The Consequences of Social Pressures on Partisan Opinion Dynamics

We simulate a theoretical agent-based model of opinion dynamics in a two-party framework that captures the effects of social pressures that compel individuals to publicly conform to their party line even when they may disagree with it privately. The results of our model indicate that opinions acquire a distinctly partisan character over time despite being initialized uniformly across most members of both parties. Further, the socially acceptable range of opinions in each party and the level of partisanship prevalent in the polity play an important role in determining the membership sizes of both parties, the median opinions of both parties and the polity, the extent to which extreme opinions get marginalized within a party, and the level of polarization within and across parties. We find that our simple framework can explain certain features of recent data such as the influence of parties on individual opinions and the increasing polarization of the polity.