The study of sexual physiology -- what happens, and why, and how to make it happen better -- has been a paying career or a diverting sideline for scientists as far-ranging as Leonardo da Vinci and James Watson. The research has taken place behind the closed doors of laboratories, brothels, MRI centers, pig farms, sex-toy R&D, labs, and Alfred Kinsey's attic. Mary Roach, 'the funniest science writer in the country,' devoted the past two years ...

tags: leonardo da vinci, pig farms, james watson, mri centers, closed doors, brothels, sideline, coupling, physiology, sex toy, scientists, science