The term homosexuality did not exist until K.M. Benkert coined it in 1869. The phenomenon, however, has existed probably as long as humans have walked the earth. The many enigmas of sexual orientation that have baffled people for centuries--including what makes some children grow up to behomosexual, while others become heterosexual or bisexual, and to what degree is gender identity determined before birth--continue to do so. John Money, one of the foremost investigators of human sexuality, cogently addresses many of these questions in this authoritative, thought-provoking study. Drawing on case studies from his sexology clinic, he explores the diverse historical, cultural, and physiological influences thatdetermine sexual orientation. Covering such topics as prenatal and postnatal history, gender differentiation in childhood, and postpubertal hormonal theories, Money offers a much-needed, highly informative, and timely exploration into this important subject.