Student ethnic organizations have become widespread at colleges and universities, yet few studies examine ethnic identity on campus. Their existence assumes commonality among members, yet, in fact, students come from diverse backgrounds and experiences. This work examines how groups negotiate their differences to create a common identity and maintain cohesion. My study of three Affinity Groups at Haverford College finds that maintaining cohesion is a constant, active process. By emphasizing shared symbols or experiences, or at least the shared perception that such symbols and experiences exist, and by distinguishing themselves from the mainstream community, group members find commonality. But ultimately, the groups maintain cohesion differently, perhaps attributable to the different socioeconomic status of each ethnicity within the United States. Thus one theory of ethnicity is insufficient; we must account for each group's persistence within the context of the history of its own ethnicity. This analysis sheds light on how and why such groups continue to exist and should be useful to those interested in the dynamics of intra- and interpersonal ethnic/racial relations.