Bending and bonding: a randomized controlled trial on the socio-psychobiological effects of spiritual versus secular yoga practice on social bonding

Participating in rituals gives rise to exceptional social bonding, but how this happens is not well understood. We assess the roles of four potential mechanisms activated during the rituals which may promote social bonding: (1) the spiritual nature of the ritual, (2) proto-transcendental experiences (i.e., the feeling of connection to something bigger than oneself), (3) mu-opioid receptor activation (measured via a pain proxy), and (4) positive affect. In this pre-registered, longitudinal (5-week) experiment of ritual in controlled conditions, one group (N = 21) took part in spiritual yoga while another group (N = 19) took part in a behaviourally identical secular version. Multilevel linear modelling was used to analyse the contribution of each of the proposed ritual mechanisms and their interactions. Only positive affect and a proto-transcendental experience significantly predicted levels of social bonding. A follow-up Two-One-Sided-Test found significant evidence of ritual type (spiritual versus secular) having no effect on social bonding. These results suggest that rituals’ social bonding effects are associated with changes in affect and the induction of feelings of connection to something bigger, but not the rituals’ religious/spiritual nature.