Ethnic Norms and Interethnic Violence: Accounting for Mass Participation in the Rwandan Genocide

This article specifies a simple mechanism - a behavioral norm defined in ethnic terms - to understand the dynamics of mass participation by reluctant Hutu in the 1994 Rwandan genocide. The mechanism, which has not been analyzed systematically in the scholarly literature, is specified using an agent-based model of within-group interaction that captures the role of intra-Hutu coercion in precipitating genocidal violence, yet is general enough to be applied to other group conflicts and contexts. The model highlights the role of individual heterogeneity, within-group punishment, behavioral adaptation, group networks, and ethnic entrepreneurs, and generates a set of results on norm formation and change, a number of which are not intuitive. These findings suggest that (1) norms are not equally likely to form in groups with similar aggregate preference; (2) a violence-promoting norm can emerge in a group dominated by moderates, and violence is not the inevitable outcome in a group dominated by extremists; (3) strong punishments are a prerequisite for the emergence of norms that promote interethnic violence or cooperation; (4) interaction patterns matter - for example, the segregation of an ethnic group clearly inhibits norm formation; and (5) an ethnic entrepreneur can effectively amplify norm formation within a group in the absence of strong punishment.