For many of us, the groups to which we belong define who we are. For Harry Potter, being a student at Hogwarts and belonging to Gryffindor House are arguably the most important things in his life. However, even the most casual reader of the books has noticed that groups are also the source of the greatest conflicts in Harry’s world, particularly at Hogwarts School of Witchcraft and Wizardry. In many ways, Hogwarts seems to be a “perfect storm” in terms of intergroup tension. Knowingly or not, the school administrators have created and reinforced a structure that has all the necessary ingredients to brew some potent intergroup conflict.

Groups are important and provide us with innumerable benefits. For example, becoming a Gryffindor and joining the Quidditch team add more to Harry’s life than just labels or new friends. These group memberships change the way Harry defines himself, and for Harry— like the rest of us—group memberships are an important source of self-esteem. Still, there are consequences in identifying with one group over another, as clearly seen at Hogwarts School.

Intergroup Conflicts Can Arise Quickly: The Minimal Group Paradigm

Research on social identity theory has found that once people are divided into groups—even randomly divided by the toss of a coin—they start to show remarkable favoritism to their own group members. In a classic study, Henri Tajfel (1970) researched how schoolboys would divide rewards among others. First, boys were divided into groups by guessing how many dots flashed on a screen. Once  …