The folks over at Science-Based Medicine (SBM) have decided that the hill they’ll defend (if not die on) is that sex in humans is a continuous trait, though there might be modes at “male” and “female”. This of course flies in the face of biology, which argues that there are only two sexes in vertebrates: i.e., sex is binary). While there is a low percentage of people (and presumably animals) having “disorders of sex development”, these individuals are not “third sexes” or “new sexes”, but simply those in which the developmental system has gone awry, and they are either sterile or produce sperm or eggs (but not both in a functional way).
I believe the denial of the sex binary is motivated by ideology—to show people who don’t adhere to a “male” or “female” identity that that’s is okay because there are different sexes in nature, too. If you think about that argument, though, you’ll find that it’s not only fallacious but also pretty irrational. Nevertheless, Steven Novella makes it in this article from last year. I’m writing a bit about it because only recently has the second of two rebuttals of Novella’s piece appeared (see below).
You may remember that a while back SBM removed from its website Harriet Hall’s positive review of Abigail Shrier’s book Irreversible Damage, a book that argued against a rush to “affirmative care” for gender dysphoric youth and also speculated that the rise in transgender youth (mainly girls claiming a male identity) could be partly attributed to social contagion. That rubbed Novella & Co. the wrong way, so they removed Hall’s piece and explained why. You can read about that here and here; Jesse Singal also criticized the SBM take on Hall (see links)
Click below to read Novella’s article from last year.
Novella gets it wrong right at the outset (below); no, the notion that sex isn’t binary is controversial, and not held by any biologist I know, though some of the “progressive” stripe have claimed this. But even their arguments rest on the same fallacies as Novella’s:
The notion that sex is not strictly binary is not even scientifically controversial. Among experts it is a given, an unavoidable conclusion derived from actually understanding the biology of sex. It is more accurate to describe biological sex in humans as bimodal, but not strictly binary. Bimodal means that there are essentially two dimensions to the continuum of biological sex. In order for sex to be binary there would need to be two non-overlapping and unambiguous ends to that continuum, but there clearly isn’t. There is every conceivable type of overlap in the middle – hence bimodal, but not binary.
And here is one of the big problems of Novella’s take: he wants to take sex as a multifarious but nebulous and undefined combination of many traits: gamete type, genitalia, chromosomes, and even stuff like gender identity, gender expression, and sexual orientation! No wonder that the bimodality of sex (based on whether you have small mobile gametes–sperm–or large immobile ones–eggs–) becomes confused. Here are a few quotes from Novella’s piece:
. . . .First we need to consider all the traits relevant to sex that vary along this bimodal distribution. The language and concepts for these traits have been evolving too, but here is a current generally accepted scheme for organizing these traits:
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Genetic sex
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Morphological sex, which includes reproductive organs, external genitalia, gametes and secondary morphological sexual characteristics (sometimes these and genetic sex are referred to collectively as biological sex, but this is problematic for reasons I will go over)
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Sexual orientation (sexual attraction)
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Gender identity (how one understands and feels about their own gender)
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Gender expression (how one expresses their gender to the world)
. . . This is another concept that many people get caught up on, thinking in evolutionarily simplistic ways. The argument often goes that “sex is only about reproduction”, and since gametes are binary, sex in total is binary. This is incredibly reductionist, and misses the fact that traits often simultaneously serve multiple evolutionary ends. Sex, for example, is also about bonding, social relationships, power, and dominance. Think about this – what percentage of the time that humans have sex is the express purpose reproduction? How many people have no desire to ever have children, but still have an active sex life? Can there be romance without sex? Why are there so many aspects of sex that are not strictly reproductive?
We’re talking about gamete types, but Novella drags in bonding, parental care, and other traits—traits that ultimately flow from a difference in gamete types but are not definers of sex themselves.
