In their early twenties, they were Generation X, rejecting the idealism and ambition their parents had at that age for a life of drifting. And as they look aghast at the prospect of middle age, the Generation X-ers of the 1990s are apparently still refusing to grow up.
Research by the magazine group Emap has found that half of people in their late twenties and thirties have the interests and spending habits as those 10 years younger.
Instead of becoming earth mothers and new dads, they have been described as "Super Youths", who refuse to forgo clubbing and shopping for walks in the park. The group is headed by celebrities such as the model Kate Moss, who partied at Glastonbury with her daughter Lila, and Damon Albarn, the Blur singer and father.
The study shows a contrast with lifestyle habits in 1995. In 2002, 46 per cent of those aged 25 to 39 said they were passionate about fashion trends, compared with 34 per cent of the same age group in 1995.
Two thirds are still interested in music, when only 50 per cent of their peers claimed to be in 1995.
More than half of people in their late twenties and thirties still go clubbing, and seven out of 10 attend music concerts.
Jason Brownlee, head of Emap Insight, which spots social trends, said: "This is a generation which is completely unlike their parents. It is not simply that they get married or have children later in life.
"They have more education and much more economic clout, and do not see getting married and having children as the end of their lives. They do not want to be 'grey-listed' - they want to carry on indulging their passion for music and fashion and technology into their thirties and forties."
The survey identified four groups within the Super Youth generation. Black Collar Workers (BCW) are highly ambitious men who like to work hard and play hard, combining designer clothes and trendy bars with having children.
Their heroes are the actor Jude Law, the Big Brother presenter Dermot O'Leary and Damon Albarn. Emap Insight says there are more than 1.2 million BCWs.
Hometown Heroes are young men who flaunt their money but stay within the social norms they have grown up with. They perceive themselves as "lords of the local manor".
Examples include the Gallagher brothers, David Beckham and the Pop Idol presenters Ant and Dec. They are 12 per cent of men between 25 and 39 and more than half have children.
Cool Career Girls (CCG) are women who have worked hard for money and fame, and buy clothes, holidays and a lifestyle that reflect their individualism.
Their heroines include the designer Stella McCartney, the actress Gwyneth Paltrow and the pop star Kylie Minogue.
Fun Lovin' Mums combine family life with fashionable careers and refuse to be "un-sexed" by motherhood. Their role models include Victoria Beckham and Sadie Frost.
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