Neural bases of ingroup altruistic motivation in soccer fans

Jorge Moll,Roland Zahn,Patrícia Bado,Sebastian Hoefle,Ricardo De Oliveira Souza,Annerose Engel,Tiago Bortolini,Jean-Claude Dreher

doi:10.1038/s41598-017-15385-7

Abstract

Humans have a strong need to belong to social groups and a natural inclination to benefit ingroup members. Although the psychological mechanisms behind human prosociality have extensively been studied, the specific neural systems bridging group belongingness and altruistic motivation remain to be identified. Here, we used soccer fandom as an ecological framing of group membership to investigate the neural mechanisms underlying ingroup altruistic behaviour in male fans using event-related functional magnetic resonance. We designed an effort measure based on handgrip strength to assess the motivation to earn money (i) for oneself, (ii) for anonymous ingroup fans, or (iii) for a neutral group of anonymous non-fans. While overlapping valuation signals in the medial orbitofrontal cortex (mOFC) were observed for the three conditions, the subgenual cingulate cortex (SCC) exhibited increased functional connectivity with the mOFC as well as stronger hemodynamic responses for ingroup versus outgroup decisions. These findings indicate a key role for the SCC, a region previously implicated in altruistic decisions and group affiliation, in dovetailing altruistic motivations with neural valuation systems in real-life ingroup behaviour.

Highlights

The capacity to develop strong social bonds to genetically unrelated group members may have played a central role in hominin evolution and in gene-culture coevolution[1,2]
Previous fMRI studies addressing the neurobiology of ingroup altruism have mainly employed arbitrary groups, based, for example, on a bogus perceptual task or personality test forming groups indicated by different colors[9,10]
In addition to the evidence pointing to the reward system in ingroup cooperation and social valuation[28,29,30], the subgenual cingulate cortex (SCC; BA25 and parts of BA24/32 and 33) has been

Summary

Introduction

The capacity to develop strong social bonds to genetically unrelated group members may have played a central role in hominin evolution and in gene-culture coevolution[1,2]. Group belongingness is considered a basic human need[3] and behavioural research has demonstrated the human tendency to favour ingroup over outgroup members, even when groups are defined by arbitrary surface features like those created in the laboratory[4,5] Such important advances on the understanding of the psychological mechanisms of ingroup bias and ingroup-outgroup categorization[5,6] have recently been bolstered by neurobiological studies[7,8]. Recent studies have investigated natural social identities built on long-lasting, strong ties based on daily engagement[6] (such as ethnical groups[11] and university affiliation12), inferring participant’s altruistic motivations from their behaviour in classic economic games These studies showed increased responses in the ventral striatum (VS), a key region of the reward system[13], for ingroup donations compared to self-rewards[11]. These lines of evidence suggest that the SCC may be an important neural component for enabling culturally-defined ingroup attachment and behaviour[37,43,44,45]

Methods

Results

Conclusion