(NaturalNews) Partners in romantic relationships don't just share interests, habits and secrets, according to a pair of studies published in the journal Emotion and the International Journal of Psychophysiology. Researchers from the University of California, Davis and the University of Arizona found that even when seated several feet apart, couples synchronize their heart rates and breathing.
"We've seen a lot of research that one person in a relationship can experience what the other person is experiencing emotionally, but this study shows they also share experiences at a physiological level," researcher Emilio Ferrer said.
The study was funded by the National Science Foundation.
The researchers instructed members of 32 separate heterosexual couples to sit several feet apart from each other in a calm, quiet room without speaking or touching. All participants were hooked up to breathing and heart rate monitors.
The researchers found that both breathing and heart rate quickly synchronized between the two members of the couple. The same effect was seen when the participants were told to sit across from each other and attempt to mimic each other's actions, but still not permitted to touch or speak to each other. The researchers then repeated the experiment, this time mixing up the couples so that each person was paired with a stranger. No synchronization of breath or heart beat was seen.
Upon more closely analyzing the details of how the breathing and heart rate of each participant changed over time, the researchers found that women's respiration and heart beats tended to adjust more dramatically than men's.
"In other words, we found that women adjust in relationship to their partners," lead author Jonathan Helm said. "Her heart rate is linked to her partner's. I think it means women have a strong link to their partners - perhaps more empathy."
Supporting this conclusion, the researchers found that the women in the couples were significantly more likely to adjust their day-to-day emotional experiences to match their partners' than the other way around.
The power of social bonds
The researchers do not yet know how or why couples synchronize their breathing and heart beats, but it is possible that this phenomenon might in some way be linked to the well-established finding that people in stable, romantic partnerships are healthier and live longer. The researchers are now planning another study to determine whether the observed synchronization has any health benefits.
Synchronized heart rates are not just found in romantic partners, however. A recent study conducted by researchers at Aarhus University in Denmark and published in the journal PNAS found that when people watched a friend or relative of theirs walk across hot coals, the observer's heart beat sped up at the exact same moment as their friend or relative's.
These studies suggest that social bonds can have profound physiological effects on our bodies and health.
"We can find markers of emotional connectedness in bodily measures as well," lead researcher Ivana Konvalinka said. "It's not just a cognitive effect.'