What is the relation between self-evaluation and being liked by others? Does being liked by others lead to more positive self-evaluations (as in sociometer theory), or do positive self-evaluations lead to being liked more (self-broadcasting)? Furthermore, what might affect the extent to which self-evaluations are influenced by likability (and vice versa)? The purpose of the present study was twofold. First, it used a naturalistic design to test the direction of the effect between social self-evaluations and others' judgments of likability in real relationships. Second, it examined how individual differences in attachment avoidance and anxiety relate to self-evaluations and likability and whether attachment differences moderate the relation between the two. Social self-evaluations, actual interpersonal liking, and attachment were assessed in participants taking part in a longitudinal group study. The findings supported the sociometer theory: Being liked by others led to more positive self-evaluations. Both anxious and avoidant attachment predicted lower self-evaluations, and anxious attachment predicted stronger reactions to others' liking (i.e., potentiated the sociometer). These findings have several implications for research on self-evaluation, adult attachment theory, and the importance of integrating interpersonal processes and individual differences.