Moral conviction and metacognitive ability shape multiple stages of information processing during social decision-making.

Moral conviction has the potential to inspire activism and change, but can also instigate divisiveness and great harm. Moreover, attitudes held with moral conviction are experienced as universal objective truths and are less likely to demonstrate social conformity. Some evidence suggests that holding strong moral views may be a consequence of a cognitive style which includes lower metacognitive sensitivity. This study combined measures of attitudes, moral convictions, psychophysics, and electroencephalography (EEG) to determine how metacognition and moralization influence different stages of information processing during social decision-making, as well as the neural mechanisms underlying these effects. First, 170 participants were asked to indicate their attitudes and moral convictions about specific social issues that are currently important to US college students. Later, a subset of 81 participants completed a perceptual confidence task to assess their metacognition. Then, they underwent EEG while evaluating photographs of protests ostensibly about the same social issues. Prior to each photo, participants were provided with statistical information about social consensus from their peers for each issue. As predicted, stronger moral convictions were associated with lower social conformity. Furthermore, this effect was more pronounced in individuals with lower metacognitive ability. Moralized content was prioritized in multiple stages of information processing, including both early automatic attention and later deliberative stages, with medial frontal negativity (MFN) and early posterior negativity (EPN) predicting reduced conformity. Changes in alpha and high beta power indicated increased attention and engagement for moralized content. Together, results from these complementary methods and levels of analysis both converge to indicate that moralization alters sensitivity to social influence by shifting neural responses to efficiently prioritize information related to moralized beliefs.