Dozens of studies about kids raised by gay parents were mischaracterized for political reasons so as not to draw the ire of homosexual activists or encourage anti-gay rhetoric, a new report suggests.

The report, by sociology professors at the University of Southern California, says that that, contrary to earlier assertions, children of same-sex parents exhibit significant differences when compared to children raised by heterosexual couples.

The study's authors conclude that earlier researchers downplayed those differences when they found them — and this has stunted research that might further highlight and explain these differences.

"The pervasiveness of social prejudice and institutionalized discrimination against lesbians and gay men… exerts a powerful policing affect on the basic terms of psychological research and public discourse on the significance of parental sexual orientation," Judith Stacey and Timothy Biblarz write in a report in the American Sociological Review.

"It’s not that [researchers] are being dishonest," Stacey said in an interview. "But what we say is there are intriguing, provocative differences found in these studies."

Lots of Research, Much of it Flawed

For several years now, judges and lawmakers have relied on a growing body of research on same-sex parenting to make decisions in cases and legislation regarding custody battles and adoption. The numbers vary, but estimates of the number of gay parents in America is somewhere between 800,000 and 7 million, and the number of dependent children raised by homosexual parents is between 1 million and 9 million.

Until now, most studies have suggested there are no significant behavioral, psychological or sexual differences between children raised by gay parents and those in heterosexual households. The studies are often invoked to erase fears about the developmental health and well-being of children raised by gay parents.

But in their examination of 21 studies conducted between 1981 and 1998 on the affects of gay and lesbian parenting on child development, Stacey and Biblarz say this conventional wisdom is wrong and they "challenge the predominant claim that the sexual orientation of parents does not matter at all."

For example, one 1996 study concluded that "The majority of children who grew up in lesbian families identified themselves as heterosexual in adulthood."  Stacey and Biblarz say the finding is "technically accurate" but it "deflects analytic attention from the rather sizable differences in sexual atitudes and behaviors that the study actually reports."

Claiming that "few respectable scholars today oppose [same-sex] parenting," Stacey and Biblarz suggest that most scholars fear that highlighting the differences will be used by opponents of homosexual parenting and marriage to oppose gay adoption and gay marriage.

In reexamining the data from earlier studies, Stacey and Biblarz in fact found significant differences between gay-parented and hetero-parented children. Among them:

• A significantly greater proportion of young adult children raised by lesbian mothers than those raised by heterosexual mothers say they have experienced sexual intimacy with a partner of the same sex. They were not, however, statistically more likely to identify themselves as gay or lesbian.

• Young girls raised by lesbians are more likely to be sexually adventurous and active than their counterparts raised by heterosexual parents.  However the sons of lesbians exhibit "an opposite pattern" and are likely to be less adventurous and active than boys raised by heterosexual households.

• Lesbian mothers reported that their children behave in ways that do not conform to "sex-typed cultural norms." And the sons of lesbians are reportedly less likely to behave in traditionally masculine ways than those raised by heterosexual couples.

Stacey and Biblarz claim that "it is difficult to conceive of a credible theory of sexual development that would not expect the adult children of lesbigay parents to display somewhat higher incidence of homoerotic desire, behavior, and identity than children of heterosexual parents."

Researchers, they say, ought to be honest about their personal convictions and let the political chips fall where they may. Stacey and Biblarz admit in their own review that they believe in a "diverse" and "pluralistic" family structure that does not discriminate against same-sex households. Any differences found in research on children do not necessarily constitute "deficits," they say, and ought to be acknowledged and studied more thoroughly.

The 'Politicization' of Research

David Murray of the Washington-based Statistical Assessment Service and co-author of It Ain’t Necessarily So: How Media Make and Unmake the Scientific Picture of Reality, agrees that most of the research on homosexual parenting is politically contaminated. He blames it on a fear of "arousing the dog chained on the left side and arousing the cat chained on the right side" of the political spectrum.

"We have allowed the politicization of this issue to erode our capacity to see clearly and to effectively decide policy issues," Murray said.

"It’s all about the politicization of the academic community, the federal grant-giving community and news reporting on these issues — they’ve all failed to provide good information about these important issues of social change," he said.

As a result, he said, most of the research conducted until now tells us "squat" and only speaks to battling agendas. It has brought the public and the scientific community no closer to knowing the truth about such hot button issues, he said.

Rabbi Daniel Lapin, the President of the conservative public advocacy group Toward Tradition added that "flawed science is not new, right now it’s swirling around the controversial area of sexuality."

But he said that science ultimately may not be able to resolve the fundamental questions some people have about controversial issues, including gay parenting and gay marriage.

"We all have to acknowledge that when push comes to shove this is not an issue that is solved by science," he said.  "It will be decided, based on beliefs and convictions."