Cognitive Expectations of Homophily in Village Social Networks

Homophily, the tendency for individuals to associate with similar others, has long been treated as a central principle of social organization. Yet people may overestimate its importance in reasoning about their social networks. Here, we investigate individuals’ cognitive expectations of homophily and compare these expectations to actual homophily among 10,072 adults in 82 isolated Honduras villages. We elicited subjects’ beliefs about whether pairs of people in their village social networks were socially tied. We show that people deploy cognitive heuristics that substantially overestimate homophily, including based on wealth, ethnicity, gender, and religion. We also find that people exploit network structure when predicting ties between others, independent of expectations about homophily. Understanding cognitive homophily has implications for models of network formation, interventions targeting social behavior and information diffusion, and the maintenance of social inequality.