4-7 89 86 75 82 83.0 F40 ye 681. 858 N78) 68 697 88 1ly Be eS 66.6 F41 4or8 94.- 69. 69 .66 97. 89 88 +84 82.0 F42 4— 8 G4 7c tRO Uv eo | O86 BT Soe ee 85.2 Average 85.0 76.6 79.7 76.7 78.0 75.5 75.2 77.5 8.D. 9.1 184° 88,110.10 -17.4° 710.5" 10-6 lit MOTOR CO-ORDINATION IN YOUNG CHILDREN 35 TABLE 13 Individual Scores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Five Years Age ee 2 Direction of movement Child ae A 3 E oe eh ae eee ay ae Be z Gram ee NN. F44 4259 Sie 7 Se 67 seed On 08 fe OT 2 0G 86.1 F43 4— 9 SA terse enya ve C7 83.0 F45 4-10 Sener ero ren Gls 74k SoG GO 70.8 M35 4-11 57/560. 5500-67 59.8 M36 4-11 Of OSH EO TAme SON Ur Oe Th eR lee (90 90.9 M37 4-11 Si Slats Rie Oo 79.8 F46 4-11 19- ISACI SS ETO ST TG. Se 80.6 F47 4-11 O10 84 5 *89 B00 86.8 F48 5- 0 O4 Me 7 ester O Ss: 1) 80 Fh tO4s 5h 860) 85 89.0 M38 5- 0 Rama cess ees Oe OL ust Ol areal 687 87.4 M39 5- 0 ST aG> ee OTe 6S 49.8 F49 mea | SO Oli Ol meee Ru aeO | ome Oi) 904.4. eee 90.1 M40 Raa] OR e593) WlO4 ae 00 93.8 F50 se | 69780740199 410589 96.0 M41 Bae oD SSeey Sar Romesh wee Of 1 Soe 58H ay 079 85.0 M42 5- 2 OSS eR ho ean One OFT) eeO4e eS 86.4 F51 5- 2 Verse RT Mee Ton MOTT ee St yO tht to 80.4 Average 83.9 80.6 80.1 81.3 85.8 87.7 84.8 84.6 sake Ly Oat Opel 2.Or L032) 8.270 6,950 8.65.57,0 the standard deviations that one sex is more variable than the other in scores. For determining sex differences in scores on the tracing path, the average score for each direction of movement for each sex was computed for each age. Standard deviations were calculated for the three and five-year age groups, since the largest number of cases fell in these two groups. Table 17 shows that there is no con- sistent tendency for one sex to be ahead of the other. The boys are ahead on some directions and the girls are ahead on others. Since year groupings are rather coarse for such young children, however, it seemed wise to investigate the array of ages within a eroup. The average age for the four-year-old girls was found to be 2.2 months greater than for the four-year-old boys, the average age for the six-year-old girls to be 2.6 months greater than for the six-year-old boys, and the average ages for the three and five- year-old boys and girls to be the same. Two months might mean sufficient growth at these early ages to influence the scores, and the two sexes were therefore divided into groups in which the ages were 36 IOWA STUDIES IN CHILD WELFARE TABLE 14 Individual Scores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Five and One-Half Years sens Direction of movement mM at j wo Average eee S § fsa Meese es IG Ties _ Pe OOS a ae Rtas gh sete M44 5-— 3 85 92 a1 eGo 84 83 93 83 81.6 F52 5- 3 97 92 90 93 89 90 94 85 91.3 M43 5- 3 92 81 80 82 83.8 F53 5-38 99 91 96 91 91 86 90 £96 92.5 M46 5— 4 80 (Aybar ots T3 85 86 88 81 81.6 F54 5- 4 99 99 95 97.7 F55 5— 5 94 93 95 96 96 90 95 £96 94.4 M47 5— 5 96 87 90 80 94 90 90 93 90.0 F56 5— 5 84 83 ri Bane 84 86 79 78 81.0 F57 5— 5 96 99 99 99 87) 283) 8S 85 91.4 F58 5- 5 89 99 97 + 88 96 93 96 94 94.0 F59 5—- 5 82 68 82 56 72.0 M45 5— 6 98 98 93 90 93 92 90 93 93.4 M48 5- 6 68 Stith noo Ry i Pie tate At 88 85.4 M49 5—- 6 91 80 84 86 85.3 M50 5— 6 94 93 92 93 98 93 90 95 93.5 M51 5— 6 91 83 95 86 88.8 M52 5—- 6 pte Us valeed) 87 87-» 596. 2296296 91.6 M53 5— 6 94+ ‘93.1007 (92 88 87 91 86 91.4 M54 5-— 7 81 67 75 SOs TTT it ae 79 88 79.5 F60 5-— 7 81 80 95 84 91 90 97 91 88.6 F61 5-— 7 100 92 89 87 94 91 84 91 91.0 F62 5-— 7 96502 Dis O04 ve Slee Of S09 hae Oe 93.9 Average 90.0 87.9 89.6 84.1 89.3 89.4 90.5 89.6 S.D. S20 ROL FB SOO G2. a Seo. eae TABLE 15 Individual Scores (Average of Three Trials) on the Tracing Path with the Right Hand by Children of Six Years Age : : Direction of movement Child 2 A i H Se ee a ree erage sé 1). 2D, Pe a wee ee eee eee ae & Ue ee F63 5- 9 73 76 tL 78 87 73 87 73 78.0 F64 5- 9 96 86 91 93 94 94 99 96 93.6 F65 5-10 72 74 72 75 73.3 M55 5-11 86 83 59 85 91 92 95 87 84.8 M56 5-11 99 87 96 84 92 91 84 97 91.3 M57 5-11 100 100 100 99 99 100 99 99 99.5 M58 6-1 94 96 83 90 87 94 88 91 90.4 F66 6— 1 98 97 96 92 99 99 97 96 96.8 F67 6— 2 100 99 99 97 98 96 95 98 97.8 Average 90.9 88.7 85.9 88.1 93.4 92.4 93.0 92.1 8.D. 10.60 °°9.8- 18.40 27.8) SA Te eat 37 MOTOR CO-ORDINATION IN YOUNG CHILDREN Rete Olea? Vio osh SLOL- CSL* SSL Gl 9 Ole L 29s lel SUS eel tile bola Us 66 s[ILD Sel Pale Syl tlhe T8l 8 L9. POL 87h SLT DO Lee LL lS be 286 bee OL eS be ee yyed Uly}IM OUI, JO 9svJUIDIOg se 69 Vee LL ac : : : " S11 6& 69 : : : ; ‘ OS Gi came ve OL VP GZ | sO 498409 SIE FO JUTOT "ag e1009 | ‘G's 21009 | ‘q'g e100g | “G'S 91099 | ‘G's 81009 | “G's O109g | ‘q'g 91009 | eS eA ths oe y <= dh Sat 9 G P : rd T ase = ls | he QUOUIBAOUL FO WOTPOIICT stingy Aq pue skog Aq pivog Suroeviy, oy} UO ye ULY}IM OUT FO ssVzUSdIEg UO PUB JOLIWOH 4SILT FO JULIO WO SUOI}VIAIG PLVpUBTG PUB soLOdg osBIOAYV OL @IaViL IOWA STUDIES IN CHILD WELFARE 38 0°S9 0°16 6 €8 90 GGG 8°S9 1°68 & S8 9°S9 GLY 81099 CLE esh 99 9°06 6°¢8 9°L9 eat oh L’8 Gor 6612-89 816 6 V8 8°S9 6 LP GL Laat ‘a'g 91009 “st Lg9 9°16 L°G8 9°69 hs) 61T U&rI 96T O09 L°06 6°S8 0'v9 GP 09 ee "a'g 91009 N 8 he L L 61. -5:S9 G16 L’&8 g'g9 VVS 6°6 O°sT GOL 0°66 9°78 € EL 6 OF 0°06 0°6 VFL "a'S o1099 SS 9 LLT 9°69 8°66 G°é8 6°69 8g S'GL VOL SLT. 9°69 v'88 9°18 9°69 C6P 68 T6L ‘G'S 91099 ve S GIs € 19 P98 608 V19 6 6P GGL Lot od BS 9) Eloae rity G88 8°08 9°LG 6ST G9P skog ‘a's 21000 o> v SL JUOULOAOUL FO WOIJIIIG 6&9 9°16 G68 GOL GLP 9°GS ot O°9T LTs 9°€9 188 6&8 GL9 67L G6 EP GL ‘d'g 91009 y € TT9 188 618 9°&9 6°6F 9°S3 OTT imal Sto 9T9 168 9°98 P'8S OFT TSP 8G ‘G'S 91009 amd G &L9 poyozeyy 0°66 € 18 TEL 9°0S 68 O'ST 66 L2L9 9°88 168 8°89 LGl OFS 69 ‘G'g v1009 t I 6 [as 6 JO 1oquinyy €s | Peqeyvey 9 g v 6 sivok osy OV FO SIVOX XIG 0} ooIYY, WoT sary Aq pus skog Aq YY Bue1y, oy} UO SUOTZVIAAG PIBpPUIG PU SoIO0Dg oSRIOAV LT Wav MOTOR CO-ORDINATION IN YOUNG CHILDREN 39 matched to the exact month. There were forty-six boys and girls whose birthdays were identical to the month who had seores on all eight directions. The average score for these boys was 65.8, for the girls 65.0. The averages, which are given in Table 17, are almost identical for the boys and girls for each direction. It would seem, therefore, that in the scores on this test there are no real sex differ- ences. PERFORMANCE WITH RIGHT AND LEFT HANDS When the right hand was used, the child did not usually have difficulty in attaining a fairly good grasp of the stylus or pencil m an ordinary writing position. When the left hand was used, this adjustment appeared to be more difficult. In the experiments with the left hand the stylus or pencil was given to the child so that he took it naturally in the left hand, but he almost invariably transferred it to his right hand. It became necessary in many cases to readjust it to the left hand before every trial. Verbal protest at the use of this hand was rare in the younger children, but there were sometimes movements of confusion and consequent self-con- sciousness. The older children often voiced their objections, re- marking that it was ‘‘hard’’ or giving some reason why the right hand was preferable. If the performance did not progress satis- factorily to the child, he sometimes shifted the stylus or pencil dur- ing a trial or stopped to readjust it with his right hand. Mention has already been made of the lower level of scores on the tracing board with the left hand and of the increasing difference between scores with right and left hands as age increases. There are only a few cases in which a child’s left hand average exceeds his right hand average, although cases in which the left hand score exceeds the right hand for a particular direction are not rare. Hx- cept for two directions, direction 5 ( “ ) and 8 ( \_ ), for the three- year group, there is no direction of movement for any age on which the group average on point of first contact (Table 5) for the left hand exceeds that. for the right hand, and even in these two instances the differences can not be considered s‘gnificant. Presumably, any advantages due to transfer of training or to practice should have gone to the left hand scores, since the tests with the left hand came later than those with the right hand. The correlation between the combined average of the points of first contact for all eight directions with the right hand and this 40 IOWA