Positive thought disorder in a hypothetically psychosis-prone population

Proverb interpretations of subjects who scored high on the Perceptual Aberration-Magical Ideation Scale (Chapman & Chapman, 1985) were compared with those of low-scoring controls. Responses to 10 familiar and 3 unfamiliar proverbs were scored for Bizarre-idiosyncratic thinking (Marengo, Harrow, Lanin-Kettering, & Wilson, 1986) and literalness (Hertler, Chapman, & Chapman, 1978). A Group by Type of Proverb (familiar versus unfamiliar) interaction was found for bizarre-idiosyncratic scores; (Per-Mags) scored higher than controls on unfamiliar, but not familiar proverbs. The Group X Familiarity interaction for bizarre-idiosyncratic scores indicates that the Per-Mag group displayed a subclinical, positive-thought disorder that is affected by the familiarity of the proverbs.