clash is a term used to describe the friction that can develop when two or more people from different cultural backgrounds meet and experience misunderstandings due to their ignorance of each others' customs. Cultural clashes have caused many a business meeting, date, and conversation to go sour.
One of the most common cultural "clashes" concerns personal space. Personal space is the area around a person that they feel is their own and that should not be entered by another person. The size of this area varies from culture to culture. In the United States, this area is about two or three footsteps. In some South American countries, this space is less, about one step away. If people from the two countries were to meet, the American would likely feel that the other person is practically sitting on top of them, and would almost certainly step back to restore their space. The South American would likely feel that the American was being distant and standoffish, and would probably take a step closer. This could quickly turn into a very amusing dance-like shuffle. That is, amusing to an onlooker; to those involved, it could be extremely frustrating.
Another, somewhat cliché, clash is the way different cultures treat eye contact. In most western cultures, people look each other in the eye when speaking. Avoiding eye contact is usually interpreted as being evasive, dishonest, disinterested, or ashamed. In some cultures, direct eye contact is considered intimidating and aggressive and is therefore regarded as being rude. Just imagine how frustrating it would be if you were speaking to someone and they wouldn't look you in the eye. Likewise, to the other person, it would the same to them as if someone were to put their face an inch away from yours, and start loudly speaking at you .
The amount of time that two people know each other before they consider each other friends or acquaintances also varies from culture to culture. Per, a Swedish friend of mine, introduced me to one of his buddies from Sweden who had come here to California to visit him. The entire time we were all together, the guy hardly spoke to me, and when I spoke to him, his replies were very short and he quickly went back to speaking to Per again. When he left, Per asked me what I thought of him. I said I thought he was kind of a jerk, since he ignored me the entire time. Per explained that in Sweden, people don't just start talking to each other right away, that it takes longer for that initial period of "awkwardness" to end, and that I shouldn't take it personally. Lo and behold, the next time I met him, things went a bit more smoothly.
I myself encountered a form of culture clash when I moved from my home of New York City to the far suburbs of Los Angeles. Now, you might think, "Hey, it's the same country, it's the same culture!" but it's really not. I was like a fish out of water for a long time. For instance, in NYC, I never had a problem knowing who was a friend and who was not, because the people who weren't my friends made their disdain for me abundantly clear. When I first moved to California, I thought everyone was so nice, because everyone seemed so nice. I didn't understand the whole "happy-face" mentality (namely, "Even if I'm having a horrible day and hate your guts I'm going to smile and act like I think you're the best thing since sliced bread), that many Californians have and therefore often made a nuisance out of myself by over-staying my welcome. Also, the people here are much more sensitive about jokes than my friends in NYC were. There, I could make fun of someone I just met, and they'd understand I was only kidding and laugh with me. Here, people were likely to take me seriously and think I was an ass.
Culture clashes are one of the main obstacles to overcome in international communication and interaction. Educating oneself about the local customs of an area before visiting is a good way to avoid unnecessary misunderstandings. Sensitivity and patience are of the utmost importance when dealing with people of other cultural backgrounds. A little bit of mutual effort and understanding can go a long way toward bridging the cultural gaps that separate us all.