Not only is the curriculum not adapted to individual differences in general intelligence, but it is far less adapted to individual differences in special defects and aptitudes. The child who can never learn to sing is compelled nevertheless to pursue singing, even after school hours. The child who cannot learn reading by the method generally used is still treated by that method and no other. The schools were established with an undifferentiated curriculum, which they have tried to force upon intellects of an enormous range of diversity. Their purpose, so benign, has resulted in extraordinary cruelties and wastes.
III. THE IMPORTANCE OF GENERAL INTELLIGENCE FOR SCHOOL PROGRESS
If we examine mentally the large numbers of retardates in any public school where attendance is compulsory, we find that by far the majority of them are inferior in general intelligence. A child of superior general intelligence (IQ) is seldom found among retardates. Of children of 120 IQ and over, Terman reports that they are almost invariably at least up to grade. Whatever the vicissitudes of fate—illness, absence, special disability—a child of superior general capacity manages to hold his own, at least.
It is not true, however, that the superior child is allowed, under the undifferentiated curriculum, to make full use of his power. He is compelled to slow down to the typical progress of his group, and to use only a portion of his capacity for learning. It is rare to find a superior child who is doing “a full day’s work” in school, because the tasks assigned do not call for maximum effort. Superior children could easily do much more than is allowed.
General intelligence is, then, the single most important factor for school progress. The same may be said of progress in vocational careers. The life success of a human being may be said to depend upon general intelligence, character, health, and opportunity (including the factor of sex). If any of these factors is reduced to zero, so that the individual is totally lacking in intelligence, character, health, or opportunity there can be no achievement. The order of importance of the various factors is probably that in which they have been mentioned, with general intelligence certainly at the top of the list. Intelligence may create character, opportunity, and even health, but none of these can create intelligence.
IV. SPECIAL ABILITIES AND DISABILITIES AS DETERMINANTS OF SCHOOL PROGRESS
As before stated in these pages, no census has ever been taken of special aptitudes and defects, in the functions which we have been discussing, and which are important for progress through the elementary school. No one can tell whether any have been advanced on the basis of a special gift. No one can say how many children are retarded, because of a specialized disability, though we know from reports rendered, that some pupils become retarded in school status through special failure in one or two respects.
The children described under the topics of special retardation in reading and in arithmetic, in this volume, are illustrative of the way in which specialized defect contributes to retardation in school status. Without passable mastery of these “tool” subjects a child cannot proceed through the elementary school. His progress is halted, much as it would be if he were deficient in general intelligence.
It is quite possible, on the other hand, that children may be occasionally overrated as to intellect by teachers, who are deceived by conspicuous talent in a special function. Coy, who studied for two years a class of highly intelligent children in Columbus, has given an account of a boy who was thus overrated. When the children were being selected for the special class described, this boy was sent by his teacher to join the group. She considered that he must be “very bright,” “since he could draw cartoons, play the ukelele, and sing.” He was said by the art teacher to have more ability than any other child in the building. He was retained in the special class by the investigator, but he was not able to do good work there. His IQ on three annual testings stood as 114, 119, and 120. (The other children in the group possessed general intelligence clustering about an IQ of approximately 135.) This boy surpassed the others in music, acting, and drawing, but “his ability to reason was far below the class level,” and he could not compete successfully in general intellectual work. His teachers had been misled by his special gifts to recommend him as a child of surpassing intellect.