In an amicus brief filed this week, the American Sociological Association (ASA) argues that gay couples make fine parents.

The ASA's brief is among the dozens filed in two cases challenging the constitutionality of voter-approved amendments in Utah and Oklahoma which limit marriage to heterosexual couples.

The bans were declared invalid in separate cases but both have been appealed to the 10th Circuit Court of Appeals in Denver, which has scheduled hearings on the cases in April.

Founded in 1905, the ASA claims 13,000 members, including most sociologists holding doctoral degrees from accredited universities.

“[T]he claim that same-sex parents produce less positive child outcomes – either because such families lack both a male and female parent, or because both parents are not the biological parents of their children – is contradicted by abundant social science research,” the group's brief states.

“The social science consensus is clear: children raised by same-sex parents fare just as well by different-sex parents. Numerous nationally representative, credible, and methodologically sound social science studies form the basis of this consensus. These studies reveal that children raised by same-sex parents fare just as well as children raised by different-sex parents across a wide spectrum of measures of child wellbeing: academic performance, cognitive development, social development, psychological health, early sexual activity and substance abuse.”

In a press release announcing the brief, ASA Executive Officer Sally T. Hillsman criticized the claims made by Mark Regnerus, a sociologist at the University of Texas at Austin. Regnerus concluded in a 2012 study funded by a conservative think tank that children are negatively affected by having gay parents.

“As I have stated before – and as I will continue to state – the Regnerus papers and other sources gay marriage opponents often rely on provide no basis for their arguments because this research does not directly examine the well-being of children raised by same-sex parents,” Hillsman said. “Therefore, these analyses do not undermine the social science research consensus and do not establish a legitimate basis for gay marriage bans.”

Regnerus on Monday testified as a witness for the state of Michigan in a similar case. He said that because the research is inconclusive “it's prudent for the state to retain its definition of marriage to one man, one woman.”

(Related: Michigan defense of gay marriage ban stumbles out the gate.)

The cases could lift prohibitions in five states overseen by the 10th Circuit, including Kansas, Oklahoma, Utah, Colorado and Wyoming. Colorado currently recognizes gay couples with civil unions. New Mexico, which is also under the court's jurisdiction, legalized such unions last year.

(Read the ASA's brief.)