I'm going to have to find and read this book.
The author seems to think that successful and good looking people close themselves off to less successful/good looking people. Those who are slightly less successful/good looking in turn close themselves off to those who are even less successful/good looking as a rational response. This is not so much a response but rather as instinct as people tend to look for mates who are as successful/good looking possible. This in turn ensures that people look for others who are similarly successful/good looking as they are, leading to a stratifying social order.
Unlike Emmanuel, however, I do not believe an emergence of a global multi-cultural elite because, let's face it, social order is to a large degree, racial in nature. People will trade success/good looks for other things simply because the color of their skin. This is especially true for women. The implication of this is probably a great deal of resentment.