Читать книгу Deficiency and Delinquency: An Interpretation of Mental Testing - James Burt Miner - Страница 15

If most of the feeble-minded for whom society should provide were of the type which is only conative and not detectable by our present objective tests, a quantitative definition would be abortive. We must, therefore, study our assumption that it is worth while to direct our attention to those who are intellectually deficient. We shall attempt to discover how frequent are the primarily conative types.

Before examining the quantitative evidence we may note that it is in conformity with two prominent recent tendencies in psychology to subordinate specialized abilities, as compared with abilities which function commonly in many situations. The first of these tendencies is represented by the fundamental researches of Hart and Spearman (123) (185). This is not the place to set forth the technical work on which their conclusions are based. It may be said, however, that, with 17 different psychological tests, they were unable to discover any important specific mental weakness which distinguished adults who were suffering with any one of various mental abnormalities, including imbecility, manic-depressive insanity, dementia praecox, paranoia, and general paralysis of the insane. This may have been the fault of the tests, but it seems to be more likely that the fault lies in the custom of emphasizing special abilities and disabilities, at least from the point of view of tested capacities. On the other hand, all of these mental abnormalities showed a weakness in general intellectual ability. This is true whether this general ability be regarded, as it is by Hart and Spearman, as due to a general fund of brain energy, or whether general ability be taken to refer to the common recurrence of many specific abilities in much of our mental life. Its significance for this study is that a series of varied tests, such as that of Binet, may be expected to give a good estimate of general ability, and its failure to disclose specific disabilities is thus less important.

The second influence in psychology tending to emphasize average tested ability is the establishment of the biological conception of the mind which recognizes the mutual interdependence of the mental processes, organically united through the activity of the brain. So long as intellectual, emotional and volitional processes are all mutually dependent, a disturbance of one aspect of mental life is bound to affect the others. In considering the mutual dependence of the mental processes, it is important to weigh carefully the striking examples which Bronner^[4] has brought together, illustrating special abilities and disabilities. She has made an admirable start toward a differential diagnosis of special defects in number work, language ability and other mental activities. The degree of special deficiency which results in social failure could be placed upon an objective basis, but the rarity of special deficiencies as compared with general deficiency will make this a slow task. In the meantime we may rely upon the mutual dependence of the organic processes as a point of view which emphasizes the common spread of deficiency to many activities. Knowledge of a single case of specific disability is sufficient to make us recognize that such cases do occur. On account of the rarity of those cases and the absence of objective criteria, it seems necessary to leave the further differentiation to the future, considering here only those cases which may be grouped together as conative, as contrasted with those detected by our general intellectual tests.

Whether the group of primarily conative cases is of any considerable size can be only very roughly estimated at present, since the diagnosis of such cases of feeble-mindedness rests at present almost exclusively on the subjective opinion of the examiner. Before their diagnosis is put upon an objective basis we must have a different form of test directed at such traits of will as initiative, perseverance, stability and self-control. These probably center on the mental side around the instinctive emotional background of interest and the passions, while, on the physical side, they raise the question whether the subject's energy is adequate to endure the strain of competition or whether it shows itself only in sudden bursts.

If the diagnosis of conative cases could be determined objectively, it is possible that most forms of social unfitness would be found highly correlated with intellectual deficiency. On the other hand, when the diagnosis of unfitness for school or social life depends merely upon the opinion of experts or teachers, the inaccuracy of the diagnosis may show a wide discrepancy between the so-called conative and intellectual types of deficiency. Binet, on the basis of his acquaintance with the pupils in special classes, suggested that the number of unstable children is probably equal to the number of those who are intellectually unsuited for the ordinary schools or institutions (77). Since he then places the total number of the two classes at four or five per cent., it is apparent that he is discussing a higher type of ability than is usually included under the term feeble-minded. We can get somewhat better evidence on this question by studying the results of Binet tests applied to children cared for in special classes or in institutions for the feeble-minded. Chotzen (90) presents a table of 280 children in the Hilfsschule in Breslau, only 201 of whom, however, he himself diagnosed as feeble-minded, i. e., debile or lower. Of these only 51 were intellectually deficient as indicated by the Binet tests when we include the doubtful cases according to the criteria we have adopted in this study. If we suppose that, in addition to those in the special classes, there would be one intellectually deficient child in an institution for feeble-minded for every child testing deficient, we would then guess that only 40% of the feeble-minded children in Breslau were intellectually deficient. This sort of estimate seems to agree with Binet's belief that half of the children requiring special care, at least during school ages, are cases which are primarily conative.

