Linking Temperament and Personality Traits from Late Childhood to Adulthood by Examining Continuity, Stability, and Change

Theories of personality development emphasize the continuity between who we are as a child and who we are as an adult. However, there are major unanswered questions about this (dis)continuity because research on traits has long been divided into studies of temperament in childhood and studies of personality in adolescence/adulthood. To bridge this divide, the present study used longitudinal data from a sample of 674 Mexican-origin youth who completed assessments of temperament traits (i.e., Negative Emotionality, Surgency, Affiliation, Effortful Control) from ages 10-16 and assessments of Big Five personality traits from ages 14-26. Leveraging two waves of overlapping temperament/personality trait assessments at ages 14 and 16, we found: (1) continuity between childhood/adolescent temperament and age 26 personality, with the strongest associations between conceptually similar traits, and Effortful Control predicting all Big Five traits (except Extraversion), suggesting self-regulation broadly promotes maturation; (2) temperament starts predicting adult personality traits by age 12-14, indicating that temperamental foundations of adult personality development crystallize in adolescence; (3) conceptually similar temperament/personality traits reflect different expressions of the same underlying trait from age 10-26, established using latent growth models of joint temperament/personality factors; (4) mean-level personality development across late childhood to adulthood showing that all joint traits maintain consistent rank-order stability and youth increase in Effortful Control/Conscientiousness, decrease in Negative Emotionality/Neuroticism and Surgency/Extraversion, and do not change in Affiliation/Agreeableness. Findings add novel support for widely accepted–yet largely untested–theories, although some unexpected results undermine prevailing assumptions about personality development.