They embrace the power of touch.
Nonsexual touch can be very powerful. (Yes, I’m aware that sexual touch can be powerful too.) Touch can influence behavior, increase the chances of compliance, make the person doing the touching seem more attractive and friendly.
Go easy, of course: Pat the other person lightly on the upper arm or shoulder. Make it casual and nonthreatening.
Check out Clinton’s right-hand-shakes-hands-left-hand-touches-Mandela’s-forearm-a-second-later handshake in the link above and tell me, combined with his posture and smile, that it doesn’t come across as genuine and sincere.
Think the same won’t work for you? Try this: The next time you walk up behind a person you know, touch them lightly on the shoulder as you go by. I guarantee you’ll feel like a more genuine greeting was exchanged.
Touch breaks down natural barriers and decreases the real and perceived distance between you and the other person–a key component in liking and in being liked.