I'm not trying to come across as self-righteous or worse, "politically correct", but I can't even imagine being able to sort out "which race" because I just don't see any group of people as "all thinking alike". I'm white and grew up seeing very few people of other races and knowing even fewer of them (none, actually, or at least not people in "personal circles". Some people think that's a bad thing, but knowing how I've always thought and think now, I've always seen it as having the luxury of viewing people as individuals without having different races in the mix (at the time and location) to confuse the issue. One might see that as "everyone is an individual in theory", but to have that as a background meant that I just grew up taking for granted that things were not about race.
I think any divisions among any group of people, whether that's a race, an income level, or anything else that makes SOME people view others as "different" in some way; are caused by a lack of understanding - and also the failure on the part of some parents (past, present, whatever) to adequately help their children have priorities that amount to "the only real measure of a person is whether he's kind and tries to do the right thing, and whether he at least tries to have integrity". Kindness is free and can be taught and lived regardless of income. It's not always convenient, but it's free. Teaching that and a number of other things has to happen when kids are a certain age range and before they're eighteen and out on their own with no time or inclination to have long talks with a parent.
There are a number of things that are a matter of either a vacuum that gets filled by the wrong people, or else people who (for the reasons I mentioned) are 1) misguided themselves, and 2) sharing that think they know with yet more other people.
Too many people don't know what the don't know, so the cause of the "divide" in any group is invisible to a whole lot of people. I know some issues can be associated more with one race than another, but I think the cause of any divide in any group goes back to that same thing (basically, too many people not knowing how to talk to their own kids and/or people thinking kids are all grown up long before they really are (and therefore not talking to/with them when they still need that.
Of course, garbage in/garbage out can be a problem, which is how (particularly in this increasingly complicated society) schools could step in earlier or better.