Amanda Hellwig

This study examines links between self‐disclosure and relationship quality with close friends from adolescence to adulthood. A diverse community sample of adolescents ( N = 184) participated in survey and observational measures annually from ages 13 through 29, along with their close friends and romantic partners. Random intercept cross‐lagged panel modeling (RICLPM) was used to parse markers of within‐individual change from age 13 to 18. Long‐term longitudinal path models also investigated cascading associations among self‐disclosure and relationship quality, on aggregate, from adolescence to adulthood. Adolescents who reported a higher‐quality friendship in a given year demonstrated greater‐than‐expected increases in self‐disclosure the following year, and an adolescent demonstrated high self‐disclosure one year reported greater‐than‐expected increases in friendship quality the following year. Higher mean self‐disclosure in adolescence predicted higher mean self‐disclosure in adulthood. Results are interpreted as identifying high‐quality adolescent friendships as key contexts for developing intimacy‐building capacities (i.e. self‐disclosure), which sets the stage for satisfying close relationships in adulthood.