It's because of this broad consensus that the "no-difference" finding has gained increasing acceptance from the courts. In its 2014 decision in the same-sex marriage case, DeBoer v. Snyder, the Sixth Circuit Court of Appeals dismissed out of hand three social-science studies presented by expert witnesses as evidence that children of same-sex parents face heightened risks. Even in her dissent to the ruling, Judge Martha Craig Daughtrey pointed out that, "with the admitted biases and methodological shortcomings prevalent in the studies performed by the defendant’s experts, the district court found those witnesses 'largely unbelievable' and not credible." And in 2013, the American Sociological Association filed a brief in the Supreme Court case United States v. Windsor, pushing back against claims made by the defense that "same-sex parents produce less positive child outcomes than opposite-sex parents—either because such families lack both a male and female parent or because both parents are not the biological parents of their children." This argument, the brief said, "contradicts abundant social science research."
As the Supreme Court considers the question of same-sex marriage, it's unclear that child welfare will even play any substantial role in its ruling. As Judge Jeffrey Sutton wrote in his opinion in the Sixth Circuit case, "Over time, marriage has come to serve another value—to solemnize relationships characterized by love, affection, and commitment. Gay couples, no less than straight couples, are capable of sharing such relationships."
In an email, Sullins wrote that he hopes his research will help shape the same-sex marriage debate. "We define it as a question about marriage, but it is really a question about families. Same-sex persons say they have certain rights regarding marriage not involving a person of the opposite sex (and who am I to judge?)," he wrote in apparent reference to Pope Francis's now-infamous 2013 remark on homosexuality. (Sullins is a Catholic priest and professor at Catholic University.)
"But don't children have rights too?" he continued. "Is it justice to solemnize as marriage a social arrangement that says to every biological (i.e., non-adopted) child involved, you can never have the love and care of both your mother and your father?"
Justice: This is an important tell. At times, social science may be used in the service of justice, influencing the decisions of lawmakers or judges or everyday citizens. But this is problematic when the veneer of science is used to disguise an argument for a deeply help moral or religious belief. By design, social-scientific research is meant to be transparent, testable, and reproducible at every step; but in reality, regular people don't necessarily have the skills or interest or time to engage in that kind of process. Instead, as the large audience for the Witherspoon Institute's post shows, people may be drawn to articles that confirm what they already think.
"This is part of the nature of politics and science in the public realm," said Rosenfeld in an interview. "Science competes with all sorts of other pseudoscience." It also competes with arguments based on religious and moral beliefs, as it should; but when those beliefs come packaged as data-based findings, that's a problem.