STUDIES IN CHILD WELFARE combined average with the left hand was .52 + .08, when the entire sroup of children was included. When age was held constant by means of partial correlation, the correlation between right and left hand scores lost its significance, dropping to .15 + .10. Apparently there was no relationship between performance with the right and left hands, apart from that influenced by age. The number of children at any one age was too small for reliable correlation within an age group. Forty-one children were given the tracing path test with the left hand as well as with the right hand. For purposes of comparison Tables 18 to 21 give their individual scores, by age groups, with the left hand and with the right hand. There are lower average scores for the left hand than for the right hand for the various directions of movement, the difference between the two hands being less at three years than at any other age. | When individual children’s records on the tracing path for the two hands are compared, it is found that the scores for the left hand exceed those for the right hand for some specific directions, although which the directions are depends upon individual differ- ences in the children. In this group of forty-one children there are more cases on direction 2 (— ) in which the score with the left hand exceeds the score with the right hand than on any other direction. When the directions are ranked for the age groups, directions 2 (—) and 7 (7) rank markedly higher than any other direction for the left hand. It is probably justifiable to con- clude then that directions 2 (—) and 7 (7) were the easiest movements for these children to make with the left hand. It is not justifiable, however, to conclude that direction 4 (<) with the right hand is comparable with direction 2 ( — ) with the left hand. In fact, judging from the rankings for the age groups, direction 4 seems to be a particularly difficult one for either hand. The correlation between the average score on the tracing path with the right hand and the average score with the left hand was “74 + .05, when the group included children from three to six years of age. When age was held constant by the partial correlation method, the correlation was .40 + .09, indicating that a child who ranked high in score with his right hand tended also to rank high in score with his left hand. The correlation between age and the average score with the left hand was .69 + .06 for children from 41 MOTOR CO-ORDINATION IN YOUNG CHILDREN Sor VOV GbP 6&r OLF SIb OSP 6°8S EE at 68 ea ee 1 i oe OTS OG tec Os tas Gian CO 8'9F ESR att ner 0°6S OVP OPE os 9S als 8°87 Se LY ae LG RLS OTP Go Ure y, tee L OLE Dre eke UY eS 0°9S Bote Shy ah Ge LK 8°8& 68s {ene Oana kh POF OD Dore e Re oS F. 6'0F Ore aren’ OG. SP 8°87 Nar apn ema 8 L 9 S OSBIOAW JUOMLOAOWL JO WOTOOITICT puvy 4j07 LG PS iat TS 8P 8G 8h vP IG O€ LY 66 6& 6P —> v 0S LP OP BY pan ate NP see) Cees 9S SP eas 1S See Gd bo OG, 2 8G LV) sy UE 86 GE 66 US oe aly YG" 8S oly Saar ey aan 6 alo! OF OP GE 0G OFS) 9S: SP ya tS el 6 6 vi 0°69 G°8G 0-GS oes 9°6S 9°9S VSP 8°9F VV 6 0F GPP OEE TEP 8°8g OSBIOAV Gobo PTS Ci SLO wen Oye ae Chet Lhe 2 OG ca 9G Clit LY OO ae OU Clie Lear iS Fee 3 Rais 6 paris el 6G OPS SS Sey Soy i geaniines. 3 Siac tenes 1, GEO OS Ake 22 ey OG OS ae Ge eae AD Reais 2 eae ieee 2 Ly 6 60F «© 99. 9g GE 16) 86 ealy VY ~ ~6S =~ GS. = 6S ST Soggy! Ratt 9 faved 6. a eA pace 60S SP O9u ose=t coo). 08 OSE. Duma pao Ean As LY oor. SSS ELGG a" 6g OS eG era wd ySe*- GL OLN: LF Ya oes. woe eae Boo '36Fie meu er oo GE -6F 8S GG2" Sec 1G) iP LG sO Tel Peete Liv 286% Se 2-8 eae (9 OMY BS me BS OO ES Le ear Leela oo TN aia oa JUOWMOAOUL JO WOTZWdOIIG puevy yqsIy SCCOHANMMAMINWMIW | on OSBIOAY LI 9TH LT reg Gl TT OTA ITN Si 9. La STU E re ANE od SIBVOK VOIYT, FO UorppiyO Aq spuvy yoy pure ZYSIY YIM WIV SuLoViy, oy} UO (STVILY, oo1yYJ, JO osvIoAW) soloog [VNPIAIPUT ST @1av], IOWA STUDIES IN CHILD WELFARE 42 T0S $9 €24¢ OTIS TIS TS T09 9'8¢ VTL 27 eas Ol uo el Ss eek Seer GO Ge US 6°S8 v 8°8P Obs US we Bo Ge Ge eer ep ai VLG ¢ 8°99 ee eee a ee SH G08 ¢ gcZ Shae Of s -OLe se s9 2 e007 2 OU 69 €8 G'E8 US 00 ear On rst Gr 64>" 50.- 0045-83-88 © 6P PG) OV e097 0teerer oo) 19 19 0°L9 SS. SV Ee GO ale al Oy eee Oe eS Ve for aes OGL L L 9g 9 9 9°69 1'8G 8°99 L09 §T9 8'0L 819 93L oOBIOAV chai SL" ESL e7G> S66" ss ea BS eR Co 19 = 60 La aoa eee 8& . 9 924 LL GL - 16 8'F6 View OC OL ae UG Mem Glo — Bue Gis a 9°GP GO. bk 100s be eel ee cde eee 205 die pa esOle me Ou 22 OG GP PG LP 0°0S Ay SEP Pee rit oF. 99% 69-19 PTS Bye eG ho Oa =e Le GS he 6G [369 Cee, LE U9. ER OO ee ee eae 6C97 79 BL. FO. 68-80 -Po = 6G. ec 58502) GE. 92) 9, ig OG wb ie ep eom eee €'6F Pie ele or afore eee 19. .19> 6%. 08 -¢ | 8tW > BN Mee ee ee nm Ye oies aN bes a Oe ee Kd 3 ee AR Gee ee ee AL 3 tein eae eee aa 2 Men eee | “ = ae eee 2 eee” SALE BE | pro ag JUSMBAOW FO WOTQoI1IG ag PUOWBAOUL FO WOTWOIICG o puey 4Jo'T puey yqsry asV SIBaX INO JO VoipliyO Aq spuvy yJo'T puve FySrY YIM YI Suroery, oy} uo (spray, ory, Jo oSes0ay) Sd100Q [BNPIAIpUT 6T AIEvL 43 MOTOR CO-ORDINATION IN YOUNG CHILDREN | 90L B88 OBL 0°69 0°89 LHL O'9L F99 WSS Xx OOSME SEES Gh SSB SS 0 $8 E88 OSBLOAY F'98 Co elOe OL Se CO Ps toe 2684 0.76 ¥6 = 96> “C6 = -06 2-88-16" 6G. GSh i eo Sq 6'F8 Sie gy em Seen), oe COMan Gg GSr o Pho! oF16 GR GQ ere O NEE os Ae 8G et 667-662 = 06. fGen LGA €°39 RO eee CCT 00 2 0G On 09 - Det ATS SoU eT Cg Clo PC ae oO aa Lit cog = Coa eee PrIN Gc) Tee eee 80 90-- 6h Cee 10 tt P08 Tee LOR SOR OF PAST ae hes (a wc eer ee 1S f'0 Toe Clee hes oh] O08 BQ> MOA ANS Tite COt ep Gy tI-? OFA 8'F9 Pom er ete 0 = LU ae Ole ee B00 G1 GG 2TG) - 69 er SO eee, Oe eC eg OFA GEG CG ee Ce Cle Gls Glo TR 80= Sige =e oy Oe Pee nee 6 > NN RN Rs aE ght tes eat dK b DS at ra A lames tae Fegemy dh cieth ~ = 8 L 9 ia g Z I O 8 ef 9 Goer g g I ay ge 3 S & = | Pao 3 JUOWIOAOUL JO WOTJOIIIG 08 qUOMBAOU JO UOTJIOIIG, = puey 4yo'T puey yyory ooV SIVA SALT JO UoIplIyO Aq spuey Jo'T pue FYySty YIM Ye Supeiy, oy} Wo (S[VIy, voy, JO vsvIoAV) so1odg [eNpIAIpuy 0% Wavy, IOWA STUDIES IN CHILD WELFARE 44 €GZ 98 LL 9EL SOS BLL Fes L9L T'L9 $9 06 Td 09 8G 8¢ Fl 69 OTL 69 CL OL 89 La PL 6L €9 Crs 98 9L SL 48 06 98 C8 88 0°89 08 89 GG L9 69 GL TL 69 G8 06 18 16 EL 8°SL 92 9) 9) tL 88 OL GL OL 8’[8 Ts £6 [8 L9 8 th F8 €6 C98 68 16 C8 98 6L C6 06 F8 8°06 68 L6 68 06 06 16 16 68 OFL 8S L8 89 L9 LL L9 G8 €8 b A Sos OIE ger Fee Hate net) S SE eae a ae ee ame a JUIMOAOUL JO TWOTPVOITC puey Jol 818 66 88 L98 88 F98 8E8 NF8 GT8 Ss S6l SPSS als Cee LS Saree 2 age 8°F8 £3 = G6. 568-16 ee SS OS oe CR A 8 9°&6 96> 66" 7G 5 =eP6 feeaue kO 0s sere 08 aie 1 - RAO 9 ay oan As Fa ok PAS 9 9°88 LG 232165 2 0G 5 a Oana US ae G6L SB 6L — 68> tia OS2.- L0H TR P16 Oe TO L8e SS. oO UO is GG mere 9°16 90-106 OG =o 28 e 2o segue ene e G"€6 BO... 206) > 26> BO 036. 6b. set ameg v'S8 BS. eSO-* OR se ae SU te oes Pie A eet @ 8 L 9 G v € G T 03 JUOMLIOAOU FO WOLJIOIIG puey yqsty VSBLOAY y -9 89uL Tt-S ccIN 6 —-§ POA O..7 COL L-G OL L-G PS 9°-g coW 9 -¢ 6SW 9-9 OSI 9 ~§ Sr &, 4 | PITGO ™ ooV SIvOX XIG FO UoIp[IyO Aq spusyT iJOT pus yYSyY YIM YI Supov1zy, oy} uo (sje, sory, JO osvsoay) so1oog enprarpuy IZ @iavy MOTOR CO-ORDINATION IN YOUNG CHILDREN = 45 three to six years of age. This correlation is lower than the cor- relations between age and scores on the right hand (.81 for boys and .82 for girls). This probably means that the tendency for scores to increase with age was not so marked when the left hand was used as when the right hand was used. PRACTICE EFFECTS AND TRANSFER OF TRAINING In order to determine whether a child who had had previous ex- perience with the tracing board benefited sufficiently from this experience to raise his score on a second test, the scores on points of first contact of the fifteen children who had had the test a second time were examined. Since the intervals between tests were irregular, the scores on the repeated test were averaged according to the age of the child and these averages checked against the averages on the first test for all children for whom there were scores at these ages. In Table 22 it will be seen that at each age the averages for the children on the repeated test are ahead of these tentative norms. Two explanations for this advantage might be offered: practice effects may have accrued from having had the test before and the group