In debates over the legalization of same-sex marriage, the issue of child-raising often arises in rhetorical form, but a new study from Stanford recently added to the conversation with empirical research.

Stanford sociologist Michael Rosenfeld’s study published in August on same-sex families uses U.S. Census data to provide important information to a previously scarce body of research on the results of same-sex parenting. The study, which compared the rates at which children of same-sex couples repeated a grade with those of children of married heterosexual couples, showed that the two groups of children have essentially the same level of educational achievement.

Rosenfeld’s research helps address a pre-existing lack of evidence on the effects of same-sex parenting and infuses the argument in favor of gay marriage with further evidence.

“I recognized, in reading the literature on same-sex marriage and court decisions and reading the briefs in those court decisions, that there was a fundamental lack of empirical research on children raised by same-sex couples,” Rosenfeld said.

The research that did exist prior to Rosenfeld’s study was often derived from a narrow sampling size and lacked the representative legitimacy afforded by Rosenfeld’s use of the census. Opponents of gay marriage have often used that evidence in their arguments. Claims that the educational achievement of children of same-sex parents was comparable to those of married heterosexual couples could therefore be disputed by those opposing gay marriage or adoption on the basis of narrow sample sizes or unrepresentative data.

“The problem was that people who were opposed to same-sex marriage made the argument that all of the empirical literature on same-sex couples and their children didn’t amount to much because we didn’t have a real representative study… and how could we endorse this social change if we didn’t know what the ramifications would be?” Rosenfeld said.

“That was a big argument in the literature and I saw it as my job to see if I could find evidence in the census,” he said. “The census is the largest individual-level data set that we have, and it has a pretty good way of identifying same-sex couples and the children living with them, and it had never been used in this way. I took it upon myself… to see if it could be used in this way.”

It turns out it could be. Rosenfeld’s findings help to de-legitimize at least some of the claims against gay marriage and parenting. The study also serves as an example of the growing cooperation between the academia and activism and the ways in which scholarly research can significantly elucidate often complex and biased political debates.

“I thought that it might have an impact on some real issues that I care about, and I thought it would be nice if I could bring some evidence to this issue where people have been calling for data and have been unable to find it,” he said.

Rosenfeld also added that in issues such as this one, a dichotomous distinction between social science research and political activism may be incorrect or misleading.

“We live in a political world,” he said. “Anything that humans are involved in has a political dimension, so I’m definitely aware of the political dimension of it.”

“I probably wouldn’t have undertaken the research if I wasn’t in at least partly interested in the political events of the day,” he said.