Laura Barton: This Week

It has been a week of putting one's finger on it. The fun started in earnest on Sunday, when the Observer's resident psychologist, Oliver James, devoted himself to discussing what gentlemen find attractive, concluding roughly (and here I confess to a touch of paraphrasing): men like plumptious young misses, ripe for the picking.

Once they hit the big three-zero, James explained gently, ladies are simply no longer attractive. We must, he instructed, with a faintly patronising tinge to his voice, resign ourselves to the bald fact that thereafter we are destined to be hollow-cheeked, shrivelled husks of womankind. "Just as countless impoverished former millionaires and deposed politicians suddenly discover that friends, wives and lovers no longer have time for them," he revealed, "many women are shocked by the extent to which their looks affected others' reactions to them."

Further clarification arrived with the latest edition of Cosmo Girl! Whereas fully fledged Cosmo might serve up umpteen ways to achieve mind-blowing orgasm, its little sister offers the somewhat tamer, though no less enticing, 165 Ways to Wow Him. Although Oliver James might like to note that nowhere among the 165 did we find "Be thankful you're under 30, honey" (and believe me, Oliver, we checked, twice) the article did divulge the useful nugget of advice that men go for a bit of chutzpah: "Borrow celeb confidence," came one of the wowing recommendations, "by asking yourself, how would J-Lo handle this?"

But the pinpointing reached its inevitable crescendo (and, really, I hesitate to use the word climax under the circumstances) on Wednesday evening, with David Aaronovitch's new three-part television series Whatever Turns You On, a sort of epic voyage of sexual mores, in which David, like a lascivious Odysseus, travelled the globe investigating precisely what different cultures find erotic.

In Brazil, of course, it's the bottom. In the US and the UK it's bosoms, and in Japan it was, traditionally at least, well-rounded sorts who showed themselves capable of reproducing. Pubic waxing, meanwhile, was regarded as increasingly attractive among both sexes and, as American culture spreads, not entirely unlike like dry rot, throughout the world, we are finding that the US pornographic ideal of blonde buxomness is becoming the widely accepted norm.

In short, even if one really learned nothing new from Mr Aaronovitch's exploration, the programme served as a kind of general audit of sexual attraction. In addition, it gave us not only the chance to hear one of our foremost political commentators use the word "schlong", but also the mind-boggling opportunity of witnessing him insert his finger two-knuckles deep into a pretend posterior under the instruction of a bespectacled pornography expert. This last was thankfully more of a titillating amuse-bouche, encouraging us to tune in next week for part two, than a further attempt to define sexual attraction.

There was really just one problem with the combined efforts of Messrs James and Aaronovitch, and indeed Miss Cosmo Girl! to define sexiness, and that was the fact that it left sexual allure looking like an over-dissected laboratory rat. It was rather a taxonomy of sexiness. And one couldn't help but be reminded of the fact that, in their relentless efforts to classify the various species of butterfly, the Victorians had to first kill the butterfly itself.

Similarly, this week's investigations did not take into account the delightful peccadilloes of living, breathing sexuality, but instead gave us hard and fast rules as titillating as algebra. Isn't all this talk of turn-ons just a little bit of a turn-off.