Adults as practical sex educators have appeared, perhaps apocryphally, in many anthropological accounts of other societies. This may turn out to be part of the explanation of the brutal rites of Pitcairn Islanders-more capitulation to uncle than anything edifying-but there are precedents, I’m assured. The boy’s dream (usually damp) is of a winsome young lady who takes him through Rumpy Pumpy 101, all gentle show-and-tell with no fear of failure. Onwards and upwards (downwards?) to advanced or even scholarship level. Now, before you become incandescent, do remember that most of our renowned Lotharios-from Dylan Thomas to Errol Flynn-have turned out to be sexual squibs, so remedial courses for men are well overdue.

Reversing the genders in this example is trickier. Nowadays no sensible older person would dare go within shouting distance of a teenage girl-let alone tickling distance, even when she is well beyond the age of consent. What needs to be understood is how far these ideas can be taken, and how quickly. Would it not be worth trying sex lessons, then-like drug use, guided by someone medically responsible-to see whether this can be of benefit?

If only robots were clever enough, and halfway sexy. Maybe the Stepford Wives experiments were on to something. How far could we go? How flexible and pliable are human cultures? This is complex and difficult to predict. (The possibility of using robots for sexual tuition in the future is not as straightforward as it seems. Though wet-dream cyber-surrogates might be designed to suit your wishes, perhaps even by 2012, there are potentially adverse side effects. The Ig-Nobel Prize for Medicine three years ago was awarded to the author of a paper on how a Norwegian seaman caught gonorrhea from an inflatable rubber woman borrowed without permission from an unsuspecting fellow sailor’s bunk. This award, given in a ceremony at Harvard, stands as a warning about the limits of robotic surrogacy.)

On the one hand most of us accept that societies cannot be engineered from the top down. Stalin failed in Russia, George W. Bush in Iraq. We are usually solidly wedded to our traditional ways. Yet, in the West today, sexual mores are spectacularly different from the grope-and-grieve ways of our grandparents. With the exception of the British aristocracy, professional porn stars, and a number of American evangelical Christians (until they were caught), most of our elders have always been strictly buttoned up. Poor dears. How boggled they are by the present apparent free-for-all.

Other cultures, too, seem strict. Yet appearances can be deceptive. I remember an incident in 1967, when I was studying biology at the University of London. My then wife and I had just finished hitchhiking across the world. An extensive part of our trip was in India, where we stayed with an immensely rich family in Amritsar, in the Punjab. Their overwhelming hospitality, with its morning jugs of scotch (Amritsar is dry!) and daily curried banquets, left us eternally grateful and we said so: ‘Any time you’re in London, do call and we’ll do you proud!’ And off we went.

Some nine months later I was doing an essay on fossil botany in our five-pounds-a-week flat in Wandsworth when the bell rang. I swore and leapt downstairs, pulling the front door open like a man in a hurry about to give two Mormons marching orders. But, no. There stood eight of my Punjabi friends, smiling and nodding-one a sublimely elegant matron dressed in a priceless shawl made from the throat feathers of small birds-waiting to accept my largesse.

I took them upstairs, frantically made a pot of tea (we had four cups) and discovered some sad biscuits from the previous week. They sipped, shuffled-and politely suggested we repair to their hotel, just across from Kensington Palace and Gardens.

Off we went. Once installed there, with curry couriered from the best Indian restaurant in London and vast glasses of scotch in hand, we settled in for a comfortable evening. More guests came, from distinguished Punjabi families resident in England. Then my host came over to me suavely and asked: ‘Robyn, do you know where we can get some pornographic films?’

I was so taken aback I could not answer. It was as if the Pope had asked for a willing harlot. ‘Sorry, not my line, I’m afraid,’ came out eventually. ‘That’s OK, Poppy,’ intervened one of the smooth fellows based in England, who had all the graces and fine garb of the top diplomat. ‘I know a chap. He can get here in no time.’ Calls were made.

Mystified, I sat next to the lady in the shawl and began to hear how Indian women are chaperoned everywhere, with mother or elder brothers before marriage and in the company of senior relatives or other wives afterwards. ‘We are not permitted to go out alone, ever, or just walk solo down the street as we fancy. Certainly not our girls. Absolutely strict!’ And she smiled with approval, nodding.

At which point a bloke in a raincoat and cap-a sleaze from Central Casting-came into the luxurious hotel room, set up an old-fashioned two-reel projector, plugged it in and spooled film through the settings. With a mere nod to the assembled, who were chatting over drinks as if at a reception hosted by Indira Gandhi, he pressed a switch and the film started. There, on the pristine white wall of the Kensington Gardens Hotel, hostelry to the world’s great dignitaries, we saw rough sailor shagging willing tart in Roedean School uniform, from every angle known to man plus a few more. No one missed a beat. Apart from me.

My distinguished shawled companion, employing the Oxford tones of an Indira Gandhi, continued blithely to describe the protocols of female incarceration as her relatives did quiet business in different parts of the room, while sailor and ‘schoolgirl’ reenacted the Kama Sutra in front of them. I am still at a loss to understand the gap between public propriety and private prurience in this traditional upper-class Indian social group. It is

The Future of Sex typical of contradictions about sex throughout every society on Earth.

I am not sure whether the future of sex really will involve practical classes at school and afterwards, but I remain available to help any education minister, state or federal, who is willing to take things further.

More worrying than missing skills is the possibly imminent end of sex itself. Many scientists, of whom Bryan Sykes is the most famous, have warned of the demise of the male. Our Y chromosome is puny, responsible for too many of the ills of civilisation and on the way out. His book Adam’s Curse shocked the world when it came out in 2003, not least because he described the end of men as an advantage. Men are troublesome, noisy, rapacious and, now that science has offered alternatives, unnecessary. Eggs can be fertilised by means of the nuclei of body cells from other women. You don’t need sperm any more. Men have done their historic bit, says Sykes, so it is time to exit stage right.

Barbara Ellen, of the London Observer, wrote a piece on this a while ago. She looked forward to a future existence free of masculinity.

I can easily imagine a world without men. It is the year 2061 and men have been barred from the reproductive process for 60 years. For 40 years, they’ve been banned completely, even as pets. We keep them in cages at Man Zoos, feeding them scraps, beating them when they complain. Occasionally, we take our artificially conceived girl children to Man Zoos to see what females used to have to put up with. There are only girls, because it has long been possible to choose the sex of the baby, and no one wants boys. What men still exist are in these zoos, and dying off, but it is considered unethical to breed them.