Written with the same clarity, directness, and humor that have made Simon LeVay one of the most popular lecturers at Harvard Medical School and at the University of California, San Diego, The Sexual Brain examines the biological roots of human sexual behavior. It puts forward the compelling case that the diversity of human sexual feelings and behavior can best be understood in terms of the development, structure, and function of the brain circuits that produce them. Discarding all 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 Sexual Brain is broad in scope, covering evolutionary theory, molecular genetics, endocrinology, brain structure and function, cognitive psychology, and development. It is unified by LeVay's thesis that human sexual behavior, in all its diversity, is rooted in biological mechanisms that can be explored by laboratory science. The book does not shy away from the complexities of the field, but it can be readily appreciated and enjoyed by anyone with an intelligent interest in sex.