With this preamble, I wish to call attention to a possible method of experimenting with young children, which has not been before noted to my knowledge.^ In endeavouring to bring questions like the degree of memory, recognition, association, etc., present in an infant, to a practical test, considerable embarrassment has always been experienced in construing the child's responses safely. Of course the only way a child's mind can be studied is through its I expression — facial, lingual, vocal, muscular; and the first ^ question, i.e., What did the infant do.? must be followed by a second, i.e., What did his doing that mean } And the second question is, as I have said, the harder question, and the one which requires more knowledge and insight. It is evident, on the surface, that the farther away we get in the child's life from simple inherited or reflex responses, the more complicated do the responsive processes become, and the greater becomes the difficulty of analyzing them, and arriving at a true picture of the real mental condition which lies back of them.
To illustrate this confusion, I may cite about the one problem which psychologists have attempted to solve by experiments on children: the determination of the order of rise of the child's perceptions of the different quali- ties of colour. Preyer starts the series of experiments by showing a child various colours and requiring the child 1 My first discussion of it was in Science, New York, April 21, 1893.
40 A New Method of Child Study.
to name them, the results being expressed in percentages of true answers to the whole number. Now this experi- ment involves no less than four different questions, and the results give absolutely no clue to their analysis. It involves, i. The child's distinguishing different colours simultaneously displayed before it, i.e., the complete de- velopment of the child's colour sensation apparatus; 2. The child's ability to recognize or identify a colour after having seen it once; 3. An association between the child's colour- seeing and word-hearing and speaking memories, by which the name is brought up; 4. Equally ready facility in the pronunciation of the various colour names which the child recognizes: and there is the further embarrassment, that any such process which involves association, is as varied as the lives of children. The single fact that speech is acquired long after objects and some colours are distinguished, shows that Preyer's results are worthless as far as the problem of colour perception is concerned.
That the fourth element pointed out above is a real source of confusion is shown by the fact that children recognize many words which they cannot pronounce readily. Binet, who represents the second phase in the development of this experimental problem, realized this, and varied the conditions by naming a colour and then requiring the child to pick out the corresponding colour. This gave results different not only from Preyer's, but also from those which Binet reached by Preyer's method. For example, Preyer's child identified yellow better than any other colour, a result which no one has confirmed.
The further objection that colours might be distin- guished before the word-association is established at all, or that colour-words might be interchanged or confused by CriticaL 41 the child, ^ is also seen by Binct, and his attempt to elimi- nate that source of error constitutes what we may call the third stage in the statement of the problem. He adopts the DietJiodc de reconnaissance as preferable to the mctJiodc d' appellation. This consisted, in his experiments, in show- ing to a child a coloured counter, and then asking the child to pick out the same colour from a number of differ- ent coloured counters.
This reduces the question to the second of the four I have named above. It is the usual method of testing for colour-blindness. It answers very well for colour-blind- ness; for what we really want to learn in the case of a sailor or a signal-man is whether he can recognize a deter- mined colour when it is repeated; that is, does he know green or red to be the same as his former experience of green or red } But it is evident that there is still a more fundamental question in the matter — the real question of colour perception. It is quite possible a child might not recognize an isolated colour quality when he could really very well distinguish colour qualities side by side. It is the question just now coming to the front, the question of absolute vs. relative recognition, or immediate vs. mediate recognition.^ The last question is this: When does the child get the different colour sensations (not recognitions), and in what order } A further point of criticism of Binet's results serves to illustrate my argument. Binet rules out the influence of the word memories which were necessary to Preyer's ^ A good instance of such confusion, between red and blue, and its correct interpretation, is given by Miss Shinn, N'otes on the Development of a Child, 2 See the discussion of the question of tone recognitions, below. Chap.
