"For the life of me, I don't understand why women's attire must be so damned complicated," says Ralph Fiennes, as he starts undressing Keira Knightley in The Duchess. "I suppose," she replies, "it's just our way of expressing ourselves." As Georgiana, Duchess of Devonshire, Knightley is dressed in the uniform of her class: huge, powdered wig and, beginning with a simple cotton shift and ending with a mass of frills and ruffles, as many layers of clothing as an onion. Oh, and hoops and a corset, of course. If ever there was a metaphor for the condition of the 18th-century female aristocrat, then this was it: secondary sex organs plumped and primped for male titillation, heart and lungs laced to near-suffocation and primary sex organs encased in what can only be described as a cage.

The cage, in this particular case, was huge. It extended beyond Chatsworth, the Devonshire family seat, and into houses in London and Bath. And as long as the Duchess stuck to her ordained role as manufacturer of healthy male humans to keep the show on the road, the Duchess had the right to roam this vast cage, the right to charm and party and even, if certain rules were obeyed, to allow someone other than her husband to unlace those stays. The trouble is that certain rules weren't obeyed. Georgiana fell in love, embarrassed the Duke (who was, incidentally, living in a ménage à trois with her best friend) and all hell broke loose. Drawbridges were drawn up and Georgiana was threatened with that age-old choice: total obedience to tyranny or your children.

Luckily, things have changed. Most women in our culture don't have to obey their husbands. They don't even have to have them. They can produce sons and heirs all over the shop, without worrying too much about the fathers – without, in quite a lot of cases, even telling the fathers. As a psychologist on a TV programme about young women in Britain said this week, "It has become more acceptable for girls to ape the way that men behave." The programme, in fact, was about "girl gangs", groups of teenagers who have adopted the social mores of their male peers by responding to slights, real or imaginary, with punches, kicks and knives. And now they were about to take on their biggest challenge so far: a series of meetings with Ann Widdecombe.

"I got a bottle and I smashed his head open," a young woman called Kim told the former shadow home secretary, who pursed her lips and hugged her arms to a bosom bigger than Keira Knightley in a crinoline. The answer, thought Widdecombe, was a short, sharp shock, and so she took a group of violent teenage binge drinkers – all dressed in the uniform of their age and class (skinny jeans and tiny T-shirt) – to a prison. Widders clearly thought that a quick chat with some young women in a state of state-sanctioned disgrace would yield an instant cure for this unfeminine behaviour, but when she saw them three weeks later they were binge-drinking again.

Actually, she'd have done much better to take them to Joey McKneely's production of West Side Story (hitting Milton Keynes next week), an utterly mesmerising, and spine-chilling, portrayal of gang warfare and its consequences. "What does it take to get through to you?" says the police officer to one of the young men killing each other in Manhattan's west side. "You make this world lousy." "That's the way we found it," he retorts.

And that's what we all do: respond to the world as we find it. In Georgiana's case, it was a world of vast country estates and lips stiffer than a psychopath's. In the case of Bernstein's Jets and Sharks, and Shakespeare's Verona, it was a world in which women watched their lovers die in turf wars, and in Kim's Peckham it's a world in which, according to a social worker on the programme, "if you're from an area, say SE15, and you go to another area, you're attacked". Most of us, when it comes down to it, follow our tribe.

But Georgiana did, in certain ways, have the courage to escape the constraints of her gender. She was a vigorous political campaigner more than a century before women got the vote. And Kim, who has some of the rights as a woman that Georgiana didn't, but none of the privilege that came with her background and class, is trying too. "I don't think it's possible to be the character I am and be a wuss," she says. But she's fighting the urge to fight.

In a week when some of the most privileged people in our culture have had their eyes trained on catwalks to learn their uniform for next season, we could learn a thing or two from Georgiana and Kim and some of those women who try to swim against the tide. Perhaps we could even learn from Ann Widdecombe .

c.patterson@independent.co.uk