May 2, 2011 -- The hearts of people who perform the daring feat of fire walking beat in sync with loved ones watching them complete the ceremony.
A new study shows the heart rates of fire walkers were synchronized with friends and family watching a fire walking ceremony in a way different from other non-related onlookers.
Researchers say the results suggest that collective rituals may bond participants and onlookers in a physiological as well as social way.
The results appear in the Proceedings of the National Academy of Sciences.
Rituals Bond Hearts
For the study, researchers recorded continuous heart rate information from 12 fire walkers, nine spectators who were friends or relatives of the fire walkers, and 17 other spectators during an annual fire walking ceremony in San Pedro Manrique, Spain.
Using a mathematical model, researcher Ivana Konvalinka of Aarhus University in Denmark and colleagues found similar patterns of heart rates during the 30-minute ritual among fire walkers and friends and relatives in the audience but not among fire walkers and unrelated spectators.
Researchers say the mathematical model used distinguishes between changes in heart rate due to adrenaline surges that would be expected at such an event.
They say the unique heart rate patterns reflect subtle heart activity associated with shared emotional experiences and suggest that people can be linked in physiological as well as emotional ways.