Why Do Homogeneous Friendships Persist in a Diverse Population? Making Sense of Homophily
Homophily is one of the robust findings in social network studies. It persists even in a diverse population where the opportunity to develop homogeneous friendship is not greater than a mere chance and the process of developing heterogeneous friendship is facilitated. In this study, we introduce the Framework for Intergroup Relations and Multiple Affiliations Networks (FIRMAN), derived from social identity theory and social network framework, that can explain why that is the case. We begin by explaining its components: social identity space, social identity distance, length of ties, tie outreachability, and tie capacity. Then, through 7000 agent-based simulations, we demonstrate how the interaction of tie outreachability and tie capacity constraints heterogeneous friendship formations, which in turn make homophily inevitable even in a very diverse population. Surprisingly, the presence of even a small percentage (< 15%) of agents who can only develop homogeneous friendships can affect the whole population, preventing other agents from developing heterogenous friendships. We conclude by providing some directions for future research.