Given that we are monkeys (or Naked Apes to use Desmond Morris's term) don't you find it odd that we don't touch or groom each other more often?
And when we do, it is usually in a carefully constrained context: hairdresser, the handshake, a touch on the shoulder or elbow, massage - no, not that kind, and so on.

So what happened? Turns out that most of those he touched produced the coin willingly; most of those not touched said, in effect, "Sorry, but no". That simple light touch on the elbow turned the interaction into something special where the person did not want to deceive. And get this: when they were told that they had been part of an experiment and asked about their experience of it, none of them could recall being touched!
Cue the delightful French, who unlike the English, still understand the importance of contact. I claim no authority for all French, and all of France, but here in the Dordogne we do press the flesh as follows:
- I shake hands with my male friends every single day
- This courtesy extends to, for example, artisans. If I have someone working on the house we will shake hands every single morning when he arrives
- I shake hands with strangers who turn up
- I shake hands with women that I do not know well
- I kiss women that I do know well. In the Dordogne it is once on each cheek. None of your "air kissing". This is proper close friendly contact. (The Parisian woman who lives near here kisses four times - e.g. left, right, left, right; a Belgian does it three. So you do need to know who you are dealing with!)
- All children (the term enfant seems to cover birth up to about 14), boys or girls, will expect to kiss you if they know you, and manners dictate that they will kiss a stranger during introductions
- One may, or may not, kiss on parting. It is a matter of context and somehow you learn it
- I kiss men at moments of great passion (e.g. we win the rugby) or New Year's eve
- You do not kiss women when first introduced. However, this can be relaxed in certain contexts, such as a group setting where all the others are on kissing terms
- You progress to kissing by some invisible criterion that I generally get right
- And very important, at least in this locale, having greeted someone and shaken hands or kissed as case may be, you do not repeat same later in the day. If you try they will remind you that "je t'ai déjà vu".
There are times when the contrast could not be more marked. In my English Pub I would be lucky to get a greeting at all from the landlord, or perhaps "Evening, what will it be?".
At Chez Edith I will be kissed by Barbara the landlady, kissed by each of her two daughters, kissed by Marie behind the bar, kissed by Isabel in the kitchen when she passes through, will shake hands with Stefan the landlord; and that's before further greetings with other clients. And Barbara will definitely kiss you goodbye on your way out.
The effect? Well naturally I can't prove anything, but I do find the French very warm and friendly, great chatterboxes, and always willing to find the time to cement social relationships.
They still have something the English have lost, and the willingness to reach out to each other, physically, is part of it. Long may it last.