Partner choice in human evolution: The role of cooperation, foraging ability, and culture in Hadza campmate preferences

Abstract

<p>The ability to choose the partners we interact with is thought to have been an important driver in the evolution of human social behavior, and in particular, our propensity to cooperate. Studies showing that humans prefer to interact with cooperative others is often cited as support for partner choice driving the evolution of cooperation. However, these studies are largely drawn from Western samples, where conditions for partner choice to operate may be especially favorable. Here, we investigate qualities associated with being a preferred partner (i.e., campmate) in Hadza hunter-gatherers of Tanzania in 2016 and 2019. A total of 156 Hadza participants from 17 camps ranked their campmates on generosity, foraging ability, and their preference for them as future campmates. In 2016, Hadza preferred more generous people and better hunters as campmates, with evidence suggesting a stronger preference for better hunters; however, the relationship between generosity and being a preferred campmate was greater in 2019 than in 2016, such that the preference for generous people was stronger than the preference for better foragers, suggesting that campmate preferences are changing. These new findings contrast with reports on data from nearly a decade ago, suggesting that the Hadza do not prefer more cooperative campmates. Further, in 2019, there was anecdotal evidence that Hadza with greater exposure to outside cultural institutions (e.g., schooling, having a job, or living in a village) had a stronger preference for generous campmates than those with less exposure. Taken together, the results suggest that preferences for social partners may, in part, be culturally shaped.</p>

Hadza Hunter-Gatherers Disagree on Perceptions of Moral Character

“…Hadza do not choose the most generous people, whether generosity is measured using an economic game (Apicella, Marlowe, Fowler, & Christakis, 2012) or via reputation (Smith & Apicella, 2019). Rather, Hadza prefer to live with better hunters (Smith & Apicella, 2019;Wood, 2006). If moral behavior changes across time and situations as our results here suggest, then choosing campmates based on their current behavior is useless.…”

Eisenbruch &amp; Krasnow_Why warmth matters more than competence - new evolutionary models_preprint Aug 16 2019

“…These models therefore connect the warmth and competence literature to the growing literature suggesting that the need to choose cooperative partners in fitness-enhancing ways was a powerful selection pressure in human evolution (e.g. Barclay, 2016;Cosmides et al, 2010;Cottrell et al, 2007;Eisenbruch, Grillot, Maestripieri, & Roney, 2016;Eisenbruch, Grillot, & Roney, under review;Eisenbruch & Roney, under review;Hall, 2011;Lewis et al, 2011;Lukaszewski, Simmons, Anderson, & Roney, 2016;Smith & Apicella, 2019;Vigil, 2007).…”

False beliefs can bootstrap cooperative communities through social norms

“…A paradigm in the cooperation literature is that anonymity hinders cooperation and onymity (where partners' identities and reputations are known) facilitates it (Milinski, Semmann, & Krambeck, 2002;Wang et al, 2017). Onymous settings can promote cooperation by direct or indirect reciprocity (van Apeldoorn & Schram, 2016), partner choice (Smith & Apicella, 2020) or punishment (Lergetporer, Angerer, Glätzle-Rützler, & Sutter, 2014), all of which can materially incentivise cooperation. Indirect reciprocity (Seinen & Schram, 2006;van Apeldoorn & Schram, 2016) as well as partner choice through competitive altruism (Sylwester & Roberts, 2013) have been shown to maintain cooperation in experiments.…”