Sustainability of minority culture when inter-ethnic interaction is profitable

Members of some ethnic minorities are interested in the sustainability of certain cultural traits typical of their group. However, theoretical and empirical evidence suggests that sustaining such cultural variation can be difficult, given inter-ethnic interactions between groups differing in size, prestige and power. Here we examine the dynamics of cultural norms by constructing a model of interaction between members of minority and majority ethnic groups. We incorporate asymmetric coordination benefits to represent ethnic asymmetries in resource control and bargaining power. In the absence of other processes, we find that sustainability of minority cultural norms may be enhanced by establishing a group boundary that minority members can cross freely, but members of a powerful majority cannot. We show how model predictions can complement empirical studies of cultural change, and demonstrate the model’s relevance to our understanding of norm dynamics in an indigenous Amazonian population.