And why is “reductionist” always used as a pejorative word? In fact, sex is reductionist, because evolution has worked on the gametes themselves to turn them down two pathsways–and only two pathsways, and from that everything else flows, including sexual dimorphism in appearance and behavior, difference in parental attentiveness, hairness and other secondary sexual traits, and so on. Male vs. femaleness can rest on chromosomal constitution, rearing temperature, environment, the sex of others around you, and other factors, but it in the end it always results—in all animals—in just two outcomes: individuals with the reproductive equipment to produce eggs, or the equipment to produce sperm. We know why, too: evolution will take a system beginning with all gametes the same (isogamous) and turn it into a system into which there are two, and only two, types of gametes. The two-gamete system (“gonochorism”) is then stable against the evolutionary invasion of new sexes. That’s why there are just two sexes. All vascular plants, too, produce sperm and eggs, and more often than animals in fertile hermaphrodites, but you won’t see botanists claiming that plants have three sexes.
The website Quackometer has published two critiques of Novella’s misguided take in a pair of articles called “The muddling of the American Mind” part I and part II. They’re both by Andy Lewis; the first appeared of July of 2022 but the second just came out: on March 22 of this year. They’re not too long and can be read as a pair. Together they totally demolish Novella’s claim that sex is bimodal, showing that Novella really doesn’t understand the biology of sex (he even relies on Anne Fausto-Sterling’s ancient claim that there are five sexes in humans with the “new” three comprising 2% of the population—a claim that Fausto-Sterling herself later repudiated).
I’ll give just a few quotes from Lewis, but, as always, I urge you to read Novella’s claims, Lewis’s rebuttals, and decide for yourself. (I’m clearly in Lewis’s camp).
Steven Novella rejects idea that sex is “binary” and claims that is it ‘not even controversial’ that sex is “bimodal”. In doing so, he is saying that we can characterise an organism’s sex, not by a discrete classification, but by some degree along a continuum of maleness or femaleness. There is in essence no such thing as 100% male or female, but all organisms are some sort of amalgam of features and function from both ideals. It is though quite difficult to understand quite what Novella means by “bimodal” as his explanation is, at best , somewhat vague.
The killer:
The claim sex is bimodal suggests we can make a measurement on an individual and use that to plot them along a distribution. The most basic question you can ask about a bimodal distribution is “what is the measurement you are taking that leads to this bimodal distribution”? We are not told this in Novella’s blog. At least, not one that defines “sex”. If you are going to claim “sex is bimodal” you need to say what measurement characterises sex. No-one ever has.
About Novella’s conflation of sex dimorphism (the different appearance of males and females) with sex itself:
Perfect dimorphism is rare though in any given feature. There are very tall women (I have worked a lot in the Netherlands). There are males with small hands. But being a small handed male does not make you a lesser male on some sort of spectrum. A male is a male regardless of the size of your things. Morphological variation does not create a spectrum of sex and bimodal distributions of sex related traits does not make sex bimodal. The idea that you are a lesser female human for being more flat chested is as offensive as it sounds.
The dichotomy of sex is not equivalent to dimorphism in sex. These are two different concepts. Just because dimorphism may be low in humans, does not mean the sex dichotomy is weakened.
And although there are disorders of sex development in humans, there is one intermediate morphology we don’t see: one of single individuals that produce both types of gametes, or hermaphrodites. These exist in some animals and many plants, but again: they are not a third sex, but a mixture of two sexes. Still, we don’t see them in humans; I’ve scoured the literature, and though I’ve found individuals that have both types of sex tissues, they are never fertile as both males and females, and I’ve only found one case each of a fertile male and fertile female hermaphrodite:
What is not observed is an individual who is fertile both as a male and female. If fertile at all, it will be as one sex. The cross-sex tissue is typically under-developed. No human is a true hermaphrodite (in the biological sense as being able to reproduce as both a male and female). Unfortunately, medicine also uses the term “true hermaphrodite” to describe people with these very rare disorders. Do not be fooled by this equivocation.
