Résumé
Aging comes with seemingly inevitable changes, but there is a great variability in how young or old people feel, and the majority of adults feel considerably younger than their chronological age. Little is, however, known about the individual determinants of this subjective age bias across adulthood. We examined whether the variability in an individual's subjective age can be explained by (a) openness to experience and (b) (non)essentialist beliefs about aging. Specifically, we predicted that individuals who have high (vs. low) levels in openness and those who believe that aging is a flexible (vs. fixed) process have a younger rather than an older subjective age. Evidence from one cross-sectional (N = 228) and one longitudinal study (N = 3848) confirmed our hypotheses that a more malleable view of aging mediates the effect of openness to experience on subjective age bias. We discuss these findings in the light of social-cognitive and motivational antecedents and mechanisms of subjective aging.