The Story of the Mind

by James Mark Baldwin

Distance and Colour Perception.—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, and also to investigate her sense of distance. 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 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 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 desired 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 them. So far from being distasteful to the infant, I found that, with pleasant suggestions thrown about the experiments, the whole procedure gave her much gratification, and the affair became one of her pleasant daily occupations. After each sitting she was given a reward of some kind. I give the results, both for colour and distance, of 217 experiments. Of these 111 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).

Colour.—The colours range themselves in the order of attractiveness—blue, red, white, green, and brown. Disregarding white, the difference between blue and red is very slight, compared with that between any other two. This confirms the results of the second method described above. Brown, to my child—as tested in this way—seemed to be about as neutral as could well be. A similar distaste for brown has been noticed by others. White, on the other hand, was more attractive than green. I am sorry that my list did 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 probably 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. At 15 inches and over, the newspaper was refused in 93 per cent of the cases, while blue was refused at that distance in only 75 per cent, and red in 83 per cent.

Distance.—In regard to the question of distance, the child persistently refused to reach for anything put 16 inches or more away from her. At 15 inches she refused 91 per cent of all the cases, 90 per cent of the colour cases, and, as I have said, 93 per cent of the newspaper cases. At nearer distances we find the remarkable uniformity 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 7 per cent. There was a larger percentage of refusals at 11 and 12 inches than at 13 and 14 inches, a result 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; (1) the very fine estimation visually of the distance represented by the arm-length; and (2) the great uniformity at this age of the phenomenon of Motor Suggestion upon which this method of child study is based, and which is referred to again below. In respect to the first point, it will be remembered that the child does not begin to reach for anything that it sees until about the fourth or sixth week; so it is evident at what a remarkably fast rate those obscure factors of size, perspective, light and shade, etc., which signify distance to the eye, become associated with arm movements of reaching. This method, applied with proper precautions, obviates many of the difficulties of the others. There are certain requirements of proper procedure, however, which should never be neglected by any one who experiments with young children.

In the first place, the child is peculiarly susceptible to the appeals of change, novelty, chance, or happy suggestion; and often the failure to respond to a stimulus is due to distraction or to discomfort rather than to lack of intrinsic interest. Again, fatigue is a matter of considerable importance. In respect to fatigue, I should say that the first signs of restlessness, or arbitrary loss of interest, in a series of stimulations, is sufficient warning, and all attempts at further experimenting should cease. Often the child is in a state of indisposition, of trifling nervous irritability, etc.; this should be detected beforehand, and then nothing should be undertaken. No series longer than three trials should be attempted without changing the child's position, resting its attention with a song, or a game, etc., and thus leading it fresh to its task again. Furthermore, no single stimulus, as a colour, should be twice repeated without a change to some other, since the child's eagerness or alertness is somewhat satisfied by the first effort, and a new thing is necessary to bring him out to full exercise again. After each effort or two the child should be given the object reached for to hold or play with for a moment; otherwise he grows to apprehend that the whole affair is a case of "Tantalus." In all these matters very much depends upon the knowledge and care of the experimenter, and his ability to keep the child in a normal condition of pleasurable muscular exercise throughout.

In performing colour experiments, several requirements would appear to be necessary for exact results. Should not the colours chosen be equal in purity, intensity, lustre, illumination, etc.? In reference to these differences, I think only that degree of care need be exercised which good comparative judgment provides. Colours of about equal objective intensity, of no gloss, of relatively evident spectral purity, under constant illumination—this is all that is required. The variations due to the grosser factors I have mentioned—such as condition of attention, physical unrest, disturbing noises, sights, etc.—are of greater influence than any of these more recondite variations in the stimulus. Intensity and lustre, however, are certainly important. It is possible, by carefully choosing a room of pretty constant daylight illumination, and setting the experiments at the same hour each day, to secure a regular degree of brightness if the colours themselves are equally bright; and lustre may be ruled out by using coloured wools or blotting-papers. The papers used in the experiments given above were coloured blotting-papers. The omission of yellow is due to the absence, in the neighbourhood, of a satisfactory yellow paper.

The method now described may be further illustrated by the following experiments on the use of the hands by the young child.

The Origin of Right-handedness.—The question, "Why are we right or left-handed?" has exercised the speculative ingenuity of many men. It has come to the front anew in recent years, in view of the advances made in the general physiology of the nervous system; and certainly we are now in a better position to set the problem intelligently and to hope for its solution. Hitherto the actual conditions of the rise of "dextrality" in young children—as the general fact of uneven-handedness may be called—have not been closely observed. It was to gain light, therefore, upon the facts themselves that the experiments described in the following pages were carried out.

My child H. was placed in a comfortable sitting posture, the arms left bare and free in their movement, and allowed to reach for objects placed before her in positions exactly determined and recorded by the simple arrangement of sliding rods already described. The experiments took place at the same hour daily, for a period extending from her fourth to her tenth month. These experiments were planned with very great care and with especial view to the testing of several hypotheses which, although superficial to those who have studied physiology, yet constantly recur in publications on this subject. Among these theories certain may be mentioned with regard to which my experiments were conclusive. It has frequently been held that a child's right-handedness arises from the nurse's or mother's constant method of carrying it, the child's hand which is left free being more exercised, and so becoming stronger. This theory is ambiguous as regards both mother and child. The mother, if right-handed, would carry the child on the left arm, in order to work with the right arm. This I find an invariable tendency with myself and with nurses and mothers whom I have observed. But this would leave the child's left arm free, and so a right-handed mother would be found with a left-handed child! Again, if the mother or nurse be left-handed, the child would tend to be right-handed. Or if, as is the case in civilized countries, nurses largely replace the mothers, it would be necessary that most of the nurses be left-handed in order to make most of the children right-handed. Now, none of these deductions are true. Further, the child, as a matter of fact, holds on with both hands, however it is itself held.

Another theory maintains that the development of right-handedness is due to differences in weight of the two lateral halves of the body; this tends to bring more strain on one side than the other, and to give more exercise, and so more development, to that side. This evidently assumes that children are not right or left-handed before they learn to stand. This my results given below show to be false. Again, we are told that infants get right-handed by being placed on one side too much for sleep; this can be shown to have little force also when the precaution is taken to place the child alternately on its right and left sides for its sleeping periods.

In the case of the child H., certain precautions were carefully enforced. She was never carried about in arms at all, never walked with when crying or sleepless; she was frequently turned over in her sleep; she was not allowed to balance herself on her feet until a later period than that covered by the experiments. Thus the conditions of the rise of the right-handed era were made as simple and uniform as possible.