Personality and sleep predict longevity; however, no investigation has tested whether sleep mediates this association. Thus, we tested this effect across a 20-year follow-up (N = 3,759) in the Midlife Development in the United States cohort (baseline M age = 47.15) using proportional hazards in a structural equation modeling framework. Lower conscientiousness predicted increased death risk via the direct, indirect, and total effect of quadratic sleep duration. Although there were no other direct personality-mortality effects, higher neuroticism and agreeableness and lower conscientiousness predicted increased death risk via the joint indirect effects of quadratic sleep duration and higher daytime dysfunction. Lower extraversion predicted increased mortality risk via the indirect effect of daytime dysfunction. Our findings have implications for personality-based health interventions.
Keywords: Big Five; health; mortality; personality; sleep.