Two hearts in one room

Sit two people facing each other and ask them to talk for half an hour. The two hearts beat separately: each heart keeps its own rhythm, in its own body.

Yet for more than forty years, researchers have measured that the two heart rhythms resemble each other more during the conversation than before the conversation. The phenomenon is called physiological synchrony. Here is what the studies show, and their limits.

The study that launched the field

The study is by Robert Levenson and John Gottman, published in 1983 in the Journal of Personality and Social Psychology under the title “Marital interaction: physiological linkage and affective exchange”. Thirty married couples were recorded while they talked, sometimes about a point of disagreement, sometimes about the ordinary events of their day.

Several measures were taken from both people at once: heart rate, skin conductance, bodily movement. The degree of coupling between the two people accounted, on its own, for sixty percent of the differences in reported marital satisfaction.

The result surprised researchers: the couples in most difficulty showed the strongest coupling, and the gap widened during the conflict conversation. A shared rhythm is a sign of intensity between two people.

What has been measured since

The field has widened well beyond couples. A systematic review published in 2017 in Personality and Social Psychology Review by Palumbo and colleagues gathers the work on what the literature calls interpersonal autonomic physiology. The review finds that coupling shows up in new relationships as much as in established ones, across a wide range of settings.

Other work has observed coupling in more intense situations. Konvalinka and colleagues published in 2011, in the Proceedings of the National Academy of Sciences, the recording of a fire-walking ritual in Spain: thirty-eight people, walkers and spectators, followed through the thirty minutes of the ceremony. The heart rhythms of the walkers’ relatives tracked the walkers’ rhythms; the rhythms of the other spectators stayed independent.

Goldstein, Weissman-Fogel and Shamay-Tsoory examined, in 2017 in Scientific Reports, what touch changes about that coupling. Twenty-two couples, one of the two in pain: the other’s physical contact increased the coordination of heart and breathing rhythms between them.

The limits of the studies

Literature reviews of this field point to three limits.

• Methods vary enormously from one study to the next: what is measured, the time window considered, the way coupling is computed. Two studies can both say “synchrony” while meaning different things.
• Part of the resemblance between two curves comes from the shared situation: two people sitting in the same room breathe the same air, hear the same sounds, stand up at the same time.
• The direction of the finding varies: depending on the study, strong coupling accompanies sometimes a solid relationship, sometimes a struggling one.

The phenomenon is real and documented. Its interpretation remains open.

What these studies bring to an Arsentis artwork

During a capture, the two smart rings record only the heartbeat variations of the two people: each smart ring reads the blood flow in the finger about twenty-five times a second. What is said during the conversation stays between the two people.

This body of work explains why Arsentis composes the two traces together. Two people talking for half an hour in the same room produce two linked recordings, and the composition makes that link visible. Each heartbeat of the two people becomes a line, and the artist balances the two traces according to the chosen artwork, then prints the final artwork on fine-art paper.

Hung on the wall, the artwork keeps the emotional imprint of that unique half hour the two people lived together.

References

Levenson, R. W., & Gottman, J. M. (1983). Marital interaction: Physiological linkage and affective exchange. Journal of Personality and Social Psychology, 45(3), 587–597. https://doi.org/10.1037/0022-3514.45.3.587

Palumbo, R. V., Marraccini, M. E., Weyandt, L. L., Wilder-Smith, O., McGee, H. A., Liu, S., & Goodwin, M. S. (2017). Interpersonal autonomic physiology: A systematic review of the literature. Personality and Social Psychology Review, 21(2), 99–141. https://doi.org/10.1177/1088868316628405

Konvalinka, I., Xygalatas, D., Bulbulia, J., Schjødt, U., Jegindø, E.-M., Wallot, S., Van Orden, G., & Roepstorff, A. (2011). Synchronized arousal between performers and related spectators in a fire-walking ritual. Proceedings of the National Academy of Sciences, 108(20), 8514–8519. https://doi.org/10.1073/pnas.1016955108

Goldstein, P., Weissman-Fogel, I., & Shamay-Tsoory, S. G. (2017). The role of touch in regulating inter-partner physiological coupling during empathy for pain. Scientific Reports, 7(1), 3252. https://doi.org/10.1038/s41598-017-03627-7