No, Sex is not a Spectrum

 National Catholic Reporter had a recent piece in which the author tries to pull a big "but ACTUALLY!" on Pope Francis on the topic of what the pope called "gender ideology", and what might be more bluntly called transgender ideology. There's little new ground broken in their piece. The most notable thing about it is that it is so typical a recitation of the claim that modern understandings of biology show that sex is a spectrum not a binary, and that it then goes from there to urger the Church to reassess her understanding of sex in light of this modern biological "insight". However, the NCR piece is a useful jumping off point in that it's claims are so very typical of this line of argumentation, and so it's a good place to start from in showing how these claims simply do not follow.

To extract the piece's line of argument, here are the relevant milestones:

"I was trained to believe that it was. In my college philosophy classes, I was taught that there can only be two sexes, that gender identity was based exclusively in biological sex, and that the male/female distinction was not only about physical characteristics but also about immutable essences of "masculine" and "feminine," rooted in the unchanging mind of God, and informing all of nature.

...

So I began reading about how maleness, femaleness, sex and reproduction occur across different species and kingdoms in the natural world, and what I found was that the "truth" I had felt obligated to defend was a simplistic fantasy. The categories of male and female, as they exist in nature, are not an either/or, nor an absolute binary. Rather, they reside on a spectrum. Maleness and femaleness manifest in different ways depending on the species. It is difficult to pin down any set of conditions or characteristics we could point to as the sine qua non for identifying an organism as one or the other. Additionally, some species can change sexes. Others are hermaphrodites.

In the human species, male and female categories also exist on a spectrum. There is no singular cluster of necessary or sufficient conditions for male versus female identity. So sex organs can't be used as absolute determinants for gender identity. Chromosomes also won't work as determinants, because individuals can be chromosomally male or female while presenting characteristics typically associated with the opposite sex. Intersex people exist, and some researchers argue that intersex conditions are more common than once believed.

The gender binary I had long considered a way of categorizing all living beings was, I realized, more like a general taxonomical marker signaling a fluctuating set of characteristics on one side of a scale. As a kind of organizational shorthand, it is useful. But this does not mean that "male" and "female" are fixed and immutable metaphysical categories, or even fixed and immutable natural categories. What people refer to today as "gender ideology" is closer to accurately reflecting reality than the traditional binary view I grew up with.

The debate over gender is framed by traditionalist Christians as a struggle between "reality" and "ideology." But the church already has a preferred ideology of gender, which is complementarian, essentialist and committed to a rigid binary view of the entire natural world. The real debate is not over whether gender ideology is bad but over which ideology about gender aligns better with reality.

There's still a lot we don't understand about sex and gender, in the natural world and in humans. But a view of gender as existing on a spectrum and allowing for flux and change more closely corresponds to what we do know."

First off, it's important to note that this piece, performs a subtle change of terms part way through its argument.  First it claims that biological sex is itself a spectrum rather than a binary, saying that this is based in the findings of modern science about the natural world.  Then it introduces another topic which sounds similar but is in fact totally distinct and argues that therefore male and female "identity" are also on a spectrum, and that there is not "gender binary".

Let me start by talking about the question of whether science has broken down the biological sex binary.  Is that true?  No.

Consider how it is that organisms on earth reproduce. There are two models: sexual reproduction and asexual reproduction. 

In asexual reproduction, the animal is capable of splitting off (or being split external forces) into two distinct organisms with the same genetics aside from any copying errors from the process of the split. 

In sexual reproduction, an egg is fertilized by a sperm (to use the relevant terms in human reproduction) with the result that the genetics from both are combined to produce the new organism. 

Some organisms can reproduce both through sexual and asexual reproduction. An example many of us have practical experience with is plants which can both be reproduced through cuttings (which essentially produces a clone of the original plant) or through flowering and politization (one of the plant solutions to the problem human organisms solve with egg and sperm) which results in sexual reproduction and the combination of genetics from both parent plants.

However, although science fiction authors have imagined all kinds of complicated ways in which three or more sexes might exist in some imaginary biology, on earth we find these two basic means of reproduction, asexual and sexual, and sexual reproduction involves the combination of a small (male) sex cell and a large (female) sex cell to produce a single offspring which combines the genetics of the two.

Around this basic duality of sexual reproduction, there is a lot of variation between species. Some organisms can have individuals capable of producing either kind of cell (for example, plants that are self fertilizing) and some individual organisms can produce only one kind of reproductive cell at a time but can change which type they produce over the course of their lives. So while a clown fish or a copperhead snake may at one point in its life produce sperm and at another produce eggs, it always functions as one of the two sexes. There is not spectrum of sex on which they exist. Rather, they oscillate due to time and circumstances between the two binary points.

