Cooperation during cultural group formation promotes trust towards members of out-groups

Abstract

People often cooperate with members of their own group, and discriminate against members of other groups. Previous research establishes that cultural groups can form endogenously, and that these groups demonstrate ingroup favouritism. Given the presence of cultural groups, the previous literature argues that cultural evolution selects for groups that exhibit parochial altruism. The source of initial variation in these traits, however, remains uninformed. We show here that a group's economic production environment may substantially influence parochial tendencies, with groups formed around more cooperative production (CP) displaying less parochialism than groups formed around more independent production (IP) processes. Participants randomized into CP and IP production tasks formed cultural groups, and subsequently played hidden-action trust games with in-group and outgroup trustees. We found CP to be associated with significantly greater sharing and exchanging behaviours than IP. In trust games, significant parochial altruism (in-group favouritism combined with out-group discrimination) was displayed by members of IP groups. By contrast, members of CP groups did not engage in either in-group favouritism or out-group discrimination. Further, we found the absence of out-group discrimination in CP to persist even following 'betrayal'. Finally, belief data suggest that members of CP are not more intrinsically generous than IP members, but rather more likely to believe that out-group trustees will positively reciprocate. Our results have important implications for anyone interested in building cooperative teams, and shed new light on connections between culture and cooperation.

The Evolution of Power and the Divergence of Cooperative Norms

“…It is therefore important for group success that members maximize their productivity, even if doing so means cooperating with outsiders from groups with whom their group may eventually be in conflict. This is consistent with empirical results indicating the ascendance of cosmopolitan strategies (i.e., cooperation with outsiders) in the presence of group-level conflict (Buchan et al, 2009; Pan & Houser, 2013). As we will demonstrate, it is the presence of institutions of power makes this rise of cosmopolitanism possible.…”

The evolutionary interplay of intergroup conflict and altruism in humans: a review of parochial altruism theory and prospects for its extension

“…After control for this influence, no significant effect of intergroup competition remained. Furthermore, a number of studies found that when given the opportunity of in-group cooperation with no negative effect on the out-group or of between-group communication, subjects frequently chose to avoid conflict and even cooperated with out-groups [67][68][69][70]. Noteworthy rspb.royalsocietypublishing.org Proc.…”

Risk buffering and resource access shape valuation of out-group strangers

“…While much research on inter-group relationships in human evolution has focused on competition and conflict 1 2 3 4 , out-groups as sources of danger 5 6 , and in-group favoritism at the expense of out-groups 7 , evolutionary researchers have paid little attention to the conditions that favor building connections with individuals from different ethnic groups, individuals who practice different modes of production, or – more recently in human history – individuals from different religious groups (cf. 8 9 10 11 12 ). Chimpanzees and other primates are mostly indifferent or hostile towards strangers from other groups 13 , yet archaeological and ethnographic evidence provide many examples of relationship building with out-groups throughout human history, as facilitated by marriage, trade, and friendship 14 15 16 17 18 19 20 .…”