Just look at a prison yard. People separate into their racial/cultural groups. It's anthropological. The only exception is when you are super good looking like me and women from every culture swoon at your feet.
Not just by women but all people... good looking people just have an edge over ugly, from any sex... its one of lives cruel realities, no political correctness given by nature... every culture though? I wonder if there is a listing of what cultures are most attracted to other cultures, and if there are any pairing that goes into negative territory when compared... now thats interesting...