Once again, Scientific American screws up an article claiming that the binary definition of sex is harmful and limiting

October 26, 2023 • 9:30 am

Scientific American just can’t help itself; it has to keep pounding away at the biological definition of sex, which is based on differential gamete size. Just the other day they published a full article in the “evolution” category, arguing that women hunted just as much as men in ancient times (and in hunter/gatherer societies today), but part of that article claimed that sex and gender were both “spectrums”. To quote from my post on this execrable and tendentious piece (my bold):

For the purpose of describing anatomical and physiological evidence, most of the literature uses “female” and “male,” so we use those words here when discussing the results of such studies. For ethnographic and archaeological evidence, we are attempting to reconstruct social roles, for which the terms “woman” and “man” are usually used. Unfortunately, both these word sets assume a binary, which does not exist biologically, psychologically or socially. Sex and gender both exist as a spectrum, but when citing the work of others, it is difficult to add that nuance.

Now the magazine has a new op-ed arguing the same thing: a binary view of sex is not only wrong, but constricts us; is also harmful to people who don’t see themselves as “male” or “females”, like transsexuals (who do in fact see themselves as members of their non-natal sex); and doesn’t work for people who don’t produce gametes (note: postmenopausal women aren’t female under this criterion). But I digress. This piece is short, but is full of distortions and mistakes. Also, one of the authors (Cara Ocobock) also coauthored the article on hunting mentioned above. She gets a lot of space to propound her views, while the magazine prohibits me from writing an op-ed.that contradicts some claims of other op-eds. It is in effect a journalistic dictatorship that prohibits dissent.

I’ll put the authors’ claims in bold, and have indented their quotes:

The authors claim that sex is defined by gamete type, but we don’t check people’s gametes when judging their sex.  And people who don’t have gametes are problematic.

When we ask, “How many sexes are there in humans?” we can confidently answer “two,” right? Many people think sex should be defined by a strict gamete binary in which a person’s sex is determined by whether their body produces or could produce eggs or sperm. But when you are out and about in the human social world, are you checking everyone’s gametes? And what of the substantial number of people who do not produce or carry gametes?

Well, yes, in public we judge people’s sex by characters correlated with sex: appearance, including size, shape, presence of breasts, vocal timbre, and so on. So what? When doctors diagnose jaundice, they first look at the patient’s color, and then examine the underlying condition: liver function. There is no problem here; the idea of secondary sex characters, imperfectly but highly correlated with biological sex, is well ensconced in the literature. That doesn’t affect the definition, which is there because it clearly shows the binary and leads to many interesting lines of research.

And the claim that people who don’t produce gametes—sterile males, postmenopausal females, castrati, and so on—these pose no problem. They are male or female. Postmenopausal women should be furious at the implication that they are not biological women.

The authors raise the old, tired, and refuted “clownfish fallacy”. Clownfish switch sexes: when the sole alpha female in a group dies, a male fish changes sex to take over as the boss female. But there are still only two sexes. The article confuses the reader by bringing up other aspects of sex that involve how it’s determined.

The vast majority of life-forms—including bacteria and archaea—do not reproduce sexually. But if the question concerned the number of animal sexes present in a given tide pool or backyard garden, the answer would need to account for organisms that switch sexes, sometimes mate with themselves or switch back and forth between sexual and asexual reproduction.

. . . We have to appeal to a multiplicity of binaries, however, because sexual reproduction has evolved many times and in many different ways across the living world. Reproductive capacities in birds and mammals largely involve inheritance of different combinations of sex chromosomes, whereas in many reptiles, sex is determined based on environmental cues such as temperature.

Yes, but again, all animals have two sexes. They can arrive at that binary using temperature, chromosomes, environment, and other cues, but in all cases they wind up with two sexes. (And that binary hasn’t blinded us to working out how it’s attained in organisms like reptiles!).  The ubiquitous binary is scientifically useful because it raises the question, first raised by evolutionists Ronald Fisher, of “why are the sexes only two?”.  And we think we know the answer now. As I’ve said, there are many paths to sex but only two destinations: males and females.

The authors claim that defining sex is a bottom-up project and we should arrive at our definition from the “top down”: by asking questions.

We think the ongoing discussion about sex might benefit from a fundamental change in approach by turning the question around such that we ask, “If ‘sex’ is the answer, what was the question?”

They have a point here, and have used, as have I and others, a comparison with the definition of biological species. The species definition is fundamental because it explains an observation of and question about nature: “Why, in one area, do animals and plants come in neat packages, like the birds in my backyard. Why isn’t nature a spectrum rather than comprising discrete groups?”

The value of this [“questions first”] approach becomes clear when you consider the long-running debate in biology over how to define species. One definition, the biological species concept, posits that species are groups of actually or potentially interbreeding organisms capable of producing fertile offspring. It is not universally applicable because, as noted earlier, most organisms do not reproduce sexually. It does, however, provide a framework for asking questions about how sexually reproducing organisms can evolve ways to avoid mating with organisms distinct enough that their offspring’s survivability or fertility would be compromised. This framework has led to a bounty of work demonstrating that speciation in organisms living in the same area is rare and that physical separation among groups appears to be a key component of evolving reproductive barriers.

We can extend this “ask questions first” framework to concepts about sex.

What the authors don’t seem to realize here is that the Biological Species Concept, based on reproductive barriers between groups, itself started with a question: “Why is nature discontinuous?” And that question led to the definition of species.  The discreteness of species in sexually reproducing creatures living in the same area is based on reproductive barriers.

Likewise, the definition of sex, based on equipment to produce one of two types of gametes, is also based on a question derived from observation: “Why do there seem to be two classes of organisms in animals, classes that have different reproductive roles and (usually) different appearances?”  Once we arrive at a gamete-based species definition, that helps us answer all sorts of questions, most notably ones involving sexual dimorphism and sexual selection.

So the top-down, question-asking method succeeded for both sex and species. The authors are kvetching about nothing.

Other aspects of organisms don’t adhere to a strict binary.

