The parent trap: Britain's high-fliers who refuse to fly the nest

They're young, successful - and still living at home with mum and dad

The American columnist Erma Bombeck once wrote: "Families aren't dying. They're just merging into big conglomerates," and I know plenty of 20-somethings who would ardently agree. Just when their exhausted parents thought they'd seen the back of them, they fly back to the nest - and bring their girlfriends/boyfriends with them.

Affectionately known as "Kippers" (Kids in Parents' Pockets Eroding Retirement Savings), recent research showed that 6.8m over-18s still live with their parents and almost one million are still at home by the age of 40. With ever-increasing mountains of student debt, rocketing house prices and laissez-faire attitudes to the "serious" business of marriage and children, could it be that a cosy new family-demographic is emerging, which includes two parents and at least one of their adult offspring?

I have at least 15 friends between the ages of 23 and 33 who still live with their parents. You could be forgiven for thinking that these young people are a snotty-nosed bunch of unemployable freeloaders, incapable of going to the toilet without holding their mummy's hand - but you'd be wrong. Rather, this is a generation of smart, professional university-leavers who have chosen to live at home rather than haemorrhaging £500 per month for the privilege of renting a damp broom cupboard in the grottiest part of town.

"It's not like I'm lying around on the sofa at home, living on welfare," complains 26-year-old, Oliver, when I asked him if he felt like a pathetic sponger. He has been living at his parents' posh house in Islington, north London ever since starting up his own business two years ago. "I just don't see any point in wasting hundreds of pounds a month on rent when I could be saving money to put towards my own place." Another friend, Natasha, has a successful job in music PR, but has been living on the top floor of her parent's house for the past three years: "I don't think it's embarrassing," she says, "it's just a fact of life for people our age. If you want to save enough money to buy your own flat, then living at home is often your only option."

TV property expert Louisa Fletcher says this is a "direct reflection of today's spiralling house prices". She bought her first house 15 years ago at the age of 19 with a deposit of just £3,000, but says, "there aren't many 19-year-olds who could do that now" - I certainly don't know any. According to the latest Social Trends Report by the Office for National Statistics, first-time buyers faced a 204 per cent hike in average house prices over the decade to 2005, while over the same period, their incomes rose by just 92 per cent. This generation just don't stand a chance.

For me, moving home was the only option after four years at university, drinking away my student loan. It was cheap, near a Tube station and - most importantly - gave me the freedom to follow the (badly paid) career path I had chosen, without having to worry about rent, an expensive mortgage or curtailing my extravagant social life. For 18 months I lived like a queen on cocktails and expensive meals while my nice, liberal parents footed the bill, and patiently waited for me to earn enough money to move out.

Lots of people my age have a similar story to tell. "My life is like one massive contradiction," said one 26-year-old who has a well-paid job in the city, but is still living with his parents under the pretence of "saving up" for his own flat. "During the day I'm going to all these high-powered business meetings and playing at being "grown-up", but in the evening I go back to my parents' house and it's like I've regressed back to being a child again."

Essentially, we are the generation that want all the perks of adulthood - the good job, nice clothes and glamorous lifestyle - but without any of the mundane trappings of being a homeowner. And as more of us "children" linger at home, and our adventuring baby-boomer parents jet off on gap-years, it seems that the traditional boundaries between childhood and adulthood become increasingly blurred.

Sixty years ago adulthood was marked by distinct rites of passage: the "key to the door", getting married or having all your teeth pulled out, but today, says social psychologist Dr Sheila Keegan, "we have a far more woolly idea of what it is to be an adult". 14-year-old girls have the right to an abortion without parental consent, while others are allowed to dodge the responsibilities of adulthood by not leaving home until the age of 28. Keegan says the problem is, "a delayed sense of responsibility coupled with an increasing sense of rights".

But our increasing sense of "rights" as adults are not always compatible with the practicalities of living with your parents - and have some potentially awkward repercussions. One friend, Jenny, 25, lived with her mum after leaving university - but refused to curtail her love life. Instead she got into the habit of leaving a big note on the kitchen table before she went to bed saying: "Mum, DON'T come into my bedroom - I've got a boy in there."

But the men are even worse, and, according to statistics, are a third more likely than women to stay at home until they get a mortgage. I once dated a 31-year-old company director who would unashamedly ring his mother via the intercom every morning, to bring his breakfast up on a tray. The laundry went in a pile on the bathroom floor. This could be because "women learn domestic independence at a younger age than their male counterparts", according to clinical psychologist Dorothy Rowe. Young men are pampered and cosseted for much longer, while women are far more likely to have taken on some domestic responsibility as adolescents.

So perhaps our parents are to blame? No longer hemmed in by the fierce disciplinarians of yesteryear, my generation has been spoilt by 1970s liberal parenting. "There is a trend of parents wanting to be friends with their children," says Keegan. "With greater personal involvement there is less chance for the child to be independent and make their own way in the world." The rules have changed, she says . "Once upon a time it would have been quite unseemly for boyfriends or girlfriends to stay under the parental roof, whereas now home environments are more relaxed and it's more acceptable for people and their partners to move in." Without any of the traditional incentives to fly the nest you can understand why so many young people decide to slope back home and escape the financial onslaught of modern-day living. But is it ever possible to live a fully adult life while under the same roof as your parents?

"You can never live in you parental house as an equal - you always remain a child," says Keegan. "All children need to separate themselves from their parents, and if they don't get that chance, they never become quite fully formed. In some ways separation is the definition of adulthood."