A politically powerful lobby today thinks your sex is not genetically determined but is malleable under your personal whim. That it is a social construct. That if you feel you are a woman, you are a woman. Never mind if you have a Y-chromosome, testes, and a penis, no matter if you have breasts and ovaries, your male or female identity is something you get to decide for yourself, as easily as you might choose your political party or favourite football team.
It is a doctrine that has become highly influential. The American Medical Association in 2023 laid down “best practices for sex and gender diversity in medical education.” Medical students are to be taught that both sex and gender are “[socially] constructed.” And “it is appropriate to affirm each individual’s self-determination regarding both sex and gender labels.” But are “male” and “female” really social constructs like money or like our 12-month calendar? Is that really the considered view of the American Medical Association? Are we seriously training a generation of young doctors to think that the sex of a patient is a matter of individual choice, not objective anatomical and physiological reality?
There are welcome auguries that the fashion is finally on the wane, at least in Britain. It is to be hoped that, in America, it will soon go the way of McCarthyism. The otherwise loathsome President Trump made the upholding of biological maleness and femaleness the subject of an Executive Order, as one of his first actions after taking office (perhaps the only good thing he has ever done). I could imagine future lawsuits against surgeons who, in violation of the first clause of the Hippocratic oath, have cut off the breasts of girls below the age of consent for no better reason than a subsequently regretted claim to have been “assigned” the wrong sex. What, after all, does “below the age of consent” mean if not too young to make permanent, life-changing decisions?
Two and only two sexes
How can I be so sure that there are only two sexes? Isn’t it just a matter of opinion? Sir Ed Davey, leader of the British Liberal Democrat party, is of the opinion that women “quite clearly” can have a penis. Words are our servants, not our masters, and he might claim that it’s open to him to say, “I define a woman as anybody who self-identifies as a woman; therefore, a woman can have a penis.” That is logically unassailable in the same way as “I define ‘flat’ to mean what you call ‘round’; therefore, the world is flat.” I think it’s clear that if we all descended to that level of sophistry, rational discourse would soon dig itself into the desert sand.
The question is whether a particular redefinition is helpful for any constructive purpose. The flat Earth example clearly is not. It’s simply perverse. How about the redefinition of woman (or man)? I shall make the case that the redefinition of a woman as capable of having a penis, if not downright perverse, is worse than unhelpful. I shall advocate instead what I shall call the universal biological definition (UBD) based on gamete size. Biologists use the UBD because it’s the only definition that applies all the way across the animal and plant kingdoms and all the way through evolutionary history.
Gametes come in two radically different sizes, the phenomenon of anisogamy. Female gametes are very much larger than male gametes, and that is how biologists define female and male. A human egg contains at least ten thousand times as much matter as a human sperm. In ostriches, the discrepancy is obviously even greater, by a very large amount. The UBD is universal in the sense that it applies to all animals, vertebrate and invertebrate. All plants, too, unless you count algae as plants.
“The redefinition of a woman as capable of having a penis, if not downright perverse, is worse than unhelpful.”
The UBD has the virtue that, in addition to being universally applicable, it explains a diverse load of facts. And it’s grounded in a body of powerful and widely illuminating theory. Here’s how. It’s an argument that should appeal to economists. In the words of R.A. Fisher (1930), “In organisms of all kinds, the young are launched upon their careers endowed with a certain amount of biological capital derived from their parents.” When two gametes unite to make a zygote, they must, between them, provide this requisite quantity of expensive nourishment. In a fair and equitable world, you might expect the two parents to contribute equally, each bearing half the necessary costs. Such a system is known as isogamy. It doesn’t exist in animals and plants but can be found in some microorganisms and algae. Clever mathematical modelling by various scientists, including Geoffrey Parker of the University of Liverpool, indicates that, under plausible conditions, isogamy is unstable. It tends to be replaced, in evolutionary time, by its opposite, anisogamy: two different kinds of gamete, radically different from one another.
Imagine you are an individual in an isogamous system. If you produce slightly larger than average isogametes, each zygote will be better endowed and therefore more likely to survive. On the other hand, since there’s no such thing as a free lunch, you can only afford to make fewer zygotes. Conversely, by stinting on gamete size, you could contribute to making a larger number of zygotes, but they’d be poorly endowed and less likely to survive. Unless, that is, your smaller-than-average isogametes could somehow seek out larger-than-average isogametes to partner with.