Binaries start to fail us once we move into questions about how organisms live out their lives. This can be seen in the example of transgender athletes. Arguments revolving around including or excluding trans athletes often rest on notions of strict binary differences in hormone type and concentration that associate female individuals with estrogen and male ones with testosterone. This assumes testosterone is at the root of athletic performance. These hormones do not hew to a strict binary, however. Female and male people need both estrogen and testosterone to function, and they overlap in their hormone concentrations. If we are interested in how estrogen and testosterone affect athletic performance, then we need to examine these respective hormone levels and how they correlate with athletic outcomes. We cannot rely on gross average differences between the sexes as evidence for differential athletic success. Adherence to a sex binary can lead us astray in this domain of inquiry.

My response is basically “This is irrelevant to whether sex itself is a binary.”  It also shows the ideological motivation of the paper, which is the usual motivation for denying the sex binary: “If sex is binary, then that erases people, like people of dual gender or trans people, who don’t feel that they belong to one of the two sexes.”  Well, that’s not true, as many trans people do feel they belong to one of the two sexes; they just feel they were born in the wrong one. But the biological definition of sex is irrelevant to the moral and legal rights of people of nonstandard gender, and, as I’ve always said, these folks should be treated with the respect and dignity their beliefs afford.

As for hormones not being in a strict binary, testosterone, for example, forms nearly a completely disjunct distribution in males and females, so the overlap is virtually nil.Below is a graph of hormone titers given by Carole Hooven in her book T: The Story of Testosterone, the Hormone that Dominates and Divides Us. The distributions are bimodal and almost nonoverlapping (a tiny bit of overlap, from people with sex disorders, isn’t shown because of the scale), with men at the higher mode and females at the other (h/t Robert):

But this is irrelevant, for, many sex-related characters, like height and strength, also show more overlap. The question is whether sex itself is bimodal, not sex-related traits.  And we know plenty about overlap in those traits, so the sex binary has not impeded us from studying things that overlap!

Further, people are already examining how hormone levels affect athletics-related traits.

Importantly, the fact that the Olympics and other groups used to use a hormone cutoff between athletes allowed to compete in “male” versus “female” categories has nothing to do with the sex binary. This is an artificial classification binary imposed on people for allowing them to compete in the two classes. (And it didn’t work.)  The authors are deliberately conflating two distinct issues here: the binary of sex and an artificial binary subjectively imposed by athletic organizations.

Other species, say the authors, don’t hew to a sex binary. 

Further problems arise when we compare humans to other species. Some organisms are incapable of reproducing. Some that are capable may end up not reproducing. Others may alternate between reproducing asexually and sexually, and still others may switch sexes. Such organisms provide fascinating insights into the diversity of life. But when we refer to clown fish changing sex to emphasize the diversity of ways in which sexual beings move through the world, we risk losing sight of the issues of consent, autonomy, well-being and self-determination that form the bedrock of all dimensions of human health, sexual or otherwise.

Every animal we know of has two, and only two, sexes, though sometimes they reproduce asexually. Alternation of sexes still leaves two sexes; like clownfish, organisms can change from one to the other —but there are no cases involving three or more sexes.

And what on earth do “consent, autonomy, well-being, and self determination” have to do with the sex binary? These are social issues that have nothing to do with how many sexes we have.  The authors are committing a form of the appeal to nature here, saying that because human sexuality is complicated by our social system, there must not be two sexes in nature!

This paper is deeply misguided, and its aim is to cast doubt on the utility of the sex binary because it distracts us from other stuff.  But the other stuff they mention has already been investigated and discussed extensively. In the end, I can conclude only that this is part of Scientific American‘s continuing “progressive” effort to convince us that there are more than two sexes in humans.  (For articles other than the two mentioned here, see here, here, and here). They won’t succeed, for Nature can’t be fooled. It’s infuriating that a science magazine repeatedly tries to deny empirical fact to serve a political agenda.

Yes, there may be good article in Scientific American, but there are also abysmal articles and op-eds, and I lay these at the door of the editor.


For more kvetching about the magazine, see “The Fall of Scientific American” in Spiked, published two days ago.

Jesse Singal takes apart a bad paper on sex

October 25, 2023 • 11:30 am

I don’t think I’ve analyzed this paper on my site, but, since it came out recently, it’s become well known among rational biologists for being tendentious, ideologically based, and largely incoherent, something you might intuit from its title. You can read it by clicking on the screenshot below:

The paper’s object is to dismantle the “simplistic” views of sex as being binary, because there is variation of things like hormones and other physiological and biochemical conditions within each sex, and somehow using the concepts of “male” and “female” obscures this variation. And that obscuring is harmful. Here are a few excerpts:

Our collective overreliance upon the simplistic heuristic of “sex” in data collection, hypothesis formation, analyses, and data interpretation leads to inaccurate and underspecified scientific knowledge. Uncritically dividing subjects into “female” and “male” categories (or other hypersimplistic models) obscures relevant physiologies and precludes the possibility of more specific (and more accurate) analyses. This obscuring effect of “sex” was elegantly demonstrated in a recent neuroendocrine study, where researchers analyzed their data by “sex” and then by estrous stage. Their analysis revealed that collapsing sex category hid the dynamic nature of ovarian hormones (Rocks et al., 2022): if the experiment had assumed the internal coherence of sex categories (as is common practice), important dynamics within these categories would have been overlooked to the detriment of our scientific understanding.

You probably see that this is itself incoherent, as to see variation in the estrous cycle, which certainly exists within females, you first have to identify the subjects as female. They’re assuming a sex binary, and then telling us that it’s harmful because. . .  well, I don’t understand what they’re saying, and neither, as you can read below, does Jesse Singal (see below).