42 A New Method of Child Study.
results, by his vietJwdc de reconnaissance. The child recog- nizes again the colour just seen. Now those who have fol- lowed the course of recent discussions of recognition will remember that the mediation of word-associations is not ruled out in these cases in children of three to five years old or even younger. Lehmann finds coloured wools are recog- nized when the colours are those whose names are known {Bencnnimgsassociatioii), and that shades which have not peculiar names, or whose names are not known, are not recognized. Others have held that an unobserved or unintelligible element — a Nebenvorstellnng — may serve as the link of recognition without rising again to clear consciousness a second time. It is, of course, useless, if these results be trustworthy, to attempt to get recognitions clear of word memories after colour names have once been learned by the child. It would seem that the question ought to be taken up with younger children. Binet's experiments were in the interval between the child's thirty-second and fortieth months. It is perhaps a con- firmation of Lehmann's position, that the colours least recognized in Binet's list are shades whose names are less familiar to children; his list, in order of certainty of rec- ognition, is red, blue, green, rose, maroon, violet, and yellow, by the metJiode d appellation; and, by both methods together, red, blue, orange, maroon, rose, violet, green, white, and yellow.^ § 2. Expository.
This colour question may suffice to make clear the essen- tials of a true experimental method. Only when we catch 1 Calculated from Binet's detailed results {Revue Philosophiqiie, 1890, II., 582 ff.) by Mr. F. Tracy; see his book, The Psychology of Childhood, p. 14, and cf. the results of my own experiments below, Chap. IV., § i.
Expository. 43 the motor response, or a direct reflex, in its simplicity, is it a true index of the sensory stimulus in its simplicity. I have accordingly attempted to reach a method of child study of such a character as to yield a series of experi- ments whose results would be in terms of the most funda- mental motor reactions of the infant, which could be easily and pleasantly conducted, and which would be of wide application. (-The child's hand movements are, I think, the most nearly ideal in this respect. The hand reflects the first stimulations, the most stimulations, and, becom- ing the most mobile and executive organ of volition, attains the most varied and interesting offices of utility. We have spontaneous arm and hand movements, reflex move- ments, reaching-out movements, grasping movements, imitative movements, manipulating movements, and vol- untary efforts — all these, in order, reflecting the devel- opment of the mind. The organs of speech are only later brought into use, and their use for speech involves an already high development of mind, hence the error in Preyer's results. It has accordingly seemed to me worth while to find whether a child's reaching movements would reflect with any degree of regularity the modifications of its sensibility, and, if so, how far this could be made a method of experimenting with young children.^ I may adduce one or two considerations which tend to show that some such dynamogenic method is theoretically vaHd. There are some results already recognized in the psychology of sense and movement which lend confirma- 1 The suggestion of Mrs. Ladd Franklin ( The Psychological Revieio, I., 1894, p. 202) is quite in accord with this requirement, i.e., that Sach's discovery of reflex changes in the width of the pupil when certain colours are looked at might be used to test the colour sensations of very young children.
44 ^ New Method of Child Study.
tion to this idea. The facts that the most motile organs have acutest scnsibiUty, notably the hand and fingers; that certain marked types of action, such as imitation, arise first in connection with the hand; that the central organic preparation for volition is secured first in the arrangements for hand movements:^ all these facts indicate that the hand movements are the best index of general and special sensibility in the infant. Fere maintains that sensory stimulations of all kinds increase the maximum hand pres- sure. Colours seen have regular, and each its peculiar, effect upon movement. Tones have similar influence. The ticking of a watch is more clearly perceived if movements are made at the same time. Further, the reaction-time of hand movements is shorter if the stimulus (sound, etc.) be more intense. There is an enlargement of the hand, through increased blood pressure, when a loud sound is heard. The fact of muscle-reading, and its experimental demonstration by Jastrow, together with the whole series of facts shown by recent experiments in so-called 'uncon- scious movements' by diseased patients ^ — these, and a variety of other facts upon which the law of ' dynamogene- sis ' rests, seem to afford justification for the view that the infant's hand movements in reaching and grasping are the best index of the kind and intensity of its sensory ex- periences. Magendie ^ long ago suggested measuring changes in sensibility by the corresponding changes in blood pressure.
