The US Census Bureau estimates that 40% of young adults return nowadays to live with their parents after leaving home, compared to 20% 50 years ago.
Emblematic of this generation was American singer Britney Spears, whose 2001 song "I'm not a girl, not yet a woman" was one of her first big successes.
A raft of sociological studies try to explore the phenomenon, which has already produced big headlines in the American media. A number of web sites, like www.quarterlifecrisis.com, are helping people exchange advice and opinions on the subject.
"So here I am, 28 years old, living with my parents once again, and still no realistic job possibilities," writes a young engineer from Phoenix, Arizona. "There is no light at the end of the tunnel and I'm more convinced than ever that higher education is America's most overrated product."
Tapping into this sentiment, ABC television is currently working on a show called "1/4life," which focuses on a group of people aged 25-30, who have trouble making a choice in their lives.
A recent opinion poll conducted by Time magazine among 601 people aged between 18 and 29 showed that 22 percent of those surveyed believed people become adults with the birth of their first child and about the same number thought the threshold of adulthood was being crossed after leaving their parents' home.
Some 70 percent said they had spent some time home in the previous week the poll was taken and 48 percent admitted that they maintained daily contact with their parents by telephone or via e-mail.
In another survey conducted by the University of Chicago in 2003, a majority of respondents said people reach adulthood at the age of 26.
Assessing the situation, educator Susan Morris, who co-authored the book "Mom, Can I Move Back In With You?", came to the conclusion that the bond between parents and their grown-up children had been reinforced in the late 1980s, when graduation from college stopped being followed by marriage and childbearing.
Psychologist Jeffrey Arnett describes this new phase in life in his book "Emerging Adulthood."
"From their late teens to their late twenties they explore the possibilities available to them in love and work, and move gradually toward making enduring choices," he writes.
He believes that for people in this demographic group it is more difficult to give up their freedom and individualism.
The average age of women getting married in the 1970s was 21, and for men it was 23. In 2000, it changed to 25 and 27 for women and men, respectively.
The first child is usually born one year after marriage, which in part can be explained by the fact that education now takes longer than before as well as by the tendency among young people to enter adulthood in a different way, according to Arnett, who teaches at the University of Maryland.
"I think it is here to stay, as long as the marriage age remains that high," he told AFP. "Parents don't mind as long as it is temporary, as long as there is some kind of plan. Parents are usually quite happy to help out."