Pearson has approached the same problem in another way (164) (167). He has used the results of the psychological tests applied by Norsworthy to children in New York in special classes and institutions for feeble-minded compared with those in the regular school classes, and the results of Jaederholm obtained with the Binet tests applied to 301 children in Stockholm in the special classes compared with 261 others selected from the regular classes. He found that “70.5% of normal children fall into the range of intelligence of the so-called mentally defective; and 60.5% of so-called mentally defective children have an intelligence comparable with that of some normal children” (167, p. 23). On the statistical assumption that those in the normal classes would distribute according to the Gaussian normal probability curve he estimates that, with the Binet tests, among those in the special classes “10% to 20%, or those from 4 to 4.5 years and beyond of mental defect, could not be matched at all from 27,000 children” (164, p. 46). Another 20 to 30% could be intellectually matched by those in the regular classes having from 3 to 4.5 years of mental deficiency, but they would be matched very rarely. On the assumption that 1% of the children were feeble-minded, not more than about two children in a thousand of this regular school population would be expected to be 3 or more years retarded and thus overlap those of like deficiency in the special classes (167, p. 30). Considering the results of Norsworthy's study he says on similar assumptions: “It seems, therefore, that a carefully planned psychological test, while not sufficing to differentiate 50 to 60% of the mentally defective from the normal child, would suffice to differentiate 40 to 50%” (164, p. 35). Again we come back to the estimate that psychological tests may well be expected to select nearly half of the children at present found in special classes for retarded pupils. Moreover, a considerable part of the overlapping of intellectual deficiency in the regular classes with that in the special classes which he found may be accounted for by the inadequate methods of selection of pupils for the special classes by teachers or examiners who have used no objective tests. Some who were left in the regular classes should undoubtedly have been transferred to special classes and vice versa. There seems to be nothing to indicate that less than half of those properly sent to special classes would be of clear or doubtful intellectual deficiency. If the tests served to select even a smaller proportion of those assigned to special instruction, the “school inefficients” as Pearson calls them, their value as an aid to diagnosis would be demonstrated.

Among groups of delinquents, where we would expect the purely conative cases to be more common, we find that a careful diagnosis of feeble-mindedness on the basis of test data, medical examination and case history indicates that conative cases without serious intellectual deficiency are much rarer than intellectually deficient delinquents. At least this is the evidence of one study where such information is available. Kohs at the Chicago House of Correction found among 219 cases over 16 years of age, which he diagnosed as feeble-minded, only 28 tested XI and there were only 52 who did not test either presumably deficient or uncertain intellectually according to our criterion. Another bit of evidence is that collected at the Clearing House for Mental Defectives in connection with the New York Post-Graduate School of Medicine, where 200 consecutive cases (108 males) were examined by Miss Hinckley. Her graphs show that only 15% tested X or above with the Binet revised scale, i. e., above those presumably deficient in intellect. The cases were from 13 to 42 years of age. The clearing house provides an opportunity for social workers to have suspected deficients examined and the few cases over X seems to indicate that the purely conative type is not very commonly met with among the social workers.

When we turn to the institutions for the feeble-minded we find that they are today caring for few solely conative cases. Although I can find no tables which give both the life ages and mental ages of the individual inmates, we can at least be sure that few test so high as X, or above with the Binet scale. This means that only a few have as yet reached the threshold for passable adult intellects, which should be attained by 15 years of age. At the Minnesota state institution for the feeble-minded in Faribault among 1266 inmates, excluding epileptics, 41 tested X; 28, XI; 12, XII; and 8, XIII, a total of 7% (154). At Vineland, N. J., Goddard reported among 382 inmates, 14 tested X; 5, XI; and 7, XII, about 7%. Some of the children who were under 15 in life-age might later develop above the limit for intellectual deficiency. Of the 1266 at the Minnesota institution, however, 508 were 15 or over at the time of their admission, so that at least 82% of the 508 were clearly intellectually deficient. Eight per cent. more tested X and were in the doubtful group in intellectual ability according to the criteria we have adopted. This suggests that not more than about 10% of those who are at present isolated in institutions are there for feebleness of will alone. It seems to confirm our presumption that the intellectually deficient discovered by tests form the great majority of the social deficients who need prolonged care or assistance.