that was given the test a second time may have been a selected group and could be expected to make superior scores. If the group was a superior one, then the scores made on the first test could be expected to be above the average scores for all children at the same ages. That this was not the case may be seen from Table 22, where the scores for these fifteen children on the first test show no significant deviations in a positive direction from the tentative norms. It therefore appears that previous ex- perience with the test tended to increase the scores for these children when the test was repeated. These results are not in accordance with those of Bryan,® who, as subject, made 800 trials over a period of three weeks with his tracing board and did not find an observable improvement with practice. The question as to whether practice in one direction of move- ment carries over to another direction is difficult to answer from these data, since the matter is complicated by the relative difficulties of the directions. However, if we could assume that all directions were of equal difficulty, and that other conditions were equal, we should expect the scores on the last direction to be higher on ac- count of practice than those for the first direction on a particular IOWA STUDIES IN CHILD WELFARE 46 Soi 9 teow SOS OTL SL (9'9e sree SCH Pelee 6 ClO Sclel LLacee EF LDemie eo 4so} pg—dnois 4s0} poyeodey GY) 0G LL 86. $6 88 GE. FS PS |OOT OIL 29. OTL O8E 8S. SOL LO0E- Se) F } 480) geq—an0 4s0} poyvodoy Relea eee ye GG SO Pr TO Poli OL POL SIL P6166 Ser OUleeoL OU sar 489} 4ST —dnois o1juy sivok G Ueda ys Fl Oca OLAS Leese rol Pee Oro 1 Oh aan ae OU Oe, 2 Li 6-9 ar ee) Ge eo eae 8 4s0} pg—dnois 480} poyvodoy Dapotidts 406 —6'G = OP OP eo 0e a6 10891509. 21 9:9 = £0L— 6:6. 6 Oe on Oe SO Lil oO) eed ener 480} poyvodoy Deyo Vea Ve eae OL eG ay Poe a Sh Pe Oe ee pda 9 OL PR Ol vee Cee ST 480} 4ST —dnois o1tjuy sivok F cht Gare): teat este Vy Veal Soo 80 Ge Ga OR oieO LL eee ss & Lie 8:9 oe GO. 5 Oe ke Pe 8 Oa ees 4s0} pg—dnois 480} poyeodoery LG Uae on Rares LP ek Pe WES EEE Gol She we peo L Pa GP. 0 Gs eG Le ci Gees Rie ee Pee ae Deer ee 480} poyeodoy Vile eon sa meen oP. 0S 29 Se VP Pb SUL ees e'Ge - LO 0G = Gy (eGo Ga OG ST 480} 4ST —dnois oyun sivodk ¢ SEN a) NSN eee See trae ee OemeeC wee foe Ga Or eT he ue ae Ge. ee a 4804 EE ee ——| as pue 03 qUOWIOAOW JO WOTOIICT de JUETOAOU JO WOTOOLIG a dnoiy ® 4 Pee ek puey yqsry S SjsaJ, puoveg pu 4SsILT uo dnoig ysoq, poyeodoy Aq pue ysoq, ysitq wo dnory oayjugq Aq plvog Surovry, oy} UO yoRIUOD SILT JO UIOg WO solodg oSvOAWy oo wav MOTOR CO-ORDINATION IN YOUNG CHILDREN 47 day, and the scores on the second day could also be expected to be higher than those on the first day. Neither of these results is found. The last direction on a particular day does not give the highest score, and the second day’s scores are not higher than the first day’s scores. How much experience with the right hand on a particular TABLE 23 Average Scores on the Tracing Path by Entire Group on First Test and by Repeated Test Group on First, Second, and Third Tests hy ° Direction of movement G 26 en roup re © 6 and strsaver 2 3 4 5 6 7 Bap ees test & a LS Se idee ac api oes ait “x pth os Pay Aen Entire group— Ist test 33 | 52.4 47.6 45.8 47.9 53.2 51.0 51.4 51.0 |50.0 Repeated test group—lIst test | 16 | 51.3 44.8 47.4 51.6 52.0 50.8 50.0 49.0 |49.6 Repeated test group—2d test » | 64.0 56.6 58.8 59.4 61.0 51.0 55.0 56.0 [57.7 4 years Entire group— Ist test oo jot O10 69.1 59.9" 69:8" 63:1" 63.1 67.0 4166.2 Repeated test | group—lIst test | 15 | 71.0 65.9 73.6 63.8 66.8 71.8 65.4 70.0 Repeated test group—2d test | 16 | 74.7 70.8 71.7 68.1 83.0 73.4 75.2 80.3 |74.6 5 years Entire group— | Ist test 39 | 88.0 83.7 82.8 80.4 84.6 84.1 83.9 84.0 | 83.9 Repeated test sroup—ist test | 15 | 83.1 78.3. 77.7 75.0 81.2 80.6 78.1 79.0 |79.1 Repeated test group—2d test | 21 | 89.2 82.5 81.1 81.7 91.5 91.0 88.5 88.8 |86.8 Repeated test group—3d test T (90.7) 66,1.- 31.8 81.2°,92.3- 00.3! 83.3.5°85.8 | 86.4 6 years Entire group— Ist test 20 | 89.8 88.2 89.4 86.9 90.1 91.4 92.3 90.8 | 89.9 Repeated test group—-Ist test | 3 | 77.0 80.3 83.7 82.7 77.0 86.0. 95.0 88.0 |83.7 Repeated test group—2d test @ | 93.0 90.7 91,8" °90;89498.6" 94.4. 96.0 948) 1.93.8 Repeated test group—3d test 3 | 97.7 96.0 94.7 92.0 98.0 95.3 91.3 93.7 |94.8 48 IOWA STUDIES IN CHILD WELFARE direction may transfer to the left hand on that same direction is not apparent from these data. Forty-nine children were given the tracing path test twice; ten of these were given the test a third time. Table 23 gives the aver- age scores by ages for these children on these repeated tests, with their scores on their first tests compared with the average scores of all the children on the first tests used as tentative norms. It will be seen that the averages for the second test group are ahead of the norms for practically every direction of movement at every age. The combined average for all directions is higher at each age for the second test group than for the norm group. That this ad- vantage was not due to the selection of the group for the repeated tests may be seen by comparing the scores of this group on their first test with the tentative norms. Their averages for the first test fall slightly below the norm averages for their ages. It would seem then that the children made higher scores on their second test be- cause of previous experience with the test. Data that are at hand for ten children who were given the test a third time seem to indicate that while the advantage from the second test was maintained, there was no appreciable gain, from the second to the third test. However, the number of third tests is too small to consider the findings more than an indication of tendency. That the scores on the tracing path do not show an increase that can be attributed to order of testing of the directions is evidenced by the rankings for the various age groups. Although the actual rankings vary at the various ages, the general tendencies are similar. At no age does the eighth direction ( \_ ) tested rank first in score. The fourth direction tested (< ), which was the last of the series on the first day, ranks lower than any other direction, and the first direction (J ) ranks highest of all eight. If there was transfer of training from one movement to the next, it is not evident from these data. RELATIVE DIFFICULTIES OF THE EIGHT DIRECTIONS Tracing Board Experiment No one direction of movement on the tracing board stands out as consistently easier or more difficult than the others for all age groups, when actual differences alone are considered, irrespective of the significance of these differences. The rankings for order of difficulty within an age group change according to whether the MOTOR CO-ORDINATION IN YOUNG CHILDREN 49 score used is the point of first contact or the percentage within the path. When the formula for determining the standard error of differences between the means when correlated measures are in- volved8 is applied, and a correlation of .40 is assumed when the actual correlations have not been computed, it is found that there is no combination of two directions in which there are significant differences between the means in at least three of the four age eroups by both methods of scoring (point of first contact and per- centage within the path), although there are occasional significant differences within an age group. The correlations between the points of first contact on different directions of movement were worked out for five combinations of directions for the fifty-four children: r PE, Direction 1 ( J ) with 3 ( * ) 16e 09 Direction 2 (=>) with 4 ( « ) 45 + .08 Direction 5 ( A ) with 7 ( BA ) 71-2 U6 Direction 6 ( a ) with 8 ( nS ) Oe -te.09 + .09 Direction 2 (—>) with 7 ( JA ) 46 All of these correlations are significant, except for the combina- tion of directions 1 ( | ) and 3 ( 7 ), indicating that a child who makes a high score on one of these directions tends to make a high score on another of these directions. Bolton}? found that with children of eight years and older move- ments toward the body, as tested by the tracing board, were more steady than movements away from the body. Right and left hands were tested in four directions: directions 1 (J), 2 (—), 3 (7), and 4 (<). Thompson®® also found that adults made better scores on movements toward the body than on movements away from the body. Town? tested five and six-year-old children on direction 2 (— ) with the right hand and on direction 4 ( <— ) with the left hand, but found it necessary to discard the left hand scores because of their large probable errors. The present results do not show significant differences between the scores made on movements toward and away from the body. Tracing Path Experiment If the rankings of the means in the tracing path experiment for 8. 