what? how is there going to be friction if people separate themselves?
right now multiculturalism says that if you come to this country you have some inherent right to your culture and your language, which is not the proper way to integrate, that mentality actually causes less friction as people separate themselves more in their enclaves
Well, separation happens in degrees. If you look at the way studies like this one are done, they're about social networks that define your interactions. You can have dense or sparse networks, but there's no hard and fast cutoff point. Even the most segregated neighborhoods still interact with the outside, at least in cities, where diversity is the highest, and so there is still some friction. There's also a very, very strong tendency towards homogeneity in general that a common language alone doesn't fix. Black neighborhoods and white neighborhoods are largely separate. The question is what combination of sameness and difference is ideal, and there are many kinds of both.