Influence of reputational concern and social distance on moral decision-making under the harmful dilemma: Evidence from behavioral and ERPs study

Reputational concern has been suggested as an important determinant of human cooperative behavior and moral judgment in social interactions. Previous studies have demonstrated that reputational concern influences behavioral and neural responses during prosocial behaviors and decision-making, such as moral decision-making. Moral decision- making is a typical social decision-making process involving trade-offs between the self and others. It refers to the process in which individuals make optimal choices under the guidance of social systems and norms according to their own value orientations when faced with a variety of possible dilemmas and conflicts in behavioral choices. Emerging studies have shown that social distance modulates behavioral and neural responses during moral decision-making. However, little is known about how reputational concern and social distance interact to affect moral decision-making, particularly regarding the underlying cognitive neural mechanism of moral decision-making associated with proscriptive morality (i.e., harmful behavior). In the present study, we adopted the “shock-benefit dilemma” task and event-related potential (ERP) technology to examine temporal processing of the interactive influence of reputational concern and social distance on moral decision-making when faced with harmful dilemmas. Participants were instructed to complete a series of alternative dilemmas in an anonymous or public context. After being instructed whether their decisions were going to be made public to the target person, participants decided whether to deliver a certain intensity of painful electric shocks toward the targets (i.e., friends, acquaintances, or strangers) to receive money. A choice not to shock the targets meant that they would forego the benefit. Behavioral and neural responses were recorded while the participants made their decisions. The experiment consisted of 360 trials, including two blocks of anonymous and public situations and 120 trials with friends, acquaintances, and strangers. The results showed that participants administered fewer electric shocks to friends than to acquaintances and strangers, which suggested an obvious “egoistic altruism” decision tendency in anonymous situations. Participants spent more time and experienced greater disgust in dilemmas involving acquaintances relative to those involving friends and strangers, which showed an obvious “acquaintance effect”. However, these differences were weakened in public situations. As for the ERP results, the dilemmas involving acquaintances elicited a larger P260 component, which is associated with emotional responses, and late positive potential (LPP, 300~450 ms), which is associated with cognitive reasoning. However, these differences in ERP indices disappeared in public situations. The aim of this study was to explore the interaction between reputational concern and social distance in behavioral and neural responses during moral decision-making involving harmful dilemmas. The results supported the hypothesis that individuals follow the egoistic altruism moral principle to conduct moral decision-making involving reputational concern and social distance. These findings suggest that the uncertainty of acquaintance relations induces stronger negative emotions and cognitive load during moral decision-making, and reputational concern effectively weakens the aversion and dilemma conflict brought about by self-interest tendencies and interpersonal uncertainties.