How did ritual emerge in human evolution and how has it changed with the rise of social complexity in historical time?
Many species besides humans exhibit ritual-like stereotypic behaviours that have adaptive functions, serving diverse roles from hard-to-fake signals of fitness to establishing pair bonding partnerships. In the case of humans, collective rituals appear to generate social cohesion and motivate cooperation. Recent research has implicated a number of proximate mechanisms in these processes. For example, cultural rituals commonly involve synchronous movement and recent experiments suggest that this increases the social bonding of individuals to one another within the group. Overimitation (the tendency for children to imitate both instrumental and ritualised/redundant actions at high fidelity) has also been linked to the transmission of ritual behaviours, which may be a byproduct of evolved social learning strategies or an adaptive mechanism for affiliating with groups. Collective rituals also differ across human societies and appear to have evolved over the course of history. For example, regional and global rituals standardized through routization and institutionalized policing appear early in the evolution of social complexity. This panel will draw on evidence derived from comparative studies of humans and their closest primate relatives, carefully controlled lab-based experiments with children and adults, and innovative quantitative historical analysis.