A new study has been published in the US which appears to suggest that children born in the twentieth century to parents who had a gay relationship have encountered more personal problems in adult life than those born to married, straight parents.

The population-based survey published in July’s Social Science Research is the largest of its kind, the University of Texas said, to feature children with gay parents in such a broad, probability-sampled population.

Of 3,000 adults now aged 18 to 39, “How Different are the Adult Children of Parents Who Have Same-Sex Relationships? Findings from the New Family Structures Study” examined 175 children with mothers who had had a gay relationship and 73 with fathers who had had a gay relationship.

Mark Regnerus, an associate professor of sociology at The University of Texas at Austin led the research said the size of the 3,000-strong sample was important.

He said: “Most conclusions about same-sex parenting have been drawn from small, convenience samples, not larger, random ones.

“The results of that approach have often led family scholars to conclude that there are no differences between children raised in same-sex households and those raised in other types of families. But those earlier studies have inadvertently masked real diversity among gay and lesbian parenting experiences in America.”

The study results appear to show that adults who were raised by a parent who reported having had a gay relationship went on to have different life experiences from those who were raised by married, straight parents, but the author says this is more likely to be a result of other factors associated with having a gay parent in the twentieth century.

69 percent of children of mothers who had had gay relationships said their family received public assistance at some point, compared with 17 percent from married, biological parents.

Just under 50 percent of children of intact biological families said they were employed full time at the time of the survey, compared with 26 percent of children of lesbian mothers.

Children whose mothers had reported gay relationships were more likely to be in therapy, more likely to have had an affair while married or cohabiting and more likely to have been sexually assaulted than those raised by straight, married parents.

Children of lesbian mothers were more likely to be cohabiting than those of straight, married parents.

But Dr Regnerus stressed the study did not show a causal link between having a gay parent and experiencing negative outcomes in later life, with instability more likely to have been the cause of such outcomes.

The study, he said, needed to be taken in its historical context, representing an “earlier generation” of children.

“This study may not reflect the experience of younger children growing up today in same-sex families, particularly because society has become more accepting of gay and lesbian families in the last decade,” he said.

“Nor does the study tell us that same-sex parents are necessarily bad parents. Rather, family forms that are associated with instability or nonbiological parents tend to pose risks for children as they age into adulthood.”

Analyses posted on the Box Turtle Bulletin website pointed out that the figures compared above are between straight, married parents and parents who had a gay relationship of any length, an “unequal footing”.

Concerns were raised, and acknowledged by Dr Regnerus, about implying that sexual orientation had any effect on parenting skills and using this in political debate, particularly about marriage rights for gay couples in the US.

In the same issue of Social Science Research, Cynthia Osborne, of the University of Texas LBJ School of Public Affairs pointed out: “Because the [group raised by a mother who had a gay relationship] is comprised of young adults who experienced multiple family forms and transitions, it is impossible to isolate the effects of living with a lesbian mother from experiencing divorce, remarriage, or living with a single parent.”

She added: “Importantly, one cannot clearly link having a lesbian mother (or gay father) with any of these [negative] outcomes. As stated earlier, the group is comprised of young adults who experienced multiple family structures, not only a same-sex parent household (indeed, some of the respondents never lived with the mother’s same-sex partner). It is quite possible, for example, that many or most of the negative outcomes result from the divorce of the young adult’s biological parents that preceded the mother’s same-sex relationship.”

Dr Regnerus agreed that instability in the lives of those who took part in the study was a more likely culprit for negative outcomes in adult life, noting that given the age of the participants, they were more likely to have been born into a straight relationship which broke down than they were to have been planned children of gay parents.

He said organisations might use these findings “to press a political program. And I concur that that is not what data come prepared to do […] Implying causation here—to parental sexual orientation or anything else, for that matter—is a bridge too far.”