People generally enjoy gently touching and being touched by the people they love. Psychologists at University College London have found that our brains may encourage this behaviour by making other people feel softer to us than they really are.
In their experiments, published today in the journal Current Biology, 133 volunteers were paired up and asked to gently stroke both their own and a partner's palm and forearm and rate how the skin felt. Participants consistently thought their partner's arm was softer and smoother than their own skin — something that couldn't be objectively true for both people in each pairing. Researchers saw the same results when they mixed skin touching with soft objects.
Study lead Aikaterini Fotopoulou and her colleagues think that this sensation of a partner's skin-softness is a perceptual illusion that rewards social bonding. Gently touching the hairy skin of another person activates neurons in the toucher's skin that are tuned to soft caresses and connected to regions of the brain that control emotions. So not only do they feel so lovely and soft, you feel good about touching them that way.
The illusion disappeared when volunteers were asked to rub their hand over their partner's skin quickly or to simply touch their partners without moving their hand. The relevant neurons only activate at slower, caressing speeds. So be sure to keep those caresses light and slow for maximum sensual appreciation of your partner's skin.