Mindful minds: How group identity shapes brain and behavior in social decision-making.

Social mindfulness is a form of prosocial behavior that requires limited effort and considers other's needs and desires. But does this consideration persist when the other person supports opposing political ideologies? Using the social mindfulness (SoMi) paradigm with 45 adults holding strong pro- or anti-refugee stances, the current functional magnetic resonance imaging study investigates how group identity influences socially mindful behavior and its neural underpinnings. Consistent with prior research, individuals were more socially mindful toward ingroup members than toward outgroup members or unclassified others. This behavior engaged regions associated with mentalizing, decision-making and reward processing, including the temporoparietal junction, dorsal medial prefrontal cortex, dorsolateral prefrontal cortex, middle temporal gyrus, and orbitofrontal cortex. No neural differences emerged during socially mindful decision-making between ingroup and outgroup members or ingroup members and unclassified others. Interestingly, socially mindful decision-making for outgroup members, compared with ingroup members, elicited heightened activation in the right anterior insula, possibly reflecting the social and emotional significance of outgroup interactions resulting from experienced norm violation. Additionally, such decisions for outgroup members, as opposed to unclassified others, were associated with increased activation in the dorsal anterior cingulate cortex (dACC). Given the dACC's role in cognitive control during complex decision-making, this finding suggests that individuals exerted more effort to align their behavior with prosocial norms, even when these conflicted with self-interest. Overall, this study highlights how shared group identity shapes social mindfulness, reflecting both the emotional processing of outgroup interactions and the mental effort required to maintain prosocial norms in intergroup contexts.