Since Faris and Dunham (1939) found that the mental hospital admission rate for schizophrenia was higher in the central slum districts of Chicago than in the rest of the city, many studies have been carried out on the association between low social status and hospital admission with a diagnosis of schizophrenia. With few exceptions (for example, Clausen and Kohn, 1959; Jaco, 1954) these studies have confirmed that those in the lowest social group (in this country class V in the Registrar-General's scheme) have the highest admission rates. Some of these investigations have been “ecological” or “indirect”; i.e., admission rates have been calculated for areas of a city defined, for example, as slum, working, or middle class areas, and the rates for these areas compared; other studies have been “individual” or “direct”, where admission rates have been calculated for aggregates of individuals, defined as belonging to particular social classes, and the rates for the classes compared. An ecological study, like that of Faris and Dunham, may show that rates are higher in poor districts, but it does not necessarily follow that the patients admitted are themselves poor. Individual studies, however, do show that men in unskilled jobs have the highest admission rates.