This is important because sometimes Schumm would come across a passage of children of gay parents who said they were "adamant about not declaring their sexual orientation at all." These people would be labeled straight, even though the passage's implication was that they were gay.
Schumm concluded that children of lesbian parents identified themselves as gay 31 percent of the time; children of gay men had gay children 19 percent of the time, and children of a lesbian mother and gay father had at least one gay child 25 percent of the time.
Furthermore, when the study restricted the results so that they included only children in their 20s -- presumably after they'd been able to work out any adolescent confusion or experimentation -- 58 percent of the children of lesbians called themselves gay, and 33 percent of the children of gay men called themselves gay.(About 5 to 10 percent of the children of straight parents call themselves gay, Schumm says.)
Schumm next went macro, poring over an anthropological study of various cultures' acceptance of homosexuality. He found that when communities welcome gays and lesbians, "89 percent feature higher rates of homosexual behavior."
Finally, Schumm looked at the existing academic studies, the ones used to pillory Cameron's work. In all there are 26 such studies. Schumm ran the numbers from them and concluded that, surprisingly, 20 percent of the kids of gay parents were gay themselves. When children only 17 or older were included in the analysis, 28 percent were gay.
Abbie Goldberg is a psychology professor at Clark University, and the author of "Lesbian and Gay Parents and Their Children: Research on the Family Life Cycle," which this year won the Distinguished Book Award from the APA. She hasn't read Schumm's study, only seen the abstract. But she says, in general, that a meta-analysis of this nature relies on sample sizes that are often too small and may furthermore brim with participants whose perspective is firmly aligned with the LGBT community. In other words, they're aware of these sorts of studies and seek them out.
"The fundamental problem with this [type of meta-analysis] is such samples tend to be biased," Goldberg tells AOL News.
Schumm says he guarded against that by seeking out so many different works. And across all his data -- the 10 books he consulted, the anthropological study, the scientific articles -- he noticed how lesbians begat more lesbians. In Schumm's study, he quotes from the extant literature the stories of young women, describing how being gay was never frowned upon in their household, and so that "option" was available to them. That said, Schumm also finds evidence of gay mothers pushing their daughters, upset over a relationship with a man, to "try out women."
But couldn't gay men also tell their sons this? Yes, but Schumm tells AOL News that most gay men have at some point been with a woman, so they understand why their sons might date them. Whereas the literature shows some lesbians "have a hatred of men that's intense," Schumm says.
Schumm says it shouldn't have taken until 2010 to do the meta-analysis. Too often his colleagues impose "liberal or progressive political interpretations" on their studies, which inhibit further inquiry. "It's kind of sad," he tells AOL News.
As if expecting a political backlash himself, Schumm concludes his study with a quote from philosopher Arthur Schopenhauer. "All truth passes through three stages: First it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident."