Religious rituals in the United Kingdom and Brazil are associated with increased social bonding and pain threshold.
Charles SJ., van Mulukom V., Dunbar R., Brown JE., Delmonte R., Maraldi E., Turner L., Watts F., Watts J., Farias M.
From an evolutionary perspective, large-scale human groups face an adaptive challenge: maintaining cohesion beyond the limits of one-to-one grooming. Cultural practices that recruit evolved bonding systems may help solve this problem by harnessing mu-opioid psychobiological mechanisms. Religious rituals are cultural practices that consistently promote social cohesion, and here we report a pre-registered large-scale field study examining psychobiological mechanisms underlying these rituals. Participants were tested in the United Kingdom and Brazil at 24 ritual sites (N = 265), with measures taken pre- and post-ritual. Results showed that levels of social bonding (5.4% increase, rR = 0.30) and positive affect (13.1% increase, rR = 0.27) were higher after ritual participation. Importantly, increased social bonding was independently predicted by increases in pain threshold (a proxy for mu-opioid activation; β = 0.13, R2 = 0.02), positive affect (β = 0.25) and connection to a higher power (β = 0.15), even after controlling for country, gender, age and religiosity (R2 = 0.15). This multi-site field study provides experimental yet naturalistic evidence that religious rituals recruit an evolved mu-opioid-based affiliation system that may help sustain cohesion in large congregations, supporting the brain-opioid theory of social attachment.