AbstractObjectiveWe investigate how the education effect on affective polarization is mediated by people's cognitive behaviors.MethodWe employ a causal mediation analysis model and the American National Election Studies (2016 and 2020).ResultsBoth voters’ psychological engagement in politics and their authoritarian attitudes mediate the education effect on affective polarization, but the directions of the two mediation effects are different. While a person's attainment of higher education lowers her affective polarization through her weak authoritarian attitude, it raises her affective polarization through her psychological engagement in politics.ConclusionThe result implies that educational expansion does not warrant the waning of affective polarization. It also implies that education may have differing indirect effects on other political behaviors such as party support.