The paper has an overt ideological premise: the dismantling of the sex binary is necessary to empower those people who don’t feel like they’re members of one sex or another:

In addition to impeding rigorous science, our continued used of “sex” in basic and biomedical research perpetuates misconceptions that legitimize harmful social and medical practices. In human-oriented research, simplistic (and often binary) models of sex pathologize trans, non-binary, and gender nonconforming people (as discussed during the SBN 2022 Symposium on Hormones and Trans Health). And those studies that do focus on the needs and interests of these populations are treated as “niche” and marginal to the fields they contribute to (Aghi et al., 2022). Current

First of all, trans people are members of one sex that feel like they are members of another, which assumes a sex binary. Also, non-binary and gender nonconforming people are not “pathologized” simply by defining sex as the condition of having the apparatus for making either large, immobile gametes (females) or small mobile ones (males).  Nonbinary and gender nonconforming people are almost invariably members of one sex or the other, even if they don’t feel like it, and that’s a fact. If there’s any “pathologizing”, it’s done by bigots, not by a scientific definition.

Here’s the paper’s tendentious conclusion:

To be clear: this is a call-to-arms. This is not a how-to or a roadmap. This is an invitation to continue the conversations begun in the SBN 2022 Symposium on Hormones and Trans Health. With the enclosed guidance and our collective creativity, we believe that the behavioral neuroendocrinology community is well-positioned to implement this deconstructionist approach in lieu of binary sex frameworks, to move away from this hypersimplistic sex model and conceptualize “sex” (and non-sexed) physiologies as multiple, interacting, variable, and unbounded by gendered limitations.

A real scientific paper is not a “call to arms”, and this one is almost duplicitous in trying to reject the idea of sex by saying that within sexes there is meaningful biological variation that needs to be studied. But who could possibly object to that? Carole Hooven notes this in a tweet:

Jesse Singal, who’s very good at analyzing papers is (like me) baffled by this one, as you can see from the title of his Substack article below. Click to read:

Singal on the ideological motivation of the authors:

In my view, this paper is the latest example of what has become a yearslong effort on the part of some left-leaning scientists, activists, and journalists: fuzzing up the concept of biological sex as much as possible, attempting to turn it into a troubled, subjective, unknowable mystery.

This movement seeks to distract from the fact that more than 99% of people can be described as straightforwardly male or female, solely (as I see it) in the service of a single goal: making sure no one can ever claim someone who says they are a man or a woman or nonbinary isn’t really that thing. That is, if it’s not only cruel or mean but scientifically inaccurate to point to a trans woman and say “That’s really a male!” then — the thinking goes — this will advance the cause of justice. [JAC: Actually, the figure of those who conform to the sex binary is about 99.982%.]

I’ve argued in the above-linked post that this causes a lot of shoddy and confused thinking, and is unnecessary. There are all sorts of moral arguments for treating trans people how they would like to be treated that don’t rely on the belief that they are really in some biological sex, X or Y or Z. You see the same logical leaps over and over again. In this paper, for example, Massa and her colleagues argue that “the use of simplistic (and often binary) models of sex ignores the existence of intersex, trans, non-binary, and gender non-conforming people,” without explaining what this means. But it doesn’t necessarily follow. If you point out that someone is biologically male or female in a context where that matters, you’re of course not denying the possibility that they don’t identify with that sex or might seek to change it to the extent biomedical technology allows. In fact, until recently this was the Trans 101 definition of. . . well, being trans! It described the condition of having a gender identity at odds with your biological sex.

As for the variation of the ovarian cycle somehow eroding the sex binary, demonstrated in mice, he says this (the authors cited a paper by Rocks et al. from 2022)

This is a very odd choice of paper for Massa and her colleagues to present as evidence that sex categories aren’t “internally coherent.” (For what it’s worth, I asked a philosopher if this term has an agreed-upon meeting and he said it didn’t. I also emailed Massa to ask her what definition of the term she was relying on, and didn’t hear back. The Rocks team didn’t return an email, either.)

It’s an odd choice because Rocks and his colleagues certainly view sex as internally coherent in their paper! They don’t even define the terms in question — male and female — because of course, anyone reading the journal Biology of Sex Difference already knows what they mean — the male mice are the one who produce the small gametes (sperm), while the female mice are the ones who produce the large gametes (eggs). There’s nothing incoherent here, and no, gesturing vaguely at (say) murine disorders of sex development doesn’t really change that. Just because there is some fuzziness at the edges of these categories doesn’t mean the categories themselves aren’t exceptionally useful — vital, even. For example, Rocks and his colleagues also include charts like this. . .

. . . . . . and it just seems pretty clear that they somehow knew exactly which the male versus female mice were. They couldn’t have really run their reanalyses otherwise.

Note that everything is divided up by “male” and  “female” (click to enlarge):

He concludes, correctly, after quoting some social-justice-speak from Massa et al. (estrus fluctuations apply to “cis women, non-binary individuals, and transgender men who menstruate”, all of which of course are biological females):

These obviously aren’t reactionaries — they know how to speak the necessary social justice lingo to ensure their paper gets published without much protest. But they’re also pointing out that however one identifies, there’s still a biological sex lurking underneath that has explanatory power. Yes, in this case, factoring in the estrous cycle provides far more data than merely factoring in sex, but the former depends on the latter. If you didn’t have the concept of sex, and if you can’t easily and accurately identify which are the male versus female mice, you wouldn’t be able to run these analyses!

And his conclusion:

But I will say that I’ve noticed a pattern where when I look into these claims about the supposed fuzziness and lack of importance of the basic male/female difference, I often find the arguments 1.) are straightforwardly wrong or misleading, 2.) collapse into something obvious, 3.) are so hard to follow, in terms of their basic logic (rather than technical language), that I don’t know what to make of them, or 4.) are quite philosophically muddled, such as by confusing and freely mixing distinct terms like sex, gender, and gender identity.

In the end, Singal gets humble and says that he might be missing something and begs his readers to explain what it might be that he’s doesn’t get. But read the paper for yourself and see if it doesn’t fit into one or more of the four categories above.

Group of “science-savvy” UK liberals urge denial of the sex binary

October 6, 2023 • 12:30 pm

This is an object lesson not only in the pollution of science by ideology, but also in how to make a fool of yourself by not learning about other areas of science before you pronounce on them.

