"Rationalizations and political polarization"
with Peter Schwardmann and Joël J. van der Weele

Abstract :
We propose a self- and social-signaling model that formalizes influential results in political psychology documenting how moral and political judgments are primarily based on intuitions and emotions, while reasoning merely serves to rationalize these intuitions in pursuit of an image as a reasonable decision-maker. In social interactions between both co-partisans and counter-partisans, agents’ rationalizations are strategic complements, as an increase in others’ rationalizations undermines their ability to critically judge the agent, and makes their actions less revealing of the (potentially inconvenient) truth. When agents are naive about their own rationalizations, our model generates both ideological and affective polarization, with each side assigning inappropriate motives to the other. The social exchange of narratives reduces polarization when occurring among counter-partisans, but might exacerbate it otherwise. Our model sheds light on the origin of partisan disagreement about the consequences of public policies, matches empirical facts about polarization, and speaks to the effects of initiatives that seek to break up echo chambers.