Morality, competence, and sociability have been conceptualized as fundamental dimensions on which individuals ground their evaluation of themselves and of other people and groups. In this study, we examined the interplay between self-perceived morality, competence, and sociability and relationship quality within the core social contexts with which adolescents have extensive daily interactions (family, friends, and school). Participants were 916 (51.4% girls; Mage = 15.64 years) adolescents involved in a three-wave longitudinal study with annual assessments. The results of cross-lagged analyses indicated that (a) self-perceived morality was more important than self-perceived competence and sociability in strengthening family, friend, and school relationships; and (b) high-quality friendships led to increasing levels of self-perceived morality over time. Overall, this evidence advances our theoretical understanding of the primacy of morality from a self-perspective approach and highlights the developmental importance of friends.