Better together? The neural response to moral dilemmas is moderated by the presence of a close other.

Abstract

We investigated the modulation of neural and behavioral responses to moral dilemmas by the physical presence of a close friend. We argue that the presence of a close other not only changes the moral response but also the process of decision-making, something that can only be discovered by combining insights from social and cognitive psychology. Our participants rated the acceptability of sacrificing ingroup members to save outgroup members and vice versa while being alone or in the presence of a close other. We obtained behavioral and functional MRI data from a within-participant functional MRI study (N = 17, native Dutch women). The behavioral data replicated classical identity theory with regard to higher acceptability to sacrifice the outgroup (vs. the ingroup) but did not show any differences when deciding alone or in the presence of the friend. The imaging results did not reveal main and interaction effects in our hypothesized brain areas. Exploratory analysis however revealed an interaction effect in a region previously found to be related to guilt and shame (superior frontal gyrus), such that reactions to the sacrifice of the outgroup evoked increased activation when being together with a close other. (PsycInfo Database Record (c) 2020 APA, all rights reserved)