When on March 26 the Supreme Court hears oral arguments about whether California’s ban on same-sex marriages violates the constitutional right to “equal protection of the laws,” these arguments will invoke the intersection of law and social science. The court should tread cautiously, if at all, on this dark and bloody ground.
The Obama administration says California’s law expresses “prejudice” that is “impermissible.” But same-sex marriage is a matter about which intelligent people reasonably disagree, partly because so little is known about its consequences.
When a federal judge asked the lawyer defending California’s ban what harm same-sex marriage would do to the state’s interests in “the procreation purpose” of heterosexual marriage, the lawyer said, “I don’t know.” This was mistakenly portrayed as a damaging admission. Both sides should acknowledge that, so far, no one can know.
A brief submitted to the U.S. Supreme Court concerning the California case by conservative professors Leon Kass and Harvey Mansfield and the Institute for Marriage and Public Policy warns that “the social and behavioral sciences have a long history of being shaped and driven by politics and ideology.” And research about, for example, the stability of same-sex marriages or child-rearing by same-sex couples is “radically inconclusive” because these are recent phenomena and they provide a small sample from which to conclude that these innovations will be benign.