This book introduces readers to sex researchers and explains the questions they are asking and the methods they are using to discover the answers. Renowned sex researcher Simon LeVay asks: Why do humans have sex? What happens in the brain when we're getting it on? How do 'kinks' develop? What is love? And many other topics - some frivolous, some tragically serious - all studied by fearless but fallible researchers. Sex, they have shown, is as worthy of scientific inquiry as any other facet of human nature.