With a Little Help From My Friends? Examining the Role of Peer Homophily in High School Success

Abstract

Scholars have long noted the importance of friends for teenagers and much of this work has focused on understanding the relationships between peer characteristics and adolescent experiences and outcomes. Building on this research, I study the importance of peer demographic homophily, which is the sharing of three key demographic features (race, gender, and age) between friends for students’ high school graduation and college enrollment outcomes. With data from two longitudinal studies of adolescents – the Educational Longitudinal Study of 2002 (ELS) and the National Longitudinal Study of Adolescent Health (Add Health) – I examine the relevance of peer homophily in three contexts. In the second chapter, I use ELS data to assess the relative importance of teacher and peer demographic homophily. I find that peer homophily is positively and significantly associated with on-time high school graduation and immediate college enrollment and that it is shared age (measured by grade-level) that likely drives this association. I build on these findings in the next chapter, again using ELS data, to highlight important variations by race: peer homophily is positively and significantly associated with high school completion and immediate college enrollment for white students but not for black students. Similarly, same-age friends appear to be especially important for white students and insignificant for black students. Given the salience of shared age, in the final empirical chapter, I rely on Add Health data to examine whether there is grade-level variation in the association between peer homophily and students’ trajectories out of high school. These analyses reveal that peer homophily appears to be salient for students during their sophomore and junior years of high school. Furthermore, increasing peer homophily during these years is positively and significantly associated with graduating from high school on time and enrolling in college. Taken together, these findings suggest that, however unevenly, peer homophily is a critical aspect of adolescent secondary and postsecondary success. In highlighting this facet of adolescents’ high school experiences, I underscore the entwined nature of teenagers’ social and academic lives and seek answers, in future research, for the mechanisms that might help us better understand these relationships.