Minority-group incubators and majority-group reservoirs for climate change adaptation

Successful climate change adaptation depends on the spread and maintenance of novel adaptive behaviors. Social structure is a fundamental determinant of the spread of innovations and evolution of cumulative culture. Current theory suggests that the heterogeneity of metapopulation structure can help foster the diffusion of innovations. In this paper, we develop an agent-based model of the spread of adaptations in populations with such minority-majority metapopulation structure, where subpopulations have different preferences for social interactions (i.e., homophily) and, consequently, learn deferentially from their own group. In our simulations, minority-majority-structured populations with moderate degrees of in-group preference better spread and maintained an adaptation compared to populations with more equal-sized groups and weak homophily. Minority groups act as incubators for a novel adaptations, while majority groups act as reservoirs for the adaptation once it has spread widely. This suggests that population structure with in-group preference could promote the maintenance of novel adaptations, in the absence of out-group aversion. Our work advances the goal of this special issue by developing new theoretical insights and demonstrating the utility of cultural evolutionary theory and methods as important tools in the nascent science of culture that adaptation needs.