Personal space
In the United States people have their "personal space". That is, a person feels uncomfortable if another person get too close, physically--if another person invades personal space. For most men, that means other men need to remain about arm's length away. Men will allow women to get a little closer, and good friends closer yet. For family members the personal space almost disappears. Women tend to keep a smaller personal space.
It seems that in Latin cultures personal space is not very important. I often see men walking down the street almost bumping into each other with each step. That wouldn't happen in the US. I see men who are almost strangers to each give each other a hug (abrazo) after working or talking together for just a short period of time. To me, it seems that people in the Latin culture are much more open emotionally. Strangers don't remain strangers for very long. Women often greet each other with an abrazo and a kiss on the cheek (or into the air as they press their cheeks together), even when complete strangers.
Is the Spanish culture the same, or are the people of Spain as jealous of their personal space as the folks in the US'
3 Answers
Didn't you mother ever teach you not to stereotype? Some people are gregarious and some are "rugged, individualists".
I wouldn't put your theory to test in a dark alley on a Saturday night, at 3 a.m. outside your local bar. (either in the U.S., Spain, or Latin Am.)
From a news broadcast that I heard today on the persecution of Gays in Iran, you might want to test your theory in downtown Tehran. Walk up and hug a strange man. Tell him that you're Latin American. Let me know how that works out for you. 
In Guatemala, at least in the capital city, straight man walk with their arms around each other shoulders in sobriety or otherwise. Not me, man, I want my space.
Most of Latin American customs were inhereted from Spain. So, it might be the same in Spain,
