Touching the head appears to have more of a beneficial effect than touching the torso, some studies found. Michon couldn’t explain that finding, but thought it could have to do with the greater number of nerve endings on the face and scalp.

 https://www.sanjuandailystar.com/post/large-scientific-review-confirms-the-benefits-of-physical-touch

Large scientific review confirms the benefits of physical touch

The analysis revealed some interesting and sometimes mysterious patterns. Among adults, sick people showed greater mental health benefits from touch than healthy people did. Who was doing the touching — a familiar person or a health care worker — didn’t matter. But the source of the touch did matter to newborns.

“One very intriguing finding that needs further support is that newborn babies benefit more from their parents’ touch than from a stranger’s touch,” said Ville Harjunen, a researcher at the University of Helsinki in Finland, who also reviewed the study for the journal. Babies’ preference for their parents could be related to smell, he speculated, or to the differences in the way parents hold them.

Touching the head appears to have more of a beneficial effect than touching the torso, some studies found. Michon couldn’t explain that finding, but thought it could have to do with the greater number of nerve endings on the face and scalp.

Michon stressed that the types of touch considered in these studies were positive experiences to which the volunteers agreed. “If someone doesn’t feel a touch as being pleasant, it’s likely going to stress them out,” he said.