Fluid insight moderates the relationship between psychoticism and crystallized intelligence

To elucidate potential relationships between personality and intelligence it is necessary to move beyond the ad hoc reporting of correlation coefficients and focus instead on testing deductions from well-established theories. To this end the present paper references Eysenck’s (1995) theoretical work linking the dimension of psychoticism to both psychosis and creative genius. Drawing on this theory it was argued that the relationship between psychoticism and crystallized ability will be conditional on the level of fluid intelligence. Participants (N = 100) completed the Eysenck Personality Questionnaire-Revised (EPQ-R) and the Kaufman Brief Intelligence Test (K-BIT). Moderated multiple regression revealed a significant interaction effect. Crystallized ability (K-BIT vocabulary) was negatively related to psychoticism at low levels of fluid ability (K-BIT matrices) and positively related to psychoticism at high levels of fluid ability. These findings highlight the potential importance of psychoticism within GfGc investment theory.

► Fluid ability moderated the relationship between P and crystallized ability.
► At low levels of fluid ability P was negatively correlated with crystallized ability.
► At high fluid ability P was positively correlated with crystallized ability.
► The results justify a continued focus on the role of P within GfGc investment theory.