The twin impact of homophily and accessibility on ideological polarization

We present an agent-based model to explore the causes of one aspect of ideological polarization: the extent to which members of a society have social ties only with those they agree with. Specifically, we look at two variables that affect how an artificial social network structure is built: homophily, or the preference of individuals to form connections with others of the same "kind"; and accessibility, or the ease with which agents can form connections to others distant from it, as opposed to only local agents in its immediate vicinity. Our model builds a graph according to these two parameters, and then executes the classic Binary Voter Model (BVM) process on it whereby connected nodes influence one another's opinions. We find that counter to our original hypothesis, increasing the society's accessibility decreases its polarization, especially for high levels of homophily. Also, we discover that the rate at which agents form and dissolve friendships during the simulation plays a nuanced role in the way the society evolves.