When a kid is in distress the mother or father comforts it with a hug. What is so typical about the way the mother or father hugs?
One hand on the back the other holding the head. Maybe you don't think there is anything special about but I think it is significant. I'm sure you will get this embrace cross-cultural therefore it is imbedded in human instinct. If it is human instinct it has a purpose.
The purpose being the result, the child calms down.
Touch calms us down, it is healing in the most primitive form. Touch can activate parasympathetic activity which is calming (compared to sympathetic activity it activates)
BioMotions Body-Coaching is using this touch therapeutically. It helps to unwind the neuropsycho-immunology and thus activates self-healing / regulation.