Few things are as fundamental to human happiness as sex, and few writers are as entertaining about the subject as Mary Roach. Can a woman think herself to orgasm? Is your penis three inches longer than you think? Why doesn't Viagra help women - or, for that matter, pandas? Does orgasm boost fertility? Or cure hiccups? The study of sexual physiology - what happens, and why, and how to make it happen better - has been taking place behind closed doors for hundreds of years. In this fascinating and funny book, Mary Roach steps inside laboratories, brothels, pig farms, sex-toy R&D labs - even Alfred Kinsey's attic - to tell us everything we wanted to know about sex, and more we'd never even thought to ask.