Touching another person can increase oxytocin levels — but it depends on the relationship and the context. The researchers found that not only do you hug, you hug when it matters most.

A hug from a parent, a warm hand on the shoulder, or a caress from a loved one are examples of how touch can strengthen social bonds between people and affect emotions. Animal studies have previously shown that the hormone oxytocin is linked to touch and social bonding. What role does oxytocin play in human social interactions and what are the effects of this hormone on the brain? has not been finally resolved.

Affects different people

To learn more about this, scientists looked at what happens in the human body when we feel a gentle touch. 42 women took part in the study: In the experiment, the woman's male partner stroked her hand while her brain activity was measured using functional magnetic resonance imaging (fMRI). Repeated blood samples were also taken to see if the levels of oxytocin in the woman's blood were changing over time. By combining different measurements, the researchers were able to investigate whether hormone levels are related to brain activity.
 Half of the trials her partner was stroking her hand, the other half an unfamiliar, non-threatening male was stroking her hand. The participating women were told who was stroking them. Then the social interaction measurements of the woman and her partner were compared to the interaction with the stranger.

Hormone than less clear

"Our main question was whether oxytocin levels are higher when a woman's partner touches her hand than when a stranger touches her hand. The answer was yes, but only if her partner stroked her hand first," says study author Professor India Morrison. "So we've seen that the body's oxytocin response to touch is affected by the situation: what happened just before and who you're interacting with. The hormone doesn't act like an on/off button, it's more like a dimmer switch, but one that's turned on. said Morrison.

The context is important

The researchers found that the women's oxytocin levels first rose during social interaction, then fell, and only rose again when the stranger first did the same as their partner. However, when a stranger touched him for the first time, his oxytocin levels didn't change. And when her companion then stroked her hand, the rise was only easy. Changes in oxytocin levels were associated with activity in brain regions important for contextualizing events.
"One has to remember that context is important, for example when synthetic oxytocin is administered as a nasal spray as part of the treatment of mood disorders," says Professor Morrison.