Behavioural synchronization has been shown to facilitate social bonding and cooperation but the mechanisms through which such effects are attained are poorly understood. In the current study, participants interacted with a pre-recorded confederate who exhibited different rates of synchrony, and we investigated three mechanisms for the effects of synchrony on likeability and trusting behaviour: self-other overlap, perceived cooperation, and opioid system activation measured via pain threshold. We show that engaging in highly synchronous behaviour activates all three mechanisms, and that these mechanisms mediate the effects of synchrony on liking and investment in a Trust Game. Specifically, self-other overlap and perceived cooperation mediated the effects of synchrony on interpersonal liking, while behavioural trust was mediated only by change in pain threshold. These results suggest that there are multiple compatible pathways through which synchrony influences social attitudes, but endogenous opioid system activation, such as β-endorphin release, might be important in facilitating economic cooperation.

Department of Anthropology University of Connecticut Storrs CT 06269 USA; Interacting Minds Centre Aarhus University Aarhus 8000 Denmark

Department of Human Evolutionary Biology Harvard University Cambridge MA 02138 USA; LEVYNA Masaryk University Brno 60200 Czech Republic

Department of Psychology National University of Singapore 177572 Singapore

LEVYNA Masaryk University Brno 60200 Czech Republic; Institute of Ethnology Slovak Academy of Sciences Bratislava 81364 Slovakia

Religion Programme University of Otago Dunedin 9012 New Zealand

References provided by Crossref.org

The Effects of Synchrony on Group Moral Hypocrisy

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The Boundaries of Trust: Cross-Religious and Cross-Ethnic Field Experiments in Mauritius