Over the past 30 years, research on how college impacts student development has continually pointed to the peer group as perhaps the dominant change agent during the college years (Feldman & Newcomb, 1969; Pascarella & Terenzini, 1991). A college student's peers act as a reference group, or an environmental source of sociocultural norms in the midst of which a student grows and develops (Clark & Trow, 1966). A large body of empirical evidence has been collected over the years to support this conclusion (Astin, 1977, 1993a; Feldman & Newcomb, 1969; Pascarella & Terenzini, 1991).
A review of the research on the impact of college peer groups reveals an interesting trend. The earliest work on peer groups (primarily in the 1950s and early 1960s) focused on peer associations that were structured organizationally by either residential circumstances or formal group affiliations (Feldman & Newcomb, 1969). Most of this work was conducted at single institutions. Furthermore, there was recognition that while the student body characteristics of individual colleges may accentuate initial differences between students attending different institutions, student subcultures and friendship groups within institutions probably mediate the developmental impact of the student body (Feldman & Newcomb, 1969). Despite consensus on the important role that friendship groups play in socialization in college, however, the majority of published peer group studies since the mid-1960s have been multiinstitutional and have operationalized the student peer group as a singular, campus-wide entity (Pascarella & Terenzini, 1991). Peer group effects, in other words, were studied as between-institution effects (e.g., Astin, 1977; Bassis, 1977; Davis, 1966; Thistlewaite & Wheeler, 1966; Werts & Watley, 1969). Our current understanding of these institutional effects is that they are likely mediated through interactions with students within a variety of interpersonal environments (Astin, 1993a; Kuh, 1995; Pascarella & Terenzini, 1991). Given concurrent research underscoring the importance of student interaction and engagement on campus for development and retention (Astin, 1984; Pascarella, 1985; Tinto, 1975; Weidman, 1989), it is surprising that little current work on peer group influence in college focuses on interpersonal environments such as friendship groups and cliques.
The campus environment itself has changed greatly since the 1950s and 1960s. Colleges and universities are rapidly becoming ethnically and racially diverse student communities (Justiz, 1994), and increasing campus diversity has been accompanied by a rise in racial tension on campus, battles over free speech and the curriculum fought across racial lines, and social self-segregation by race (Altbach, 1991). These troubling patterns are forceful reminders that issues of racial and ethnic difference pervade many corners of the university, and questions regarding student experiences and student development on today's campuses must include the role of racial diversity in their formulation. The general purpose of this study is to conduct a contemporary examination of peer group influence in college that focuses on interpersonal environments and also addresses the role of racial diversity in those environments.
Peer groups and peer group influence
Researchers in the fields of sociology and social psychology have tended to view student peers as a determinant of school context, which acts as a referent against which students evaluate themselves (Alwin & Otto, 1977). The vast majority of the work that has drawn conclusions on the influence of college peer groups reflects this view, if not explicitly so, in the manner in which the peer group is operationalized methodologically. In these studies, the peer group was thought of as a reference group encompassing the entire student body. Early work, for example, likened the campus to a frog pond within which students formed judgments of their abilities and aspirations. …