Neural basis of in-group bias and prejudices: A systematic meta-analysis

Neurosci Biobehav Rev. 2021 Dec:131:1214-1227. doi: 10.1016/j.neubiorev.2021.10.027. Epub 2021 Oct 29.

Abstract

In-group favoritism and prejudices relate to discriminatory behaviors but, despite decades of research, understanding of their neural correlates has been limited. A systematic coordinate-based meta-analysis of functional magnetic resonance imaging (fMRI) studies (altogether 87 original datasets, n = 2328) was conducted to investigate neural inter-group biases, i.e., responses toward in-group vs. out-group in different contexts. We found inter-group biases in some previously identified brain regions (e.g., the medial prefrontal cortex, insula) but also in many previously non-identified brain regions (e.g., the cerebellum, precentral gyrus). Sub-group analyses indicated that neural correlates of inter-group biases may be mostly context-specific. Regarding different types of group memberships, inter-group bias toward trivial groups was evident only in the cingulate cortex, while inter-group biases toward "real" groups (ethnic, national, or political groups) involved broader sets of brain regions. Additionally, there were heightened neural threat responses toward out-groups' faces and stronger neural empathic responses toward in-groups' suffering. We did not obtain significant publication bias. Overall, the findings provide novel implications for theory and prejudice-reduction interventions.

Keywords: BOLD; Brain; Discrimination; In-group favoritism; Out-group derogation.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bias
  • Brain Mapping*
  • Brain* / diagnostic imaging
  • Brain* / physiology
  • Humans
  • Magnetic Resonance Imaging / methods
  • Prejudice