Birds of a feather: Homophily in social networks

Similarity breeds connection. This principle-the homophily principle-struct ures network ties of every type, including marriage, friendship, work, advi ce, support, information transfer, exchange, comembership, and other types of relationship. The result is that people's personal networks are homogene ous with regard to many sociodemographic, behavioral, and intrapersonal cha racteristics. Homophily limits people's social worlds in a way that has pow erful implications for the information they receive, the attitudes they for m, and the interactions they experience. Homophily in race and ethnicity cr eates the strongest divides in our personal environments, with age, religio n, education, occupation, and gender following in roughly that order. Geogr aphic propinquity, families, organizations, and isomorphic positions in soc ial systems all create contexts in which homophilous relations form. Ties b etween nonsimilar individuals also dissolve at a higher rate, which sets th e stage for the formation of niches (localized positions) within social spa ce. We argue for more research on: (a) the basic ecological processes that link organizations, associations, cultural communities, social movements, a nd many other social forms; (b) the impact of multiplex ties on the pattern s of homophily; and (c) the dynamics of network change over time through wh ich networks and other social entities co-evolve.