Homophily and competition: a model of group affiliation

How can we understand the interaction between the social network topology of a population and the patterns of group affiliation in that population? Each aspect influences the other: social networks provide the conduits via which groups recruit new members, and groups provide the context in which new social ties are formed. While many social simulation models exhibit group formation as a part of their behaviour (e.g., opinion clusters or converged cultures), models that explicitly focus on group affiliation are rare. We introduce one such model, based upon the ecological theory of group affiliation, and use it to explore the effect of two system properties—bias toward the creation of homophilous ties and competition between groups—on the dynamics of social evolution and group formation.