9 difference = Ve, “1072 28) 5095 Kelley, T. L. Statistical Method. New York: Macmillan, 1923. Pp. 390 (p. 182). 50 IOWA STUDIES IN CHILD WELFARE the eight directions for the half year groups are considered irre- spective of the significance of the differences of the means, it is found that direction 1 (J) ) ranks first or second in five of the seven age groups and that direction 4 (<) ranks eighth in three of the groups and never higher than fifth. Direction 2 (—) is next to 4 (<) in rank, and 3 (7) comes next, while the four angle move- ments rank between 1 (J) and3 (7). Judging from the rankings alone, directions 4 (< ) and 2 (—) were the most difficult move- ments and direction 1 (J) the easiest. These rankings can only give indications of difficulties, however, since the significance of the differences of the means should be taken into consideration. The significance of these differences will be discussed later in con- nection with the correlations of scores. It seemed probable that the averages might cover up individual differences and that a certain direction or combination of directions might be easy for one type of child and difficult for another type. Attempts to classify the individuals into types on the basis of com- binations of the ranks of the directions on the tracing path were, however, unsuccessful. Accuracy and Time of Each Trial_—tThe scores thus far reported for the children have been the averages of three trials in each direction of movement. In order to determine whether there was the same degree of accuracy for each of these trials, the average score of all children on the tracing path was computed separately for each trial. Since the child was allowed to choose his own rate of speed for the experiment, it seemed probable that there might be some relationship between the accuracy of a trial and the time that the child spent on it. The average number of seconds spent by all children on each trial was therefore also computed. Table 24 gives these average scores and average times for each direction of movement. While the differences in scores are small between the first, second, and third trials, it will be noted that the first trial was the most accurate of the three for each direction of movement. Longer times were also spent on the first trial than on the other two trials for each direction except direction 6 (\,). There was a gradual quickening in time from one direction to the next within a day’s experiment, so that the average time spent on the fourth direction tested on each day was considerably less than the time spent on 51 MOTOR CO-ORDINATION IN YOUNG CHILDREN Coie Oboe 6 olemter se Lolo 9 UL -e Slina cle LOL L997 SP 0 S69 @ 36 Choe 00s 0 Sea re FO2G Gio OL tO Le 2 OY OSL Tole 2 Sie -T OL S8or Tl r0n (eh 290 ULE. Och Dab hia ol 0 dees Gl. SL oT She Gls. 8 OF OL Sel 6 eh 26-0 8 oh 8-0 ca oe OUIL], 8109G | OUT, 9100G | OWT, o109g | OUI, e100g | OWI, o100g | OUT, 9100G | OILY, 01009 | OWT, 01009 N L AN ye cae J = t g 6 I JUOTIOAOW JO UOTDOIIG dnoiy oityuq Aq Ye SuoeLy, oy} UO s[eLIy, ooLYY, OY} FO YORUM WO Soully, wdVIOAW PUB SOL0DG VSVIOAY So WIAV.L PATEL puov09 WILT TerL 52 IOWA STUDIES IN CHILD WELFARE the first direction that day. This quickening in time might be interpreted as meaning that the directions became progressively easier, that the child was benefiting from each previous trial and ‘‘oetting into the swing’’ of the test, that he was becoming more confident, or that he was losing interest and becoming careless. Introspections would have helped here, had it been possible to get them from preschool children. It was possible to test some adults to learn whether the same tendencies in time operated and to get their introspections. Six adults were tested on the first four direc- tions. Their average times in seconds were as follows: Direction 1 2 3 4 J erat kd <— First trial 18.2 a 8.2 7.2 Second trial aie 05° 6.7 8.0 6.3 Third trial 9.8 6.7 8.2 6.0 Their times showed the same tendency as those of the children, that TABLE 25 Correlations between Times on First, Second, and Third Trials for the Hight Directions on the Tracing Path Direction of movement Direction of ; 1 2 3 4 5 6 i movemen | = " = Y x JZ 3 to 7 years (88 children, 264 correlated pairs) rian .66 oF 64 .64 aires 62 70 .63 Dear, 45 31 22 37 Ue se 36 37 32 25 42 Vf 18 25 21 34 26 31 SNS 36 35 30 40 45 .40 a yf 3 years (24 children, 72 correlated pairs) fe gate 72 Set b ae | .68 4 ew .66 64 .63 Da 27 09 ~.01 .07 Bran 39 37 23 21 54 te / 10 .08 15 21 .28 41 Be 30 02 01 .24 30 30 .20 MOTOR CO-ORDINATION IN YOUNG CHILDREN 53 4 years (18 children, 54 correlated pairs) Ae} Ray f 3 1 62 ol Pes oo 41 .64 5 es 21 .03 .07 —.01 6 NS 29 39 21 aly! 21 Tf —.01 -—.08 OE .07 12 18 8 EX .08 01 ay ahs .28 .06 .04 5 years (24 children, 72 correlated pairs) re saat 09 3 4 .29 22 iS rae ay 40 .26 5 eh 50 A ly; 21 28 6 i 32 a3! Bh) 11 46 ane 14 16 25 27 .29 na hy 8 RS 30 23 21 16 44 43 38 6 years (16 children, 48 correlated pairs) Spee 87 3 * 79 .84 ea 86 92 82 5 we 58 56 SE: 59 6 A 44. my 34 34 50 es 35 29 abe 29 19 26 8 ite 47 Ase 40 48 58 54 24 is, a general decrease as the test progressed, the fourth direction (<) taking less time than any other, in spite of the fact that three of the six adults considered the fourth direction the most difficult. Two considered direction 3 (7) the most difficult and the other person was uncertain. They were conscious that their speed was increasing, but attributed it mainly to motor habituation. One tendency in the children’s time that was not evident for the adults was that for the children the first trial in a new direction took a longer time than the third trial of the preceding direction. Evidently for the child a new direction presented more elements of a new situation than for an adult. The adults made practically perfect score throughout. In order to determine how much relationship there actually was between the time and the accuracy of a particular trial, correlations between the times and between the scores on separate trials on the eight directions and correlations between the scores and times on separate trials were worked out. o4 IOWA STUDIES IN CHILD WELFARE Correlations between Times and between Scores on Separate Trials—The correlations between the times for the trials on the different directions on the tracing path are given in Table 25. There were eighty-eight children for whom scores and times were available for each of the three trials on all eight directions of movement, making a total of 264 correlated pairs. When the entire group was used, the correlations between times on the different directions were significant in all cases, but varied in size from .18 between directions 1 and 7 to .70 between directions 2 and 4. The correla- TABLE 26 Correlations between Scores on First, Second, and Third Trials for the Hight Directions on the Tracing Path Direction of movement Direction of ‘ 1 2 3 4 5 6 7 movemen J a , we sy Ny 7 3 to 7 years (88 children, 264 correlated pairs) rage et Dep e , Bhar 67 74 eye ak .66 -76 ah! anya 63 59 62 .63 Degas 58 63 62 61 .66 Gisey) .60 .69 65 66 67 09 8 Pe ES iy Beg One ete nae | ee OED ROO TENE ge, 61 61 65 .66 .69 65 70 3 Set Pe AN Cate (24 children, 72 correlated pairs) patois pL ih 27 29 r Se 2am 27 41 24 seme, .20 .08 32 17 TOTS 7 30 24 16 .29 (icy .08 33 reg 17 26 .06 8 TER ENC T TM | eke Teh OLR 1a ae Carve nine oa Ree 12 -.01 .20 21 1 20 24 4 MOS ia de bene Oe (18 children, 54 correlated pairs) RUSE Treo a Serene => 50 oom 46 64 Ae: 39 61 R519) Dine .24 33 22 42 ee ab) .26 22 33 30 ras aa as .40 40 38 29 aN 21 34 22 32 44 35 2 MOTOR CO-ORDINATION IN YOUNG CHILDREN 55 5 years (24 children, 72 correlated pairs) td Pees .28 3 @ 16 40 Deon 27 44 50 5 gf 28 aly 19 mike: 6 ns 21 a 7 aT 29 7 A 42 44 2D so0 44 .26 8 Eg 28 24 41 42 38 48 44 6 years (16 children, 48 correlated