Holding the hand of a loved one that is suffering does more than provide them emotional support, it can actually ease their physical pain. That’s according to new research from the University of Colorado at Boulder.

The act of holding hands begins the process of what is called “interpersonal synchronization” and it causes the people to begin mirroring the state of the person they are with including breathing, heart rate and brain waves. The more the two people are in sync, the greater the pain relief that is experienced.

The impetus for the study was the reaction Pavel Goldstein, a pain researcher at CU Boulder, noticed during the birth of his daughter. When he held his wife’s hand in the delivery room she felt less pain. He then decided to team up with researchers at the University of Haifa to conduct a study. The results of which were published in the journal Proceedings of the National Academy of Sciences.

"We have developed a lot of ways to communicate in the modern world and we have fewer physical interactions," Goldstein said. "This paper illustrates the power and importance of human touch." 

A total of 22 couples between the ages of 23 and 32 that had been together for at least a year agreed to take part in the study. The pairs were put through different scenarios while wearing EEG (electro-encephalography) caps to measure brain activity.

The couples were either in separate rooms, together in the same room or in the same room holding hands. Just the opportunity to be in the company of a loved one was enough to start their brains syncing.

When they held hands, the more empathy one had for their loved one in distress, the more their brains synced and the less pain the other felt. However, if they were in the same room not holding hands and one was in pain that was enough to reduce the brain syncing, as well as the mirrored heart rate and breathing patterns.

"It appears that pain totally interrupts this interpersonal synchronization between couples and touch brings it back," Goldstein said. "You may express empathy for a partner's pain, but without touch it may not be fully communicated."

While they were unsure of the reason, researchers speculated the empathetic touch made the hurting partner feel understood, which according to previous studies activates a pain-killing reward mechanism in the brain.

Click here to read more in the Proceedings of the National Academy of Sciences.