A review of clinical and anthropological studies shows that social and cultural factors affect both the definition of, and the sensory systems involved in, hallucinations. It appears that the pejorative labeling of certain reported experiences as hallucinatory is dependent on linguistic factors as well as social and cultural beliefs (e.g., the consideration of hallucinations as an index of social maturity, social competence, and social conformity). It is pointed out that the degree of rationality in the culture is associated with attitudes, emotional response, and the attribution of pathology to hallucinatory experiences. The implications of social and cultural factors for the behavioral and psychoanalytical approaches to hallucinations are also discussed.Recently there has been an increasing interest in the study of mental imagery in general and in hallucinations in particular