Further, it is not necessary to embarrass ourselves with the question whether the hand movements are voluntary ^ Soltmann; cf. the chapter below on the 'Origin of VoHtion,' especially ■^ Binet, Janet. ^ Fere, Sensalioii et Mouvement, \>. 56.
Expository. 45 or not. However we may differ as to the circumstances of the rise of volition, it is still true that after its rise the child's reactions are for a long time quite under the lead of its sensory life. It lives so fully in the immediate present and so closely in touch with its environment, that the influences which lead to movement can be detected with great regularity. In this case the sensations which are stimuli to movement become what we may also call 'effort stimuli,' and the child's efforts with his hands become indications of the relative degree of discrimination, attractiveness, etc., of the different sensations which call the efforts out.
Suppose we hang up a piece of meat over Carlo's head and tell him to jump for it. His first jump falls short of the meat. He jumps again and clears a greater distance. Why does he jump farther the second time? Not because he argues that a harder jump is necessary to secure the meat; but because by the first jump he got more smell, blood colour, and appetite stimulus from the meat. Now suppose it to be a red rag instead of meat, and Carlo refuse to jump a second time. This is not because he concludes the rag would choke him, but because he gets a kind of sensation which takes away what appetite stimulus he already had. The thing is a thing of sensational dynamogeny or 'suggestion,' and the child's state of mind up to his twenty-fourth month, more or less, is just about the same.
The following questions, I think, might be taken up by some such method as this: — I. The presence of different colour sensations as shown by the number and persistence of the child's efforts to grasp the colour.
46 A New Method of Child Shtdy.
2. The relative attractiveness of different colours meas- ured in the same way.
3. The relative attractiveness of different colour combi- nations.
4. The relative exactness of distance estimation as shown by the child's efforts to reach over distances for objects.
5. The relative attractiveness of different visual out- lines (stars, circles, etc.) cut in the same attractive colour, etc.
6. The relative use of right, left, and both hands.
7. The rise of imitative movements.
8. The rise of voluntary movements.
9. The presence and character of ' accompanying move- ments ' at different stages of motor development.
10. The strength of desire and voluntary inhibition as shown in the relative persistence of movements of grasping.
11. The relative strength of disparate sensations at dif- ferent periods of child life, as shown by their comparative expression in movement.
12. The inhibiting influence of elementary associations, especially pains, punishments, etc.
I am quite aware of the meagreness of this list; but one has only to remember the fact that there is no such thing yet as a psycho-physics of the active life, that this side of psychology is almost terra incognita to the experimental- ist.i If the method prove reliable in one-half of these 1 I see no reason that a method could not be devised for testing the motive influences of presentations of a neutral associational character in terms of the time elapsed since their experience. I have announced elsewhere (^Proceed- ings of Congress for Exper. Psychology, London, 1892) the first results of a research conducted upon adults by such a method and hope soon to publish further details and inferences. Professor Munsterberg has recently suggested Formula of the Dynaniogenic Method. 47 questions, then so much gain. I have applied it to some of them in a more or less incomplete way, in the case of my two children, H. and E., both girls, with the results recorded in subsequent pages of this book. In each case below I take occasion to say to what extent the results are of real, or only of methodological, value.
§ 3. Formula of the Dynamogenic MetJiod.
When this method is reduced to its lowest terms, as ap- plied to children old enough to reach out for objects which they see, two variable quantities are always involved. The reactions will vary in some way with the distance of the object exposed, and also in some way with the kind of stimulus. For example, a child of perhaps eight months of age reaches after an orange, when it is eleven inches in front of him, with great regularity; but very irregularly, or possibly not at all, when it is fourteen inches away. Again, he reaches for a colour, red, when perhaps he would not for a colourless object.
If we take the simplest cases — cases in which observa- tion shows the responses of the child to be regular, the con- ditions of quiet, comfortable position, interest, etc., being throughout normal and undisturbed — we may consider these two things, quality and distance, as the only important variables. By quality is meant the so-called sensational character of the stimulating object. If, then, we further inquire into the drawing-out influence of various stimula- tions, it is evident that it will vary with the quality {q), and, in some inverse ratio, with the distance {d). In other a method of studying the influence of stimulations upon eye-movements, atten- tion, etc., which is also dynamogenic and proceeds upon somewhat the same presuppositions {The Psychological Review, I., pp. 441 fif., September, 1894).
