The study found that the more empathy a comforting partner feels for a partner in pain, the more their brainwaves fall into sync. And the more those brain waves sync, the more the pain goes away.
"We have developed a lot of ways to communicate in the modern world and we have fewer physical interactions. This paper illustrates the power and importance of human touch," said lead author of the study Pavel Goldstein, from the University of Colorado at Boulder.
For the study, published in the journal Proceedings of the National Academy of Sciences (PNAS), researchers recruited a group of heterosexual couples, aged between 23 to 32 who had been together for at least one year.
The researchers put them through several two-minute scenarios as electroencephalography (EEG) caps measured their brainwave activity.
The scenarios included sitting together not touching; sitting together holding hands; and sitting in separate rooms. Then they repeated the scenarios as the woman was subjected to mild heat pain on her arm.
Merely being in each other's presence, with or without touch, was associated with some brain wave synchronicity in the alpha mu band, a wavelength associated with focused attention. If they held hands while she was in pain, the coupling increased the most, the researchers said.
The researchers also found that when she was in pain and he couldn't touch her, the coupling of their brain waves diminished.
"It appears that pain totally interrupts this interpersonal synchronization between couples and touch brings it back," the researchers said.
"You may express empathy for a partner's pain, but without touch it may not be fully communicated," they added.