Desire: What really turns us on?

John Walsh grapples with the male libido

What is desire? It's a streetcar in New Orleans. It's a Bob Dylan album, and a Marlene Dietrich movie. It's the title of 13 songs by, among others, U2 and Geri Halliwell. It's the name of a brand of dark chocolates. And it's the cause of endless trouble between men and women.

Today is St Valentine's Day when, across the nation, millions of sentient adults will announce their desire to be each other's sweethearts and live in a state of infantilised bliss, complete with emetic nicknames and a fascination for soft toys and satin hearts. What these fluffy protestations of love have to do with the dark voyages of sex, the blindness of lust, the tormenting passions of jealousy, unrequital and betrayal, the uproar of aroused genitalia and what Samuel Beckett called "the cloaca of colonic gratification" is anyone's guess.

St Valentine's Day presents mutual human desire as something smug and mutually self-absorbed. Then, for the rest of the year, it goes back to being a battleground of mutual misunderstanding and transgender bafflement.

Just under 100 years ago, Sigmund Freud spoke for all men when he told one of his lady acolytes, "The great question that has never been answered, and which I have not yet been able to answer, despite my 30 years of research into the feminine soul, is, 'What does a woman want?'" We're still asking it, and our questions have become more urgent. Do women desire sex to the same degree as men? Do they want to be stroked with a feather, pleasured with a silk glove or given a ferocious, anonymous seeing-to in a hay-barn? Do they want to be respected as beautiful Gainsborough heiresses attending a ball in cascades of tulle, or lusted after as trashy harlots posing in ripped silk pants, their rumps nosing the air, their hands gripping the bedrail? Do straight women secretly fancy each other and admire each other's beauty, bodies and scents, in a way that straight men don't, secretly or otherwise? Do women get turned on by erotica rather than porn?

The answers to the above seem to be yes, yes, yes, yes, yes and both, thanks very much – not that most women are disposed to admit to such polymorphous desire. Modern sexual psychologists are exploring unchartered territories of female desire and trying to understand its complexities. The oddest is perhaps the experiment conducted by Professor Meredith Chivers of Queen's University, Ontario, and reported recently in the New York Times.

In her laboratory at the Centre for Addiction and Mental Health, Prof Chivers showed a group of men and women footage of straight sex, male and female gay sex, male and female masturbation, a woman exercising naked, a naked man walking on a beach – and a film clip of bonobo apes mating, with some appreciative hoots and screeches dubbed in. Male viewers had an apparatus attached to their penises to gauge any trace of engorgement; women had a plastic probe inserted to measure "vaginal transudation". They also were given an electronic pad to record whether or not they felt turned on by what was being shown.

The results were amazing. Among the male participants, the degree of desire they claimed on the keypads matched the degree of response recorded on the machines: they liked to watch straight shagging and girl-on-girl action, and they knew they did. Among women, things were different. No matter how much their keypads insisted they weren't interested in the scenes before them, their internal monitors showed they were turned on by everything: straight sex, gay sex, lesbian sex, the nude gymnast – even the rutting simians got a vaginal thumbs-up.

The findings were startling: apparently, women don't know what turns them on – but an awful lot of things do so. Many lady readers of the New York Times might feel insulted by being told they could be sexually aroused by apes, but Prof Chivers goes further. She claims that evolution is responsible for the phenomenon of women's reported arousal – to the point of orgasm – during sexual assault. It goes back to ancestral days, she reports, when women had to lubricate internally during unwanted sex to reduce the possibility of discomfort, illness or death.

But being turned on by random stimuli is not the same as desire, is it? The psychology of desire, rather than the mechanics of lust, is the subject of much head-scratching in the pages of Archives of Sexual Behaviour, the leading sex-research journal. Academics are pondering the importance of being desired in inspiring desire; how women are turned on by the thought of being wanted – not just loved by a caring and empathetic partner, but urgently, physically craved to a level of derangement. "Women's desire," said one (female) professor, "is not relational, it's narcissistic." Coleridge expressed the same idea 170 years earlier: "The man's desire is for the woman," he wrote, "but the woman's desire is rarely other than for the desire of the man."

