The following reviews recent developments in the cognitive and evolutionary psychology of religion, and argues for an adaptationist stance.

Collective rituals have long puzzled anthropologists, yet little is known about how rituals affect participants. Our study investigated the effects of nine naturally occurring rituals on prosociality. We operationalized prosociality as (1) attitudes about fellow ritual participants and (2) decisions in a public goods game. The nine rituals varied in levels of synchrony and levels of sacred attribution. We found that rituals with synchronous body movements were more likely to enhance prosocial attitudes. We also found that rituals judged to be (...) sacred were associated with the largest contributions in the public goods game. Path analysis favored a model in which sacred values mediate the effects of synchronous movements on prosocial behaviors. Our analysis offers the first quantitative evidence for the long-standing anthropological conjecture that rituals orchestrate body motions and sacred values to support prosociality. Our analysis, moreover, adds precision to this old conjecture with evidence of a specific mechanism: ritual synchrony increases perceptions of oneness with others, which increases sacred values to intensify prosocial behaviors. (shrink)

We describe the results of an experiment testing for the presence of strong altruism among Christians in New Zealand. The study examined anonymous participant generosity to cohort. We found that in modified dictator games, anonymous Christians in New Zealand gave significantly more to Canadian Christians than anonymous New Zealand citizens gave to their fellow citizens. The gifting opportunities occurred after anonymous benefactors observed recipients willingly undertake costly acts of group commitment. We found that mean gifting after witnessing a fellow group (...) member metaphorically "fall on a hand grenade" to punish a member of an out-group was almost four times greater in the Christian group than it was in the New Zealand control. Our data support the hypothesis that religious altruism exists and is especially strong among Christians in New Zealand. The data also weakly support a multi-level selection hypothesis for the evolution of religious altruism. (shrink)

Adaptationists explain the evolution of religion from the cooperative effects of religious commitments, but which cooperation problem does religion evolve to solve? I focus on a class of symmetrical coordination problems for which there are two pure Nash equilibriums: (1) ALL COOPERATE, which is efficient but relies on full cooperation; (2) ALL DEFECT, which is inefficient but pays regardless of what others choose. Formal and experimental studies reveal that for such risky coordination problems, only the defection equilibrium is evolutionarily stable. (...) The following makes sense of otherwise puzzling properties of religious cognition and cultures as features of cooperative designs that evolve to stabilise such risky exchange. The model is interesting because it explains lingering puzzles in the data on religion, and better integrates evolutionary theories of religion with recent, well-motivated models of cooperative niche construction. (shrink)

McKay & Dennett (M&D) observe that beliefs need not be true in order to evolve. We connect this insight with Schelling's work on cooperative commitment to suggest that some beliefs are best approached as social goals. We explain why a social-interactive perspective is important to explaining the dynamics of belief formation and revision among situated partners.

Evolutionary researchers argue that religion evolves to support cooperation, where it is assumed that cooperation is threatened by freeriding. I identify a distinct threat to cooperation from uncertainty. I briefly explain how the distinction between freeriding and uncertainty is relevant to both ultimate and proximate explanations of the biocultural mechanisms that express religious traits.

This article examines the benefits of incorporating religious reflection into the psychology of religion and vice versa. By applying Bayes’ theorem, we discover that scientists and theologians can collaborate without sharing prior beliefs. Instead, rationality requires updating our beliefs before data collection in response to the degree of surprise generated by the data. Moreover, although people who start with different beliefs may become more aligned after data collection, rationality does not entail a convergence to identical beliefs. To illustrate the potential (...) for growth in understanding from greater collaboration between theologians and scientists, I examine a longitudinal investigation of religion after a natural disaster. This case study illustrates how conversations between theological and psychological perspectives on religion can lead to a more comprehensive understanding of virtue cultivation, benefiting both science and theology. (shrink)

We welcome Norenzayan et al.’s claim that the prosocial effects of beliefs in supernatural agents extend beyond Big Gods. To date, however, supporting evidence has focused on the Abrahamic Big God, making generalisations difficult. We discuss a recent study that highlights the need for clarity about the causal path by which supernatural beliefs affect the evolution of big societies.

Book Review. . ???aop.label???. doi: 10.1080/00048402.2014.929720.