Do religious and market-based institutions promote cooperation in Hadza hunter-gatherers?

Abstract

Humans' willingness to bear costs to benefit others is an evolutionary puzzle. Cultural group selection proposes a possible answer to this puzzle-cooperative norms and institutions proliferate due to group-level benefits. For instance, belief in knowledgeable, moralizing deities is theorized to decrease selfishness and favoritism through threat of supernatural punishment. Similarly, norms of fairness and cooperation are theorized to have coevolved with engagement in markets, which necessitate anonymous exchanges. We investigate these theories among the Tanzanian Hadza who, until recently, have had minimal exposure to markets or major world religions. Engagement with Western tourists, village markets and Christian missionaries is increasingly leading researchers to ask how such interactions have affected cooperative behavior. We interviewed 172 Hadza from 15 camps varying in market proximity, and measured cooperative decision-making using economic games. We find that exposure to missionaries is associated with increased belief in a knowledgeable and punitive deity, with mixed evidence that these beliefs, in turn, affect game play. In contrast, we find some evidence that those living in market-adjacent regions exhibit less ingroup favoritism when cooperating. These results support the claim that market-norms, and to some degree religious beliefs, facilitate greater cooperation and fairness in social interactions.

Gods are watching and so what? Moralistic supernatural punishment across 15 cultures

“…The full dataset consists of two waves of data collection across a total of 15 field sites ( Table 1 ). As such, while the present study is novel, parts of the dataset have already been analysed – for site-specific and omnibus reports, see: Tanna, Vanuatu (Atkinson, 2018 ; Vardy and Atkinson, 2022 ), Lovu, Fiji (Willard, 2018 ), Mauritius (Klocová et al, 2022 ; Xygalatas et al, 2018 ), Pesqueiro, Brazil (Cohen et al, 2018 ), Tyva Republic (Purzycki and Kulundary, 2018 ), Yasawa, Fiji (McNamara and Henrich, 2018 ; McNamara et al, 2021 ), Hadza, Tanzania (Apicella, 2018 ; Stagnaro et al, 2022 ), Sursurunga, Papua New Guinea (Bolyanatz, 2022 ), Mysore, India (Placek and Lightner, 2022 ), Cachoeira, Brazil (Soler et al, 2022 ), Kananga, D. R. Congo (Kapepula et al, 2022 ) and omnibus (Baimel et al, 2022 ; Bendixen et al, 2023a ; Lang et al, 2019 ; Purzycki and Lang, 2019 ; Purzycki et al, 2016b , 2018 , 2022c; Vardy et al, 2022 ).…”

Myopia rates among Hadza hunter‐gatherers are low but not exceptional

“…All data were collected in bush camps, far from markets. Though the distinction between market and bush camps has become blurred in recent years, it was a meaningful and measurably important distinction at the time data were collected (e.g., see Stagnaro et al, 2022 and the village/bush camp distinction continues to be situationally important (see Pollom et al, 2021 ). While, today, Hadza subsistence is rapidly changing, almost all participants in this study were full‐time foragers.…”

Reconsidering the link between past material culture and cognition in light of contemporary hunter-gatherer material use.

“…The author's field research is with the Hadza (Stibbard-Hawkes et al 2018;2022), and I augmented Hadza data with first-hand observation. As with any contemporary human population, all three groups in this study have complex systems of cosmological belief (Skaanes 2015;Ichikawa 1998;Solomon 1997;Stagnaro, Stibbard-Hawkes, and Apicella 2022), myths, oral histories (Osaki 2001;Kohl-Larsen 1956), rituals (Turnbull 2015;Skaanes 2015;Bundo 2001) and musical traditions (Nurse 1972;Marlowe 2010;Bundo 2001). Each have fully recursive languages which are phonologically and syntactically complex (e.g., Sands and Güldemann 2009;Vossen 2013).…”