The Sports Gene by Epstein
As a guy who has been involved in sports all his life, I am as certain as a scientist can be (that is, not 100%, but very close) that there are intrinsic differences in sports abilities. It is not only the early environment, not only the social environment, not only motivation or grit or persistence (which, by the way, as behavioral traits should be heritable. That means that there is an "environmental" and a "genetic" component). Looking forward to reading this book.