Which brings up another quirk of humanity, which is we tend to hate the ethnic group that is the most similar to our own. Simply, you hate your neighbor, you don't hate someone on the other side of the world you've never interacted with.
There certainly are many instances of people hating ethnicities very disimilar form them, but that happens after people from different parts of the world migrate close to each other.
Well, sure. Your neighbor is the one who waits an extra week to mow his lawn, which looks bad, and drags down everyone's property values. Your neighbor is the one whose dog pooped in your yard that one time.
I suspect that proximity has a great deal more to do with it than similarity. If your neighbor is actually significantly different than you (ugh, the weird smells from the strange food those people eat!) I would think it makes it even worse.
There certainly are many instances of people hating ethnicities very disimilar form them, but that happens after people from different parts of the world migrate close to each other.