Rational Reasons for Irrational Beliefs

According to many, we live in “posttruth” times, with the pervasiveness of falsehoods being an existential threat to democracy and the functioning of free societies. Why do people believe and propagate falsehoods? Current accounts focus on psychological deficiencies, heuristic errors, self-enhancing motivations, and motivations to sow chaos. Here, we advance a complementary, outwardly (vs. inwardly) oriented, and ultimate (vs. proximate) account that people often believe and spread falsehoods for socially functional reasons. Under this view, falsehoods can serve as rare and valued information with which to rise in prestige, as signals of group commitment and loyalty tests, as ammunition with which to derogate rivals, or as outrages with which to mobilize the group toward shared goals. Thus, although people often generate and defend falsehoods through processes that are epistemically irrational, doing so might be rational from the perspective of the functions falsehoods serve. We discuss the implications of this view for puzzling theoretical phenomena and changing problematic beliefs.