Hugo Mercier and Helene Landemore describe an evolutionary psychological theory of deliberative polarization in their paper, “Reasoning is for Arguing: Understanding the Successes and Failures of Deliberation.” From the paper:
We suggest that the function of reasoning is not the betterment of beliefs and judgments through private ratiocination and this is why reasoning does not accomplish this task well. According to the theory that will be defended here the function of reasoning is social. More specifically it is argumentative, i.e., it is to enable individuals to argue with each other. Here is the rationale behind this suggestion.
As a species, humans are strongly influenced by communicated information: communicated information affects many, if not all, decisions, and these decisions are, on the whole, better for it. However, being able to communicate comes at the cost of an ever present danger of manipulation. Accordingly, humans do not trust blindly what other people say: they use a set of cognitive mechanisms to evaluate communicated information. Sperber has dubbed these competences epistemic vigilance. For instance, we calibrate the trust granted to different speakers, paying more attention to the medical opinion of our doctor than that of our neighbor, and to the personal advice of our friends than that of strangers. We also use the coherence between the information we are communicated and our previous beliefs to determine its a priori plausibility, and tend to reject that which is not coherent with what we thought. More to the point here, we formulate arguments supporting our claims, and evaluate those provided by others. By adducing arguments in support of a conclusion they want to convey, speakers provide listeners with extra means to evaluate its validity. This allows for a more efficient communication: listeners are better able to evaluate communicated information, and speakers can convey their messages more effectively. According to this scenario, reasoning is the mechanism that evolved to perform this function: the primary goal of reasoning is then to find and evaluate arguments so as to convince others and be convinced when it is appropriate.
I think this kind of evolutionary psychological account is consistent with epistemic norms of reason-giving and reason-responsiveness and the basic “community of inquiry” model. The authors detail various paradigm cases of argumentative reasoning, both successful and unsuccessful, and show how “epistemic vigiliance” is tied to various small group reasoning experiments. This is the direction I had hoped would emerge out of naturalized epistemology. Well worth reading. (Tag, Steven. You’re it!)