The mental capacity of adult persons is indicated rather accurately by the number and variety of things they have learned from the school of life, omitting from the count so far as possible those things directly taught by the formal schools. The intellectual capacity of an infant is likewise indicated roughly by the changes which his brief experience in life has brought about in his ability to control himself and his immediate surroundings. At birth the child is practically without control of his own body, except for certain sucking reflexes, certain crying reflexes, and the reflex which causes it to grasp with its fingers or toes the finger or pencil which is brought into contact with them. These reflexes can hardly be said to be a part of the child’s control of his own body, for the child could not avoid obeying them if he so desired. The new-born infant is practically helpless even so far as his own body is concerned. Any degree of control he may later develop over his body or over other things outside is attained because he has a system of nerve and brain cells capable of forming connections and being modified by these connections and their results.
The degree to which the child’s nervous system is organized and supplied with potential connections by inheritance is reflected very early in life by the quickness with which it learns to control itself and its immediate environment. The most ready method of testing this inherited capacity is therefore to determine at any particular age just how complex and adequate a system of control has been developed. The tests for measuring infants and young children consist, then, in those performances under specified standard conditions, which are typical for children at various ages.
The Mentimeter for young children is based directly upon the findings of Prof. Lewis M. Terman and his students in their investigations of children from three to twenty years of age. This investigation was so carefully devised and executed that to improve on the product, the Stanford Revision of the Binet tests, would be almost impossible. The tests for children three and four years of age presented in the following pages are therefore not claimed to be new or original with the present authors, who hereby express to Doctor Terman their admiration for his excellent contributions in the field of psychological measurements. The tests here suggested for children under three years of age are modifications of those suggested by Doctor Kuhlmann. All investigators in this field are, of course, indebted to the pioneers, the French psychologists, Binet and Simon.
The method of this test series consists in putting the child into a well-defined situation and observing how he acts. The situation may consist partly in words or other noises impressing themselves upon his ears, or it may consist largely in visual sensations, or even in sensations of physical well-being in his own body. Under a given situation a normal child of a given age or older will act in a certain standard way. The measurement then is in terms of the age for which a given child’s reactions are typical.
The test can best be given by one who is fairly familiar with the infant to be tested, although interest in having the child make a good showing should never be allowed to change one’s judgment of the facts as to the child’s performance. Another danger of too great familiarity is that the examiner may, without intention to do so, drill the child upon those things which are later to be required in the test. In so far as the parent knows what performances are to be included in the tests there is real danger that the child will be “coached up” on these things, even at as early an age as six months.
List of Typical Performances.
Three Months (3 tests, credit 1 month each)
1. Control of eyes (Both eyes look in same direction. Follows with eyes the movement of bright objects). 2. Hearing (Reacts with sudden start or scream to loud noises, such as slamming of door, hand clapping. Turns eyes or head in direction of less startling noises, such as opening of door, footsteps).
Six Months (3 tests, credit 1 month each)
1. Muscular Control (Balances head without support. Sits ten minutes or more when supported). 2. Self-Direction (Attempts to catch self when beginning to fall from sitting posture. Reaches out for toys and near-by objects. Attempts to pull self to sitting posture if given a hand to grasp). 3. Enjoyment (Plays longer and more persistently with one toy than with another. Laughs aloud when bounced on bed or when familiars indulge in strenuous exercise).