The Biology (or Lack Thereof) of Gender

As a sci-fi author, I wrote a world of characters who disagree with each other about what gender is, but all think that our gender binary is illogical. This drives some real world cisgender people wild. “But isn’t dividing into men vs. women natural?” they argue. “Humans only have two reproductive roles. Defining gender based on who has a penis versus who has a vagina just makes sense!” (Pointing out the existence of intersex people makes a remarkably small dent in this logic. Instead, intersex people get shuffled off as a minor exception to an otherwise logical system grounded in the fundamental facts of reproductive biology.) Many trans activists and theorists have countered this argument far more eloquently than I. However, I would like to take a moment to respond to this argument purely from within the experience of a cisgender straight person. Even the cis people most wedded to conventional divisions of gender fail to take those professed beliefs seriously. From the standpoint of its own professed logic, the gender binary is incoherent.

Arguments about gender typically focus on kicking trans people out of their declared gender, but the logical issues are most easily seen if we turn our gaze instead to the cis people who are not kicked out. The rationale given for why dividing humanity into men and women is natural is an appeal to reproductive biology, yet a person’s actual reproductive abilities are irrelevant. At no point does someone going through her life as, for example, a cis woman encounter a specific physical act that she must be able to perform or else be kicked out of her gender. Although acts like childbearing and intercourse purport to be this, they are not. Cis women who never bear children—or who are unable to—don’t lose their pronoun. Nuns who are celibate their entire lives don’t either. Childlessness, bottle feeding, adoption, and celibacy are all allowed without endangering one’s right to be called “she.” 

For the purposes of assigning gender, we might as well be sculptures instead of reproducing organisms. Function is unimportant; what matters is form. We can see this most clearly in the contrast between the lack of concern with whether a childless person “claiming” to be a woman actually has a working uterus versus the obsession with whether a tall, deep-voiced woman has the “right” external genitalia. Neither of these is observable by casual acquaintances, neither is polite to ask a stranger about, and neither is relevant to anyone except an intimate partner (of which there are proportionally very few). Yet one of these is the subject of intense scrutiny, and one is something no one could care less about. What sensible reproduction-based system is more concerned with form than function? 

Furthermore, were gender actually to be based on reproductive role, it would make no sense to divide into two groups. For starters, the existence of intersex people should be enough to strike this down. Even if it is not, most of the animal kingdom, including humanity, cannot be coherently divided into fewer than three sexual/reproductive categories. At a bare minimum, there are those who bear children, those who sire children, and those who can do neither—especially youngsters prior to sexual maturity. Arguing that everyone who has a vulva has the same reproductive role is clearly false. Pre-pubescent and post-menopausal people have a completely different reproductive role than fertile people do. Creating a binary system requires ignoring the actual reproductive status of a vast swath of the population!

The variations on sexual roles in the animal kingdom don’t stop there, either. Many species, such as mandrills, also have a fourth sexual role: those who biologically could sire children but are not permitted to do so. Ants and bees have workers that remain infertile for their entire adult lives. Monomorphic species like earthworms have only one reproductive form, which produces both eggs and sperm. Other species, like clownfish, naturally change from sperm-producing to egg-producing during their lifetimes. The list goes on. Insisting that gender is a static concept assigned at birth makes no biological sense when the reproductive role of basically every animal on the planet (except aphids, which are born pregnant) shifts dramatically during its lifetime. There are even species who make those dramatic shifts multiple times a year by going into heat only during a particular season, a time-based variation on sexual/reproductive role for which we have no analog.

How can a gender system that purports to be based on reproductive specialization ignore the actual reproductive role of an organism? Take, for example, the futile attempt to assign gender to caterpillars. Caterpillars can’t reproduce and don’t have genitalia. Genetic analysis may be able to predict what reproductive role it will have after metamorphosis, but it takes a lot of straining to fit caterpillars into a gender binary. Even for those species that do have genitalia at birth, those genitalia are irrelevant to reproduction until sexual maturity. In fact, even when a species has highly sexually dimorphic adults, immature youngsters generally display a relatively homogeneous third physiology. This is certainly true in humans. Step back and watch a park some time. Pre-pubescent children are far more similar to each other in their hairlessness, short stature, and cognitive development than they are to their own adult forms. They are explicitly excluded from having a sexual role. The transformations that they will undergo during puberty are more than enough to qualify them as having changed gender. 

