Friend influence in adolescence is well-documented, but the characteristics that contribute to individual differences in susceptibility to influence are not well understood. The present study tests the novel hypothesis that within a friend dyad, having fewer friends than one’s partner increases susceptibility to influence as it reduces dissimilarity and thereby promotes compatibility.
Longitudinal Actor-Partner Interdependence Models assessed peer influence, operationalized as individual change in the direction of increased friend similarity. Consistent with the hypothesis, partners with fewer friends were influenced by partners with relatively more friends in self-reported social anxiety and somatic complaints, as well as teacher-reported academic engagement and prosocial behavior.