More people are living alone or with their parents
Almost a third of men and a fifth of women aged between 20 and 34 live at home with their parents, according to the Office for National Statistics.
The statisticians' annual survey on the state of the nation also found more people were living alone in the UK, up from 6% in 1971 to 12% in 2008.
The figures also suggest marriage is becoming increasingly unpopular.
In 2006, there were 237,000 marriages in England and Wales, the lowest number since 1895.
The Social Trends survey suggests people are getting married later in life and women are delaying motherhood, while grandparents are likely to be helping out with child care.
In the second quarter of 2008, 1.8 million young men and 1.1 million young women were still living with their parents, an overall increase of about 300,000 since 2001.
The Office for National Statistics (ONS) suggests this may be down to high property prices, unemployment and people choosing to continue their studies.
The average age to wed for the first time in the UK was nearly 30 for women in 2006 and about 32 for men. This is about two years later in life than a decade earlier.
The average age of women in England and Wales having their first baby was 27.5 in 2007 compared with just under 24 in 1971.
One trend that has been bucked is home ownership, according to the survey.
Over the quarter of a century up until 2006, the number of homeowners in the UK rose by 49% to 18.5 million. However, between 2006 and 2007, the number of homeowners fell by 1%.
The report also paints a picture of how social trends are affecting the next generation.
In England, 31% of households with dependent children are living in housing without adequate heating or facilities.
And in 2007, almost a third of all two-to 15-year-olds in England were said to be overweight or obese. This comes despite more children taking part in sport at school.
The report also outlined the nation's relationship with new technology, how people like to spend their free time and their travelling habits:
• Around half (49%) of all eight to 17-year-olds with internet access have a profile on a social networking site
• Ownership of a home computer has risen from 29% in 1998 to 70% in 2007
• Web use is higher among men than women but, overall, 34% listen to the radio or watch TV on the web and 12% use file-sharing sites
• Less than half (44%) of people in the UK read a national daily newspaper in 2008 compared with 72% in 1978
• Watching television remains the most popular pastime - named by more than 80% of men and women as their favourite way of spending their free time
• More British residents are making trips to eastern Europe. For example, about 50,000 visits were made to Latvia in 2007, compared to 4,000 four years earlier
• Spain accounted for 27% of the overseas trips made in 2007
• Package holidays made up more than half (52%) of all overseas holidays in 2002, but this figure fell to 41% in 2007
• People in Britain travelled 508 billion miles by road, rail and air in 2007, almost double the figure in 1971