pairs) rete 01 3 t 12 sab 7 hg orate CLT 18 28 5 i, 42 —.30 .03 24 6 NG oat —.06 04 20 BY | 7 oe —.07 —.07 .30 28 —.04 at 8 NS 25 18 40 45 -.01 36 24 tions between the first four directions were much higher than the other correlations. The average for a specific direction with all others ranged from .35 to .46. There was thus a definite tendency for the children to be consistent in the amounts of time that they spent on two directions. They were much more consistent for directions 1, 2, 38, and 4 than for any other combinations. This does not mean that they spent the same amounts of time on the different directions, but that the trend for time taken was in the same direction for different children. Correlations between times on the tracing path for the separate age groups were also computed. At three years, seventy-two pairs were included in the calculations, at four years, fifty-four pairs, at five years, seventy-two pairs, and at six years, forty-eight pairs. At seven years there were eighteen pairs for which correlations were not computed because of the small number of children. A correlation of .21 or above is significant for the three and five-year groups, and a correlation of .27 or above is significant for the four and six-year groups. The correlations between scores on the separate trials that are given in Table 26 are all significant and high for the entire group, indicating that a child making a high score on one direction is likely to make a high score on another direction. The same group IOWA STUDIES IN CHILD WELFARE D6 PA eee Lee Loe ee 6 LSAT L oT G Tyr DL dr. erent oes Gree Was OOP sweet owe Silas 6. Tel oes S Is |2Lb-) OS TS — 6eT A6UL aLOt Gubes CF ‘as S'06_ 766 GI6 0°06 98 T'68 0°68 §68 | GZI S'S 2EL O'8T TFL LPL L’8t_ 06 suBOTL sIBok 9 ES Ss SAE VE Ronde a ie ns lore ke ig Ak A ee Lae TS a AS =, Sea Gi. Lpeen teed bee Ose OD See GT Oty v L L oboe ae L 8° VT W's WV OnlLecryleLel 0 cleoGl Lr ie 6. LOee0O. GUL OS 6C) OOM PET ‘a's Lise vente S45 ois U tse S Pees | OO Peis GLeOLL orl FL Lote ue suBoyl pe EO ee LV VEG ee Obes SEV Le Pbk SLOG erm, et een ee ee sivok G AEE AUST Ss _ EES Ts Sd EMO Haak POA. Be aa RR ad Paes 8 a Sea POSER EN Oe OG a) Ge Ob Coe wn eee G L 6 i) Ei i 8 Bag Os LOS N's Lar OS Oey cae Le oad Rage Sy 4 81 € sa] ES “Gd | as a] ES MG] aS Ma) aS Ma] as wa] as a] oy | op ie oe ee aap eae | ae es a es | ee we play aan ae, nf ER A ae age glee ae a en ae Bee 09 \ "4 & Ze ab | gS 8 i 9 G ea ies te bR o Ph JUSMIBAOW FO WOTZDIIIG aSy JO sIVIK XIG 0} oolyy, woz VorpIyO Aq YV_ Surovczy, oy} WO oury FYSTBIZG B WOLF UOTZVIAOG JO osvjUodIEg VSvIOAV Og UIavL MOTOR CO-ORDINATION IN YOUNG CHILDREN _~ 63 8 (\_) to show less deviation than the other directions, with its opposite direction 6 ( \, ) and direction 3 (7) ranking next in order, while 1 ( | ), 2 (—), and 4 (<) tended to show the great- est deviation. RELATION BETWEEN CO-ORDINATIONS IN EXPERIMENTS WITH TRACING BOARD AND TRACING PATH Correlations between scores on the separate directions on the tracing path and point of first contact on the tracing board were worked out in order to determine whether a child tended to make similar scores on the same direction for the two tests. The cor- relations for the entire group, ages three to six, were as follows: imi taal OE Direction 1 ( J ) 20.09 Direction 2/(° 5 ) oot .07 Direction 3 ( f ) 23.09 Direction 4 ( e ) A8= .07 Direction 5 ( / ) 40.09 Direction 6 ( \, ) 04.08 Direction 7 ( J ) 52.08 Direction 8 ( \ ) A4+ .09 Combined 6922.05 While there was a positive relationship between scores on the same direction for the two tests, the correlations were considerably lower than the correlations between the directions on the tracing path (.80 to .86), but were about the same as the correlations between the directions on the tracing board. These correlations between the two tests would probably have been reduced if the age range had been narrower. When all eight directions were combined, the correlation was raised to .69 + .05, but when age was held constant by the method of partial correlation, the cor- relation dropped to .29 + .09, which, while positive, was only slightly greater than three times the probable error. The cor- relation between the combined scores for the eight directions on the tracing path and the combined scores for the eight directions on percentage within the path for the tracing board was .75 + .04, when the entire group of children was used. When age was held constant, the correlation became .47+ .07. This correlation is considerably higher than the .29 obtained when point of first con- tact was used as the score, and indicates that when percentage within the path was used children who scored high on the tracing 64 IOWA STUDIES IN CHILD WELFARE path test also scored high on the tracing board test. From these correlations it seems, therefore, that there was a very slight re- lationship between the point of first contact on the tracing board and the tracing path scores, considering that they were intended to measure practically the same function, but that scoring by the > method of percentage within the path brought the tracing board results into closer agreement with the tracing path results. CHAPTER V PSYCHOPHYSIOLOGICAL ELEMENTS OF MOVE- MENTS IN EXPERIMENT WITH TRACING PATH Examination of the lines made by the children in attempting to keep within the path in the tracing path experiment on motor coordination shows that there were marked differences in the prod- ucts at the various age levels. The younger child who succeeded with the test kept within the path but a relatively short time, made a Sweeping curve out of the path, and in attempting to get back in the path swung as much to the other side, so that his line crossed and recrossed the path in a rhythmical fashion. The still younger child who failed to understand the task made a quick slashing movement down the sheet of paper outside the path and did not attempt to swing into the path. The line that he produced was straighter than that of the child who made a low score. Figures 4,5, and 6 are photographs of the records of six children for directions 2 (—>), 3 (7), and 5 (/) respectively, selected to show the general trends of lines and how the same type of line was produced by a given child throughout the various directions of movement. The record at the extreme left in each figure is that of F4, whose line sweeps back and forth across the path. This child was two years, eleven months old. The next record is that of a child three years, one month old who made a slightly higher score because she was able to change the direction of movement more abruptly. The remaining records show progressively more abrupt changes in the direction of movement and a consequent ironing out of the lines to the lme of M59, who kept almost entirely within the path al- though he fluctuated back and forth. This boy was six years, nine months of age and his scores were 95, 100, and 100 respectively for these three directions. What are the muscular factors that operate to produce these differences in performance at the various age levels? Are there differences in muscular adjustments that affect the scores, and, if so, are these differences intrinsic and necessary or are they due to psychological control? The question of differences in muscular 65 66 IOWA STUDIES IN CHILD WELFARE F4 F8 F24 F48 F52 Fig. 4. Lines of six children on direction 2 (—») Child F4 F8 F24 ¥F48 Age, years and months 2-10 3-1 3-8 5-0 Score 35 38 66 83 Time, seconds 6 4 8 14 ee F52 5-3 90 th 6-9 9 13 MOTOR CO-ORDINATION IN YOUNG CHILDREN 4 F8 F24 F48 F52 Fig. 5. Lines of six children on direction 3 (4) Child F4 F8 F24 ¥F48 Age, years and months 2-10 3-1 3-8 5-0 Score 34 41 64 88 6 9 10 Time, seconds 6 F52 5-3 90 16 67 68 IOWA STUDIES IN CHILD WELFARE nT A or SE NE TN AO OT ON EE II a eg i | ! f \ f | | : F4 F8 F24 F48 F52 Fig. 6. Lines of six children on direction 5 Le Child F4 FS F24 F48 ¥F52 Age, years and months 2-11 3-2 3-8 5-1 5-3 Score 44 60 73 81 86 Time, seconds 9 13 12 18 16 — ee —— — MOTOR CO-ORDINATION IN YOUNG CHILDREN _ 69 adjustments may be answered in part by an analysis of the me- chanies of the movements that the children make while perform- ing the task. Some insight into the psychological factors of con- trol may be gained by changing the psychological conditions of the task but keeping the muscular