A reader affiliated with a UK earth-sciences department sent me a letter circulated around that department, but it’s also circulating widely. The link goes to the whole letter but I’ll reproduce only part of it:

From an authority figure:

I know that many of us are concerned with the current ‘kicking woke ideology out of science’ rhetoric.  An open letter drafted by a number of scientists urges politicians to reject that:  ttps://hull.onlinesurveys.ac.uk/edi_in_science.  Please do sign and share as you think appropriate.

Note the urging to sign the letter, which, since it comes from a university official,  be considered a violation of the Kalven Principle of Institutional Neutrality if it were in Chicago.


Thank you for expressing an interest in signing the letter to the Prime Minister, Secretary of State for Science, Innovation and Technology and Chairman of the Conservative Party, regarding their position on ‘kicking woke ideology out of science’.

The text of the letter is given below. This text has been generated collaboratively by scientists from different disciplines, people with expertise in the relationship between science and Equity, Diversity and Inclusion (EDI), and those with lived experience of marginalisation. Some have signed the letter, while other valued contributers have felt unable to sign publically. A fully referenced PDF version of the text is available at Open Letter to UK Government.

Here’s a bit of the letter. You can see the full text at the link.

Dear Prime Minister and Secretary of State for Science, Innovation and Technology,

We are writing to express our anger and disappointment at the speech given by the Secretary of State for Science, Innovation and Technology at the Conservative Party Conference 2023, and accompanying social media post. These state that government policy will be ‘kicking woke ideology out of science’ and that Conservatives are safeguarding scientific research from the denial of biology and the steady creep of political correctness.’ This was described as a plan “to depoliticise science”.

We are extremely concerned about both the content and possible implications of the speech, and what it says about the government’s views on both science policy and inclusion. We address these directly as follows:

And here’s the invidious bit involving denialism of scientific fact in the name of ideology (it’s apparently in response to the speech discussed above):

  • ‘Denial of biology’. From the Secretary of State’s speech it is clear that this refers to the government’s increasing adoption of policies that put the lives and wellbeing of trans people at risk. When it comes to sex determination it is simplistic binary arguments, such as those used by the Prime Minister himself, that deny biology. The biology of human sex is significantly more complex than just XX chromosomes = female and XY = male. There are multiple levels of “biological sex”, including genetic, anatomical, physiological and hormonal, which may not align with each other 11,12. Even within genetic definitions of sex, there are multiple interacting genes involved in complex networks 11,12. Sex determination at birth is on the basis of external genitalia, so does not consider the multiple factors contributing to “biological sex”. Additionally, up to 1.7% of the population have Differences in Sex Development (DSD) or are intersex 11–13. To appeal to “biological sex” as the Secretary of State has done is over-simplistic, unscientific and exclusionary rhetoric under the pretence of objectivity 14. Furthermore, as the Secretary of State acknowledges, biological sex and personal/social gender identity are distinct. At least 0.5% of the UK population identify as a different gender to their sex registered at birth 15. Combining DSD, intersex, non-binary and trans communities, this represents nearly 1.5 million people in the UK that the government implies should be excluded from participating in biomedical, sports science and other research. Research in many contexts does not need to (nor should) restrict itself to a binary definition of sex or gender, and can be inclusive of intersex, non-binary and/or trans participants without losing scientific rigour. The Secretary of State directly criticises initiatives such as the Scottish Chief Statistician’s guidance with respect to sex and gender 16, but such pragmatic advice ensures accuracy in data collection and research design, and alignment with legislation including the Equality Act 2010 and the Data Protection Act 2018. We find it disturbing that over-simplistic or scientifically illiterate arguments about complex biological systems are being used to stoke so-called culture wars and make the UK increasingly hostile towards people identifying as intersex, non-binary and/or trans. Reductive and discredited biological models have been used to underpin historical and contemporary human rights abuses through scientific racism and eugenics 17,18, and have no place in modern scientific inquiry.

Virtually everything in this section is a distortion or outright lie. First, if you’re defining male and female, then you don’t use chromosomal complement, even in humans, but rather determine whether someone has the equipment to make small mobile gametes (males) versus large immobile gametes (females). Determining someone’s sex is as simple as that, though the other stuff, like chromosomes, genitalia, and hormones, are highly correlated with biological sex. It’s a big mistake, but a deliberate one, to conflate the definition of sex, which shows that sex is indeed a binary, with the correlates of sex, which are bimodal and almost binary, but could be called “strongly bimodal.”

The “it’s complicated” argument floated above is made for only one purpose, and that purpose is outlined in the first sentence:

From the Secretary of State’s speech it is clear that this refers to the government’s increasing adoption of policies that put the lives and wellbeing of trans people at risk.

No, the “simplistic binary notion of sex”, which happens to be true, does NOT put the lives and wellbeing of trans people at risk. Biological truth doesn’t have the ability to do that. What would risk the lives and well being of trans people is true transphobia: the fear and hatred of trans people that could translate into mistreatment and denial of their fundamental rights. That’s a question of morality, not biological fact.

And this bit is wrong in three ways:

Additionally, up to 1.7% of the population have Differences in Sex Development (DSD) or are intersex 11–13. To appeal to “biological sex” as the Secretary of State has done is over-simplistic, unscientific and exclusionary rhetoric under the pretence of objectivity 14. Furthermore, as the Secretary of State acknowledges, biological sex and personal/social gender identity are distinct. At least 0.5% of the UK population identify as a different gender to their sex registered at birth 15. Combining DSD, intersex, non-binary and trans communities, this represents nearly 1.5 million people in the UK that the government implies should be excluded from participating in biomedical, sports science and other research.

Once again, we see exaggeration of the proportion of people who don’t fall into the sex binary. It is at most 0.018%, not 1.7%, the latter a frequently-seen  and erroneous figure based on wonky data from Anne Fausto-Sterling, a figure that even she retracted later.

