Looking through some guidebooks for international businessmen who have to be hypersensitive to cultural differences in non-verbal communication, it seems like there's a single general factor, that some cultures are closer and others distant. This includes lots of separate things like touching others more, standing closer to others, making more prolonged eye contact, showing more facial expressions (especially smiling), and making more dramatic gestures, which, like facial expressions, "tip your hand" or reveal how you're feeling, instead of keeping your guard up by locking your arms at your sides.
At the closer end are cultures from the Mediterranean, Middle East, India / Pakistan, Latin America (whose international businessmen are Mediterranean), and Eastern Europe. At the distant end are China, Korea, and Japan. Northwestern Europeans and their off-shoots like America are in between.
So it looks like the main difference in how close or distant people are is the subsistence mode they're adapted to -- the intensive agriculturalists of East Asia are distant, the pastoralists of the Mediterranean through milk-drinking South Asia are close, and the mixed agro-pastoralists of Europe are in between.
If that's right, then we should see differences even within a continent. So most of the high-touch "Eastern Europeans" are probably from the Balkans or other hilly places like the Carpathian mountains, where herding but not farming pays off, and probably not so much from the stricter farming areas in the Ukraine. Also, among Northwestern Europeans, the Irish and Scottish should be closer than the English or Dutch. I've been to lots of clan reunions for the Scotch-Irish hillbilly side of my family, and they are very close and boisterous, just as much as Italian or Persian families would be. But I haven't had enough experience among, say, New England descendants of Puritans, who were mostly farmers, to compare first-hand.
There could be all kinds of gradients that are lowest in East Asia, highest in the Middle East, and intermediate in Europe. Why pastoralism? Well again because it seems to scale down to explain differences even within a continent, like Spain vs. Holland, and smaller regions still, like Ireland vs. England.
But also because pastoralism is what drives the culture of honor and the culture of hospitality, for reasons I might review later. When your honor and reputation are always at stake, you don't want to hide how you feel -- you let them know right away that they should back off. In a large, sedentary agricultural state, where a culture of law prevails, you should keep your feelings to yourself and let some bureaucracy or council or maybe just your elder kin determine who's right or wrong.
In a culture of hospitality, you try to cultivate an image of someone who hosts any guest, and more lavishly than you would treat yourself, as well as re-paying the hospitality that someone else has shown you. This obsession with benevolent reciprocity is just as strong in Italy, Lebanon, and Appalachia as is the machismo and vendetta mindset. This shows up in their body language too: they smile more and laugh harder in a friendly context, but in a confrontational context they contort their faces and gesticulate more wildly.
So assuming you're going to get anywhere near another person in the first place, in a pastoralist culture you'll go off into guest-host mode and strive to establish a tight social bond. Hence closer distances, more touching, and more eye contact. Where guest-host relations are less sacred, even weak, as among farmers, you'll keep all strangers at arm's length, and not give away what you're feeling or thinking.
Our immigration policy is idiotic beyond belief, so there are all sorts of things we should be screening potential immigrants for. But these kinds of differences don't show up much in the discussion. I'd rather live next door to proud Persians who would show some sign of real affection between neighbors, even inviting me over for dinner, and not inscrutable Oriental drones who only wanted to be left alone to plug into the hive.
Overall I'd much rather stay here than in Spain, but one thing I miss about living in Barcelona was how much closer their culture is. Maybe it's the hillbilly genes, but I'm more touchy-feely and kinesthetic than the average American, and my only outlet these days is socializing at dance clubs -- especially at '80s night, when the music puts everybody in that mood. I'm truly grateful for that, but still wish there were more everyday chances to enjoy it.
Relationships among guys over there did seem more buddy-buddy, not that we're aloof over here either. What really stood out was the between-sex physical closeness. Every babe I met gave me the cheek-to-cheek "kisses," stood close, often reached out to rub my shoulder when she asked how I was doing (always with a bright smile), and tracked every slight movement of my eyes with her own. Little things like that, accumulated over the day and across the years, go a long way toward making people feel more tightly integrated into a cohesive community.