The Subnormal Mind: By Cyril Burt. (The Oxford University Press, London, 1935. Pp. 368. Price 10 s. 6 d.)

Professor Burt has elaborated into an excellent text-book the lectures he gave at the London School of Hygiene in 1933 as the third series under the Heath Clark Bequest to the University of London. In the first half of the book he deals with defective mental development and in the second with delinquency and neurosis both of which he brings into his concept of subnormality. After a detailed introduction in which the modern methods of measuring intellectual and temperamental characteristics are described he describes the development of the present attitude of more adequate ascertainment and care of the mentally deficient. The evidence for a definite increase in mental deficiency in England during the present century is presented in detail and considerable work on inheritance is critically reviewed. Professor Burt concludes that although many of the conclusions concerning inheritance which have been published appear faulty after detailed analysis much is to be expected from further more accurate work. Backwardness without deficiency is seven times as common as deficiency and both are about twice as common in rural as in urban districts. Poverty, inadequate sleep, irregular school attendance, faulty promotion on the one hand and subnormal intelligence, specific disabilities such as reading difficulty in younger boys and arithmetical difficulties in older girls, memory defects and to a slight extent physical disorders on the other hand promote backwardness. In addition to the special schools already functioning Professor Burt suggests that a classification into three parallel series of school grades for the subnormal, the average and the advanced is now worthy of trial.

Among delinquents Professor Burt considers that inheritance determines sexual and aggressive offences to a marked degree. Poverty, lack of parental discipline, parental disharmony, lack of facilities for filling