Middle-class girls now in their late thirties whose parents split up were found to be half as likely to have gone to university as the daughters of stable marriages. At the same time 45 per cent of the middle-class girls were married before the age of 20, compared with 15.6 per cent of girls whose parents stayed married. The chances of carrying marriage break- up into another generation were already set, since the younger people marry, the more likely they are to divorce.
Middle-class boys had a quarter to a third less chance of getting to university, according to the study.
Martin Richards, director of the Centre for Family Research at Cambridge University, said children whose parents split up did less well at school, had more behaviour problems, cohabited, married and had children younger. In early adult life they were likely to be poorer, in worse jobs and have more psychological illness.
The work is based on a number of studies, including a continuing survey of 17,000 children born in a week of March 1958. In this group, 800 had parents who divorced by the time the children were 16 and they have formed the basis for much of Dr Richards's work.
"Divorce may be the best thing for some women but it is very seldom the best for the children. What is unique about divorce for a child is that a parent has chosen to leave," he said at the annual meeting of the British Psychological Society at the University of Warwick.''
"There is something special and specific about divorce as it affects children ... It is partly poverty, as income in divorced families tends to fall, and partly to do with self-esteem. If a father has left and is not supporting the home in the same way, the child sees it as a judgment on their self-worth. Low self-esteem is not good for school work.''
Dr Richards believes some of these effects could be lessened by easily available counselling: "If they talked more I'm sure it would help them." He criticised the recent Green Paper on divorce for not including specific practical help directed at the children. "There is nothing in it at all about child-counselling."
Nor was it ever too late to get help. "There is now very good evidence that events in the later lives of children of divorced parents can get into difficulties when they move into relations themselves and when they have their own children," Dr Richards said.
Asked if he could envisage a day when a child might take its parents to court to prevent them divorcing because of its possible effects on that child's life, he said it was a possibility.
He also pointed out that single parenthood by itself did not seem to disadvantage children in the same way. "It appears that it is the upheaval of divorce plus the associated drop in income which is crucial."
Mothers and fathers whose children were conceived by test tube baby technology are "better" parents than those who conceived their babies naturally.
Dr Rachel Cook of the City University, London, told the meeting that genetic ties were less important for family functioning than a strong desire to have children.
She compared 41 families where a child had been conceived by in vitro fertilisation, 45 where the child resulted from donor insemination, 43 where the child had been conceived naturally and 55 where the child had been adopted.
She found that the mothers who had IVF or donor insemination babies were warmer towards their child than those mothers who had conceived their baby naturally. Similarly, they were also more emotionally involved with their child.
Parents using either method of assisted reproduction showed more interaction with their children and were also more relaxed. Parents whose children were conceived naturally showed more stress.
There had been concerns about the new reproductive technologies, said Dr Cook, but the quality of parenting in such cases was "superior to that shown by the families with a naturally conceived child".
Susan Golombok, Professor of Psychology at City University, said that a separate study has shown that children of lesbian mothers are no more likely to be homosexual than others.
She has followed 25 young adults who grew up in lesbian families, and 21 raised by heterosexual single parents. While two girls of the lesbian mothers - but none from the other group - formed same-sex relationships, this was no greater than the reported incidence of homosexuality in the community. To think lesbian mothers perversely influenced their children "would be a mistake".