An association between biased impression updating and relationship facilitation: A behavioral and fMRI investigation

Is ingroup bias associated with any benefit for maintaining close relationships? We examined the link between biased impression updating for ingroup members (i.e., friends) and relationship maintenance, as measured by the number of friends participants reported having (Studies 1 and 2). We also investigated the underlying neural basis of this possible effect, focusing on activity in the right temporo-parietal junction (RTPJ), a region of the social brain involved in moral updating (Study 2). Specifically, we tested whether selectively discounting negative information about close others, manifested in reduced impression updating, and indexed by reduced RTPJ activity, is related to maintaining close relationships. In Study 1, after imagining a friend and a stranger performing different positive and negative behaviors, participants who were reluctant to update how close they felt to their friend (friend-closeness) reported having more friends in real life. In Study 2, participants were led to believe that a friend and a stranger gave money to them or took money away from them, while they were in the scanner. Participants who engaged in less negative updating of friends versus strangers reported having more friends. Participants who engaged in less friend-closeness updating also showed reduced RTPJ activity when their friend took money from them, and this neural pattern was associated with reports of having more friends. Together, these findings suggest that selectively discounting close others' negative behavior is linked to maintaining close relationships, indicating a potential social benefit of ingroup bias.