requirements as constant as possible. MECHANICS OF MOVEMENTS Analysis was made of the movements in terms of physiological adjustments, flexion, extension, abduction, adduction, pronation, supination, and torsion. The analysis was made by observation of the children as they actually performed the test according to the usual procedure. For about half of the records obtained, two observers? noted the active movements involved in the perform- ance; one recorded the movements of the trunk, shoulder, and elbow, while the other recorded the movements of the forearm, wrist, and fingers. It was not possible for both observers to be present for all of the tests, hence the notations on some children were made by one observer working alone. The records were made as complete as possible. For each of directions 1 (J), 2 (—), 3 (fT), and 4 (<), 183 records on sixty-one children were ob- tained. At three years of age there were six children, at four years, sixteen children, at five years, twenty-six children, at six years, eight children, and at seven years, five children. For directions 9(/7),6(N), 7(7), and 8 (_), seventy-two records on twenty-four of these children were obtained. Fuller accounts of the movements made and the muscles em- ployed might have been gained had it been possible to have motion pictures of the children as they did the test. This was not feasible at the time, however, for such a large group of children. The present analysis brings out some rather significant gross differences in the children’s methods of approach. Unfortunately it could not include differences in the rhythm of movements and in the speed of the separate adjustments, which are important factors in the unity of a movement. The time for total performance was kept as usual. The sequence of the adjustments observed is indicated in gen- eral in the discussion by describing first for each direction the 9. The writer was assisted in this work by Idell Pyle, research assistant in anthropometry in the Iowa Child Welfare Research Station. 70 IOWA STUDIES IN CHILD WELFARE basic movements that were carried on through the entire perform- ance and describing next the additional adjustments that occurred as the performance progressed. At all ages, at the beginning of each of these tests the pencil was grasped by fingers 1 (thumb), 2, and 3, with 4 and 5 in free flexion, and the forearm was in a semipronated position. For direction 1 (J) the position taken was that of flexion of the fingers, elbow, and shoulder. The basic and predominating active movement at all ages for direction 1 was elbow flexion com- bined with shoulder extension, except at age seven, when wrist flexion was the primary movement, supplemented by finger flexion, and alternating with elbow fiexion and shoulder extension when the wrist had reached its maximum flexion. Wrist flexion was not used at any other age. Active finger flexion was noted in some children at all ages, but more in the older children than the. younger. Body torsion was notable in the three-year-old children and trunk flexion and extension were present in half of the four- year-old children, but were gradually eliminated in the older groups. Pronation was evident as early as three years, but was not largely used except at age four, when it was observed in about one-third of the children. For direction 2 (— ) the position at the beginning of the move- ment was elbow and finger flexion, and the basic active movements at all ages were elbow flexion and shoulder extension. Wrist flexion was not used for this direction except in the case of two seven-year-old children, since it was particularly difficult and practically impossible without elevation of the wrist from the paper. Body movements were again noted at the younger ages, although less frequently than for direction 1. Pronation occurred to some extent at all ages except age seven, and shoulder abduction at all ages except age three, when pronation and body torsion were substituted. Ulnar adduction occurred in about one fourth of the four- and five-year-old children. For direction 3 ( t ) the position was elbow flexion, shoulder flex- ion, and shoulder abduction. The basic active movement was elbow extension, combined with shoulder flexion at ages three, four, and five, and with wrist flexion in addition at age seven. At age six the supplementary movements were varied, pronation, shoulder adduc- tion, shoulder abduction, wrist flexion, and body torsion occurring with some of the children and in different combinations. Ulnar ad- MOTOR CO-ORDINATION IN YOUNG CHILDREN 71 duction, finger flexion, and body flexion were noted in one third of the five-year-old children. For direction 4 ( <— ) the position was that of elbow flexion and shoulder extension. The basic active movement was elbow extension with shoulder flexiun and pronation. Body torsion and trunk exten- sion were quite prominent ini the four-year group, and trunk flexion was noted in several instances in the five and six-year groups. Some wrist flexion was present in the seven-year-old children. Ulnar ad- duction occurred in one fourth of the four and five-year-old chil- dren. For directions 5, 6, 7, and 8 the number of cases was too small for age analysis of the movements. Directions 5 and 6 were largely ac- complished by elbow flexion, combined with wrist flexion, and sup- plemented sometimes by shoulder extension and sometimes by shoul- der abduction. Shoulder extension occurred in a larger number of cases in direction 6 than in direction 5, and wrist flexion was more prominent in direction 5 than in direction 6. Finger flexion. was prev- alent for both directions. For directions 7 and 8 elbow extension, shoulder abduction, and shoulder flexion were the basic movements. Ulnar adduction, was used by practically all of the six-year-old chil- dren, and by some of the five-year-old children, although pronation was more common at five years. Radial adduction was used by some children at seven years and wrist extension by some. In summing up the results for all of the directions, it is found that body movements—hody torsion, trunk flexion, and trunk exten- slon—were common among the younger children, that these body movements were gradually eliminated as age increased, and that localization of control in the wrist was prevalent among the older children. What are the muscular adjustments, apart from those mentioned in relation to age, that a child makes who earns a high score on the test and how do they differ from those of the child who earns a low score? To throw light on this question some individual records were compared. Two pairs of children of the same age were selected on the basis of widely differing scores, one child of each pair making consistently high scores and the other child making consistently low- er scores. The active movements of each child in the pairs are pre- sented here: 72 IOWA STUDIES IN CHILD WELFARE F28 Age: 3 years, 10 months Score 94 Finger flexion Elbow flexion Shoulder abduction Score 92 Elbow flexion Shoulder abduction Finger flexion Wrist extension Ulnar adduction to Radial adduction Score 76 Finger flexion Elbow extension Shoulder flexion Shoulder abduction Radial adduction Seore 81 Finger flexion Radial adduction to Ulnar adduction Elbow extension Shoulder abduction F 31 Age: 4 years, 1 month Seore 94 Elbow flexion Body flexion Finger extension Shoulder extension M 27 Age: 3 years, 10 months Direction 1 ( | ) Score 73 Finger flexion Elbow flexion Shoulder abduction Ulnar adduction Pronation Shoulder extension Direction 2 ( ~» ) Seore 64 Elbow flexion to Elbow extension Shoulder adduction Pronation Body torsion Direction 3 ( f ) Score 49 Finger flexion Elbow extension Shoulder flexion Ulnar adduction Direction 4 ( e ) Seore 60 Ulnar adduction Shoulder flexion M29 Age: 4 years, 0 month Direction 1 ( | ) Score 78 Elbow fiexion Body flexion Pronation Shoulder flexion MOTOR CO-ORDINATION IN YOUNG CHILDREN 73 Direction 2 ( ~—» ) Score 91 Score 78 Elbow flexion Elbow flexion Ulnar adduction Wrist flexion to Pronation Radial adduction to Supination Direction 3 ( 4 ) Seore 95 Score 47 Elbow extension Elbow extension Shoulder flexion Shoulder flexion Pronation Direction 4 ( — ) Seore 85 Seore 51 Elbow extension Elbow extension Shoulder flexion Shoulder flexion Pronation Pronation Wrist flexion Body extension Radial adduction Body torsion The two