How binary is sex?
(Science Week, Day 6!)
I've skirted my comfort zone to favour biology in Science Week this year, and this will be this week's last biology-related post.
One of my own questions about biology was churned up by a social contention I'd encountered online recently: the idea that sex in humans, typically categorized simply as male and female, is actually a "spectrum."
I'm no biology expert, but I understand that mammals develop from a fertilized egg to an infant by systematic cell replication, that it's possible for such developments occasionally to manifest atypically, and that such developments might make it difficult to identify an infant as male or female. I've never been aware of knowing such a rare person, but I had supposed it might be appropriate to refer one as neither male nor female. But could such a person, in fact, be somehow, somewhere, between male and female?
The "spectrum" camp, now that I've spent some time studying the view, seems to suggest something more multi-dimensional than a spectrum: they list various indicators of sex, such as sexual organs, hormones, genes and chromosomes, and "secondary sex characteristics" (such as breasts and beards), as well as the aforementioned atypical developments. Because each of these can vary, they seem to propose, our traditional two-label system of classifying sex is inadequate to describe such ambiguity and complexity. On top of all that, some add, consider the variability of "gender" (defined in this sense as a person's sense of one's sex independent of their body, relative instead to social stereotypes – for which "man" and "women" are also among descriptors in use), and the landscape of sexes approaches resembling something more like a hyperspace lattice of possibilities than a two-position switch.
On considering that, the question that finally arose in my mind was: where did the idea of sex come from? What was it for?
That question is about biology. And while I knew, essentially, what I'd always meant by "man" and "woman," I hadn't been equipped with such inquisitional precision before considering that radical alternative. Even settings aside more downstream characteristics such as "gender," vocal pitch. and facial hair, had the idea of sex always been about chromosomes, specifically? Or genitalia, specifically? One and the other in some combination? Did one of those things map directly and reliably to the other?
The concept I was searching for was reproduction. It was obvious to a layperson like me that reproduction is one thing men and woman are capable of, but I hadn't put my finger on the idea that reproduction was the crux of the word "sex"'s meaningfulness.
At its broadest, reproduction means replication, or self-copying. All life on Earth can replicate, but single cells (unlike humans, clearly,) are capable of copying themselves in a one-to-one fashion, and there's more than one known method of this. That idea seems wondrous and mystical, and it should seem that way – it's the unique process known to have arisen only on this planet, in order for humans and other animals to come later. To learn more about life that can copy itself independently like that, what should you search for? Asexual reproduction.
Of course it's called that, because this kind of reproduction happens without two separate organisms needing to come together. The opposite – sexual reproduction – does require such a team. In some animal species, the members of this team can be just about any two members of it (another wondrous and almost alien-seeming arrangement). But of course, in contrast, you can be certain that every human you've met had one mother and one father. You can be certain that if their father had instead shared an intimate evening with another male, for example, reproduction would not have occurred.
That summarizes the answer I'd long circled, but finally pinpointed. Once biologists understood that life replicates, "asexual" and "sexual" became the terms to describe the two primary types of replication.
What implications does this have for the "spectrum" camp? Does it deny the reality of occasional atypical sexual development, or the idea that reproductive function needn't match perfectly with bodily build, or with facial hair, or that some people feel they "identify with" the opposite sex? No, not at all. But the terms "male" and "female" – and "man" and "woman" in the corresponding sense – simply aren't attempts to describe those characteristics. It's not that sex is a spectrum: it's that any number of human traits that may indeed be spectrum-like are not sex.
I try to keep Science Week posts brief and digestible, so I hope you'll forgive today's longer one. As I've further discovered this week, biology (even this narrower topic of reproduction alone) is vast and fascinating, deserving its countless chapters and volumes. But I wanted at least to explain my own answer to this seemingly simple question followably.
I also link one thing per day, so I've selected a recent article from Richard Dawkins, who addresses the "social issue" side of the question more directly. More topically, though, he contrasts non-spectral sex with the truly spectral quality of skin tone, and as more than a bonus, goes into some detail about why that should be. I'd recommend reading the whole thing, but I probably needn't – the first paragraph is temptation enough to wade further.
(Oh, and if anyone with expertise reads this and would like to correct me on anything, please do.)