Second, trans people are not the same as intersexes. Trans people are, most often, people of one of the two sexes who want to assume the persona of a member of the other sex. The sex binary has nothing to do with invalidating trans people; in fact, trans people, being of one sex but wishing to be of the other, demonstrate the binary nature of sex.

Third, except for participation in sports, I don’t understand how the 0.018% of people who are true intersex, or people of different genders (a social construct) are “excluded from participating in biomedical and other research.” Perhaps the tiny number of true hermaphrodites would be excluded from being in the category “male” or “female”, but they could still be subject to biomedical research.  As for sports, well, transwomen should not compete with biological women in athletics, and that’s the one “exclusion” I support.

The people who are circulating this letter are damaging science by denying scientific truth, as well as using outmoded data that we all know is wrong. They also damage the debate over trans people by pretending that their treatment must somehow depend on whether there’s a sex binary. Once again I’ll say it: the binary nature of human sex has no bearing on the debate about the rights and treatment of trans people. 

To say that the sex binary is “overly simplistic” or “scientifically illiterate” is to brand oneself an idiot.  If this reflects the conventional wisdom of the Labour Party (for the attacks above are on positions apparently espoused by two Tories), then Labour is in trouble.  First they got in trouble by being anti-Semitic, now they’ll get into more trouble by being anti-biology.

More on the “binarity” of biological sex

August 24, 2023 • 11:30 am

I guess today is a Sex Day, as I think every post will be on sex and gender. Right now I just want to call your attention to an excellent discussion of sex versus gender published at the end of last year. Had I known of it, it would have been cited in the “sex is a binary” section of the paper Luana and I wrote for The Skeptical Inquirer. Well, here’s my chance to let you know about this paper now.

Perhaps you’ve already had the gamete-based biological definition of “male” and “female” drilled into you on this site, but in case you didn’t, or even if you did but want to read about purported exceptions to this binary, the paper below in BioEssays is essential reading. It’s the paper you want to give to your friends who doubt that there is a sex binary. (It’s accessible to laypeople.)

Click below to read it, or you can find the pdf here.

I’ve written enough about the sex binary that I don’t want to say more, but I do want to give some nice quotes from this paper to give you an idea of its contents. If nothing else, they provide a review of what I and many other biologists think about sex and gender.  So here they are, indented (I’ve omitted most of the references, which are given in the original paper.

Biomedical and social scientists are increasingly calling the biological sex into question, arguing that sex is a graded spectrum rather than a binary trait. Leading science journals have been adopting this relativist view, thereby opposing fundamental biological facts. While we fully endorse efforts to create a more inclusive environment for gender-diverse people, this does not require denying biological sex. On the contrary, the rejection of biological sex seems to be based on a lack of knowledge about evolution and it champions species chauvinism, inasmuch as it imposes human identity notions on millions of other species. We argue that the biological definition of the sexes remains central to recognising the diversity of life. Humans with their unique combination of biological sex and gender are different from non-human animals and plants in this respect. Denying the concept of biological sex, for whatever cause, ultimately erodes scientific progress and may open the flood gates to “alternative truths.”

. . . Yet, the attempt of influential science journals to re-define sex is done for a laudable cause: namely, they wish to promote a more inclusive environment for gender-diverse people in academia and beyond. However, there is no need to deny the biological concept of sex to endorse the rights of gender-diverse people, because biological sex and gender are two entirely separate issues.  The gist of the problem seems to be that the definitions of sex and gender and their relationship are not generally appreciated, promoting the spread of flawed notions among readers of high-impact journals.

. . . Biological sex is defined as a binary variable in every sexually reproducing plant and animal species. With a few exceptions, all sexually reproducing organisms generate exactly two types of gametes that are distinguished by their difference in size: females, by definition, produce large gametes (eggs) and males, by definition, produce small and usually motile gametes (sperm).  This distinct dichotomy in the size of female and male gametes is termed “anisogamy” and refers to a fundamental principle in biology (Figure 1).

. . . .Biological sex reflects two distinct evolutionary strategies to produce offspring: the female strategy is to produce few large gametes and the male strategy is to produce many small (and often motile) gametes. This fundamental definition is valid for all sexually reproducing organisms. Sex-associated genotypes or phenotypes (including sex chromosomes, primary and secondary sexual characteristics and sex hormones), sex roles and sexual differentiation are consequences of the biological sex. Genotypic and phenotypic features, as well as sex roles are often used as operational criteria to define sex, but since these traits differ vastly between sexually reproducing species, they only work for selected species.

This biological definition of the two sexes is, however, not based on an essential “maleness” or “femaleness” of individuals, but it merely refers to two distinct evolutionary strategies that sexually reproducing organisms use to produce offspring. Sexual reproduction does not require the existence of separate male and female individuals, though. While in the majority of animals, female and male gametes are produced by different individuals, they can also be produced by the same individual, either simultaneously or at different times. For instance, many corals, worms, octopuses, snails and almost all flowering plants are simultaneous hermaphrodites, combining the production of male and female gametes and functions in the same individual at the same time. Many fish species, on the other hand, are sequential hermaphrodites, that is, they change their biological sex during their lifetime. Clownfish (Walt Disney’s Nemo), for example, start their reproductive career as males and only the largest individual of a group turns into a female. Some cleaner fish, on the other hand, are initially all females and later the largest individuals convert to males.

. . . Lest we are misread, we fully endorse the endeavor to create a more inclusive environment for women and gender-diverse people. Gender equity is a humanistic matter of course and it will also benefit science, which – for much too long – has been dominated by a male perspective. It appears, however, that the rejection or the disregard of the biological definition of sex by some philosophers, biomedical scientists and influential science journals is founded in a short-sighted perspective that only considers humans (or mammals) and neglects all other species.

