How small-scale societies achieve large-scale cooperation

Children across societies enforce conventional norms but in culturally variable ways

“…Based on previous research and theoretical accounts, we expected lower third-party intervention rates in small-scale societies as compared with large-scale, urban societies ( 12 , 14 , 36 ) and speculated that hunter-gatherer groups may show the smallest effect due to their egalitarian social structure and high tolerance of children’s noncompliance ( 37 , 48 ). However, we found that Haiǁom children displayed the largest intervention effect (i.e., difference between same-rule and rule-conflict conditions).…”

“…These previous studies, however, used ratings or judgements of hypothetical scenarios and provide only limited insight into actual behavior—children and adults may think that conventional norms should be enforced in a certain way but may not take the risk of actually sanctioning others. In addition, these studies have mostly taken place in urban, large-scale societies, and there is evidence from cross-cultural research on costly third-party enforcement of fairness norms that use of informal sanctions increases with community size ( 12 , 14 ), likely because small-scale communities often rely on other mechanisms such as direct reciprocity and reputation management ( 36 ). It is an open question whether small-scale communities also engage in less third-party enforcement of conventional norms than large, urban populations, and it is possible that egalitarian hunter-gatherer communities may be particularly tolerant of conventional transgressions ( 37 ) and not show any enforcement.…”

Human social organization during the Late Pleistocene: Beyond the nomadic-egalitarian model

“…But several lines of research challenge this conclusion. Not only have researchers found that mobile foragers are ensconced in cooperative networks that extend beyond their immediate cooperative group (Bird et al, 2019;Glowacki & Lew-Levy, 2022;Hill et al, 2011;Migliano et al, 2017Migliano et al, , 2020, but Boyd and Richerson (2022) recently reviewed numerous examples of large-scale cooperation among mobile foragers in North America, Australia, Europe, and the Arctic. The examples cover many domains, including warfare, communal hunting, and construction of shared facilities, with cooperative projects often involving hundreds of people, sometimes from neighboring groups.…”

Parochial cooperation in wild chimpanzees: a model to explain the evolution of parochial altruism

“…In contrast with large-scale cooperative systems between unrelated and unfamiliar individuals observed in humans and human ancestors [ 44 , 45 ], we refer to a parochial small-scale group cooperation model for non-human animals ( figure 1 ), hereafter parochial cooperation model (PCM), where all individuals in the in-group are familiar to each other. In this model, social ties, constructed through repeated interactions and promoted by the oxytocinergic system, constitute a cement by which non-related individuals maintain group-level cooperation.…”