Co-Development of Personality and Friendships Across the Lifespan: An Empirical Review on Selection and Socialization

This article examines changes in the co-development of personality characteristics and friendships across the lifespan. We address how personality traits shape friendship development (i.e., selection effects) and how friendships shape personality traits (i.e., socialization effects). By integrating separate empirical studies, we look at how selection and socialization effects change across the lifespan. A review of longitudinal research supports our hypothesis that selection effects on friendships intensify during adolescence, peak in young adulthood, and diminish throughout middle and late adulthood. Socialization effects through friendships seem to be moderately sized during adolescence, then small to negligible from young adulthood onwards. For future directions, we discuss effects of the transactional development of friendships and personality regarding associated dispositions within individuals, associated individuals within friendship dyads, and individuals associated within wider social networks.