["Journal of Personality, Volume 94, Issue 2, Page 304-319, April 2026. ", "\nABSTRACT\n\nObjective\nIdentity development research often applies the identity status approach, which distinguishes different dimensions of identity‐relevant commitment levels and exploration behavior. However, age differences in these dimensions have mostly been examined in adolescence and young adulthood, leaving questions about their variation across the adult lifespan. Additionally, associations between identity and life satisfaction have been equally understudied in adult populations.\n\n\nMethod\nWe examined these questions in a large, nationally representative U.K. sample (N = 3869; age range 18–97). Identity processes were measured using an abbreviated Dimensions of Identity Development Scale. After invariance testing by age groups, we examined age differences across identity dimensions: Commitment and Exploration (depth, breadth, ruminative).\n\n\nResults\nOlder individuals reported lower scores on all exploration dimensions until late adulthood. However, though no age differences in commitment were observed between early and middle adulthood, less commitment was reported from middle to late adulthood. Additionally, commitment and exploration in depth were consistently positively associated with life satisfaction, whereas ruminative exploration negatively predicted life satisfaction, with stronger associations appearing in later adulthood.\n\n\nConclusions\nThese findings demonstrate the feasibility of studying identity across adulthood from a measurement perspective and highlight how identity dimensions relate to well‐being at different ages.\n\n"]