Oxytocin dynamics in interpersonal sensorimotor synchrony: Controlled experiments in humans

Interpersonal sensorimotor synchronisation is the coordination of movement between individuals that underlies successful interpersonal communication. Previous research has indicated the potential involvement of oxytocin (OXT) in the process of synchronisation. We conducted 2 randomised controlled experiments to test the effect of synchronisation on salivary OXT concentrations. In Experiment 1, 90 volunteers (65 women) performed either synchronous or asynchronous a 5-min hand gesture task with an unfamiliar partner. In Experiment 2, 67 familiar dyads of volunteers (47 female dyads) performed the same task. Salivary OXT concentrations were measured before and after the gesture task (Experiment 1) or before, after and 10 min after the gesture task (Experiment 2). Saliva samples were analysed using the ELISA method to estimate OXT concentrations. In Experiment 1, we found no significant differences between salivary OXT levels at baseline and after the 5-min task in either synchronous or asynchronous conditions. We also found no evidence for increased liking of a stranger after sensorimotor synchrony. In Experiment 2, the asynchronous condition led to a decrease in OXT levels over time, whereas synchronous interactions led to stable OXT levels over time. The effect of condition on OXT was not moderated by closeness or attachment style. The results are discussed in relation to research methodology used to study interpersonal synchrony.