The shaky science behind same-sex marriage

Unlike the physical sciences, the social sciences can rarely settle questions using “controlled and replicable experiments.” Today “there neither are nor could possibly be any scientifically valid studies from which to predict the effects of a family structure that is so new and so rare.” Hence there can be no “scientific basis for constitutionalizing same-sex marriage.”

The brief does not argue against same-sex marriage as social policy, other than by counseling caution about altering foundational social institutions when guidance from social science is as yet impossible. The brief is a preemptive refutation of inappropriate invocations of spurious social science by supporters of same-sex marriage.

For example, a district court cited Michael Lamb, a specialist in child development, asserting that the “gender of a child’s parent is not a factor in a child’s adjustment” and that “having both a male and female parent does not increase the likelihood that a child will be well-adjusted.” The conservatives’ brief notes that, testifying in the trial court, Lamb “had conceded that his own published research concluded that growing up without fathers had significant negative effects on boys” and that considerable research indicates “that traditional opposite-sex biological parents appear in general to produce better outcomes for their children than other family structures do.”

The brief is replete with examples of misleading argumentation using data not drawn from studies satisfying “the scientific standard of comparing large random samples with appropriate control samples.” The late Sen. Daniel Patrick Moynihan, a distinguished social scientist, said the “pronounced” liberal orientation of the social sciences is “well established” and explainable: “Social scientists are frequently caught up in the politics which their work necessarily involves” because social science “attracts persons whose interests are in shaping the future.”

This helps explain why “Brandeis briefs” have shaped U.S. law. Before joining the Supreme Court, Louis Brandeis defended constitutional challenges to progressive legislation by using briefs stressing social science data, or what purported to be such, rather than legal arguments. He advanced his political agenda by bald assertions inexcusable even given the limited scientific knowledge of the time. For example, in his 1908 defense of an Oregon law restricting the number of hours women could work, he said “there is more water” in women’s than in men’s blood and women’s knees are constructed differently.