In analyzing the relationship between social factors and schizophrenia one can distinguish two research strategies.

Studies can focus on individual differences or the aggregate level.

Several investigations indicate that social factors, e.g., low socioeconomic status, single status, ethnic group, are significantly associated with the prevalence of schizophrenia.

To explain this relationship most investigators favor the hypothesis of social selection rather than a social causation.

This view is also supported by an ecological study of the incidence of psychiatrically treated schizophrenic disorders in the city of Mannheim.