Research

Article

Conflicting identities and cooperation between groups: Experimental evidence from a mentoring program

Abstract

Well-functioning human societies require the integration of vulnerable minorities, yet leading scientific theories conflict on how easily diverse groups cooperate. We experimentally investigate cooperation in 14 centres of a mentoring program where participants have two possible natural identities—individuals raised under legal guardianship, suffering a negative stereotype (G; n=112) and users without such a social stigma (NG; n=82). Participants played a Prisoners’ Dilemma game with an anonymous partner from the same centre (centre-ingroup) and from another centre (centre-outgroup). For individuals without a history within-centre interaction, we find centre-outgroup favouritism among Gs and centre-ingroup favouritism among NGs. However, the longer G individuals have been in the centre the more centre-ingroup favouritism they display, while the opposite is true for NGs. Regardless of within-centre history, both Gs and NGs cooperate less with the centre-ingroup (vs. outgroup) as the probability that the centre-ingroup is G increases. Thus, we observe patterns of centre-outgroup and natural-outgroup favouritism among Gs which challenge theoretical frameworks exclusively focusing on ingroup favouritism. Our findings highlight the roles of system-justification and stereotypes in intergroup cooperation and have implications for the integration of vulnerable groups and the optimisation of social policy programs.

Article reference: RSPB-2025-1363.R1

Keywords: Group diversity, Natural identities, Negative stereotypes, Outgroup favouritism, Social integration, Stigmatisation