The expression comes up in every social justice-flavored discussion of gender norms, roles and sexuality. These aren’t topics I ordinarily write about, but the thinking or speaking on them seems a bit muddled in the discourse and a critical glance might be helpful.
How do people reason about gender?
It is often claimed¹ ² that people possessed of regressive views and maybe sexist slant conceive of gender as a rigid binary of manly men and womanly women (with attendant heterocity) and nary shall lay in between. Thus, they may find assertiveness in a woman or tears from a man inappropriate. Even the more moderate individuals might (consciously or non) expect stereotypical traits and behaviors of people and double-take in their violation. There are sexist and backward attitudes, and many people do hold to stereotypical views. However, this is not logically described as adhering to a “binary” view.
When things are binary, like the 0’s and 1’s in computer-ese, that thing has only one of two possible values. 0 or 1. There is no other possible description, nothing in between, no intermediates. A person who conceived of humans according to a gender binary would be precluded from sexism as described above because every person could only be recognized as definitely man or woman. “Sort of man” would be undefined and incoherent, like asking a computer to understand 0’s, 1’s and “0-ish”. Human psychological traits are usually analog. There is a range of possible degrees and values. One color can be redder than another, but a zero can’t be one-r than other zeros. People actually construe gender not as a binary, but as a conceptual polarity.
Genders, how do they work?
People think of gender more like magnets. There are two poles, not one, or three or twenty, but your compass needle might be slightly more north-facing than someone else’s. Now you may say A ha! but the gender polarity is the problem. People should not subscribe to this wrong-headed idea! But that isn’t right either; gender really does seem to be a polarity in humans, and in any case, is not the basis of the social problems of discrimination and injustice.
Why do genders exist?
Our species has two gametic sexes. Some of us make eggs, some make sperm. Sex is different from gender, but to tell the gender story we have to start with the sexes. It is no foregone conclusion why sexual reproduction evolved, but the best ideas so far are that it affords resistance against pathogens and parasites by shuffling our immuno-locks and keys each generation. It also affords some protection against harmful mutations and recessive traits because you have two copies of every gene. The first sexually reproducing organisms had a big problem: mitochondrial baggage. Mitochondria produce the molecules that power most cellular activity, but they are also like cells themselves with their own DNA and double-membrane. When two cells procreatively merge and both bring mitochondria, each mitochondrial team will, via natural selection, compete against the other. After all, they have DNA and reproduce.
This is a big problem because no self-respecting cell has its own organelles duking it out, like one lung fighting the other. The solution was simple: unilateral disarmament. One parent’s gamete did away with its mitochondria while the other retained them. The former were therefore cheaper to produce and smaller. The parent producing them was, therefore, investing less per gamete than the other. Unequal minimum investment in offspring means there variance in strategies for evolutionary success, necessitating matching variance in behaviors. The sexes and eventually, the foundation of genders resulted from this ancient happenstance. For a biologist, “male” ordinarily is defined as the contributor of the smaller of the gametes and female as the large. In many species, there is no other way to decide about sex.
As Robert Trivers spelled out in his Parental Investment Theory, investment does not end with the production of gametes but can also include incubation, protecting, rearing, feeding, and teaching. Gendered behaviors do not then flow merely from gamete size, but from typical relative investment in offspring. So it is that females can be aggressive, dominant, and promiscuous and males can be choosy and reserved (when their minimal investment is higher than females). Animals have proto-gender roles that follow from the economics of their mating system and ecology. Although human sexuality is unique in its complexity and arguably, its evolved purposes, Homo sapiens is no less beholden to realities of mating economics and ecology. Even if we were, our ancestors certainly were not.
That fact by itself doesn’t prove much about human biopsychological sex differences. One can find mammals in which offspring investment is similar enough that both physical and behavioral sexual dimorphism is relatively low (see prairie voles and gibbons). There’s nothing about evolution per se that insists humans should be more like harem-holding silverback gorillas than monogamous gibbons or for that matter, pregnancy-prone male Sea Horses. Each species owes whatever disposition it has to its history, and so do we.
Humans have two sexes and can be described as having two polar genders. Now here one may interject, what about intersex, trans or asexual people? I say, what of them? The features they possess all fall on ordinary ranges of behavior and dispositions. The representational flaw here is not that gender is binary, but that minds are unitary. Consider physical sex differences that nobody questions are statistically true about male and female humans: size, upper body strength, genitals, breasts, facial hair, fat distribution, etc.., But these each vary across individuals. Some men don’t grow facial hair, or have female-typical height. Therefore, none of these (polar) features alone can establish your physical sex, even in the eyes of the most regressive sexist. Rather, stereotypical physical male or femaleness is a statistical lean one way or the other across many individual traits.
Our psychology seems to be similar. We’re collections of traits that can vary independently of each other, even if statistically they tend to lean together one way or another and we label those leans masculine and feminine. People not apparently conforming to these leans are not some new gender with qualitatively different features because each trait still falls on the same range of values as everyone else, it just doesn’t match the socially expected collective lean direction. They might be statistically unusual, but the unusual has to happen quite a lot because there’s 7,300 million of us.
The real problem isn’t how many genders we have or what we think those genders ought to be— we really do agree there are many races (and subdivisions of races) without this preventing people from hating one or more of them. And like racism, the trouble lies in folks cordoning off the fat part of a bell curve and deciding anyone outside of it doesn’t get respect, consideration, or human decency. We’re unlikely to correct such bigotry by denying facts about psychology or legislating social norms with contrived, incoherent vocabulary. My opinion is that, instead, we face it directly and simply: human beings who can think, suffer, strive, and love all deserve the same regard, the same dignity, and the same consideration regardless of the uniqueness of their personal constellation of features or its remoteness from anyone’s expectations. It makes no difference whatsoever what humans are like in aggregate.
In the bargain we may dispense with unhelpful bickering about nature and nurture and how many gender categories and what to call them. The simple moral observation above makes these considerations needless in a discussion about rights and dignity.