In the debate over same-sex marriage, there is a genuine question about the welfare of children.

Strip away the emotion and the political correctness from the debate about same-sex marriage, if you can (it's baked on pretty thick). What you're left with is a pell-mell rush to alter drastically society's most fundamental institution, without anyone knowing what the consequences of that change would be.

You're also left with genuine questions about the welfare of children, which ought to be of paramount concern.

As the Washington Post noted this week, social science has scant data on the subject. That hasn't kept venerable institutions such as the American Psychological Association from declaring it settled science that there is no difference between biological parenting and same-sex parenting. Because of the emotion surrounding this issue, analysts risk their reputations if they merely examine such conclusions critically, which is a huge problem in and of itself. Any side in a debate that rejects critical thinking out of hand should be suspect.

Two social scientists who persist in studying the issue, nonetheless, are Leon Kass of the University of Chicago and Harvey Mansfield of Harvard. They have found the research so far, "… radically inconclusive."

The Weekly Standard quotes Loren Marks of Louisiana State University as having studied the American Psychological Association data and found it riddled with flaws.

The U.S. Supreme Court heard arguments this week in two same-sex marriage related cases. One option before the court is to strike down state constitutional provisions and statutes found in the vast majority of states that uphold the traditional concept of marriage as between a man and a woman.

Given how little we know about the full societal costs associated with altering the root of family life, we urge the court to uphold traditional marriage.

As Heritage Foundation fellow Ryan T. Anderson recently wrote, "Redefining marriage would further distance marriage from the needs of children and deny the importance of mothers and fathers. It would deny, as a matter of policy, the ideal that children need a mother and a father.

"Redefining marriage would also diminish the social pressures and incentives for husbands to remain with their wives and their biological children and for men and women to marry before having children. It would be very difficult for the law to send a message that fathers matter once it had redefined marriage to make fathers optional."

On the subject of fathers, by the way, social science is not ambiguous. Children raised in households headed by a single mother (the most common single-parent situation) face many disadvantages, often through no fault of the mother. It would be wrong to assume this is merely because the child needs just two people, of any gender, in a parental role. Fathers and mothers, men and women, provide unique role models and nurturing capabilities from which children develop into healthy, balanced adults.

During arguments this week, Justice Samuel Alito wondered aloud about the wisdom of rendering "a decision based on an assessment of the effects of this institution which is newer than cellphones or the Internet."

Unlike new modes of communication, however, the redefinition of marriage tinkers with the foundation of an age-old transcultural institution that has been remarkably robust at raising children. Marriage that is framed around biological parenting channels procreative passions that link parents together with the protection and nurture of children. That should not be a decision subject to emotion, one-sided demagoguery or opinion polling. The consequences at stake are far too great.