girls who earned the higher scores were from one and one- half to two years beyond their age level in score, while the two boys made scores at about their age level. Comparison of the movements of the two members of a pair show that there were differences be- tween the movements made by the child earning a high score and the movements of the child earning a low score. There were also differ- ences between the movements made by the two children earning high scores, which were practically as great as the differences between the members of a pair. In only two instances the two high scorers used an identical movement that was not used by the poor scorers. These instances were for direction 2, on which the high scorers used ulnar adduction, which was changed to radial adduction as the move- ment progressed, and for direction 4, on. which they used radial ad- duction. Pronation in directions 1 and 2 was the only movement used by both low scorers that was not used by the high scorers. These results seem to point to the conclusion that the adjustments were probably matters of individual differences and that the explanation for the likenesses and differences in scores for two children of the same age must be sought elsewhere than in the types of adjustments observed. A pair of children was also selected on the basis of scores compar- able with the scores of the other two pairs, but the members of which differed in age. One child was five years, two months old and the other three years, six months old. 74 IOWA STUDIES IN CHILD WELFARE Parr III M 36 M 25 Age: 5 years, 2 months Age: 3 years, 6 months Direction 1 ( | ) Score 96 Score 71 Finger flexion Finger flexion Pronation Pronation Elbow flexion Shoulder adduction Seore 95 Finger flexion Pronation Shoulder abduction Wrist extension Elbow flexion Seore 97 Finger flexion Elbow extension Elbow flexion Wrist flexion Radial adduction Shoulder extension Knee flexion, Direction.2.(7 >a) Score 52 Finger flexion Pronation Shoulder abduction Knee flexion Direction 3 ( ff ) Score 70 Finger flexion Body flexion Shoulder abduction Direction 4 ( e ) Score 51 Finger flexion Elbow extension Shoulder extension Body torsion Score 94 Finger flexion Wrist extension Elbow flexion In this pair the most marked differences in movement were in the presence of knee flexion, body flexion, and body torsion in the three and one-half-year-old child and in the absence of these body move- ments in the five-year-old child. INDICATIONS OF PRESSURE It was noted from observation of the movements, particularly flexion. of the fingers and pronation, and by the shade of the line produced that during a trial the children used varying amounts of pressure upon the pencil. A permanent record of the amount of pressure was desired, if such could be obtained without changing the conditions of the test. Complicated apparatus for recording pres- sure such as that used by Freeman’? in his writing experiments did not seem advisable with these young children. Dental wax was first placed under the test sheets and the test given in the usual manner. Inspection of the wax afterwards showed MOTOR CO-ORDINATION IN YOUNG CHILDREN — 75 that there were changes in the amount of pressure during a trial. These variations showed as clearly, however, on the back side of the test papers themselves, whether the wax or beaverboard was under- neath, since the beaverboard was also relatively soft. Where the pressure was extreme, the pencil point nearly broke through the pa- per; where it was slight, the line was not visible on the opposite side. There were considerable individual variations in the amounts of pressure exerted. Most children used more pressure at the begin- ning of the trial than in any other part. This heavier pressure lasted about 1 or 2 em., and in exceptional cases about 5 em.; then the line became lighter and lighter until at the end of the trial the line was not visible on the back of the sheet. If a child went off the path, stopped and began: a new line within the path, instead of continuing his movement and swinging back into the path, as happened in a few cases, the new line which was begun showed the same greater pressure at the beginning. Another method of determining relative pressure on the pencil was by the depth of the imprints in plasticene that had been wrapped around the pencil about 3 mm. thick. The plasticene was a some- what distracting factor; the children asked, ‘‘ Why do you put clay around it?’’ Twenty-four records on six children and one record each on three adults were obtained. The pressure used by one adult who had had considerable training in penmanship was so light that the positions of the fingers could not be determined later. Individ- ual differences existed among the children, but the pressure was suf- ficient in every case to make a decided imprint on the plasticene, the pressure usually being greatest with the forefinger and next with the thumb. Of the other two adults, one used less pressure than the children, and the other used greater pressure than any of the chil- dren, the greatest pressure in her case coming from finger 38, in con- tast with the other two adults, who, like the children, exerted most pressure with fingers 1 and 2. TIME FACTORS IN MOVEMENTS In the main experiment the total time of performance was record- ed by means of a stop watch. A special experiment was made in order to determine the length of time the child spent in the various parts of the movement. Light pencil dots were placed on the test sheets 2 em. apart and about 2 em. outside the guidelines. The child took the test in the usual manner, while the experimenter sat at the 16 IOWA STUDIES IN CHILD WELFARE end of the table with a stylus and tapping apparatus on her lap un- der the table and out of the range of vision of the child. As the child passed each dot the experimenter tapped and the taps were recorded on a kymograph drum in the adjoming room. ‘This method of course involved the reaction time of the experimenter, but all records were made by the same experimenter. A time line was taken simultaneously in fifths of a second by a standard chro- nometer. Most of the children did not notice that the experimenter held the apparatus, and the test was in every other way comparable to the standard method. Fifty-seven time records were taken. An examination of the time records shows a tendency to a very slow rate for the first 2 em., or starting of the movement with a gradual increase in speed through the central portion of the path, a gradual decrease for the latter portion, and the slowest rate for the last centimeter, with stopping of the movement. Special conditions, however, operated to change the speed. If the child got outside or too near the guidelines he slowed up until he felt that he was safely back again. Occasionally a child slowed up or stopped entirely to make some remark. Since these changes in the rate of movement were for the most part brought about by the attempt of the children to keep within the confines of the guidelines, general conclusions can not be made on the rate of speed they would take in drawing lines under different conditions. In a majority of the cases the first trial took considerably longer than either of the other two trials. This is in agreement with the findings on total time taken by the stop watch method during the course of the main experiment. Figure 7 is a sample record which illustrates some of these tendencies. FREELINE MOVEMENTS In order to test whether the sharp turns and curves in the lines made by the children were due to lack of muscular control or to psychological factors, a variation of the test was devised. After a rest or play period following a test given in the usual way, the child was brought back and given sheets of paper on which were two dots 25 em. apart. The instructions were: ‘‘See this dot [pointing] and this dot [pointing]. I want you to make a mark from this dot to this dot.’’? Thirty records on dot tests were secured. Figures 8 and 9 show three trials each in the same directions with the guidelines and with the dots for a girl (F30) and a boy (M12). MOTOR CO-ORDINATION IN YOUNG CHILDREN 17 Fig. 8. F30, at four years, five months, took twenty-two seconds, thirteen seconds, and nineteen seconds for the three trials on direction 7 (7) with the guidelines, but only seven seconds each for the three trials on the same direc- tion without the guidelines. 