That is, they would be if the reputed “natural” division of gender was actually based on reproductive role. It’s not. If it were, wouldn’t the focus be on trying to kick people who can’t have children out of their gender instead of trying to shove intersex people into one? I am not advocating for this, mind you, just pointing out the illogic. And if gender is to be based on form rather than function there are a myriad of traits (including many related to reproduction) that could be used to slice categories instead. Slicing into two genders based on breast size would actually do a better job (though still not that great) of correctly identifying fertile child-bearers than slicing based on genitalia does. Or better yet, just let gender be a social role and stop worrying about trying to link it up with biology.

Perhaps the binary gender system would make more sense if we thought of it as a system for organizing sexual attraction instead of reproduction. After all, this is one of its major uses: helping straight, gay, and lesbian people sort out potential partners. But do we really need a pronoun-freighted, rigid identity in order to identify people we’re sexually compatible with? Somehow we manage to figure out all the other components of attraction easily enough: personality, reciprocated interest, specific physical traits, enjoyment of particular activities, etc. You’d think that people who can specify that they’re looking for a brunette between the ages of thirty and forty who enjoys long walks on the beach could still manage to describe the physical traits they’re attracted to even if the words “man” and “woman” were to disappear from our collective vocabulary. In fact, if such a thing magically happened, I suspect it would take less than a day for dating sites to add a section for “preferred physical features, check all that apply.” While that might seem marginally less convenient that saying, “I’m attracted to men,” it wouldn’t create that big a challenge. In fact, given how much additional refining people currently have to do, being prompted to put some more thought into it up front might save time swiping through lots and lots of people who may be men (or women) but are not actually attractive to the person looking. Most people have physical criteria beyond “all people of a particular gender,” after all. Alternatively, being prompted to think about what really matters might lead to not thoughtlessly overlooking the love of one’s life.

There definitely are people for whom a particular combination of physical features is extremely important. We see this today in gay and lesbian people who have gone through extreme agony at the hands of people who insist that they ought to be able to switch their attraction to people with the “right” genitalia if they just try hard enough. Some attraction patterns persist despite what is essentially torture. Especially given this context, it is important to acknowledge that arguing that the gender binary isn’t natural in no way implies that people have to change what characteristics they’re attracted to. Some people, if they were no longer expected to be attracted to only one gender, might discover that their preferences are broader than they thought. However, someone who is genuinely attracted only to people who have lots of muscles, a penis that looks a specific way, and a deep voice will continue to have that attraction pattern no matter how the labels for identities are sliced and diced. Certain social conventions might make describing particular attraction patterns easier or harder, but at the end of the day, it is always possible to simply describe in detail what one would like.

The thing is that when straight people sit down to actually describe the details of what they’re attracted to, straightness reveals itself to be a remarkably amorphous concept. What cis straight women mean when they talk about being attracted to, for example, a “man,” varies widely. If pressed, most would first specify interest in someone with a penis, but a woman can still be straight even if she’s attracted to a partner with a catastrophic groin injury or who is unable to have heterosexual intercourse. Beyond that, straight attraction ranges all over the map. Straight women have varying preferences for every other trait, from height to facial hair to dominance to emotional sensitivity to torso shape and so on. Which of these traits are important varies even more widely. When we try to break down what it means to be straight, there isn’t a common list of traits every straight women has to be attracted to, especially not if we cease to erase cis people with disabilities or who are elderly. Some patterns of attraction may be relatively common, but when we look at the messiness of reality, no pattern describes every straight relationship.

There are two sets of characteristics that purport to be what straight people are attracted to, namely the masculine and feminine beauty standards. However, if being straight meant being exclusively attracted to people who precisely meet those standards, there would be very few straight people in the world! Getting cis people to conform to them as much as we do takes billions of dollars and countless hours of effort. We routinely alter body shape and musculature, manipulate apparent breast size with clothing or surgery, speak deliberately higher or lower, apply cosmetics, and so on. We differentiate clothing, hair styles, names, mannerisms, and speech patterns all in an attempt to create greater dimorphism than naturally exists. And despite all that, most cis people still don’t even come close, especially not after a certain age. As a result, most everyone who is attracted to a real person is attracted to someone who doesn’t fit these narrow definitions… and no one cares. In fact, cis people can deviate from their assigned beauty standards more than many trans people do and still no one cares. The only sticking point for straightness is whether one’s partner possesses (or possessed in the past, depending on who’s asked) the same genital configuration as oneself. Hysterectomies don’t matter, reconstructive surgery after a groin injury doesn’t matter, and surgical alteration of genitalia via circumcision or female genital mutilation doesn’t matter. Similarly, some cis women grow coarse facial hair, and some cis men have prominent breasts or even lactate, but attraction to people with these traits can still be made to fit within the bounds of straightness. It’s only having matching genitalia (past or present, depending) that pushes an attraction beyond those bounds.

