Conscientiousness and health outcomes: The moderating role of general mental ability and the mediating role of internal health locus of control

The study of health outcomes and its predictors remains a topic of great interest, and psychologists have long examined the connections between individual traits and health. This study focuses on the interaction between two core psychological traits—conscientiousness and general mental ability (GMA)—and their role in predicting health outcomes. This study tests a model in which conscientiousness and GMA interact to predict internal health locus of control (HLOC-I), which is subsequently associated with perceived health, body mass index, and blood pressure. The results suggest a moderated mediation process in which the relationship between conscientiousness and health outcomes is mediated by HLOC-I, and moderated by GMA such that the relationship between conscientiousness and health outcomes is lower for those higher in GMA. The results shed light on how personality and ability combine to predict health outcomes, and offers insight into the traits that potentially underlie HLOC-I, further highlighting the importance of stable, individual differences in determining salient health outcomes.