Gay rights activist Zach Wahls has criticized a study claiming negative outcomes for the kids of gay parents.

The 20-year-old Wahls is the author of My Two Moms: Lessons of Love, Strength and What Makes a Family, in which he makes the case for his two-mom family.

The study by Mark Regnerus looked at the outcomes of 3,000 people, 248 of which had a mother or a father who at one time had a relationship with a person of the same gender. Only 2 of the subjects reported having parents in a gay relationship for their entire childhood. Regnerus told The Huffington Post that his study found “that the scholarly and popular consensus that there are no notable differences between the children who grew up with a mother or father in a same-sex relationship and those whose [heterosexual] mother and father were and are still married is fiction.”

(Related: Study claiming negative outcomes for kids of gay parents called “seriously flawed.”)

Appearing on cabler Current TV's Viewpoint, Wahls told host Eliot Spitzer that the study was a classic case of “confusing causation and correlation.”

“You have the author of this paper trying to make the case that there's somehow this, you know, result that happens when you have a gay parent. But if you look carefully, and Will's right on this, if you actually look at the fine print, he says, 'I don't have a causal link,'” Wahls said in reference to a article by William Saletan which argues that the study's promotion of a stable home environment makes the case for gay marriage.

“I think Will hit it right on the head. If these families had been able, from the beginning, to be in stable, loving, committed relationships, like my moms and so many other parents across the country have today, these numbers would be much, much closer to what we see be in line with other studies in the past that have actually been about the stable, committed families.” (The video is embedded in the right panel of this page. Visit our video library for more videos.)