The Cultural Evolution of Hard-to-fake Rituals

It has been proposed that costly rituals act as honest signals of commitment to group beliefs when such rituals appear dysphoric and unappealing (costly) to non-believers, but appealing to true believers (Irons, 2001). If only true believers are willing to endure ritual behaviors and true belief also entails belief in altruistic cooperation, associating with other ritual practitioners can help solve cooperation dilemmas in groups by sorting out potential free-riders. While this hypothesis is obviously true if such ‘faking’ of ritual is strictly impossible, strict impossibility seems implausible. ‘Faking’ is defined by Irons in this context to be to be performing the ritual without commitment to group beliefs. In this paper, I posit various ways that such faking might be difficult, instead of impossible, or different ways in which such ritual faking might be ‘costly’ and then formally model the social learning and cultural evolution dynamics to see where it may still hold theoretically that such rituals help maintain altruism in group and under what conditions. Analytic solution for evolutionary equilibrium is derived for each model, verifying that under a wide range of conditions for some, but not all interpretations, such hard-to fake rituals can help groups solve cooperative dilemmas, including in some circumstances that might not be intuitively obvious, such as where such free-riding is not visible and free-riders successfully represent themselves as true believers to observers. It is also the case that while there has been some progress in cleaning up the definitional confusions in the animal signaling literature around costly signaling, the literature on human rituals as costly signals has introduced novel uses of the term ‘cost’. Theories referring to completely different mechanisms or even definitions of ‘cost’ are sometimes conflated. To contextualize the analysis of costly-to-fake rituals, this paper provides a review of the ideas proposed in the literature on costly human rituals and differentiates them from costly signaling as used in the animal behavior literature. . CC-BY-NC-ND 4.0 International license available under a The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It is made . http://dx.doi.org/10.1101/060640 doi: bioRxiv preprint first posted online Jun. 24, 2016;