Bonk By Mary Roach CANONGATE Pounds 12.99 (333pp) Pounds 11.69 (free p&p) from 0870 079 8897
Californian reporter Mary Roach puts her quick wit to good service in this entertaining romp through sex research, past and present. Keenly attuned to what she calls the "cringe factor", she manages to describe the nitty-gritty of genitalia in action without making you wish she hadn't. While she's sympathetic to scientists' desire to demystify sex and to help people with sexual problems, her sense of the ridiculous supplies regular doses of comic relief.
In her quest for the latest insights, Roach visits sex research labs in London, Cairo, and Taiwan as well as the US. All are premised on the conviction that human sexuality is as worthy of scientific study as "sleep or digestion or exfoliation". Yet even today, there's the unspoken assumption that "people study sex because they are perverts," says Roach. "It wasn't until the past half century that lab-based science embraced the pursuit of better, more satisfying sex."
The sex laboratory came of age with the ground-breaking investigations of William Masters and Virginia Johnson. Their 1966 classic, Human Sexual Response, described, in great detail and for the first time, the physiology of arousal and orgasm. But much of their data arose from their bizarre invention of an artificial- coition machine: "a thrusting mechanical penis camera that filmed - from the inside - their [female subjects'] physical responses to it." This is "as good as science gets," she writes, "a mildy outrageous, terrifically courageous, seemingly efficacious display of creative problem-solving, fuelled by a bullheaded dedication to amassing facts and dispelling myths".
Roach attempts to track down the device, and puzzles over why or how so many female volunteers seem to have reached orgasm from nothing more than "the straight-on, in-and-out motions of a plastic phallus". Her investigations lead on to a highly sceptical encounter with "sex machines" on sale in San Francisco (vibrators seemed to be a crucial adjunct), and DIY measurements of the distance between clitoris and vagina. There's a theory that the greater the distance, the more elusive orgasms via penetrative sex with little or no clitoral stimulation.
On this roller-coaster ride, Roach is soon off investigating whether orgasm boosts fertility, which entails a visit to a crack Danish pig unit where farmers sexually stimulate sows during artificial insemination to boost fertility rates. …