The measurement of intelligence

by Lewis M. Terman

Remarks. The test is one which all the critics agree in commending, largely because it is so little influenced by ordinary school experience. Its excellence lies mainly, however, in the fact that it throws light upon the character of the child’s higher thought processes, for thinking means essentially the association of ideas on the basis of differences or similarities. Nearly all thought processes, from the most complex to the very simplest, involve to a greater or less degree one or the other of these two types of association. They are involved in the simple judgments made by children, in the appreciation of puns, in mechanical inventions, in the creation of poetry, in the scientific classification of natural phenomena, and in the origination of the hypotheses of science or philosophy.

The ability to note differences precedes somewhat the ability to note resemblances, though the contrary has sometimes been asserted by logician-psychologists. The difficulty of the test is greatly increased by the fact that the objects to be compared are not present to the senses, which means that the free ideas must be called up for comparison and contrast. Failure may result either from weakness in the power of ideational representation of objects, or from the inadequacy of the associations themselves, or from both. Probably both factors are usually involved.

Intellectual development is especially evident in increased ability to note essential differences and likenesses, as contrasted with those which are trivial, superficial, and accidental. To distinguish an egg from a stone on the basis of one being organic, the other inorganic matter requires far higher intelligence than to distinguish them on the basis of shape, color, fragibility, etc. It is not till well toward the adult stage that the ability to give very essential likenesses and differences becomes prominent, and when we get a comparison of this type from a child of 7 or 8 years it is a very favorable sign.

It would be well worth while to standardize a new test of this kind for use in the upper years and especially adapted to display the ability to give essential likenesses and differences. At year VII we must accept as satisfactory any real difference.

One point remains. In the tests of giving differences and similarities, it is well to make note of any tendency to stereotypy, by which is meant the mechanical reappearance of the same idea, or element, in successive responses. For example, the child begins by comparing fly and butterfly on the basis of size; as, “A butterfly is bigger than a fly.” So far, this is quite satisfactory; but the child with a tendency to stereotypy finds himself unable to get away from the dominating idea of size and continues to make it the basis of the other comparisons: “A stone is larger than an egg,” “Wood is larger than glass,” etc. In case of stereotypy in all three responses, we should have to score the total response failure even though the idea employed happened to fit all three parts of the question. As a rule it is encountered only with very young children or with older children who are mentally retarded. It is therefore an unfavorable sign.

Although this test has been universally used in year VIII, all the available statistics, with the exception of Bobertag’s and Bloch’s, indicate that it is decidedly too easy for that year. Binet himself says that nearly all 7-year-olds pass it. Goddard finds 97 per cent passing at year VIII, and Dougherty 90 per cent at year VI. With the standard of scoring given in the present revision, and with the substitution of stone and egg instead of the more difficult paper and cloth, the test is unquestionably easy enough for year VII.

VII, 6. Copying a diamond

Procedure. On a white cardboard draw in heavy black lines a diamond with the longer diagonal three inches and the shorter diagonal an inch and a half. The specially prepared record booklet contains the diamond as well as many other conveniences.

Place the model before the child with the longer diagonal pointing directly toward him, and giving him pen and ink and paper, say: “I want you to draw one exactly like this.” Give three trials, saying each time: “Make it exactly like this one.” In repeating the above formula, merely point to the model; do not pass the fingers around its edge.

Unlike the test of [copying a square] in year IV, there is seldom any difficulty in getting the child to try this one. By the age of 7 the child has grown much less timid and has become more accustomed to the use of writing materials.