Abstract
This study examined various homophilic mechanisms by which adolescents affect, and are affected by, levels of internalized distress within their immediate peer groups. The sample included approximately 6,000 14- to 18-year-olds who were assessed twice over a 1-year period. Results showed that adolescents tend to associate with peers who report similar levels of internalized distress and that internalizers are no less successful than others at establishing friendships. Moreover, homophily of internalizing symptoms develops from 3 distinct sources: (a) Adolescents tend to choose friends who possess similar levels of internalized distress (selection effect); (b) in male, but not female, peer groups, individual distress levels grow increasingly similar to peer levels over time (socialization effect); and (c) peer group distress levels vary according to the distress of individual members (contagion effect).