Cognitive Expectations of Homophily in Village Social Networks

Homophily, the tendency for individuals to associate with similar others, has long beentreated as a central principle of social organization. Yet people may overestimate itsimportance in reasoning about their social networks. Here, we investigate individuals’cognitive expectations of homophily and compare these expectations to actual homophilyamong 10,072 adults in 82 isolated Honduras villages. We elicited subjects’ beliefs aboutwhether pairs of people in their village social networks were socially tied. We show thatpeople deploy cognitive heuristics that substantially overestimate homophily, includingbased on wealth, ethnicity, gender, and religion. We also find that people exploit networkstructure when predicting ties between others, independent of expectations abouthomophily. Understanding cognitive homophily has implications for models of networkformation, interventions targeting social behavior and information diffusion, and themaintenance of social inequality.