The publishing of academic papers denying biological reality isn't slowing down; in fact, it's much worse.
This new one, titled Sex-Associated Variables: A Framework for Neurotoxicology, was just published in Neurotoxicology, a very serious academic journal.
The abstract says, "The phrase 'sex differences'" creates a, quote, "distinct binary," and that "this binary is reductive at best" because, according to them, "sex is a spectrum containing a mosaic of factors," "an amalgamation of contributing factors that are grouped together," and "a conglomeration of variables."
This is the same tired claim we've seen again and again, that males and females are not real and discrete biological categories but rather they exist on a spectrum of maleness and femaleness. The categories are continuous, or a mosaic, or a complicated collection of chromosomes, hormones, anatomy, behaviors, and other traits.
The problem with this argument is actually very simple. It's totally self-refuting and I'll explain why. You see, the authors want to break sex down into what they call Sex-Associated Variables or SAVs. These include morphological variables like breasts and facial hair and genitalia, genetic variables like chromosomes and the SRY gene, and then endocrine variables like testosterone and estrogen.
Now, there's nothing wrong with studying those variables, but the fact that these "sex-associated" variables aren't binary doesn't mean that sex itself isn't binary. It just means the two sexes differ in a lot of ways, and that many of those differences vary continuously, or they overlap. Everybody already knows this. Nobody thinks that sex differences in height, for instance, are binary, with all men being one height and all women being another, shorter height. We all understand that sex differences in height refer to group averages, and this is true for most sex differences.
So here's where the new paper totally collapses under its own logic. The authors spend the entire paper discussing what they call "sex-associated traits," so traits that are associated with being male or being female. They talk about male and female hormonal profiles, male and female sex chromosomes, male and female genital anatomy, and even sex differences in various non-human animal species.
But how do they know, how does anybody know, which traits are associated with males and which traits are associated with females? I want you to really think about that. You can't say that XY chromosomes are associated with being male unless you already know what a male is independently of XY chromosomes. Similarly, you can't say that breast development is associated with females unless you already know what a female is independently of having breasts. And you can't say that higher testosterone is associated with being male in humans unless the category male has already been defined independently of hormone levels.
And what is it that all these "sex-associated traits" are associated with? The answer is having the biological function to produce either sperm or ova. That's it.
This becomes especially obvious when the authors bring up male and female zebrafish in the paper because zebrafish don't have sex chromosomes like humans do, yet nobody is confused about whether zebrafish have males and females and which individuals are which. But why is that? Because male and female are not defined by sex chromosomes. They're not defined by SRY genes or hormone levels. They are defined by the type of gamete an organism has the biological function to produce. This is true across all species that reproduce by fusing an egg and sperm, including species with radically different sex determination systems, endocrine systems, and morphology.
The upstream mechanisms of sex determination vary widely in nature, and the downstream consequences of sex are also very diverse. But what makes an individual male or female does not vary. It's all about gametes.
The paper also uses a figure with a color scheme that's a little suspicious, to say the least, and makes me think that there might be some hidden agenda behind their arguments Maybe it's just a coincidence, but given that the paper repeatedly frames the sex binary as inadequate for transgender, non-binary, or gender-diverse people, individuals whose sex is in no way ambiguous, mind you, it certainly appears like the science is being made to serve a certain political narrative.
And that's, I think, where the real problem actually is. The authors are taking something true and important, the idea that doctors and researchers should pay attention to individual differences, and using it to smuggle in the false notion that males and females are merely social constructs arbitrarily overlaid on continuous variation.
But medicine already understands and accounts for individual variation. A doctor can know a patient's sex while also knowing that hormone levels can vary, that DSDs exist, and that not all men and women respond the same to drugs or toxicants.
The binary nature of sex does not erase or ignore any of this variation; it organizes it. And unfortunately, because this paper is published in a relatively high-impact journal, it will probably be cited over and over again by activists, advocacy groups, journalists, and even lawyers as evidence that science says sex is a spectrum; it's not.
For a deeper breakdown of all the ways that activists and activist academics try to distort the basic biological reality of the sexes, read my paper, Why There Are Exactly Two Sexes, in the journal Archives of Sexual Behavior. It walks through the common arguments that rely on chromosomes, DSDs, spectrum models, polythetic models, and even multilevel models and explains why every attempt to get around gametes ends up relying on them anyway.
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