Homophily, Cultural Drift and the Co-Evolution of Cultural Groups

Abstract

Studies of cultural differentiation have shown that social mechanisms that normally lead to cultural convergence - homophily and influence - can also explain how distinct cultural groups can form. So long as the level of heterogeneity in the population is high enough, cultural diversity can emerge. However, this emergent cultural diversity has proven to be unstable in the face of cultural drift - small errors or innovations that allow cultures to change from within. We develop a model of cultural differentiation that combines the traditional mechanisms of homophily and influence with a third mechanism of network homophily, in which network structure co-evolves with cultural interaction. We show that if social ties are allowed to change with cultural influence, a complex relationship between heterogeneity and cultural diversity is revealed, in which increased heterogeneity can reduce cultural group formation while simultaneously increasing social connectedness. Our results show that in certain regions of the parameter space these co-evolutionary dynamics can lead to patterns of cultural diversity that are stable in the presence of cultural drift.