More:
What we have seen is that biology understands how sex is a strict dichotomy of male and female based on anisogamy (two distinct gamete types). No peer reviewed biology paper has ever characterised sex as bimodal and shown how to create this statistical distribution from measured data of sex. At best the bimodal idea is a metaphor. At worst, it is handwaving nonsense. The idea has not come from biological science but from academics in “gender studies” with explicit political agendas.
. . . We have seen how in order to support the bimodal idea, various specious arguments about sex are made. We see muddles about sex determination and karyotypes. We see conflations of sex and development disorders. We see muddling of the continuous and varied nature of dimorphism in species with the categorical nature of sex. We see how exceptionally rare ambiguities of sex development are used to justify the idea we cannot classify any person with any rigour or objectivity.
And from the newly published part II. First, on Novella’s claim that sexual orientation is one factor involved in determining one’s biological sex:
But we can only recognise sexual orientation if we recognise sex first. We can only recognise, for example, homosexual behaviour if the male sex of the individuals is independent of their behaviour. Your sex comes first: as male or female. Your sexual orientation does not shift your sex – they are orthogonal concepts.
What is Novella trying to say here? That your sexual orientation shifts you along his “bimodal distribution”? That being gay makes you less of a male? A lesbian female is not as female as a heterosexual female? We used to call such ideas homophobic. I am willing to apply Hanlon’s Razor here and just put this down to deep muddle.
Lewis discusses at length Novella’s conflation of sex with gender (a quite common error), and I’ll give just one more quote as you should read the stuff for yourself. This is on the use of “reductionist” as a pejorative term, something that infuriates me because it’s arrogant and, usually, dead wrong. Yes, there are emergent properties that cannot be predicted a priori from lower-level properties, but they are always consistent with lower-level properties. The wetness of water is a famous example.
Novella’s dismissal of sex being about reproduction as “reductionist” is at the heart of his failure to think clearly about the science of sex. His explicit approach is to never let us look at the many aspects of sex as resolvable phenomena in a hierarchy. He is always pushing to mush back together sex and reproduction, sexuality, orientation, identity, variation and disorders into one “bimodal” fog. We are never allowed to see any of these aspects in their own terms.
In The Blind Watchmaker, Richard Dawkins said,
For those that like ‘-ism’ sorts of names, the aptest name for my approach to understanding how things work is probably ‘hierarchical reductionism’. If you read trendy intellectual magazines, you may have noticed that *reductionism’ is one of those things, like sin, that is only mentioned by people who are against it.
To call oneself a reductionist will sound, in some circles, a bit like admitting to eating babies. But, just as nobody actually eats babies, so nobody is really a reductionist in any sense worth being against. The nonexistent reductionist the sort that everybody is against, but who exists only in their imaginations, tries to explain complicated things directly in terms of the smallest parts, even, in some extreme versions of the myth, as the sum of the parts! The hierarchical reductionist, on the other hand, explains a complex entity at any particular level in the hierarchy of organization, in terms of entities only one level down the hierarchy; entities which, themselves, are likely to be complex enough to need further reducing to their own component parts; and so on.
Novella is comparing hierarchical explanations of sex based in evolution, development and reproduction to this imaginary baby eating monster. We cannot hope to understand the complexities of such things as the human experience unless we are prepared to create a hierarchy of explanations. Your body existing as an evolved reproducing organism that is male or female is a perfectly good hierarchical place to start for so many conversations. To dismiss this explanation as missing out on the “complexities of human experience” is to fall into Dawkins’ Baby Eating Fallacy.
Novella’s distortion of biology in the service of ideology does nobody any good, for it involves the fallacious idea that what you think is ideologically correct is what must be seen in nature. Sadly, nature does not conform to gender ideology, and sex is not a spectrum, nor even binary. It’s ineffably sad that Science-Based Medicine, a real goldmine of attacks on quackery, is no succumbing to a form of ideological quackery.
I’ll have more to say about this when our Big Paper comes out in late June, but embargos prevent me from saying more.