Friendship and partner choice in rural Colombia

Friendship is a recurring feature of human sociality. Extant evidence has highlighted several axes upon which the formation and maintenance of friendships rest, and has emphasised the importance of market-like mechanisms and preferential assortment in such dynamics. Such evidence has emerged from qualitative ethnographic descriptions, and observational or experimental case studies in relatively homogeneous samples from Western and industrialised settings. Here, we provide one of the first empirical evaluations of the structure of friendship networks in a rural subsistence setting. We collected individual-level friendship network data, and detailed economic and demographic information from individuals in four communities in rural Colombia (N = 470). We analyse these data using a combined social relations and stochastic block model. Our results highlight the importance of preferential assortment on the basis of several socio-demographic traits in all study communities. The extent to which friendship and social support networks overlap appears to vary considerably across communities, with greater overlap being observed in more impoverished areas. Similarly, the extent of wealth homophily was greater in more impoverished areas. Such findings suggest that variation in the axes upon which friendship rests may be affected by community-level variation in economic and demographic composition.