Parker and others developed plausible models whereby, over evolutionary time, half the individuals produce gametes in ever-decreasing numbers but ever-increasing size. These gametes eventually evolve into eggs. The other half goes in the other direction. They evolve smaller and smaller gametes in larger and larger numbers, which eventually become sperms. You could, if you wish, say that the sperm producers exploit the egg producers. Or you could say that, being more valuable, eggs don’t have to go out of their way to seek sperms. They can just sit and wait to be approached. Sperms, therefore, evolved miniature outboard motors (waving tails) with which to actively seek out eggs. Both types, the macrogamete producers and the microgamete producers, flourish in the presence of the other.
The fundamental economic inequality of anisogamy illuminates a large number of biological phenomena, thereby justifying my claim that the UBD does lots of explanatory work. If you define females as macrogamete producers and males as microgamete producers, you can immediately account for the following facts:
- In mammals, it’s the females that gestate the young and secrete milk.
- In those bird species where only one sex incubates the eggs, or only one sex feeds the young, it is nearly always the females.
- In those fish that bear live young, it is nearly always the females that bear them.
- In those animals where one sex advertises to the other with bright colours, it is nearly always the males.
- In those bird species where one sex sings elaborate or beautiful songs, it is always the male who does so.
- In those animals where one sex fights over possession of the other, it is nearly always the males who fight.
- In those animals where one sex has more promiscuous tendencies than the other, it is nearly always the males.
- In those animals where one sex is fussier about avoiding miscegenation, it is usually the females.
- In those animals where one sex tries to force the other into copulation, it is nearly always the males who do the forcing.
- When one sex guards the other against copulation with others, it is nearly always the males that guard females.
- In those animals where one sex is gathered into a harem, it is nearly always the females.
- Polygyny is far more common than polyandry.
- When one sex tends to die younger than the other, it is usually the males.
- Where one sex is larger than the other, it is usually the males.
In all cases, the key is economics: large gametes cost more than small ones. In various ways, this inequality plays out. Large gametes are more precious, more worth guarding, more worth fighting for, more worth protecting against wastage through mating with the wrong species or wrong individual.
It is no idle whim, no mere personal preference, that leads biologists to define the sexes by the UBD. It is rooted deep in evolutionary history. The instability of isogamy, leading to extreme anisogamy, is what brought males and females into the world in the first place. Anisogamy has dominated reproduction, mating systems, and social systems for probably two billion years.
Amid a rainbow of sexual habits, parental practices, and role reversals, the one thing that remains steadfastly constant is anisogamy. One sex produces gametes that are much smaller, and much more numerous, than the other. That is all ye know of sex differences and all ye need to know, as Keats might have only slightly exaggerated if he’d been an evolutionary biologist.
Here are some apparently anomalous examples that test (the true meaning of “prove” in the proverb) the rule. Unlike most mammals, spotted hyena females are larger than males and socially dominant over them. They have a hugely enlarged clitoris, scarcely distinguishable from a penis. They can get erections. They have false testes made of fatty tissue. The sight of apparently male hyenas giving birth has given rise to numerous myths of hermaphroditism. Given that so many roles and signals are reversed or ambiguous, how can we even know what we’re talking about when we use the words “male” and “female” in describing the anomalies of hyenas? By the UBD, of course.
Many species of fish are livebearers. As listed above, it is usually the female who gets pregnant. But in seahorses, it’s the male, in the sense that he has a pouch for holding the fertilised eggs, and he gives birth from his pouch. How do we know it’s the male? Couldn’t we define the female as the one that gets pregnant? We could, but then, “In seahorses, it’s the female who gets pregnant” becomes a tautology that leads nowhere.
Some worms and snails, and many plants, are simultaneous hermaphrodites. They are capable of producing both micro- and macro-gametes. Not a problem: the UBD is easily applied, and sex remains binary. The earthworm has organs appropriate to both sexes defined by gamete size. Enthusiasts for fluidity of “gender” love anemone fishes, also known as clown fishes. They, along with many other creatures, are sequential hermaphrodites. The largest, most dominant fish in a group of clownfish is female. If she dies, the dominant male becomes female. But what does that even mean? By what definition of male and female? On the UBD, it’s very simple. When the dominant egg-producer dies, the largest sperm producer starts to produce eggs instead.
Relative gamete size is the only way in which the male/female distinction is defined universally across all animal phyla. All other ways to define maleness versus femaleness are bedevilled by numerous exceptions. Especially with respect to the sex chromosomes, where you can’t even speak of a rule, let alone exceptions to it.
