People certainly tend to group themselves by culture, but I don't think any particular culture lends itself toward failure to integrate any more than individual personalities do.

Similarly, where I went for undergrad, Koreans tended to have their own groups. Clearly they don't do that everywhere, and not all of them did - there were just enough of them that didn't want to integrate that it was easier for others to choose not to. A segment of any group does it if they're a large enough minority - it wouldn't be fair to criticize one particular culture for it.