good point above. race doesn't imply culture.
I'm white, and grew up in Montreal. It may be just my experience, but, I have heard ALL races talk shit about other races. My wife is chinese,my parents are divorced and re-married to non-whites. I have hung out with french people, english people, chinese, filipino, black, gay, rich ,poor, protestant, catholic..and the list goes on..
What we forget is that it's human nature to have an "us vs. them" attitude now and again. Even if you were to look at it evolutionarily, it was wise to stick close to those that were alike you, to ensure survival. In prison,gangs are by RACE, if you're black, you hang with the blacks, if you're white, you are part of the aryans..there is no choice, it's a matter of survival. You're not racist if you understand that's how it works and even if you practice it, i.e. stick with your own race. You're racist/prejudiced when you don't give people a chance to overcome the stereotype you've assigned to them when you size them up, and allow them to be a person, rather than a "race".