The literature of ethnopsychiatry was written over a sixty-year period by a diverse group of amateurs and specialists. Carothers, Sachs and Laubscher were qualified psychiatrists, Biesheuvel a clinical psychologist, Ritchie a schoolteacher with a passion for psychoanalysis. Mannoni was an ethnologist. Of this group Carothers was the best travelled and the only one to have contact with other specialists, but even he conducted his research in intellectual isolation. Given the lack of contact between individual psychiatrists, the smallness of the professional group and the absence of specialist journals, their agreement about African inferiority cannot be explained simply by the influence of one upon the other. On the contrary, the science's orthodoxy was spontaneous.

There was agreement from a variety of colonial sites about the major forms of mental illness found among patients admitted to asylums. In Africa as in Europe mental defectives were well represented among the inmates of mental hospitals. In 1950 such patients constituted almost 9 per cent of inmates in South African institutions, while in Kenya in the period from 1939 to 1943 the figure was a little over 10 per cent for first admissions. Carothers found that many of the mentally ill who fell foul of the law were intellectually deficient and that of the psychiatric homicides admitted to Mathari in 1949 almost a quarter were feeble-minded. In all African colonies organic disorders were prominent, and in Nyasaland Shelley and Watson found that 17 per cent of inmates suffered from an organically based mental illness.