The Metaphysics of Sex

Not really about metaphysics. I just wanted a pretentious title that would get your attention. Did it work? Good.

tl;dr: Defining sex is actually a really thorny topic, and there is no single definition of it you can use that will exclude transsexuals from their sex without excluding some cisgender individuals.

What makes a man a man? What makes a woman a woman? As a species we seem geared toward this kind of essentialist categorization. Brushing it aside won't work then. Instead, it has to be addressed head on.

This isn't purely theoretical for me. As a transsexual woman, questions of the validity of my gender (at this point) and my sex (in the future) directly impact my life. It's something cisgender people can take for granted. They never have to justify themselves. But I do and that makes this acutely relevant.

So what makes someone a particular sex? It's often simplistically thought of as chromosomal: XX is female and XY is male. But this is mistaken. What's relevant isn't chromosomes but genes, primarily the SRY (Sex-determining Region Y-chromosome) gene. This can be turned off sometimes, resulting in cisgender women with XY karyotype. It can be erroneously transcribed to an X chromosome. And this isn't even getting into deviations from the simple XX and XY, such as X and XXY. So we can't use chromosomes as the basis or we'd insist that fertile women are really men.

What about genotype, then? Well, this gets fuzzy. The actual expression of the gene (phenotype) can change over time. Additionally, not all cells may have the same gene expression or even the same chromosomes. Some people are chimerical, meaning some cells have one set of genes and other cells have a different set of genes. A chimera may be both SRY+ and SRY-; they can also be a blend of, e.g., XX and XY. Furthermore, SRY and other genes aren't strictly binary - they can be expressed more or less strongly. This is one of many reasons Gerald Callahan says "we're all intersex" - no one absolutely, 100% expresses one sex's characteristics, even on the molecular level. There is always some variation from the ideal expression and forms of male and female. Defining sex in these terms requires some arbitrary cutoffs. Finally, there can be XY women, even fertile XY women, with normal male coding of all known sex-linked genes. So let's toss out genes because they're a muddled mess full of exceptions that's subject to change.

Well, what about hormones, then? (Incidentally, this is what determines the type of orgasms you have.) It turns out there are all manner of hormonal disorders that can cause high testosterone and/or low estrogen in women, or high estrogen and/or low testosterone in men. There are also adrenal disorders that affect sex expression. These are people you would likely identify as women or men, respectively, due to other factors. Like, where do the hormones come from?

Okay, so we have gonads to tell us. Or not. There are people born with no gonads or with both varieties. You can have men with an ovary on one side and a testicle on the other. You can have women who have no ovaries whatsoever. The sexual development of these people is going to be different, but do we just declare them to have no sex despite primary sex characteristics, i.e., genitals? And there are medical interventions, such as hormonal pills or injections, or in some cases surgery, that match their primary sex characteristics. (But is making this match primary sex characteristics any more 'corrective' than the same interventions to match neurological sex? See below.)

Genitals - that's the one everyone focuses on. It's what's used to assign sex at birth, without any regard for the other criteria. Well, to exclude transsexuals from consideration as their actual (target) sex requires a questionable assumption: that all that matters is the primary sex characteristics at birth, not currently. If you go with this assumption, you're in a very strange place ontologically, where nothing is dynamic, nothing changes - the categories are fixed and rigid and you're going full-on Plato. You're one step from arguing that everyone is still a newborn, since no change is allowed from whatever category it's been pigeonholed into. This isn't even getting into people whose genitals don't fit the binary dichotomy of male and female - they're both, in between or something else. (And boy howdy have those people been fucked over by simplistic, slipshod reasoning on this topic.)

There are other factors that can be used to identify sex. Secondary sex characteristics, like breasts or facial hair, or facial structure, are the markers we use in day to day life to identify the sex of the people we see. We also use social cues like hair and clothing, but those are ephemeral. But even these secondary characteristics run into problems, such as women with facial hair or men with gynecomastia. (Your bloghostess takes an antipsychotic that can cause men to grow milk-producing breasts as a side effect.)

Finally, there is neurological sex. Certain brain structures have different neuron densities in men and women. In some clusters of white matter, this difference is drastic. So you could, if you wanted to, define sex based on the brain, not the gonads or genitals. And what is more fundamentally "you" than your neurology? This is what determines your thoughts and feelings. It is who you are to you. As you might expect, then, in autopsy studies, transgender people have been found to neurologically be their identified sex, not their sex assigned at birth.

Basically, defining sex is a muddled mess of at least a half dozen factors. It's complicated. (Some would even argue it can't be reduced to a binary, that there are at least 5 sexes and possibly more.) And without some weird assumptions, no criteria listed above can exclude transsexuals without excluding plenty of cisgender people from their sex. Invalidating our sex requires you to invalidate the sex of people who you'd never think to do that to.

To review: Chromosomes can go either way (e.g., XY can be male or female). Genes can go either way. Hormones can go every which way. Gonads need not match genitals, or even exist. Secondary sex characteristics need not always agree. Genitals are the standard and can be surgically changed from one to another. And neurology need not agree with birth genitals.

None of this touches on gender, which is how people perceive themselves and how we actually interact with them in the world - how we address them, how we treat them, how we perceive them. It's the psycho-social counterpart to sex. And whatever the "psycho" is, one should strive to make the "social" match up. There's a reason the AP and most other style books dictate that a person is to be identified by their self-identified name and gender (e.g., her and she for someone who identifies as female, like Chelsea Manning). But defining and delineating gender is even messier than doing so with sex - for starters, you have to grapple with non-binary genders, while here I only briefly touched on non-binary sexes (intersexed people).