An influential body of psychological and anthropological theories holds that societies exhibit heterogeneous cooperation systems that differ both in their level of in-group favoritism and in the tools that they employ to enforce cooperative behavior. According to some of these theories, entire...

In this paper we present a conceptual framework linking cultural heterogeneity to inter-group conflict. When conflict is about control of public goods, more heterogeneous groups are expected to fight more with each other. In contrast, when conflict is about rival goods, more similar groups are...