Heartbeat synchrony between performer and crowd - emotional resonance

Amazing observations on the annual fire walking ritual in the Spanish village of San Pedro Manrique. Researchers were stymied in their efforts to measure physiological parameters such as blood pressure, cortisol levels, or pain tolerance in individuals as they were walking across a bed of hot coals, but were able to put heart rate monitors on both fire-walkers and spectators. It was a small study, monitoring heart rates of 12 fire-walkers, 9 spectators related to fire-walkers, and 17 unrelated spectators who were just visiting.

The heart rates of relatives and friends of the fire-walkers followed an almost identical pattern to the fire-walkers’ rates, spiking and dropping almost in synchrony. The heart rates of visiting spectators did not. The relatives’ rates synchronized throughout the event, which lasted 30 minutes, with 28 fire-walkers each making five-second walks. So relatives or friends’ heart rates matched a fire-walker’s rate before, during and after his walk. Even people related to other fire-walkers showed similar patterns.

This cohesion and solidarity happened in spectators who were simply watching, not sharing with performers the movements, vocalizations, or rhythms usually presumed to accompany social bonding through emotional resonance.  (added later...here is the PNAS article on this.)