"The Unstable Child": An Interpretation of Psychopathy as a Source of Unbalanced Behaviour in Abnormal and Troublesome Children

What is psychopathy ? And who are psychopathic? Dr. Mateer's definition rests upon the distinction between mental level and mental function. The study of mental level decides whether the child is " bright, backward, or mentally defective." The study of mental functioning indicates whether his mind is " reliable or unreliable," no matter what his mental level may be. The former is quantitative; the latter qualitative. The former relies merely upon tests for mental age. The latter applies ten empirical criteria, which Dr. Mateer expounds in detail. Of these criteria, the first and simplest are the quality of the child's replies and the distribution of his failures and successes in the ordinary Binet-Simon tests; the unevenness of his mental level as judged respectively by the Binet tests, by performance tests of intelligence, and by standardised tests of educational ability, is almost equally significant; the intrinsic nature and the unusual character ot his replies in the Kent-Rosanoff tests of asso-