My colleagues Delia Baldassarri and Peter Bearman wrote a paper with a theoretical model of political polarization. Here’s the paper, and here’s the abstract:

This article accounts for two puzzling paradoxes. The first paradox is the simultaneous absence and presence of attitude polarization, the fact that global attitude polarization is relatively rare, even though pundits describe it as common. The second paradox is the simultaneous presence and absence of social polarization, the fact that while individuals experienced attitude homogeneity in their interpersonal networks, their networks are characterized by attitude heterogeneity. These paradoxes give rise to numerous scholarly arguments. By deploying a formal model of interpersonal influence over attitudes in a context where individuals hold simultaneous positions on multiple issues we show why these arguments are not mutually exclusive and how they meaningfully refer to the same social setting. It follows that the results from this model provide a single parsimonious account for both paradoxes. The framework we develop may be generalized to a wider array of problems, including classic problems in collective action.

It’s a cool model of multidimensional issue attitudes with a nice story about how people can overestimate polarization in their social network because, when interacting with friends and acquaintances in settings where political attitudes are relevant, they are more likely to be aware of the issues where they agree, with areas of disagreement being less salient. We can thus perceive a polarized world even if, in aggregate, the social network is not so polarized.

Even if you don’t believe all the the details of the model, it seems to capture some important aspects of perception and reality.

P.S. You’ll have to read the paper to see what the above picture is all about.