Moral conviction interacts with metacognitive ability in modulating neural activity during sociopolitical decision-making.

The extent to which a belief is rooted in one's sense of morality has significant societal implications. While moral conviction can inspire positive collective action, it can also prompt dogmatism, intolerance, and societal divisions. Research in social psychology has documented the functional characteristics of moral conviction and shows that poor metacognition exacerbates its negative outcomes. However, the cognitive and neural mechanisms underlying moral conviction, their relationship with metacognition, and how moral conviction is integrated into the valuation and decision-making process remain unclear. This study investigated these neurocognitive processes during decision-making on sociopolitical issues varying in moral conviction. Participants (N = 44) underwent fMRI scanning while deciding, on each trial, which of two groups of political protesters they supported more. As predicted, stronger moral conviction was associated with faster decision times. Hemodynamic responses in the anterior insula (aINS), anterior cingulate cortex (ACC), and lateral prefrontal cortex (lPFC) were elevated during decisions with higher moral conviction, supporting the emotional and cognitive dimensions of moral conviction. Functional connectivity between lPFC and vmPFC was greater on trials higher in moral conviction, elucidating mechanisms through which moral conviction is incorporated into valuation. Average support for the two displayed groups of protesters was positively associated with brain activity in regions involved in valuation, particularly vmPFC and amygdala. Metacognitive sensitivity, the ability to discriminate one's correct from incorrect judgments, measured in a perceptual task, negatively correlated with parametric effects of moral conviction in the brain, providing new evidence that metacognition modulates responses to morally convicted issues.