Mental Defect

Abstract

A scrutiny of the papers published during the years 1940-42 and, indeed those published in 1939 and 1943, reveals an increasing trend towards clinical inquiry. Few articles are to be found in which it is assumed that mental deficiency is itself a simple concept, about which little remains to be discovered, and writers are now more cautious in suggesting the best methods of control and treatment than they were wont to be ten or twenty years ago. It is even realized that there are no fully satisfactory methods of describing what is meant by mental defect. Kuhlmann (1941) gives this definition: “Mental deficiency is a mental condition resulting from a subnormal rate of development of some or all mental functions.” The specific functions which are weak or strong in a given case are determined by tests and other observations. As Doll (1941) points out, there seems to be no escape from basing the diagnosis of mental deficiency upon a variety of different criteria, the main symptom still being social incompetence. Standards of social behaviour at different ages have been incorporated by Doll (1942) in the Vineland Social Maturity Scale; he recommends its use in classifying cases for training. The problem of deciding what constitutes mental defect is acutely brought out when differences in education or culture have to be considered. Sparling (1941), for example, showed that American Indian children, whose mean Binet I.Q. was on the borderline between normality and defect, had a mean I.Q. of 108 on the Porteous Maze test. In New York State, Malzberg (1943) found that even allowing for educational differences, mental defect was commoner among negroes than among whites. Nevertheless, as shown by Zubin and Scholz (1941), recognized mental defect (judged by the number of admissions to institutions) is commoner among whites than among negroes in the Southern States. This effect is partly due to the fact that more attention is paid to problems of mental defect in predominantly white than in predominantly coloured populations. Conversely, prisons contain unduly high proportions of coloured inmates according to both North American and South African statistics (Penrose, 1943). The question as to how far mental defect is a contributory factor in cases of crime has received attention from Frankel (1939), who reported that 15 per cent. of 1,000 murderers came into this category, and that the mean mental age for 722 of such criminals was 11 years. Among 309 adolescent delinquents, Stefanescu-Goanga (1939) found 99, of 32 per cent., mentally defective; 47 per cent. of the children committed for homicide were in this category, and 34 per cent. of those committed for theft. Selling (1942) has investigated the degrees of intelligence in offenders under Road Traffic Acts, and finds that although uncomplicated defect is compatible with safe driving, many accidents are caused by emotionally unstable cases with subnormal intellectual capacity, and that such people should not be allowed to drive motor vehicles.