G. G. Girl, age 12-4; mental age 10-10; I Q 82. From average home. Excellent educational advantages and no physical handicaps. At 12 years was doing very poor work in fifth grade. Appearance, play life, and attitude toward other children normal. Simply dull. Will probably never go beyond the 12- or 13-year level and is not likely to get as far as the high school.
Those testing 80 and 90 will usually be able to reach the eighth grade, but ordinarily only after from one to three or four failures. They are so very numerous (about 15 per cent of the school enrollment) that it is doubtful whether we can expect soon to have special classes enough to accommodate all. The most feasible solution is a differentiated course of study with parallel classes in which every child will be allowed to make the best progress of which he is capable, without incurring the risk of failure and non-promotion. The so-called Mannheim system, or something similar to it, is what we need.
Average intelligence (I Q 90 to 110).
It is often said that the schools are made for the average child, but that “the average child does not exist.” He does exist, and in very large numbers. About 60 per cent of all school children test between 90 and 110 I Q, and about 40 per cent between 95 and 105. That these children are average is attested by their school records as well as by their I Q’s. Our records show that, of more than 200 children below 14 years of age and with I Q between 95 and 105, not one was making much more nor much less than average school progress. Four were two years retarded, but in each case this was due to late start, illness, or irregular attendance. Children who test close to 90, however, often fail to get along satisfactorily, while those testing near 110 are occasionally able to win an extra promotion.
The children of this average group are seldom school problems, as far as ability to learn is concerned. Nor are they as likely to cause trouble in discipline as the dull and border-line cases. It is therefore hardly necessary to give illustrative cases here.
The high school, however, does not fit their grade of intelligence as well as the elementary and grammar schools. High schools probably enroll a disproportionate number of pupils in the I Q range above 100. That is, the average intelligence among high-school pupils is above the average for the population in general. It is probably not far from 110. College students are, of course, a still more selected group, perhaps coming chiefly from the range above 115. The child whose school marks are barely average in the elementary grades, when measured against children in general, will ordinarily earn something less than average marks in high school, and perhaps excessively poor marks in college.
Superior intelligence (I Q 110 to 120).
Children of this group ordinarily make higher marks and are capable of making somewhat more rapid progress than the strictly average child. Perhaps most of them could complete the eight grades in seven years as easily as the average child does in eight years. They are not usually the best scholars, but on a scale of excellent, good, fair, poor, and failure they will usually rank as good, though of course the degree of application is a factor. It is rare, however, to find a child of this level who is positively indolent in his school work or who dislikes school. In high school they are likely to win about the average mark.
Intelligence of 110 to 120 I Q is approximately five times as common among children of superior social status as among children of inferior social status; the proportion among the former being about 24 per cent of all, and among the latter only 5 per cent of all. The group is made up largely of children of the fairly successful mercantile or professional classes.
The total number of children between 110 and 120 is almost exactly the same as the number between 80 and 90; namely, about 15 per cent. The distance between these two groups (say between 85 and 115) is as great as the distance between average intelligence and border-line deficiency, and it would be absurd to suppose that they could be taught to best advantage in the same classes. As a matter of fact, pupils between 110 and 120 are usually held back to the rate of progress which the average child can make. They are little encouraged to do their best.