78 IOWA STUDIES IN CHILD WELFARE ~ vere . 3 < Pras Ren needs a PSS es SRR Bm CR A ESE OE paweurer se an a ea eee Fig. 9. Abrupt changes in freeline movement were made by M12, aged three years, six months, when he missed the dots on the second and third trials on direction 1 GABE MOTOR CO-ORDINATION IN YOUNG CHILDREN = 79 The most outstanding feature of the dot records is their freedom from curves and angles when compared with the guideline tests. When the child realized that he was moving in a direction that would bring him away from the dot, he shifted the direction of movement gradually, as is illustrated in the second trial with the girl and the first trial with the boy. Sometimes when the realization that the dot would be missed came late, as in the case of the second and third trials with the boy, sharp turns were made. Another characteristic of the dot test is that the trials consumed very much less time than the guideline trials. The three trials with the guidelines for the girl took 22 seconds, 13 seconds, and 19 see- onds, respectively and with the dot test 7 seconds each. For the boy, the differences were even greater, the time being 22 seconds, 21 seconds, and 16 seconds on the three trials of the guideline tests, and 4 seconds, 4 seconds, and 5 seconds on the dot tests. Similar differ- ences in time and in type of line were noted for all of the children tested. It would seem, then, that the curves and angles in the lines on the tracing path were products of conscious attempts to keep within the path and of inhibitions aroused by the guidelines, since it has been demonstrated that the children were capable of making straighter lines when the guidelines were absent. There is probably no physi- ological reason why such fluctuations should have appeared, unless possibly the slower rate that was adopted voluntarily may have tended to cause unsteadiness. Test records with the dots differed from those with the guidelines also in the amount of pressure; with the dot test there was not yvreater pressure at the beginning of the trials, as with the guide- lines, and the pressure was almost uniform for the entire length of the trial. Children who exerted decided pressure at the start with the guidelines failed to exert this pressure when the dots were sub- stituted. Apparently the greater pressure at the beginning of a trial was not a necessary part of getting a movement started, but came about from an attempt to make an accurate adjustment within the guidelines. Differences in the focusing of the eyes for the two tests were also observed. The examiner sat in a low chair beside the child and could easily watch the movements of the child’s eyes without distracting the child. Notations were made of the eye movements of the chil- dren in thirty-three tests. When the child made the freeline move- 80 IOWA STUDIES IN CHILD WELFARE ment, he usually looked at the first dot until he had progressed about 5 em., then he shifted his gaze to the goal dot and kept it focused there until he had finished. Some exceptional children made a sup- plementary shift or two back to the pencil and then to the goal dot again. When the guideline test was given, the eye shifts were more frequent for the same children and took in smaller units. There was not the large shift to the end of the path, but the progress was gradual in fairly definite units. Sometimes there were movements of the head in addition to movements of the eye. The highest num- ber of definite movements of the eye observed for any trial was thir- teen, made by a child whose average number of shifts for the guide- line test was 8.5, plus turning of the head, and whose average number of shifts for the dot test was four, this being above the average of all children for the dot test. What evidence is at hand seems to indicate that the eye movements were not important of themselves, but were indicative of mental processes. The number of cases studied was small, but the same conditions were observed in all instances. More data are needed on this phase of the problem. ‘aTqissod Sv Ayyomb Sv (BIL, of YStuy 0} DATJOU LOLI94[N oUIOS WWoAs dtIsop B Of 10 ‘GUIYBUE SBA JYS JUVUIAOU pider oy} s0u0 4B ypoyo 03 AQITIGeUT 07 oNp usey oABY ABUL ATO}VIPEWLUT WAMOP AOT[S 0} BANTTVT oy, “JUotusaour oy4 dojs 0} lopio ur A[qevoorjyou poods 19Y posedatoop oys ynq see oy} JFO JUGM DYS 10IFB AToyeIpouLtay UMOD MO]S JOU prp ys [ely sity} uy ‘poods soy SutsvoroUut AT[eupels ‘8 yop [YUN Yyed oy} UI doy P[tys vy} ‘[Vr4} paryy vy} UT ‘UMOP POMOTS OYS YOIYM IoyZe “QT puB G SJop WoaMzoq yyed uy JO FUOM oYS jIFIM Suope ydoms woyy puv ‘yyed yy ut dsey 0} peseueum ynq “F pue g pus e PUB Z SJOP WooMyoq JUT;epINS ey} polfouo} p[lyo sy} ‘Perm. pwovss 9yZ UT ‘yzed oyy dn youq uedoq puv ‘fioued 19y poy ‘qyed oy} JfO JUOM VYS OL PUB G SJOP UsaMJoq pu ‘roused AVY FO pReT oY BYorq ays 9 puB g Sop Uee Ad “UMOD POMOTS ATOJVIPOWUIE puB E PUR | WeaAzoq yzed om} FO QUOM Ply oyy Ae yoRy OY} AQ poUTy] dxe SL g 0} & S}Oop WoLy (LL) [ety ysiy oy} UO oWITY JasuOT OT, “FO ‘paAtyZ 9YZ PUB ‘gO, “poss VY} ‘spUdd.es EZ YN04 [erty ysity yY oa "WD [ ST YOLYA\ ‘TBALOJUL ISB] ay} ydooxe ‘yous “wd J FO S[BALoJUT JV ‘SloquNU AQ PozZBOTPUL st ‘SIoJOULIJWOD UL ‘pLODIL S,P[U I], “pwooses C/T G - : JO S[BALOJUTL IB[NSI1 48 SOUT] JLOYS &q peyeolpul SL OUuLTy OULD PPL Aq WOTPIIATP JUO ut STeLty eo TT T, it “OTH SA IRI Or ire eb errs mere rrr: o b % > ane ; Pe-Gleh SW Se ep REE oe Te ce aes 3 RE) i es r - DET ROL SE URMORIAS S RRR. ithe) ~ APT amma e: He. PANT AMEN ee a ery mn ey were Pg eis aR SO pp or me * ek A dee Sa A lo coe oak al ae a oe oe TEE ORT COPE rr ee rer ey oy PP errr yee x eL au fru HOt, 84% she Pp. 142, Cowdery, K. M. A Note on the Measurement of Motor Ability. J. of Educ. Psychol., 1924, 15, 513-519. 89 90 tt29. tt31. meas *36. IOWA STUDIES IN CHILD WELFARE Cummins, R. A. A Study of Defective Pupils in the Public Schools of Tacoma, Wash. Psychol. Clinic, 1914, 8, 153-169. Cunningham, K. 8. Binet and Porteus Tests Compared. Examina- tion of One Hundred School Children. J. of Educ. Psychol., 1916, 7, 552-557. Douglass, A. A., and Dealey, W. L. Micromotion Studies Applied to Education. Ped. Sem., 1916, 23, 241-261. Drever, J. A New Method of Registering Writing Pressure. J. of Exper. Ped., 1913, 2, 25-28. English, H. B. An Experimental Study of Mental Capacities of School Children, Correlated with Social Status. Psychol. Monog., 1917, 23 (No. 100), 266-331. Foote, E. C. Thumb-Finger Opposition. Tr. 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Clinic, 1922, 14, 73-82. Bhi UNIVERSITY OF IOWA STUDIES IN CHILD WELFARE The Iowa Studies in Child Welfare may be obtained at the prices indicated by addressing the Editor of the University; they will be supplied on request to persons in the state who are actively engaged in; child welfare work. VOLUME I 1. The Physical Growth of Children from Birth to Maturity, by Brrp T. BALD- WIN, Research Professor of Educational Psychology and Director Iowa Child Welfare Research Station. 41llp. 1921. Out of print. 2. A Survey of Musical Talent in the Public Schools, by CARL E. SEASHORE, Head of the Department of Philosophy and Psychology and Dean of the Grad- uate College. 36p. 1920. $.25. 3. A Preliminary Study in Corrective Speech, by SARA M. STINTCHFIELD, As- sistant in Speech Training. 36p. 1920. $.40. 4. Analytic Study of a Group of Five- and Six-Year-Old Children, by CLARA H. Town, Research Associate, 87p. 1921. $.50. 5. 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Iowa Child Welfare Legislation Measured by Federal Children’s Bureau Standards, by A. IONE BLIss, Assistant in Sociology. 52p. 1922. $.40 4. A Test of Social Attitudes and Interests, by HORNELL Norris Hart, Re- search Associate Professor of Child Sociology, 40p. 1923. $.40 VOLUME III 1. A Study of Hereditary and Environmental Factors Determining a Varibale Character: Defective and Freak Venation in the Parastic Wasp Habrobracon Juglandis (Ashm.), by P. W. Wuitine. 80p.. 1924. $1.25. 2. The Constructive Ability of Young Children, by LovisaA C. WAGONER. 55p. 1925. $.75. 3. The Emotions of Young Children. An Experimental Study in Introversion and Extroversion, by LESLIE R. MARSTON. 99p. 1925. $.90. LB1105 .164 v.3:4 The development of motor co-ordination rinceton Theological Seminary—Speer Library P 1 1012 00141 8179