This book examines the biological roots of human sexual behavior. It puts forward the case that the diversity of human sexuality can best be understood in terms of the development, structure, and function of the brain circuits that produce it. Discarding preconceptions about the motivation and purpose of sexuality, LeVay discusses the scientific evidence bearing on such questions as why we are sexual animals, what the brain mechanisms are that produce sexual behavior, how these mechanisms differ between men and women and how these differences develop, and finally, what determines a person's sexual orientation: genes, prenatal events, family environment, or early sexual experiences? The book covers evolutionary theory, molecular genetics, endocrinology, brain structure and function, cognitive psychology, and development.--From publisher description.