Dunno about the further bit, but everyone around the planet think mixed children are the hottest, its why Brazil is a hot destination and Venezula stay whopping everyone in the Miss Universe contest.
You think people are so incline to list a bunch of random mixes for nothing? oh Im scottish and cherokee, oh Im black and indian-caribbean, oh Im swedish, german dutch and a little japanese from my great great grandmother I never seen a pic of.
subconsciously look around, they're always praised. when someone mentions they met a girl then mouth off his/her mixture, you start painting an image of someone pretty, hardly ever ugly. He's right in that respect.
Now the bit about needing to mix to advance...that's just c00ntastic.