Abstract

The present article is an elaborated and upgraded version of the Early Career Award talk that I delivered at the IAPR 2019 conference in Gdańsk, Poland. In line with the conference’s thematic focus on new trends and neglected themes in psychology of religion, I argue that psychology of religion should strive for firmer integration with evolutionary theory and its associated methodological toolkit. Employing evolutionary theory enables to systematize findings from individual psychological studies within a broader framework that could resolve lingering empirical contradictions by providing an ultimate rationale for which results should be expected. The benefits of evolutionary analysis are illustrated through the study of collective rituals and, specifically, their purported function in stabilizing risky collective action. By comparing the socio-ecological pressures faced by chimpanzees, contemporary hunter-gatherers, and early Homo, I outline the selective pressures that may have led to the evolution of collective rituals in the hominin lineage, and, based on these selective pressures, I make predictions regarding the different functions and their underlying mechanisms that collective rituals should possess. While examining these functions, I echo the Early Career Award and focus mostly on my past work and the work of my collaborators, showing that collective rituals may stabilize risky collective action by increasing social bonding, affording to assort cooperative individuals, and providing a platform for reliable communication of commitment to group norms. The article closes with a discussion of the role that belief in superhuman agents plays in stabilizing and enhancing the effects of collective rituals on trust-based cooperation.