What, though, about male desire? I recall being given, by an old girlfriend, a spoof picture of two control panels, supposedly showing what it took to turn men and women on. The panel marked "Women" was like the flight deck of a 747, full of knobs to be twiddled, valves and minute calibrations of this and that. The panel marked "Men" was just an On/Off switch. Is that how women see us?

Women would be amazed if they knew what men desire about them. Yes, of course, they want to see women naked and supine and melting, but male desire is far more readily stimulated by what the oblique glance discovers: the parted lips, the micron of eyelash which the mascara brush missed, the changing angle and shadow of cleavage, the bra-strap alternately displayed and covered up, the ripe-camembert plumpness at the edge of hips. There is, inside every adult man, a relentless Peeping Tom, a perennial 14-year-old boy, still amazed by the phenomenon of women on display, flagging their sexuality, their availability, with every square inch of visible flesh, clothing, make-up and curve.

When we've finished ogling and peeping and noting the details (the way that girl's hair follows, and touches, the curve of her chin, moves away from it, touches it again...) then desire becomes personal. We see sexual allure in movement (Maggie Gyllenhaal's fabulously slouchy walk in Mona Lisa Smile), in haughtiness (Kathleen Turner in Body Heat, looking down at the Slush Puppie smearing her front and responding to William Hurt's "Maybe I'll help you wipe it off" with "You mean you don't wanna lick it off?") and in pure sass (Lauren Bacall in To Have and Have Not, looking up through her curtain of hair and asking Bogart, "You know how to whistle, don't you Steve?"). Voices can provoke desire before anything else. It was Scarlett Johansson's beguiling croak that brought men out in a muck sweat in Lost in Translation, before they registered her juicy lips or points further south.

We desire the personality that we discern in the walk, the clothes, the laugh ... We look, and sigh, and wish to do certain things to her, first urgently, then luxuriantly, and keep doing it indefinitely; but we also hunger to have her do certain things to us, unimaginable though it may seem – we want her to want us. We don't just want her surrender, like a slave captured in battle; we want her approbation, her adoration; we want to enchant her to desire us back. For, no matter how humble we feel before the dizzying fact of female beauty, men are just as narcissistic as women.

For men, desire involves the primal urge to possess and penetrate the object of their attention, but also the more sophisticated urge to invade her (or his) life, to become the object of her attention and affection. Male desire does not cease when the initiating partner – the desirer – has finished performing the blanket hornpipe and the midnight rodeo upon (or beneath) the desiree. In many respects, his urge to explore every nook and cranny of her body and soul has only just begun.

Male lust is an ignorant, blind, bullying thing – an immediate need, as real as hunger though not quite so life-threatening. Male desire is more subtle and strategic than wanting to get laid. It yearns to satisfy something more long-term, something awkwardly freighted with spiritual components. It's about wanting to offer yourself to a person you admire, to combine your two spirits.

And if that sounds a little cute and Valentine-card-y, let me add: desire is never free of its ugly sisters, passion and conquest. Modern metrosexuals may find it hard to admit but, mingled in amid the urges to pleasure and impregnate and entwine destinies, a smidgeon of cruelty resides as well. It's the reason why sex is generally less than ecstatic when your partner is someone with whom you're really cut out to be friends. True desire seeks to conquer.

We're not proud of ourselves for having this tyrant/ caveman streak lurking in there along with Mr Nice Guy and Mr Caring And Protective. But according to the Archives of Sexual Behaviour, the girls are OK about that, albeit at a subconscious level ...

So there we are. Two genders, designed to slot together and entwine to the unending joy of both, and we're hopelessly confused about what we want from each other. For women, according to a leading sexologist, "desire is malleable, it cannot be captured by asking women to categorise their attractions ... To do so is to apply a male paradigm of fixed sexual orientation." Don Draper, the alpha-male hero of TV's Mad Men, spends one whole episode asking, "What do women want?" Finally he answers: "Any excuse to get closer." But closer to what? To whom? And why to him and not me? Overleaf: Catherine Townsend on female desire

Catherine Townsend on the truth about female passion

The experiment sounded beautiful in its simplicity. As John Walsh relates, Professor Meredith Chivers, a Canadian sexologist, put men and women in a room and screened lots of porn – of heterosexual sex, gay sex, people masturbating, and bonobo apes going at it. But the results were astounding. When Prof Chivers measured the womens' reactions using a plethysmograph (a very un-sexy device that resembles an acrylic tampon), she found that they weren't just getting off on the fit naked man walking down the beach. They were aroused by the hot monkey sex, too.

