[eropple]

That's not at all what he's saying. He's saying that, when you segment off the institutionally subjugated part of your population--the part of the population who has historically been denied economic opportunities, educational opportunities, and legal rights--you are going to have two populations that have very different growth curves.

And, historically and into the present, there are cultural incentives (racist-ass racism) and economic incentives (risk aversion) to make that happen.