This is odd in and of itself; what possible rationale is there for putting so much emphasis on genitalia but not on reproductive ability or literally any other attraction related trait? But even more indicative that gender is not really about attraction is the way that the prospect of being attracted to someone who has or had matching genitalia terrifies cis straight people in a way that nothing else related to attraction does. It’s normal on dating sites for search results to return myriads of people who don’t match any number of our criteria for attraction. Cis straight people can consider with equanimity the idea of dating shorter people than they thought they preferred or people with different hair patterns or people who have a smaller bust, but heaven forbid that anyone might suggest considering someone who meets every single criterion on their list except for genitalia! Every other characteristic can get calm consideration and a swipe, but this has been known to cause panic. Furthermore, notice how cis straight people frequently demand to know (or at least to be able to impute) intimate details about a stranger’s genitalia within seconds of meeting them. This makes no sense from the perspective of attraction. Either you’re attracted to someone you just met or you’re not. If you are and it’s reciprocated, at some point later you might explore whether that attraction lasts through getting to know more about the person, but there’s no urgency to it, and discovering later incompatibility is normally no big deal. In contrast, discovering that someone’s gender, and especially genitalia, are different than expected is a Big Deal of a completely different magnitude.

So why is gender such a big deal for cis people? I can only comment on my English speaking corner of the United States, but one culprit for us would seem to be the pronoun structure of English. Unlike many world languages, a speaker must know which pronoun to use almost immediately in order to be able to talk intelligibly about a third person. This doesn’t explain why we base pronouns on genitalia, but it seems like an explanation for some of the urgency of knowing. The problem is that while this seems like an excuse, there are plenty of other social conventions that could easily deliver the needed information. Routinely including pronoun in introductions, for example, is hardly onerous and would be even less so if it were just the expected thing to do. Unlinking pronouns from genitals would not be difficult. 

Similarly, if gender were to suddenly magically disappear as a concept, the things that it is ostensibly needed for would adjust with hardly a hiccup: third person pronouns could be assigned in other ways (or discarded); dating sites and doctors’ offices could substitute “physical traits, select all” check boxes; and potential sexual partners could just, you know, ask each other about their bodies and preferences. We are a species that is perfectly capable of figuring out any number of complex things about our world. If the reason people insist that everyone who dresses/identifies a certain way must have a particular set of genitals is that they are unwilling to talk about bodies with a potential partner, the tail is seriously wagging the dog. Heaven forbid that potential sexual partners have to communicate. That might lead to asking for consent or something. 

I suspect that the reason that letting go of conventional concepts of gender makes many cis straight people so uncomfortable is that being straight is less a statement about who one is attracted to and more a statement about who one isn’t attracted to. Consciously or not, we know that being straight doesn’t mean being attracted to everyone of a particular gender, but it sure as hell means not being attracted to those people. Not even by accident. Not even in the privacy of one’s own head. Not even for a heartbeat during the instant of initial meeting. Based on many straight people’s reactions, screwing this up feels like an existential threat. 

Why? Because homophobia and transphobia insist that being attracted to someone with the wrong genitals (or any other deviation from gender norms) justifies violence. This is ultimately why gender is so hard to untangle. Gender is linked up to a system of social control, backed by violence, that permeates our entire society. If gender as a concept were to disappear, the things it is ostensibly used for would be fine, but systems of power and hierarchy would experience an earthquake. Transphobia and homophobia aren’t just about marginalizing LGBTQ+ people (though obviously the greatest harms are done to them); they function generally to police behavior, including the behavior of cis straight people. 

This is most apparent in the socialization of teens and pre-teens. Especially among cis straight boys, homophobia and transphobia are potent weapons used to force all boys to conform to particular patterns of masculinity. Paying attention to how cis straight boys treat each other makes it strikingly clear that cis straight boys practice on each other the weapons that are later used to devastating effect against cis straight girls and LGBTQ+ people. While LGBTQ+ youth get the worst of trans/homophobic bullying, being cis and straight, and being known to be, will not save a boy who shows too much care for other’s emotions, insufficiently objectifies girls, or fails to disdain “girly” activities. Cis straight boys use trans/homophobic language and concepts against each other in ways that make it clear that no one is automatically safe. On the contrary, staying safe requires making a devil’s bargain. Transphobia and homophobia will be weaponized to throw someone off the troika to the wolves, but you can protect yourself by ensuring that you’re not the person closest to the edge. 

