Hand-holding is a feel-good gesture that is of far greater import than mere contact between palms and digits would suggest, say University of Haifa researchers.
In fact, the move creates a connection between brains that can measurably reduce physical pain being endured by one of the parties.
“Touch is very powerful,” Simone Shamay-Tsoory, a psychology professor at the University of Haifa who led the study, said in a phone interview. The study shows that “pain can be modulated by touch.”
For their study, presented last month at a meeting of the Society of Neuroscience in Chicago and published in 2018 in PNAS, the researchers studied 20 men and women in a long-term romantic relationship under several scenarios, with all of the couples being subjected to all of the scenarios.
In the first scenario, the women were subjected to pain through a device on their arm that delivered high heat, while their partner was asked to sit beside them without touching.
Next, the women were not subjected to pain, while their partner was asked to sit beside them without touching.
In the third scenario, partners were asked to hold hands with no pain being inflicted upon the women, and in the fourth scenario, the women were subjected to pain while their partners held their hands.
In all of these scenarios, the researchers used a new type of EEG technology that allowed them to measure electrical brain activity in both partners simultaneously and see if there was any correlation. They then asked the women to rate the level of pain in each scenario according to a ranking table they provided.
“We found that the level of pain experienced by the women was lower in the hand-holding condition,” said Shamay-Tsoory.
What was perhaps even more interesting, she said, was that the researchers found that the couple’s brainwaves were synchronized during hand-holding.
“The level of brain-to-brain synchrony was the highest in the pain and hand-holding condition,” Shamay-Tsoory said. “This means the two brains are synchronizing their activity, that there is a connection created between the two brains: they work together — and it is like two brains become one unit.”
When the two brains are synchronized, she said, this creates “a sense of connectedness” between the woman and the man, and this is what reduces the pain.
Shamay-Tsoory said these same findings most likely also occur in other kinds of relationships, such as that of a parent and a child, although the researchers did not specifically study the matter.
A previous 2016 study by the researchers showed that holding hands with a stranger — a nurse or a caretaker — did not have the same impact on pain as that of a close relation. “There was no effect of touch from strangers on pain reduction,” she said.
The team is now also examining the effect of touch on emotional states, to see if hand-holding can reduce emotional pain in addition to physical pain, Shamay-Tsoory said.
Commenting on the research, Juulia Suvilehto, a postdoctoral research fellow at Linköping University in Sweden who was not involved in the study, said she was skeptical that hand-holding alone could do away with pain.
Suvilehto told the Medium website that there may be other explanations for why hand-holding and empathy can dampen pain signals in the brain. One of them is that under stress people feel more pain, but it is less intense when they are relaxed. Being touched by someone you love lowers stress levels, she said, and that could lead to lower pain levels.