Note, however, that a community’s supply of social rewards…

““Note, however, that a community’s supply of social rewards is limited, so we’re often competing to show more loyalty than others—to engage in a “holier than thou” arms race. And this leads, predictably, to the kind of extreme displays and exaggerated features we find across the biological world. If the Hajj seems extravagant, remember the peacock’s tail or the towering redwoods. But note, crucially, that sacrifice isn’t a zero-sum game; there are big benefits that accrue to the entire community. All these sacrifices work to maintain high levels of commitment and trust among community members, which ultimately reduces the need to monitor everyone’s behavior.38 The net result is the ability to sustain cooperative groups at larger scales and over longer periods of time.39 Today, we facilitate trust between strangers using contracts, credit scores, and letters of reference. But before these institutions had been invented, weekly worship and other costly sacrifices were a vital social technology. In 1000 a.d., church attendance was a pretty good (though imperfect) way to gauge whether someone was trustworthy. You’d be understandably wary of your neighbors who didn’t come to church, for example, because they’re not “paying their dues” to the community. Society can’t trust you unless you put some skin in the game.””

— Kevin Simler