Think about the impact that this has. Straight cis boys, like all other human beings, have a wide range of things they enjoy, ways of expressing themselves, and pro-social impulses. The overwhelming majority do not want to commit sexual assault, homophobic violence, or transphobic violence, nor do they want others to experience it. However, staying away from the edge of the troika is an overriding concern. What it takes to keep others between oneself and the edge varies from group to group, from simply not challenging objectification of girls to actively participating in beating up the “gay” kid, but the result is to enroll people in supporting gender-based violence who otherwise wouldn’t. Many of the interactions that teach bystanders to be the opposite of allies are very small and may only be vicarious, but the cumulative impact is massive. Without the fear of transphobia, it would be much harder to overcome the pro-social impulses of straight cis boys.

This is why cis feminists who turn on trans women are shooting themselves and their mission in the foot. Reinforcing transphobia reinforces one of the primary mechanisms that support violence against cis women. Imagine what would happen if transphobia didn’t exist. If it were no longer legitimate to harm people for transgressing the boundaries of their assigned gender, it would be dramatically harder to persuade cis boys to stay complicit in gender violence or to disdain things coded feminine. Furthermore, the tools available to constrain women’s behavior would be dramatically reduced. Much of misogyny, after all, is punishing women for failing to do what women are “supposed” to do. What would happen if a woman who encounters a glass ceiling at work, for example, could show up as a man and be accepted as such the next day? Obviously, the solution to sexism is not for everyone to switch, but the point is that without transphobia and homophobia, sexism becomes largely unenforceable. That’s the real root of why transphobia is so tough to get rid of. Without sexism, many patterns of power and privilege disintegrate.

Looking at gender as a tool for enforcing power structures helps explain why the gender binary is set up the way it is. Were children to be raised as a neutral third gender, for example, it would be much harder to persuade them as adults that one group was “naturally” fit for certain tasks and one for others. Convincing an entire society that these people deserve power and privilege and those people deserve marginalization and violence does require an all-hands-on-deck approach. If it weren’t for that goal, variations in reproductive biology wouldn’t be that big a deal. While it is the case that giving birth to a new human being is something only certain people with very specific biological equipment can do, the tasks that require physical specialization are of relatively short duration—nine months to about two years  (depending on decisions about breastfeeding) out of seven or eight decades of life. Parenthood, obviously, is a longer-term transformation of social role, but any reasonably competent adult or teen can learn to do childcare well. Once past breastfeeding/birth, caregivers are physically interchangeable. Economic structures that incentivize the parent who gave birth to then also cease paid labor are social in origin, not biologically natural.

  Ultimately, the gender binary is drawn so sharply and early—and defended so vigorously—precisely because it is neither natural nor particularly sensical. If it were actually a natural and inevitable outgrowth of human biology, it wouldn’t need to be defended; it would just be self-evident. Take blood type as a contrast. That is a natural biological division of humanity. Trying to draw those lines differently self-corrects as soon as one needs a blood transfusion. Gender, on the other hand, doesn’t self-correct; it has to be enforced. That should tell us something. There is a great deal riding on persuading everyone that the gender binary is natural and that any deviations from it ought to be swiftly and violently punished, but that doesn’t mean any of it is true. 

On the contrary, when we look at what enforcing the gender binary actually entails, it’s really awful. People afraid of being victimized turn around and dish out exactly the violence that they’re afraid of. This experience perpetrating transphobic violence, in turn, reinforces the fear that any violation of gender norms will be grounds for victimization. People become their own worst nightmare. 

It doesn’t have to be this way. If cis straight people can recognize where their fear is coming from, then it’s possible to stop the cycle. It’s not even necessary to agree with most of what I’ve written here. It’s only necessary to stop putting into the world that which one is afraid of. Nothing about being trans or being gay is an inherent threat to cis straight people. No one is going to tell us we can’t use our preferred pronoun or fire us for stating our spouse’s gender identity. The solution to being afraid of violence is to get rid of justifications for beating people up, not to act them out. 

After that, let the people with the most at stake have the greatest say in how things should be. When something is an academic debate for one person and life for someone else, sometimes human kindness looks like having the grace to not demand to be persuaded. It’s okay if someone’s self-definition of their gender doesn’t make sense to everyone they meet. It doesn’t have to. Call people by their preferred name and pronoun and let the universe be mysterious. Better yet, read the books and articles that have already been written and try to resolve dissonance that way. A bunch of what trans people are asking for is to just get to go through their day and not have to deal with crap all the time. Being the first person of an identity that someone has ever encountered isn’t so bad once in a while, but dealing with it multiple times every day is a recipe for burnout. Similarly, dealing with actively hostile people is an enormous emotional drain. Cis people, the most important thing isn’t actually our opinions or making things make sense to us. What’s most important is not hurting our fellow human beings.

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