This episode looks at how sex researchers have tried to understand how the opposite sex works. One sex researcher in Canada believes men and women are turned on in very different ways. Her experiment shows heterosexual men respond to straight sex: no surprise! But women it seems are aroused by images of any kind of sex, from gay men to bonking monkeys; but they don't necessarily know their body is responding. Is sex in the mind or in the loins? And are men and women fundamentally different? Then there's the orgasm. For men it's clearly linked to making babies - but for women? What was its purpose? In the 1950s, gynaecologist Bill Masters teamed up with his secretary Virginia Johnson to take a more rigorous look. Together they recorded 10,000 orgasms in their laboratory, and concluded that, for women, orgasm was simply for pleasure. Their book, perhaps unsurprisingly, was a best seller, and they became sex research superstars
Achieving 'better sex' is the Holy Grail of sex research, but science is divided over the methods. Is it all in the mind? Or is the solution to be found in pills and surgery? The second programme in the series features the latest pioneering research into sex and into the science of finding the right partner. It looks at the pros and cons of chemical fixes, such as Viagra, and the moral dilemmas of developing 'love drugs' to pump up the libido and attract a partner. The film also features some strange episodes in the history of sex research, such as the work of Wilhelm Reich, a pal of Einstein's, who claimed he'd discovered the hidden libidinous force that makes the universe tick, which he called 'orgone'. Look out for the eye-watering operation to turn a Taiwanese man's penis into a kind of angle-poise lamp, and the attempt to rejuvenate middle-aged men by transplanting monkey testicles.
The sex researchers have spent a good deal of time watching, recording and measuring our sexual activities to find out what is normal. If you're a man, in a long-term relationship but cheating on your partner, the answer seems to be that this behaviour is normal. Men's propensity to stray from the marital bed seems to be encoded into their genes. One researcher even claims to have found the cheating gene. Another offers up even more radical evidence, claiming that the shape of a man's penis is proof positive that we've evolved to be unfaithful. The ultimate sexual survey was carried out by legendary sexologist Alfred Kinsey. He exposed the sexual antics of America and helped facilitate the sexual revolution of the 60s. In fact it's the work of the sex researchers that has paved the way for the sexual tolerance of the 21st century. In the western world homosexuality in particular has moved from being a criminal offence to an accepted part of human sexuality. And the sex researcher's focus has shifted from trying to find out if gay men are normal to trying to find out why they're different. One recent study is aiming to work out if it really is possible to pick out a gay man in a crowd; does the 'gaydar' really exist? Even though the scientific research into cheating men seems depressingly predictable there is good news for any romantics out there. Sex researchers now believe that we have not one but three competing sex drives: one is the good old fashioned sex drive (which is often prone to stray); the second is love, which unleashes a torrent of hormones, turns our lives upside down and persuades us to start a relationship with someone; and the third is attachment, which keeps us together. These three drives are not just social constructs but hard-wired into our brains and bodies. It's why, no matter what our sexual preference, monogamy is, in fact, normal.