" people in hunter-gatherer communities shared about 25 percent, while people in societies who regularly engage in trade gave away about 45 percent. Although religion was a modest factor in making people more generous, the strongest predictor was “market integration,” defined as “the percentage of a household’s total calories that were purchased from the market, as opposed to homegrown, hunted, or fished.” Why? Because, the authors conclude, trust and cooperation with strangers lowers transaction costs and generates greater prosperity for all involved, and thus market fairness norms “evolved as part of an overall process of societal evolution to sustain mutually beneficial exchanges in contexts where established social relationships (for example, kin, reciprocity, and status) were insufficient.”57 "

― Michael Shermer , The Moral Arc: How Science and Reason Lead Humanity toward Truth, Justice, and Freedom