. . . A widespread misconception among philosophers, biomedical scientists and gender theorists – and now also among some authors and editors of influential science journals – is that the definition of the biological sex is based on chromosomes, genes, hormones, vulvas, or penises, etc. or that biological sex is a social construct.  These notions very much reflect our own anthropocentric view. In fact, femaleness or maleness is not defined by any of these features that can, but do not need to be associated with the biological or gametic sex.

. . . One reason for this misconception of the biological sex lies in biomedical practices, in which mammalian sex chromosomes or sex-associated phenotypes are widely used to define sex . . . It is this definition that is targeted by critics of the fact that there are only two discrete sexes. However, sex chromosomes or sex-associated phenotypes do not qualify to define biological sex, as there are many species that do not have sex chromosomes at all. Whereas in mammals, birds, or butterflies sex chromosomes trigger sexual differentiation, in many other organisms, environmental factors, such as temperature or social regulators, initiate sex determination or sex change. Hence, sex chromosomes or other sex-determining systems cannot generally define sex. Instead, as the philosopher Paul Griffiths pointed out, “they are operational criteria for sex determination underpinned by the gametic definition of sex and valid only for one species or group of species”. Sex chromosomes, temperature gradients or social cues from group members can all be ways of making a sex, but they do not define it.

. . . Especially in biomedicine, many people are simply unaware of how evolutionary biologists define sex as biological sex. Another set of academics are fully aware of what biological sex is, but are blurring it on account of a political will to treat all people fairly. This stance seems to be motivated by a naturalistic fallacy (the mistake of a moral judgment based on natural properties), or an appeal-to-nature argument (proposing that something is good because it is natural)*, thereby overlooking that “being natural” is irrelevant for ethics. If these misconceptions are spread by scientists it may lead directly to people rejecting science in general, which will be most damaging for progress in society. Our main aim here is to draw attention to the dangers of scientific journals ignoring scientific facts, and to clarify the concept of biological sex.

. . . It is clear that the biological definition of the sexes cannot be the basis for defining social genders of people, as forcefully pointed out by the philosopher Paul Griffiths.  Likewise, the socio-cultural, and thus anthropocentric, construct of gender cannot be applied to non-human organisms.  There is a red line that separates humans with their unique combination of biological sex and gender from non-human animals and plants, which only have two distinct sexes – both of which are either expressed in the same or in different individuals. As much as the concept of biological sex remains central to recognize the diversity of life, it is also crucial for those interested in a profound understanding of the nature of gender in humans. Denying the biological sex, for whatever noble cause, erodes scientific progress. In addition, and probably even worse, by rejecting simple biological facts influential science journals may open the flood gates for “alternative truths.”

In our paper, Luana and I attribute the blurring of biological sex, and the claims that animals in nature don’t have a sex binary, to a reverse appeal to nature: the equally mistaken view that “what we see as good in human society (a sex spectrum) must be also what we see in nature.”

Richard Dawkins talks sex and gender with Helen Joyce

August 24, 2023 • 9:30 am

Here’s an engaging 51-minute conversation with Richard Dawkins as the interlocutor and Helen Joyce as the interviewee; the topic is transgenderism and sex.  You probably know about Joyce, who has a math degree but now is a journalist working for The Economist. She’s well known for having been demonized and deplatformed by gender activists for what, as you’ll see, are eminently sensible views on transgenderism and human sex. She is not a transphobe in the sense of wanting to “erase” transpeople, or hating them, or trying to deny them respect or rights (with a few exceptions I agree with), but that doesn’t matter. She hasn’t hewed to the activist party line, and so she’s persona non grata.

I’m currently reading her book Trans: When Ideology Meets Reality, and am about 40% of the way though. I recommend it highly if you want to navigate your way over the choppy waters of transgenderism.  Her points (so far) are these:

  1. Many people are prompted to change their gender from male to female (or, usually, vice versa) by social pressure, by internet “friends”, by parents, or, more insidiously, by the “affirmative therapy” practiced by therapists and doctors who don’t take the time to analyze in detail the gender issues (“dysphoria”) experienced by many young folk.
  2. And these young folk, if left alone or given “regular” (i.e., empathic) therapy, most often resolve their dysphoria without transition, usually by deciding that they’re gay. That resolution is often much better than the medicalized resolution, which leads to prescription for puberty blockers, which themselves invariably lead to hormone therapy and sometimes to surgery (mastectomies, hysterectomies, removal of genitals and reconstruction of non-natal genitals, and sterility).
  3. The long-term effects of puberty blockers, as I’ve discussed before, are not known, but they are not without side effects. Without this knowledge, no child or adolescent can give informed consent for taking them. (As we know, several European countries now consider the use of blockers to be at the clinical, experimental stage.)
  4. The activists’ mantra: “If you don’t get your dysphoric child to change their gender, the alternative is suicide” is bogus. Any suicides of dysphoric adolescents, who are very often afflicted with mental illness or stress, don’t differ in frequency from those of similarly distressed adolescents who are not contemplating transition. And the rate of suicide is very low—far from the “100%” implied by gender activists.
  5. There should be “women’s spaces” reserved for biological women and not transgender women. In the video below Joyce discusses several of these, including single (biological sex) restrooms and changing rooms, and she explains why. Beyond these few types of spaces, she favors giving trans people the same rights as those enjoyed by of non-trans people.

Do read her book. It’s clear, well-written, and sensible.

Joyce’s book got a generally good reception except by gender ideologues or woke venues,

Here are the short YouTube notes:

Here is my conversation with Helen J on ‘The Poetry of Reality’, tackling the influence of gender ideology on society, the ideological lens, and its implications for scientific facts.

Here are a few questions that Joyce answers in the discussion:

What does it mean to “treat a transwoman as a woman”?

Should transgender women compete in athletics against biological women?

Do transgender people have to have medical procedures or surgery to be taken seriously, or can they be taken seriously by simply declaring that they are a member of the non-natal gender?  As Joyce notes, “I don’t think that male or female are prizes for effort. They’re just observation of categories of what we are.”

Why does Joyce favor single-biological-sex restrooms? Many people think that these should be eliminated in favor of “restrooms for everyone,” but Joyce explains why she doesn’t agree.