48 A New Method of Child Shidy.
words, naming the calling-out or dynamogenic influence of a stimulus, D, we have the equation, in which k is the sign of proportion.
I state this formula not to be mathematical, but simply, by ringing the changes possible through substitution of values, to illustrate the applications of the method and the limits of the general principle of reaction. If q be kept constant, experiments will determine the law by which the influence of d changes. Again, experiments at different ages would show the effect on d of experience in associating visual distance with muscular distance. Again, keeping d constant, experiments would show the value of various sense qualities, the g values.
An interesting point emerges when we inquire the effect of zero and infinity values. If the child, for ex- ample, always reaches for an apple at nine inches, this would be practically the case of d=o. But, as a mat- ter of fact, distance then has no influence; the whole possible variation in D in successive experiments with different ^'s is due to the q values themselves. It is asked at once why the influence of d is not equally ruled out in any series of experiments in which d is kept con- stant, say at twelve inches. The answer is: because in each such series the influence of d changes from the fact of practice, habit, and slight fatigue. If the child reaches for a blue-^ at twelve inches, and just gets it, he will then reach for a green-^ with greater avidity at twelve inches than he would otherwise have reached for the same green-^ at nine inches. So psychology inter- Formula of the Dynamogcnic Method. 49 feres with mathematics. So the vahie for d=o, at which we have the purest influence of q, is not the least distance possible, but the child's normal reaching distance.
Again, if the child just refrains from reaching for a </ at fourteen inches, this means practically that d—^\ that is, the influence of d is so all-important that it shuts out all relative ^/-influences. The distance inhibits movement alto- gether. But just here another psychological factor inter- feres with the mathematics; in some cases the inhibition of d does not work, and the child oversteps all its expe- rience in violent straining and tears. These two so-called psychological 'interferences' are referred to again later on, the latter being, I think, the main external channel of the rise of right- or left-handedness.^ These qualifications make it evident that this form of mathematical statement shows only — what most appeals to mathematics in psychology are — an artificial show of exactness. This method, like all other psychological meth- ods, must be used with a thousand cautions and as many failures; and the last condition of such experiments, as the first condition of all work with children, is sympathetic insight into their mental movements. Only such sym- pathy and insight can cope with the subtle responses which a wide-awake child makes to the most trifling vari- ations in our treatment of him.
I shall now give further facts and experiments illustrat- ing the regularity of the child's reactions, and so put in evidence the general principle of ' dynamogenesis,' upon which all motor development, both in the child and in the race, must ultimately rest.
1 See below, Chap. IV.
CHAPTER III.
Distance and Colour Perception by Infants.
§ I. Experimental.
The method called ' dynamogenic ' has been explained in earlier pages. The application of it to particular ques- tions now demands attention, as far as the present writer has attempted to apply it.
It is evident, as was said before in speaking of the in- fant's responses in reaching for objects, that in any par- ticular case the element of distance is a variable quantity to be considered with the influence of the particular stim- ulus in question. In investigating the infant's colour sen- sations, therefore, we have the formula Z^=-, in which c d denotes colour, d distance, and D strength of dynamogeny, as already explained.
I undertook at the beginning of my child H.'s ninth month to experiment with her with a view to arriving at the exact state of her colour perception, employing this new method. The arrangements consisted in this instance in giving the infant a comfortable sitting posture, kept constant by a band passing around her chest and fastened securely to the back of her chair. Her arms were left bare and quite free in their movements. Pieces of paper of different colours were exposed before her, at varying 50 ExpcriuicnfaL 51 distances, front, right, and left. This was regulated by a framework, consisting of a horizontal rod graded in inches, projecting from the back of the chair at a level with her shoulder and parallel with her arm when extended straight forward, and carrying on it another rod, also graded in inches, at right-angles to the first. This second rod was thus a horizontal line directly in front of the child, parallel with a line connecting her two shoulders, and so equally distant for both hands. This second rod was made to slide upon the first, so as to be adjusted at any desirable distance from the child. On this second rod the colours, etc., were placed in succession, the object being to excite the child to reach for the colour.
