Empirical Support for Homophily in Internalizing Problems
Selection and socialization processes have been studied predominantly with regard to externalizing behavioral problems (Bukowski, Brendgen, & Vitaro, 2007), but these processes also play a role in youths’ internalizing problems. Specifically, adolescents seek friends with similar levels of internalizing problems and also display increases in internalizing symptoms over time when their close friends are high on internalizing symptoms (Deater-Deckard, 2001).
Prospective studies are especially important for understanding selection and socialization processes. In this regard, Goodwin, Mrug, Borch, and Cillessen (2012) followed adolescents from the 6th to the 11th grades, examining peer selection and socialization processes across school transitions. After each school transition, adolescents selected friends who were similar in their levels of depressive symptoms; friends also socialized adolescents to become more similar in depressive affect during the middle school years, but not during high school. Prinstein (2007) conducted an 18-month longitudinal study of “peer contagion” of depressive symptoms among 11th graders, finding that adolescents whose close friends reported high levels of internalizing symptoms showed increases in their own internalizing symptoms over time. Moreover, several variables moderated these associations. For girls, greater social anxiety was associated with greater susceptibility to friends’ depressive symptom contagion; for boys, lower levels of friendship quality and higher friend popularity were associated with greater susceptibility to peer contagion.
These findings are intriguing and consistent with emerging evidence that corumination processes within friendships may contribute to adolescents’ socialization of internalizing symptoms. Hankin, Stone, and Wright (2010) conducted a multiwave study of early and middle adolescents, finding that baseline corumination predicted increasing trajectories of all forms of internalizing symptoms (especially depressive symptoms and anxious arousal) but not externalizing problems. Also of interest, Dishion and Tipsord (2011) recently described how peer contagion processes are relevant to adolescent depression and identified corumination as an interactive process that may mediate these effects.
Although less well studied, evidence also suggests that homophily is relevant to understanding social anxiety in youth. Van Zalk, Van Zalk, Kerr, and Stattin (2011) recently evaluated early adolescents and their friendships, finding socially anxious youth were less popular, chose fewer friends, and tended to select friends who were socially anxious. Over time socially anxious youth and their friends influenced each other into becoming more socially anxious, and this effect was greater for girls than for boys.
Finally, homophily also comes into play in youths’ romantic relationships (Furman & Simon, 2008). For example, Simon and colleagues (2008) examined peer selection processes in middle school youth, finding that adolescents and their romantic partners were similar on levels of depressive symptoms even prior to their relationship.