Johann Hari: Why Stephanie Beacham is a model for us all

A woman's life doesn't have to end at 60 – as the star of Celebrity Big Brother is proving

I hereby renounce my republicanism – on the condition that Stephanie Beacham is immediately crowned Queen of England. Two weeks ago, the honey-voiced grande dame of Dynasty wafted into the Celebrity Big Brother house alongside a babbling gaggle of non-entities. She had nothing with her but an I'm-being-paid-lots-for-this Zen and an expensive handbag. But she has proceeded to show something that is almost never allowed on to television, or into any British workplace: a 61-year-old woman who is cleverer and wiser and more confident than anyone around her, freely expressing her complex emotions and longings and lusts. If we peer into the surprising story of Stephanie, we can see one of the great scandals of Britain today: the premature consigning of my mother's generation of women to atrophy and decline.

The Big Brother house is the graveyard of dignity. It is a place where every burp is recorded and replayed, and rows about a burnt chicken cause an international race row. It reduces everyone inside it to pettiness and tribalism and shrieks. Yet Beacham has an inherent poise that no amount of fish guts sprayed into her face while she is strapped to a roundabout (yes, they did) can dent. While the other "celebrities" neurotically fret about their status, she is the one who does the work, annihilates the fundamentalist political ravings of Stephen Baldwin, and makes languid but piercing observations about what is really going on. She gets the hot young men to massage her feet – "Darling, you can never be too hard" – and when they are given absurd tasks asks Ivana Trump with a chuckle: "Are we whores, or fools?"

Against a chorus of self-pity from the rest, she says simply: "This is the best holiday I've had in years ... I feel lighter [and] happier to just be me than I have in years. I could fuss around and try to make my hair and my face look better but [I choose] the pleasure of giving in, of just being."

This is the wisdom of so many sixtysomething women. It comes from a lifetime of seeing hopes fulfilled and dashed; from decades of being scarred and seeing the scar tissue heal, getting crinklier and richer every time. Yet we are a country that, today, is systematically writing off these women – in a way that is bad for all of us, whatever our age.

At the same time as the nation was falling for Beacham – she is favourite to win – Harriet Harman was giving an important speech about their generation. Today, when a woman turns 60, or a man turns 65, she is told her life's work is over, and to go home. Whatever expertise she has built up – my mother worked with victims of domestic violence for decades, for example, until last year – is dismissed. Retire. The end.

Millions of people don't want to live like this. While only 11 per cent of people work beyond retirement age, a recent opinion poll for Saga found that 38 per cent had wanted to carry on. The sacking of Arlene Phillips from Strictly Come Dancing – for a younger, dumber model – resonated because it happens in workplaces across the country. It hits both sexes, but women especially strictly: Brucie is still tap-dancing in his eighties, while Arlene is dismissed as a dried-out husk 20 years sooner.

Harman – another woman who has taken a kicking in her life, and only emerged more dignified and poised – says we need a more "mature" and flexible way of thinking about retirement. It should be about empowering people to live their lives, their way – not blocking them off in their prime, against their will.

It's essential to preserve the right to retire. My grandmother worked tough manual jobs, including scrubbing toilets, all her life; by the time she got to 60, her knees were ruined and she couldn't go on. That's why the Conservative proposals to rapidly jack up the retirement age, by millionaires who have never done a day's manual work in their life, are cruel. But it's equally absurd to say a woman like Beacham, or my mother, or Harman herself, is past it, has nothing more to give, and should be consigned to living life in her living room. This isn't just bad for them: it's bad for all of us, because it wastes great swathes of the country's talent.

So Harman has proposed a more open form of retirement. Today, it's a crash landing: you go from 9 to 5 to a P45 in one sudden fall. In Harman's vision, people could glide towards retirement more gradually. At 60 or 65, you would have the right (but not an obligation) to continue part-time. It's good for you, because you remain within the social network and stimulation of work, and you don't suddenly find yourself at a loss. It's good for your employer, because the knowledge you have built up continues to fertilise the company. It's good for the country, because we won't have so many clever, able people twiddling their thumbs. We are going to need their labour, too. In Britain today, there is a growing pool of older people, and a diminishing stream of younger people. In 20 years' time, half the population of Britain will be over 50. For the millions who want to work, it's crazy to block them off, and push them into dependency on a diminishing pool of the young.

Today, these are only suggestions being put up for discussion, and the current government clearly won't live long enough to implement them. But Harman has a long track record of pushing ideas that are derided at the time, and later become accepted as common sense: back in the early 1980s, she was derided for saying the Government should have a national childcare strategy and must require companies to allow parents to request flexi-time. It's a familiar pattern by now. They hurl sexist insults and call her mad, then 10 years later say that of course they support those feminist ideas – just not the mad ones pushed by Harriet Harman.

When women in their sixties are finally shown to us in all their richness, people respond: look at the glorious renaissance of Meryl Streep in the past few years. But too often they are bundled away, out of the workplace, off the TV screen, dismissed as too wrinkled to sit alongside a wrinklier man in his seventies. They are assumed to steadily lose the characteristics of human beings, like (for one) sexuality. Fellow housemates Dane Bowers and Cisco admitted Stephanie Beacham was "the fittest woman" in there, and they were startled to discover they could fancy a woman her age. We live in an airbrushed culture where 60 is always presented as sterile. It's a nasty trajectory: first jobless, then sexless, and finally characterless.

This is part of the reason that when it comes to people who are older still – the swelling army of eightysomethings and beyond – we avert our gaze. We skim over the headlines revealing that nursing homes are forcing elderly people to have unnecessary operations jabbing tubes into their stomachs because it's "a hassle" to clean them up. We don't want to know that hundreds of thousands of them are being given "chemical coshes" – anti-psychotic drugs that reduce them to drooling zombies. The dehumanisation begins at 60 and is complete by 80.

It doesn't have to be like this – but it requires a change in the culture and a change in the law. Arise, Queen Stephanie: your sixtysomething subjects await a better Kingdom.

From Paris to Playboy: Being Stephanie Beacham

* Beacham is deaf in her right ear and has only partial hearing capacity in her left. She has worked for the charity Hearing Dogs for Deaf People.

* Beacham trained in mime in Paris before joining Rada.

* Her birthplace has been falsely given as Morocco, a rumour started by the actress when interviewed by a local newspaper early in her career. She thought her real birthplace of Barnet, north London, was dull and so answered "Casablanca", where her favourite film was set.

* She posed for Playboy in 1972 and later said the only thing she regretted was the wig she wore for the shoot.

* Apart from playing Sable Colby in Dynasty and its spin-off, The Colbys, she has also appeared in everything from Shakespeare to Beverly Hills 90210 and Ibsen to Spielberg's sci-fi production SeaQuest DSV.

* She has been nominated for four awards: a Golden Globe for Sister Kate and three Soap Opera Digest Awards, including Outstanding Villainess, for Sable Colby.