And the weird thing was, they didn't even know it – or at least, what the women said was turning them on was far removed from reports coming from their nether regions.

This wasn't the first study that exposed the complexity of female sexuality. "There's definitely a mind/body disconnect in women," says Mary Roach, the author of Bonk: The Curious Coupling of Science and Sex. "One researcher found that women will say that they prefer female-centered porn, instead of the stag porn where the guy is banging away. But when you measure their blood volume, the level of arousal is the same. So the whole thing is just more subtle."'

It hardly seems groundbreaking that the sight of a flaccid penis failed to set the women on fire. And is it any surprise that women look at womens' bodies as much as men do? We are raised practically from birth to look at naked women as sex objects. I'm not surprised that they turn us on.

But I am thrilled that Prof Chivers is looking for answers without having to resort to drastic measures. After all, history hasn't always been so kind to sexually frustrated women. In her book, Roach describes how Marie Bonaparte (the great-grand-niece of Napoleon) was frustrated by her inability to climax during intercourse. She thought her lack of stimulation had something to do with clitoral-vaginal distance. So instead of changing sexual positions, she measured herself, and other women – and went so far as to have a doctor operate on her. Sadly, it didn't work.

But there are still double standards out there. The women in Prof Chivers study may not have consciously realised they felt horny, or maybe, even on a deeper level, they were embarrassed about the fact that watching screeching apes got them going.

Women have been much more concerned about having the "right" kind of sex ever since Sigmund Freud started the "vaginal vs clitoral" orgasm debate back in 1905. He gave several generations of women instantaneous inferiority complexes when he wrote that the clitoral orgasm was an "adolescent" phenomenon that "mature" women would outgrow.

This myth continued until researchers including Masters and Johnson argued that the clitoris is the primary source of both types of orgasm. (And it turned out that the so-called "little hill" actually rivalled the size of the penis!) But as long as women are getting off, who cares about having the "right" kind of orgasm? Yet the debate won't die. Now every year, it seems that there is a new headline regarding the Holy Grail of the female orgasm – the "G-spot". That is, until the "A-spot" came into vogue ...

Italian scientists said that they could find the G-spot by ultrasound, but only in certain women (way to make us feel inadequate, guys!). But scientists don't know everything – hell, they still don't know why we have orgasms in the first place.

They have searched for the Darwinian logic relating to female orgasms, but argued, since women can get pregnant without having one, what's the point? Some researchers have assumed it's because the Little Death encourages women to have more sex, that the contractions push semen nearer the cervix (Stephen Jay Gould), or that it leads women to choose stronger and healthier men.

But as Dr Elisabeth A Lloyd argued in her book, The Case of the Female Orgasm: Bias in the Science of Evolution, female orgasms are simply evolutionary artefacts left over from the initial stage of embryonic development. Like male nipples, female orgasms may simply be there just for fun.

The field of female sexuality can be maddening, because each answer seems to lead to even more questions: why can some women ejaculate? (It seems to have something to do with a combination of bladder position and training, but no one has a definite answer.) Why do some women never have orgasms at all, while other super-sensitive souls are able to "think" themselves to climax by stroking an eyebrow? Can't we relax and just accept that, as Roach says, "orgasms are like Scotch, some are single malt and some are blended?"

So female desire can be a paradox – as Prof Chivers reports, we may want to be ravished roughly in an alley and also want someone who can be tender and caring. But I'm always amazed by how male writers manage to make that sound impossible, when really, women are not that complicated. Our sexuality just doesn't parallel men's; we can't always be viewed through the same filter. So perhaps when they study women, scientists should drop the unifying theory idea.

As Mary Roach says, "[Scientists] saying that they want to increase orgasms, or boost libido is much more helpful than saying: 'I want to understand women.'"

The recent study results are fascinating and raise more questions: are we, as one researcher ventured, "narcissists" who get off on being desired? Is the genital response a total fluke, and some sort of evolutionary "self-lubrication to a sexual situation"? Or do we have much more wide-ranging sexual desires than we realise?

It may be a while before the researchers and volunteers have all of the answers. I can't wait to see what they come up with next.