What Does a Healthy Personality Do? Levels, Stability, and Change in Well-Being Across Time

Healthy personality profiles, characterized by higher extraversion, agreeableness, conscientiousness, and openness alongside lower neuroticism, are often assumed to support broad flourishing across the life course. Yet it remains unclear whether healthy personality primarily predicts higher levels of well-being, greater stability over time, or systematic change. Across two studies, we examined what having a healthy personality does for well-being by distinguishing between levels, stability, and change. Study 1 used cross-sectional data from a community sample to test whether a profile-based Healthy Personality Index (HPI) was associated with broad mental well-being. Healthy personality was strongly associated with higher well-being and accounted for substantial variance relative to demographic factors, while providing a parsimonious summary of personality-related variance. Study 2 used a four-wave longitudinal panel to examine whether healthy personality predicted evaluative well-being across time, change in psychological richness, and stability in well-being. Healthy personality was associated with higher average life satisfaction and life worthwhileness across waves and with greater temporal stability in life satisfaction. In contrast, healthy personality did not predict increases in psychological richness and was associated with smaller gains over time. Together, these findings suggest that healthy personality primarily supports the maintenance and stability of well-being rather than transformation or growth.