The neuropsychiatrist presenting evidence before Court will sooner or later be asked the question, “Was the accused, at the time of committing the offence, labouring under such defect of reason as that he did not know what he was doing, or if he knew what he was doing, he did not know it was wrong?”

In recent years many attempts have been made to improve methods of temperament testing, and to show the validity of the results by comparing test-scores of groups of subjects known to be differentiated with respect to certain traits (Cattell (1), Eysenck (2), Himmelweit (5)). Thus there has been found a very significant correlation between degree of neuroticism and suggestibility, and a correlation almost as high between degree of neuroticism and persistence. These results have suggested the possibility of using tests of this kind in an attempt to measure the neurotic tendencies of individual subjects, and to screen the more neurotic from types of occupation likely to impose too great a strain on them (Eysenck (3)).

Tests of the indefinable quality known as intelligence are legion. Many have been standardized satisfactorily, others have not. The validity of some tests is high, but results of different tests used on the same individuals have seldom been published.

Many difficulties confront the medical officer who has in his care large numbers of mental patients. In the first place, owing to the staffing problems which beset the majority of mental hospitals in this country, he is probably overworked. He has neither the time nor the energy to deal adequately with the mass of work which confronts him, and as a result his output is often not as efficient as it could be. Further, when dealing with large numbers, a physiological factor enters which is often overlooked. It is very difficult to register and retain the many small variations in behaviour which are so important in the understanding of a patient, when perhaps 350 or more patients have to be seen every day. There seems to be a definite saturation point beyond which images are not retained; indeed we know that this is so, but we rarely seem to take account of it. The very sameness of deteriorated and apathetic patients contributes to this state of affairs.