Why are the gender activists winning, i.e., dominating the conversation and silencing their opponents?

Click below to watch. I myself bridle at watching longish videos, but this one is well worth your time. Dawkins is very good at asking the right questions and drawing out Joyce’s views.

A preview of Santa Cruz island and an interlude about “sex work”

August 18, 2023 • 10:45 am

Yesterday, when I wrote this, I anticipated being on Santa Cruz island all day, the most populated island of the Galápagos, and visiting Puerto Ayora and the several biology research stations there. Santa Cruz has nearly 16,000 inhabitants and a substantial town. (The population of the entire archipelago is about 25,000.)

Here’s where it’s located:

But yesterday I did manage to produce a long post on our visit to Santa Cruz, which will be up tomorrow morning (tortoises!). Nevertheless, I wrote this before we did our full-day trip to the island, anticipating that I wouldn’t have time yesterday to write a report for tomorrow. I did! (All posts are written in the late afternoon or evening when we return to the ship.) So, here’s what I produced to fill the anticipated lacuna:


Here’s a new NYT op-ed by Pamela Paul that I recommend (click to read):

It’s always made me a bit queasy when prostitution is called “sex work,” for that implies it’s a simple job that women choose to engage in, when in reality many are compelled to enter the trade by dire circumstances or predatory men—and, in places like southeast Asia, it involves underage girls forced into the trade for the delectation of foreign sex tourists.

Some excerpts from Paul’s piece:

“The media uses terms like ‘sex work’ and ‘sex worker’ in their reporting, treating prostitution as a job like any other,” said Melanie Thompson, a 27-year-old woman from New York City who introduced herself as a “Black sex-trafficking and prostitution survivor.” The language of “sex work,” Thompson argued, implies falsely that engaging in the sex trade is a choice most often made willingly; it also absolves sex buyers of responsibility. (My colleague Nicholas Kristof recently profiled Thompson, who now works for the Coalition Against Trafficking in Women.)

“I urge the media to remove the terms ‘sex work’ and ‘sex worker’ from your style handbooks,” she said.

In reporting the event afterward, The New York Post used the term “sex workers.”

The Post is hardly alone. In what at first glance might seem like a positive (and possibly “sex positive”) move, the term “sex work” suddenly appears to be everywhere. Even outside academicactivist and progressive strongholds, “sex work” is becoming a widespread euphemism for “prostitution.” It can also refer to stripping, erotic massage and other means of engaging in the sex trade. It’s now commonly used by politicians, the mediaHollywood and government agencies. But make no mistake: “Sex work” is hardly a sign of liberation.

. . . Why, you might wonder, does exchanging money for sex need a rebrand? Derogatory terms like “hooker” and “whore” were long ago replaced by the more neutral “prostitute.” But “sex worker” goes one step further, couching it as a conventional job title, like something plucked out of “What Color Is Your Parachute?” Its most grotesque variant is the phrase “child sex worker,” which has appeared in a wide range of publications, including BuzzFeedThe Decider and The Independent. (Sometimes the phrase has been edited out after publication.)

. . .No advocacy worker wants to stigmatize the women or children who are trafficked or who resort to prostitution. Survivors of the sex trade should never be blamed or criminalized. Nor should the humanity of individuals working in the sex trade be reduced to what they do for money. Both opponents and advocates of the term “sex worker” share these goals. Many of those urging legitimacy for the sex trade also take a stand vehemently — and presumably without seeing any contradiction — against child labor, indentured servitude and slavery.

. . . But as with those close competitors for the title of “oldest profession,” the reality of prostitution isn’t worth fighting for. Though data is often incomplete, given the difficulties of tracking a black market, research from those who work with survivors indicates that only a tiny minority of people actively want to remain in prostitution. Those who enter the sex trade often do so because their choices are sorely circumscribed. Most prostitutes are poor and are overwhelmingly women; many of them are members of racial minorities and immigrants; many are gay, lesbian or transgender. Many, if not most, enter the trade unwillingly or underage (one oft-cited statistic shows the most common age of entry is between 12 and 16; some have also disputed this). They are frequently survivors of abuse and often develop substance abuse problems. Many suffer afterward from post-traumatic stress disorder. To say that they deserve attention and compassion is to acknowledge the breadth of their experience, not to deny them respect nor cast them solely as victims.

I don’t think it’s prudishness to object to this change of “language”, for the implications of “sex work” are such as to hide its dark side and inhibit people from fixing it. I agree with the statement of one woman:

“Prostitution is neither ‘sex’ nor ‘work,’ but a system based on gender-based violence and socio-economic inequalities related to sex, gender, race and poverty that preys on the most marginalized among us for the profitable commercial sex industry,” Taina Bien-Aimé, the executive director of the Coalition Against Trafficking in Women, told me.

In this case, the euphemism “sex work” hides a world of sadness and desperation, and the word is harmful—Orwellian in the reality it masks. “Prostitution” is what it should still be called, but beyond that we have to realize what it entails, most distressing when girls who are very young are forced into the trade.

Katie Herzog and Jesse Singal discuss the “dueling articles” of Dawkins and Rose

August 2, 2023 • 10:00 am

I could listen only to the free 17-minute beginning of Katie Herzog and Jesse Singal’s podcast episode, “But really, what IS a woman?”, as I don’t subscribe (I would, but I now subscribe to more sites than I can keep up with). At any rate, if you click below you can hear the 17-minute take for free, and then, if you want to subscribe and hear the whole thing, go here.

They introduce the controversy about “what is a woman” discussed by Richard Dawkins and Jacqueline Rose (see here for my link and the link to Dawkins’s and Rose’s pieces), and then go into the mistakes made when one violates the standard gamete-based definition of biological sex—mistakes famously promulgated by Anne Fausto-Sterling and repeated to this day by gender activists (though Fausto-Sterling’s calculation has long since been corrected by others). No, people, the frequency of intersexes is not 2%, they are not as common as people with red hair, they do not represent “other sexes” and thereby violate the sex binary, and, most important, people with intersex conditions are not the same thing as transgender people.

