Personality, health behaviours and physical health in young adulthood

Personality traits and health are strongly correlated, but unobserved family-level characteristics may confound this relationship. This study investigates whether associations between personality traits and physical health are spurious owing to unobserved family background.

Participants were from the National Longitudinal Study of Adolescent to Adult Health. This study employed sibling fixed-effect approach to account for unobserved family characteristics.

Main dependent variables were Framingham Risk Scores for 30-year full cardiovascular disease (CVD) and metabolic syndrome.

Sibling fixed-effects models showed that conscientiousness is associated with reductions in CVD risk and metabolic syndrome, and that neuroticism is associated with an increase in both conditions. A higher extraversion score is positively associated with CVD risk. The adverse effect of extraversion on CVD risk is larger among females, and the protective effect of conscientiousness is larger among males. Moreover, while extraversion, neuroticism and conscientiousness are associated with health behaviours in somewhat distinct ways, the associations for agreeableness and openness are spurious owing to unobserved family background.

This study ruled out the concern that unobserved family background drives the personality-physical health link. Mechanisms linking personality to physical health may be gendered.