You can tell when a news story is big, because even I will have heard about it–I who rarely spend more than ten minutes a day on news, and usually much less. But even I heard about the Catholic church’s publication, “Male and Female Created He Them,” which respectfully asserts the Catholic position on gender identify–that one’s biological sex should be the same as one’s gender identify, and that men and women were designed by God to complement each other, among other things. It also calls for dialogue about the issues while calling upon Catholic parents and educators to respectfully give their witness regarding these matters. Its publication during Pride Month predictably sparked a subdued outrage among the major news outlets, who (so far as I have seen) failed to report its arguments for why the notion of choosing your own gender is harmful for children and society, and dwelt instead on the supposed harm this non-revolutionary doctrinal statement will cause to Catholic persons dealing with gender identity issues.

I recently posted a blog article setting forth eight different non-religious arguments that honest people have found persuasive in favor of heteronormativity. My purpose was not to persuade anybody that traditional sexual mores are correct, but that there are valid arguments in favor of heteronormativity that good people might accept, and that those who (like me) stand by the traditional mores regarding homosexuality are therefore not necessarily bigotted. I explained that I used only non-religious arguments not because religious arguments are invalid, but because they are not publicly accessible.

The Catholic church’s publication reminded me that I missed one of the major non-religious arguments that people have found persuasive in favor of heteronormativity–namely, the complementarity of men and women. Obviously, the Catholic church has a religious basis for believing that men and women were created to complement each other. But (as the publication indicates) there are plenty of publicly accessible, non-religious bases for this belief as well.

Evolutionary theory is one such basis–though, unsurprisingly, it was not mentioned in the Catholic publication. My understanding of the theory is as follows. Men and women evolved in tribal societies to perform differing roles. Men, more strong and more expendable, were the warriors and hunters. Women’s survival and presence in the village was more necessary for the successful bearing and rearing of offspring (who are always the crux of evolutionary theories). Thus, they were the gatherers, cooks, and makers of clothes, baskets, etc. The fundamental biological differences between men and women marked them out for these differing roles, and then the process of evolution fitted them for these roles. Men adapted to their roles by, e.g., developing a greater inclination towards aggression, focus, risk, and teamwork within hierarchy. Women adapted to their roles by, e.g., developing a greater ability to multitask and a greater attunement towards the intricacies of social relations within a village-sized population.

So men and women are different, based (according to the theory) on biology and evolution. The next step is to assert that the differences still complement each other, and that the pairing of men and women still benefits everybody now that technology and history have removed us a great distance from the primitive village context. Evolutionary theory points to at least one very obvious and even indisputable way (reproduction) in which the genders are still complementary. But I think, and perhaps most people agree, that there are many other ways in which, at their best, men and women cross-fertilize, challenge, and call out the best in each other based in part on their gender differences. For one thing, the “village” (whether local or international) still needs protecting and nurturing, and men are still arguably better fitted for the protecting role, while the women are still (clearly in my opinion) generally better suited for the nurturing role, at least when it pertains to small children. (For one thing, breast milk is still the healthiest nourishment for at least the first full year of a child’s life.)

Obviously I write not as an expert. I am not competent to judge the strength of the evidence behind this theory or its modern-day application. Very few people are. Your feminist friend may not like it, but that is no argument. And I have watched the nature channel enough to opine that there is a similar division of labor among very many mammal species. That is not conclusive, but it is at least valid evidence, unlike someone’s emotional response to the theory.

What I can attest to from my own experience and observation (and research also bears this out) is that mothers and fathers play different roles in child development, especially during the first years. There is no precise delineation of roles that fits each mother/father pair, but is it for good, reality-based reasons that the word “mother” has different associations and a different feel from “father.” Children benefit from having role models, nurturers, loving figures, and ideally parents, of both genders.

There are no doubt many other arguments in favor of gender complementarity, just as there are certainly arguments against it. The main argument against it that I have heard is that men and women are much more similar than different. I agree, but this does not undermine the theory of gender complementarity. The differences may not be as many as the similarities, but they exist and have significance. I know for a fact that many who argue about gender complementarity (on both sides) do so for fundamentally ideological or emotional reasons. But both sides no doubt have plenty of evidence-based arguments available.

Be that as it may, the foregoing arguments in favor of gender complementarity seem to me very persuasive. I, for one, believe in gender complementarity. It seems to fit my experience vastly better than the opposite theory. I know that I am complemented and fulfilled in my own life, both as an individual and as a parent, by my wife–though this is not to say that our differences (including differences typically associated with our respective genders) do not also sometimes result in exasperation. But my beliefs are not really the point here, and I freely admit that I (in common with almost everybody else who has strong opinions on the matter) have not made a serious and prolonged study of the actual evidence.

Bottom line: without purporting to have proven the truth of gender complementarity, I hope I have established that it is valid to believe in it. And to the degree that the genders complement each other, such complementarity is an argument in favor of heteronormativity–which, after all, could be described as the view that men and women belong together in marriage.