“Relative gamete size is the only way in which the male/female distinction is defined universally across all animal phyla.”
The way the sexes are defined (the UBD, universal and without exception) is separate from the way an individual’s sex is determined during development (variable and far from universal). How we, in practice, recognise the sex of an individual is yet a third question, distinct from the other two. In humans, one look at a newborn baby is nearly always enough to clinch it. Even if it occasionally isn’t, the UBD remains unshaken.
Gender
A watered-down version of the ideology concedes that sex may be binary, but “gender” is not. The word gender enters the discourse trailing clouds of confusion. To grammarians, gender is clear. It is a classification of nouns by how adjectives and pronouns agree with them. French nouns fall into two genders, English and German nouns into three. Kivunjo, according to Steven Pinker, has fifteen genders. French genders could have been named A and B (la table, le tapis), English and German genders A, B, and C. As it happens, all males belong in gender B, all females in gender A, and that same neat separation occurs in most languages. It is, therefore, convenient to use “feminine” and “masculine” as names for two of the genders, rather than A and B. This perfect correlation permits the use of “gender” as a coy euphemism for sex. Alex Byrne, in Trouble with Gender, and Kathleen Stock, in Material Girls, both make valiant attempts to sort out the confusion. In the mind of this reader, accustomed to scientific standards of rigour, the confusion remains. Stock herself sensibly tries to avoid the term, replacing it with “concrete, clearer terms that do whatever jobs I want them to at the time.” For the same reason, gender is not a word I normally use except in the grammarian’s sense. If you want to speak French properly, you really do need to respect every noun’s preferred pronoun.
The current fashion for transsexualism belongs in a cluster of inter-related vogues, sometimes called “woke,” partly stemming from a sincere concern for social justice, largely well-meaning but misguided and scientifically ill-informed. The cluster includes “identitarianism” and the view that alternative “ways of knowing” (women’s ways of knowing, indigenous ways of knowing, personal lived experience) are just as valid as objective science in understanding nature.
Transsexualism has strictly no necessary connection to whether sex is “binary” or a continuously varying spectrum, although, in practice, the same people are often partisan with respect to both. Those of us who argue that there is no spectrum of intermediates between male and female — that sex is “binary” — should not be seen as threatening to transsexualism. Whether or not there are “intersexes” with ambiguous genitalia, or abnormal sex chromosomes, is irrelevant to transsexualism because no trans person claims to be intersex. A trans woman insists that she actually is a woman; a trans man, that he actually is a man. Neither claims to be hermaphrodite. Rather, the claim is a psychological one. There’s a disjunct, or so it is claimed, between a person’s biological sex and the gender that they feel themselves to be.
There are many dimensions along which human personality can be measured. They might include assertiveness, ambition, empathy, aggressiveness, selfishness, methodicalness, volatility, perseverance, affection, bossiness. A mathematician might see each person as situated in a multidimensional space defined by these dimensions. We are all amateur psychologists who gossip about each other. Without being mathematicians, we implicitly classify each other along dimensions such as those I have listed. Perhaps there is a psychological dimension of masculinity/femininity, which is more or less correlated with some of the other dimensions listed. In defiance of much hard-won feminist progress, you might invoke sexual stereotypes in an implicit invocation of such a dimension. “Cecil is effeminate. Ros is butch. Lizzy is a tomboy; she doesn’t like dolls, loves climbing trees, and plays with wheeled toys.”
We can situate ourselves along such personality dimensions, including the perceived dimension of masculinity/femininity. We may even go so far as to wish we had been born the opposite sex. We might phrase it as being trapped inside the wrong body. It’s a version of dualism, a belief in a kind of disembodied soul, the real you, who is of a different sex or gender from the body in which the “real” you lurks. If that is how you are inclined, it might take little encouragement from the surrounding culture to push you over the edge into full-fledged belief. And today’s surrounding culture — doctors, psychiatrists, teachers, political leaders, lawyers, and perhaps above all school friends — gives more than a little push. Sex “assigned at birth” is arbitrary, we are told, and you only discover whether the real you is male or female by introspection.
An early account of what it is like to feel you are trapped in the wrong body is Jan Morris’s Conundrum. As what she called a “true transsexual,” she had little time for “the poor castaways of intersex, the misguided homosexuals, the transvestites, the psychotic exhibitionists, who tumble through this half-world like painted clowns, pitiful to others and often horrible to themselves.”