When we talk theologically and philosophically about how humans interact with sex, we are looking at how the human experience is shaped by the way this sexual reproduction binary is expressed in the human species.  And while there is wider variety in the animal and plant kingdoms, humans do not oscillate between the sexes. Not only does our reproduction follow the same sex binary as other species on Earth, but a given individual will be able to provide only one half of the that sex binary (or in some cases of sexual disability, none at all.)

I think it's useful to think about human sex in terms of what sex actually accomplishes in biology (reproduction) rather than in terms of other characteristics, because it helps us avoid the types of confusion that can spring up.  For instance, a Scientific American piece which the NCR piece links to attempts to obscure the nature of human sexuality with this opening example:

A 46-year-old pregnant woman had visited his clinic at the Royal Melbourne Hospital in Australia to hear the results of an amniocentesis test to screen her baby's chromosomes for abnormalities. The baby was fine—but follow-up tests had revealed something astonishing about the mother. Her body was built of cells from two individuals, probably from twin embryos that had merged in her own mother's womb. And there was more. One set of cells carried two X chromosomes, the complement that typically makes a person female; the other had an X and a Y. Halfway through her fifth decade and pregnant with her third child, the woman learned for the first time that a large part of her body was chromosomally male. “That's kind of science-fiction material for someone who just came in for an amniocentesis,” says James.

This is fascinating in terms of what can happen to a human being over her lifespan, but it's important to note that while the woman in question did carry some cells which had both X and Y chromosomes (and indeed, which had different DNA than her own, being the result of a second embryo which fused with her at a very early stage of development) she was still functioning completely normally as a human female in terms of reproduction.

Saying that human sexuality is a spectrum rather than a binary is somewhat like saying that the number of hands a human has is a spectrum. Yes, there are some human individuals who due to injuries or genetic defects have less than two hands, or perhaps even more than two, but these pretty clearly represent cases where the individual has some injury or disability. Indeed, if anything, in terms of sex the human organisms is even more rigid than in number of eyes or number of limbs. Each human either 1) produces sperm and has the ability to deliver it to a female, 2) has eggs and the ability to carry a pregnancy, or 3) is incapable of reproducing.  Thus, in the blunt terms of biological reality, there are three types of human: male, female, and evolutionary dead end.

And yet all of this is in fact a bit of a sideshow to the real argument. As I noted, the NCR piece slides from one argument to another which appears in some sense to be related but does not in fact follow.  It starts with trying to argue that modern biology has discovered that sex is not a binary but a spectrum, but then moves sideways and asserts that therefore gender identity is also fluid and a spectrum.

But does "gender identity" actually have anything to do with these questions of whether biological sex is on a spectrum?

It does not seem so. When someone claims that they are "gender non-binary" does the person they are consulting proceed to order up medical tests to see if he has some XX and some XY tissue in his body?  Do they check to see if he might have an extra sex chromosome? Do they, indeed, validate the claim with any sort of test of his biological sex?  No. Claims to be non-binary or trans-sexual all have to do with what sexual identity the person feels.

Treatments which are described as "gender affirming" do not successfully transform the patient into a functioning member of the other sex. Rather, they consist of to some degree simulating the appearing of the other sex, while sometimes destroying the person's ability to continue to function as their sex at birth. For instance, a male who seeks surgery and hormone treatment to make him into a female does not become capable of conceiving and bearing children. The treatments can reproduce some of the secondary sexual characteristics of a female, but he remains a male, though a mutilated one who may no longer be capable of fathering children.

Whether it is morally right for a person comport or even modify himself to assume the appearance of the other sex is a question worth pursuing (and the Church provides answers to the question, which the author of the NCR piece perhaps does not like.) But one thing we can say with certainty is that sex itself is not a spectrum, and that the attempt to make it look like a spectrum does not in fact further the argument for transgender identity or for gender reassignment.  Discussions of sexuality which attempt to portray sex as a spectrum rather than a binary are simply a smoke screen deployed to obscure the issues at play and then to slide sideways and assert wholly unrelated claims about gender identity which it not itself a question of biological sex.

Perhaps a more fruitful area of inquiry, and one which would indeed to be rooted in the biological realities which the NCR author purports to consider important, would be to interrogate our notions of gender identity and see to what extent they actually conform to the realities of being a human person who functions either as one sex or the other in the reproductive sphere (or suffers a sexual disability such that he or she is unable to reproduce.)  It may well be the case that much of what people describe as sexual identity does not necessarily relate to being a human with one set of sex organs or the other.

But on the core issue: yes, sex is binary and sex is complementarian. It will only achieve its function of reproduction through the combination of male and female sex cells (sperm and egg).  To claim otherwise is to break with biological reality.