Debunking The ‘Complementarity’ Argument Against Marriage Equality

FRC Senior Vice President Rob Schwarzwalder
FRC Senior Vice President Rob Schwarzwalder

The Family Research Council has released a new policy analysis about “Complementarity in Marriage: What it is and Why it Matters.” In it, FRC Senior Vice President Rob Schwarzwalder reiterates several trite arguments against marriage equality, but also attempts to flesh out the argument that men and women are inherently different. This, he argues, is proof that marriage between a man and a woman is unique in such a way that it could never be extended to same-sex couples. After citing a variety of studies about how men and women’s brains function differently, Schwarzwalder concludes:

The Journal of Neuroscience and The American Journal of Psychiatry, among many other scholarly publications, are replete with studies about male-female distinctions. These distinctions are not grounded in culture or environment, but genetics.  These distinctions greatly benefit children. Little ones need a female mother and a male father to obtain the full dimensionality of what it means to be human. They benefit from, and are profoundly shaped by, experiencing the full range of differences between a woman and a man as their parents. “Decades of social science, including the latest studies using large samples and robust research methods, show that children tend to do best when raised by a mother and a father,” writes Ryan Anderson.

Schwarzwalder is drawing two big conclusions without any evidence. First, he is asserting that because men and women have some biological difference, those differences must be complimentary. Extrapolating from that, he then posits that children “need” exposure to these differences, because that’s what they would hypothetically receive if raised by their biological father and mother. But none of Schwarzwalder’s citations, which are mostly theologians or other conservative pundits biased against marriage equality, actually speak to such causation, if they even speak to correlation.


For example, as cited above, Ryan Anderson of the Heritage Foundation relies upon the flawed Mark Regnerus study, which did not study any children raised in intact households by married same-sex couples. Schwarzwalder also cites sociologist David Popenoe’s 1996 Life Without Father, which only examined the consequences of divorce, single parents, and stepfamilies — situations in which a heterosexual father was no longer involved in his children’s life. It drew no conclusions about same-sex parenting; in fact, studies about “fatherlessness” rarely include data about lesbian couples raising children together, but conservatives still use them to draw conclusions about same-sex parenting anyway.

Schwarzwalder’s narrow stereotypes ignore the broad diversity of gender expression among men and women, and of course erases transgender people entirely. FRC does not argue that straight people should not be allowed to marry or have children if they are particularly masculine women or feminine men, only that same-sex couples should be prohibited from the institution. If opponents of marriage equality truly valued complementarity, they would instead recognize that every study that has actually evaluated the parenting of same-sex couples has found that their commitment to each other and to the children they are raising together is what ensures success. Complementarity is not a defining characteristic of straight men and women, but perhaps the most obvious trait of all successful families, regardless of sex, gender, gender identity, or sexual orientation.