Nancy Etcoff published her book Survival of the Prettiest: The Science of Beautyeight years ago, but it's still selling well today. Here's one reader's review;

This book is both authoritative and surprisingly entertaining. It is Darwinian - it is the survival of the prettiest and most handsome. The author, Nancy Etcoff, proposes that valuing beauty is an essential and ineradicable part of human nature and that it is revered and ferociously pursued at enormous cost in nearly every civilization.

Also, the facts show that people are less likely to ask good-looking people for help. Our efforts to please good-looking people with no expectation of immediate reward are one way we reinforce beauty as a form of status.