By the time they reached the age of 33, a quarter of the women in the survey had been lone parents, and at the time of the survey 12 per cent of them were bringing up children alone.
But few had made a deliberate decision to do so, according to Dr Angela Dale, deputy director of the Social Science Research Unit at the City University, London, who led the research.
These single mothers were revealed to be hard-up, having lost their foothold on the job market, and faced every prospect of an impoverished old age dependent solely on state pensions.
They were trapped in a downward economic spiral in which the demands of bringing up a child single-handedly cut income. Lone mothers had jobs with lower hourly rates than anyone else. Those in full-time employment earned pounds 4.40 per hour on average, while married mothers took home pounds 5.40 and married fathers pounds 7.40.
The study of 11,500 men and women aged 33 in 1991 was part of a major piece of continuing research by the Economic and Social Research Council which has been following three groups, born in 1946, 1958 and 1970.
The latest element was released yesterday on the first day of the annual meeting of the British Association for the Advancement of Science at Keele University, Staffordshire. It indicated that the 'thirty-something' generation was in a mess, and that just when these men and women should have achieved stability in their lives they were in a state of flux.
All that the 33-year-old members of Margaret Thatcher's 'yuppie' generation had to show was a high proportion - 80 per cent - of home ownership. Professor Howard Newby, chairman of the ESRC, said the group viewed home as a haven.
The 33-year-olds were cynical and disillusioned with politics. The survey found: 'Four out of ten think politicians are in politics for their own benefit; and one in five feels that no matter who is in power, there is little direct benefit to them.'
Neither men nor women, the survey showed, had clear beliefs about their motivations, and one finding was that 'support for the work ethic was not overriding'. Fewer than half of them thought that having a job was better than being unemployed.
Ten per cent of those surveyed were cohabiting at the time of the survey; about a third who were living with their first spouse had cohabited with their partner before marriage and about 80 per cent had done so before subsequent marriages.
There was a substantial amount of step-parenting; 19 per cent of the women and 6 per cent of the men had a partner who was not the biological parent of children in the family.