So far from being distasteful to the infant, I found that, with pleasant suggestions thrown about the experiments, the whole procedure gave her the most intense gratifica- tion, and the affair became one of her pleasant daily occu- pations. After each sitting she was given a reward of some kind.
The accompanying tables give the results, both for colour and distance, of 217 experiments. Of these in were with five colours and 106 with ordinary newspaper (chosen as a relatively neutral object, which would have no colour value and no association, to the infant). In the tables R stands for 'refusal' to reach out for the object, A for 'acceptance' with effort, 7\^ for the entire number of experiments with each colour respectively, and n for the entire number with all the colours at each distance respectively. So — = the proportion of acceptances or efforts for any colour, and — = the proportion of refusals for each distance.
52 Distance and Colonic' Perception by Infants.
TABLE I.
Distance, Inches 9 lO II 12 13 14 15 Totals.
Ratio ^.
N R.A.
R.A.
R.A.
R.A.
R.A.
R.A.
R.A.
Ratio ^.
R.A.
R.A.
R.A.
News- paper Colour 7-II Totals Ratio ^ n Total.26 From these tables we might be able, if the experiments were of sufficient nmiiber and all proper precautions had Experimoi tal. 53 been taken — on which points the next paragraph may be read — to conchide important results for the perception of colour and distance. The following inferences, indeed, seem to be safely drawn.
Colour. — The results are evident in the tables (I. and II.), especially the columns marked 'Ratio — ' and 'Ratio /?
—.' The colours range themselves in an order of attrac- 11 11 tiveness, i.e., blue, white, red, green, and brown. Disre- garding white, the difference between blue and red is very slight compared to that between any other two. This confirms Binet as against Preyer, who puts blue last, and also fails to confirm Preyer in putting brown before red and green. Brown to my child — as tested in this way — seemed to be about as neutral as could well be. A similar distaste for brown was noticed in the child observed by Miss Shinn.i White, on the other hand, was more attrac- tive than green and slightly more so than red, I am sorry that my list does not include yellow. The newspaper was, at reaching distance (9 to 10 inches) and a little more (up to 14 inches), as attractive as the average of the colours, and even as much so as the red; but this is prob- ably due to the fact that the newspaper experiments came after a good deal of practice in reaching after colours, and a more exact association between the stimulus and its distance; an influence which I have remarked upon in the general discussion, above,^ of the formula for the method. At 15 inches and over, accordingly, the newspaper was refused in more than 92 per cent of the cases, while blue was refused at that distance in only 75 per cent, and red in 84 per cent.
54 Distance and Colour Perception by Infants, Distajicc} — In regard to the question of distance, the child persistently refused to reach for anything put i6 inches or more away from her. At 1 5 inches she refused 94 per cent of all the cases, 92 per cent of the colour cases, and, as I have said, 92 per cent of the newspaper cases. At nearer distances we find the remarkable uni- formity with which the safe-distance association works at this early age. At 14 inches only 14 per cent of all the cases were refused, and at 13 inches only about 8 per cent. The fact that there was a larger percentage of refusals at 11 and 12 inches than at 13 and 14 inches, is seen from the table (I.) to be due to the influence of the brown, which was refused consistently when more than 10 inches away. The fact that there were no refusals to reach for anything exposed within reaching distance (10 inches) — other attractive objects being kept away — shows two things: (i) the very fine estimation visually of the distance represented by the arm-length, thus em- phasizing the element of muscular sensations of arm- movement in the perception of distance generally; and (2) the great uniformity at this age of the phenomenon of ' sensori-motor suggestion ' ^ upon which this method of child study is based. In respect to the first point, it