A feeling of being in a body of the wrong sex seems to be a real psychological condition. Such “dysphorics” can feel genuine distress. When anorexics look in the mirror, they see an emaciated body that they think is too fat. “Gender” dysphorics look in the mirror and see the wrong genitals. Both deserve sympathy and understanding. Nobody is phobic about anorexics. Why should anyone be phobic about gender dysphorics? “Trans- phobia” is a pernicious fiction.
Partly influenced by Jan Morris and partly out of normal politeness, it is my custom to refer to people by their preferred pronouns. But I draw the line at the belligerent slogan, “Trans women are women,” because it is scientifically false, a debauching of language, and because, when taken literally, it can infringe the rights of other people, especially women. It logically entails the right to enter women’s sporting events, women’s changing rooms, women’s prisons, and so on. So powerful has this “postmodern” counterfactualism become that newspapers refer to “her penis” as a matter of unremarked routine. Even the Times, Britain’s traditional newspaper of record, could begin an article (Jan. 18, 2023) with these words: “A transgender woman has denied raping two woman with her penis as she went on trial at the High Court in Glasgow.”
“So powerful has this ‘postmodern’ counterfactualism become that newspapers refer to ‘her penis’ as a matter of unremarked routine.”
If the journalist had said “with his penis,” the Times could have been in trouble with the police for “misgendering.” In 2020, Humberside police descended on the workplace of Harry Miller to warn him that one of his tweets “was being recorded as a hate incident.” What did the offending tweet say? “I was assigned Mammal at Birth, but my orientation is Fish. Don’t mis-species me.” A neat joke, in my opinion, and pretty gentle when compared with the satire of, say, Evelyn Waugh, Tom Lehrer, Ricky Gervais, Tim Minchin, Monty Python, W.S. Gilbert, or Jonathan Swift. Evincing an almost superhuman inability to take a joke, the police recorded it as a “hate incident” and threatened the satirist. Have the British police become George Orwell’s Thought Police? Will it come to that? The resemblance occurred to Mr. Justice Knowles, before whom the Harry Miller case came up. “In this country we have never had a Cheka, a Gestapo or a Stasi. We have never lived in an Orwellian society.” Well said, M’Lud! I hope the Humberside police officers have learned their lesson. Perhaps somebody might take them aside and patiently explain about this thing called satire.
I am sorry to say it looks horribly as though otherwise sensible and certainly well-meaning political leaders are pandering to an intimidating lobby, militant activists ever ready to pounce on what they see as heresy. Such activism is especially dominant among young people. Several senior publishers have confided to me that they are under strong pressure from young employees to censor, or even suppress, books that they perceive as “transphobic.” I hereby place on record my regretful suspicion that some otherwise respected scientists, too, are betraying science in a desperate attempt to curry favour with “the kids,” perhaps especially their own.
If your science is so weak that the best you can do is yell that your opponent is a “Transphobic bigot,” a “TERF,” or a “full-on MAGA alt-right Trump-supporter,” you’ve already lost the argument. Sometimes the name-calling goes further and becomes overtly threatening. At a London Pride demonstration in 2023, “Sarah Jane” Baker (previously Alan Baker) told a cheering crowd, “If you see a TERF, punch them in the fucking face.” I don’t think I’m unduly guilty of sexist stereotyping if I say that such language is more typical of the sex that “Sarah Jane” claims to have left than the one she aspires to join.
Sky News (January 23, 2023) had a picture of two Scottish Nationalist Party politicians, members of the British Parliament and the Scottish Parliament, respectively, at a transgender demonstration in Glasgow, grinning inanely in front of a large, colorful sign depicting a guillotine and the slogan “Decapitate TERFS.”
Threats of violence have no place in decent society. “Decapitate TERFS” is not only horrible. It’s pathetic. So is an exhortation to punch a TERF “in the fucking face.” A position should be supported, or refuted, by rational discussion informed by evidence. People who terminate an argument by resorting to threats or name-calling are ignominiously signalling that they’ve lost the argument.
The human conceit that personal feelings can change reality signals an extraordinary elevation of humanity in a kind of species-level solipsism; a vain hubris in the face of the eternal and universal verities of science. And yet science is the jewel in humanity’s crown. We have every right to take pride in it. But pride as we uncover nature’s truths should be tempered by humility. Let us hope we don’t take too long to come to our senses.
This essay is extracted from ‘The War on Science’, edited by Lawrence M. Krauss (Post Hill Press).
