Are there any examples of this not being true? 
Discussion
This is putting the cart before the horse.
The term is called white flight sometimes, but it's not about race it's about money, all the rich people leave, most of them happened to be white.
They left for economic reasons.
You've got the whole thing back the front.
I've always connected hygiene with piety and God consciousness more than specific ethnic backgrounds.
The general rule is that we should wear nice clothes, modestly and moderately.
Except for the Hindus, they play with poop.