TWO-POINT DISCRIMINATION AND INTELLIGENCE: RESULTS UNRELIABLE Wide differences had developed in the data of different investigators in tactile sensibility. Binet attempted to reduce these differences and to prepare the way to more uniform methods and results, by describing an esthesiometer which he had devised (31), and, in another article, by outlining methods to be followed in esthesiometry (32). In the early part of the present century Binet published a number of articles on this subject, and he developed a "method of irregular variations," consisting of the arrangement of a series of stimuli ranging by irregular steps from a certain minimum to the maximum employed on the test. The point differences thus succeed each other irregularly, but each difference occurs a number of times that is just equal for all differences. He also showed in other articles (35–38) the effect in actual experiments of changes in attitudes due to exercise and to suggestion from the experimenter, bringing about apparent modifications in the subject's sensibility; and he warned against overlooking effects of factors of this kind. He contends in these articles, from the results of his experiments, that it is impossible to determine the individual's threshold for the discrimination of two points. For "it varies from one moment to another, and the more it is sought, the more difficult it is to discover; moreover, it is related so closely to the method of interpreting sensations that even in the cases where it seems to have a definite position, we cannot be sure that it represents the degree of acuity of the organ" (38, page 252). His attempts thus to measure effects of voluntary attention and to show differences between the five most and the five least intelligent in a group of thirty-two children therefore failed to give any positive results. EVEN HANDWRITING AND PALMISTRY INVESTIGATED BY BINET AS POSSIBLE TESTS Individuality in handwriting had been an inviting subject for students of psychology as well as for graphologists. Even before the beginning of this century handwriting had been studied from several points of view, both in normal and in abnormal subjects (105). Binet did not overlook this type of reaction, so infinitely variable from individual to individual, as a possible indicator of the aspects of character in which he was interested, particularly of intelligence. In 1903 and the following year he published (39) certain analytic studies of handwriting, and in 1906 his book, The Revelations of Handwriting under Scientific Control, appeared (40). This last study was an attempt to determine whether sex, age, degree of intelligence, and character are revealed in handwriting. The natural writing, taken mostly from envelopes that had passed through the mails, was submitted both to graphologists and to other persons. Sex was judged, it was found, somewhat better than by pure guess; age also was determined with a small degree of accuracy, the determinations averaging within about ten years of the true ages of the subjects. From the writing of some very well-known geniuses and a few inferior persons as well as from that of persons nearer the average and of some well above this average, he found slightly positive results in attempts to estimate intelligence, but many persons did not show their degree of intelligence in their handwriting. Character determination as estimated from the writings of certain notorious criminals, on the one hand, and of men of recognized character, on the other, was even less successful than intelligence determination. On the whole the professionals proved themselves in these determinations to be superior to the other judges. "It does not appear to me impossible," he said, "that graphology may yet contribute to experimental psychology a good test of intelligence" (39, page 210). Binet examined so wide a range of possible intelligence indicators that even palmistry did not escape his experimental study (44). When professional palmists were allowed to see only the hand of subjects or pictures of their hands, their estimates of their intelligence were but little above expectations based on pure guess, or chance. Thus Binet showed his open-mindedness in being willing and ready to canvass the whole range of possible indicators of intelligence from palmistry, for the study of which he felt obliged to apologize, to the most complex psychological tests. His studies of various physical traits in relation to intelligence continued, along with the improved revisions of the intelligence scales, right down to the time of his death; but the physical signs of intelligence promised to be meager indeed, as we have seen, while the scale of psychological tests, the development of which we shall presently trace, brought a revolution in educational and social service methods and made the name of the authors familiar to nearly every teacher and social worker in the civilized world. EXERCISES 1. List the tests and devices in Binet's article on "Measurement in Individual Psychology" (as reported in the text) that were later used in the intelligence scales as described in Chapters 9, 10, and 11. 2. Now take the article on "Attention and Adaptation" and do with it what you were directed to do with the article on measurement. 3. Why are persons who are ranked on any test not measured in the sense that three pieces of wood measured by a rule in inches are measured? If A gets 10 points, B gets 20, and C gets 30, why may we not say that B is twice as good in the ability tested as A, and two thirds as good as C? 4. In what sense do the ranks of individuals on the basis of given scores fail to show something as to the comparative abilities that is contained in the scores? Illustrate with the scores 29, 18, 23, 22, 15, 21, 35. 5. If the averages of Table 1 had been, respectively, 2, 5, 8, and 11, would this necessarily have indicated perfect agreement, or perfect correlation, between the results by the two tests? Show why. CHAPTER NINE BINET'S FIRST INTELLIGENCE SCALE INTELLIGENCE TESTS NEEDED IN THE STUDY OF SUBNORMALS INTEREST in defective children and in their education arose first in France, where Esquirol (1772-1840) had made the important distinction, now generally recognized, between the idiot, whose intelligence does not develop beyond a very low level, and the demented person. Distinctions were early made between different degrees of feeble-mindedness, idiocy being the term applied to the lowest degree of mentality, imbecility to the next lowest, and debility1 to the highest degree, or the degree next to the lowest cases of individuals classed as normal. But these terms had no precise significance, and before the contribution of Binet and Simon no exact standards for comparison existed. What one alienist called idiocy another would call imbecility, if his standard differed from that of the first, while a third, paying attention to yet other traits of the defective person and interpreting them differently, would probably class him as a moron. Dr. Blin (68), at the colony of Vaucluse, complained of just such differences in standards. So great uncertainty in = 66 1 In England "feeble-mindedness" is used to designate the higher class of defectiveness in these three degrees of subnormality, and "amentia" or "mental deficiency" is used to cover all three degrees. "Deficiency," however, seems also to include certain forms of instability, and is technically not as good a term as amentia.' In America "feeble-mindedness" is used as the general term to include all three degrees, and the term "moron' (mōros foolish), suggested by Goddard, is used to designate a person of the upper grade of feeble-mindedness. Thus in the English usage aments include idiots, imbeciles, and the feeble-minded, while in the American usage the feeble-minded include idiots, imbeciles, and morons. In this book we shall adhere to this latter meaning of the terms, and we shall use the term "moronity" as coördinate with "imbecility" and "idiocy." In all quotations and references to foreign works changes in the names used will be made to conform to this usage. 'Moronity" then replaces "debility” as here used in the text. 66 |