One plaint: Herzog mentions me and says that I “blog like it’s 2003,” which I gather means more than once a day, but what’s wrong with that? And what’s with the 2003?

That aside, the first 17 minutes of discussion is good, and if the podcasters loved me—since they do read this “blog”—they might give me free access. I know they’re reading this website (not a “blog”)!

Sex 1: The Labour party declares the obvious

July 27, 2023 • 9:20 am

There will be two posts on human biological sex today—at least if my exhaustion permits. Here’s the first.

I suppose this declaration by Keir Starmer will anger gender activists, especially those who insist that “a trans woman is a woman,” but it comports with common usage and avoids the fracas that the Scottish government got into last year when it declared (with court affirmation) that self-identification of a biological male as a woman, declared on a certificate, establishes the sex of a person. Here’s the declaration of Lady Haldane, a judge of Scotland’s Supreme Court, affirming the government’s decision.

“I conclude that in this context, which is the meaning of sex for the purposes of the 2010 Act, sex is not limited to biological or birth sex, but includes those in possession of a GRC [gender recognition certificate] obtained in accordance with the 2004 Act stating their acquired gender, and thus their sex,” she wrote.

Sex is not gender, for one thing, and you can’t change your gamete type by getting a gender recognition certificate, which is not about sex but about gender (see below).

Last year, the Scottish First Minister, Nicola Sturgeon, refused to define what a “woman” was, and although she was motivated by an admirable desire to protect the rights of trans women, she got into trouble for saying “I’m not going to. I’m just not going to get into this debate at a level that’s about simplified and lurid headlines.” Shortly thereafter she resigned, but of course she’d been assailed on many issues. The refusal to define “woman” is a hallmark of extreme gender activism, a fracas that Sturgeon and the Scottish government got itself into. Your either have to say that it’s an inborn biological trait or is the result of self-identification. Waffling means that you know there’s a conflict between the two.

The Scottish declaration, however, was overturned by UK’s Conservative Prime Minister Rishi Sunak, who exercised a “nuclear option” to block Scotland’s system of gender self-identification.

Now, according to the Times of London (click on screenshot, though it’s mostly paywalled; perhaps judicious inquiry will yield the piece), Labour leader Sir Keir Starmer has gone along with the Tories by not only refusing to accept self-declaration of sex (or gender, if you will), but also giving its own definition of “woman”, one that, in my view, is pretty correct in a biological sense:

Here’s the central bit:

Sir Keir Starmer has said that “a woman is an adult female” as he hardened his stance on gender.

The Labour leader insisted that biological women needed single-sex spaces and ruled out introducing self-identification for changing gender.

At Labour’s national policy forum at the weekend, the party formally ditched a policy of self-ID, which would have allowed people to change their legal gender without the need for a medical diagnosis of dysphoria.

Starmer cited controversy over the Scottish government’s law introducing self-identification, which was blocked by Rishi Sunak, and said he disagreed with Scottish Labour’s decision to support the reform.

“We don’t agree, we don’t think that self-identification is the right way forward,” Starmer said. He added that he had “reflected on what happened in Scotland”.

The Labour leader has been shifting position since struggling to say in 2021 whether a woman could have a penis, before declaring this year that 99.9 per cent of women “haven’t got a penis”.

Challenged on a BBC Radio 5 Live phone-in, Starmer went further. “Firstly, a woman is an adult female, so let’s clear that one up,” he said.

The party would “keep it a medical process” to change gender, Starmer said, while adding that he wanted to “modernise” the Gender Recognition Act and “get rid of some of the indignities in the process”.

The weekend’s policy discussion has “allowed us to be clear that there should be safe places, safe spaces for women, particularly in relation to violence against women”, he added.

Citing his own experience prosecuting violence against women as director of public prosecutions, Starmer said he felt “very strongly” about the need for safe spaces and that “biological women who have been subjected to violence against women and girls want a safe space where they can feel . . . that they are properly supported and protected”.

Asked what women needed to be protected from, Starmer raised the case of Isla Bryson, a rapist who was moved from a female to a male prison after a public outcry.

Starmer’s definition comports with that of the Oxford English Dictionary, whose first definition is this one:

The statement is not perfect (Starmer could have said “a woman is an adult human female”, as we don’t speak of “women flies”; and he could have recognized the obvious earlier instead of waffling). But at least there’s a recognition that one can change gender, though Starmer says that that would require a medical process (some would disagree), and a recognition that in some cases, like prisons and safe houses, biological women need safe spaces that don’t include trans women (I would add sports).

And the concept of “gender” is currently subject to lot of debate: is it a social sex role or a self-identification that isn’t clearly connected with how you behave in society? Or all of the above?  And what does Starmer mean by “medical process”? Does a psychological analysis count as a medical process (remember, psychiatrists are doctors), or do you need hormones and/or surgery? I would, for example, avoid all this debate by calling what most call a “trans woman” as someone who has medically transitioned to living in a female sex role”. That avoids self-identification as the sole criterion for your “role”.

But despite this quibbling, Starmer’s statement is a good one, particularly the emphasis on using the definition to provide safe spaces for women.

And I would add that I don’t consider this discussion transphobic, though some will. I agree with J. K. Rowling’s statement—except of course for the last two sentences:

I know and love trans people, but erasing the concept of sex removes the ability of many to meaningfully discuss their lives. It isn’t hate to speak the truth,” she tweeted. “The idea that women like me, who’ve been empathetic to trans people for decades, feeling kinship because they’re vulnerable in the same way as women—i.e., to male violence—‘hate’ trans people because they think sex is real and has lived consequences—is a nonsense.”

She continued, “I respect every trans person’s right to live any way that feels authentic and comfortable to them. I’d march with you if you were discriminated against on the basis of being trans. At the same time, my life has been shaped by being female. I do not believe it’s hateful to say so.”


h/t: Pyers