On the wrong side of the trolley track: neural correlates of relative social valuation

Abstract

Using moral dilemmas, we (i) investigate whether stereotypes motivate people to value ingroup lives over outgroup lives and (ii) examine the neurobiological correlates of relative social valuation using fMRI. Saving ingroup members, who seem warm and competent (e.g. Americans), was most morally acceptable in the context of a dilemma where one person was killed to save five people. Extreme outgroup members, who seem neither warm nor competent (e.g. homeless), were the worst off; it was most morally acceptable to sacrifice them and least acceptable to save them. Sacrificing these low-warmth, low-competence targets to save ingroup targets, specifically, activated a neural network associated with resolving complex tradeoffs: medial PFC (BA 9, extending caudally to include ACC), left lateral OFC (BA 47) and left dorsolateral PFC (BA 10). These brain regions were recruited for dilemmas that participants ultimately rated as relatively more acceptable. We propose that participants, though ambivalent, overrode general aversion to these tradeoffs when the cost of sacrificing a low-warmth, low-competence target was pitted against the benefit of saving ingroup targets. Moral decisions are not made in a vacuum; intergroup biases and stereotypes weigh heavily on neural systems implicated in moral decision making.

Dehumanization increases instrumental violence, but not moral violence

“…Thus, dehumanization makes possible the everyday violence and largescale atrocities that observers enable through their indifference. It allows us to refuse to help and to sacrifice others for the greater good because we are apathetic to their suffering (60,61). It undermines reconciliation following conflict because there is no point to rebuilding relationships with those we think of as animals (55,62).…”

We are human, they are not: Driving forces behind outgroup dehumanisation and the humanisation of the ingroup

“…Other research on moral dilemmas, where the death of one person could save the life of five other people, shows that it is judged most acceptable morally to sacrifice the life of a member of a low-low outgroup to save five ingroup members, and it is least acceptable to save the low-low outgroup members when an ingroup member has to die. Cikara, Farnsworth, Harris, and Fiske (2010) found special neural correlates for these evaluations.…”

Oxytocin promotes human ethnocentrism

“…Both experiments used the Moral Choice Dilemma Task (42,43), which presents participants with a series of choice dilemmas. A famous example is that of a trolley running toward five people, who will be killed if nothing is done.…”