The evolution of costly displays, cooperation,and religion. Inferentially potent displaysand their implications for cultural evolution

This paper lays out an evolutionary theory for the cognitive foundations and cultural emergenceof the extravagant displays (e.g., ritual mutilation, animal sacrifice, and martyrdom) that have sooften tantalized social scientists, as well as more mundane actions that influence cultural learningand historical processes. In Part I, I use the logic of natural selection to build a theory for howand why seemingly costly displays influence the cognitive processes associated with culturallearning—why do “actions speak louder than words.” The core idea is that cultural learners canavoid being manipulated by their potential models (those they are inclined to learn from) if theyare biased toward models whose actions/displays would seem costly to the model if he heldbeliefs different from those he expresses verbally. I call these actions inferentially potentdisplays. Predictions are tested with experimental work from psychology. In Part II, I examinethe implications for cultural evolution of this evolved bias in human cultural learning. Theformal analytical model shows that this learning bias creates evolutionarily stable sets ofinterlocking beliefs and individually-costly practices. Part III explores how cultural evolution,driven by competition among groups or institutions stabilized at alternative sets of theseinterlocking belief-practice combinations, has led to the association of costly acts, often in theform of rituals, with deeper commitments to group beneficial ideologies, higher levels ofcooperation within groups, and greater success in competition with other groups or institutions.Predictions are explored with existing cross-cultural, ethnographic, ethnohistorical andsociological data. I close by briefly sketching some further implications of these ideas for thestudy of religion and ritual...