As I reported recently, the Presidents of three organismal-biology societies, the Society for the Study of Evolution (SSE), the American Society of Naturalists (ASN) and the Society of Systematic Biologists (SSB) sent a declaration addressed to President Trump and all the members of Congress. (declaration archived here) Implicitly claiming that its sentiments were endorsed by the 3500 members of the societies, the declaration also claimed that there is a scientific consensus on the definition of sex, and that is that sex is NOT binary but rather some unspecified but multivariate combination of different traits, a definition that makes sex a continuum or spectrum—and in all species! The bolding below is mine:
Scientific consensus defines sex in humans as a biological construct that relies on a combination of chromosomes, hormonal balances, and the resulting expression of gonads, external genitalia and secondary sex characteristics. There is variation in all these biological attributes that make up sex. Accordingly, sex (and gendered expression) is not a binary trait. While some aspects of sex are bimodal, variation along the continuum of male to female is well documented in humans through hundreds of scientific articles. Such variation is observed at both the genetic level and at the individual level (including hormone levels, secondary sexual characteristics, as well as genital morphology). Beyond the incorrect claim that science backs up a simple binary definition of sex, the lived experience of people clearly demonstrates that the genetic composition at conception does not define one’s identity. Rather, sex and gender result from the interplay of genetics and environment. Such diversity is a hallmark of biological species, including humans.
A number of biologists I talked to had strong objections to both this wonky declaration, which of course is based not on biology but on ideology (see my posts here and here), as well as to its implication that biologists, including members of the three societies, generally agreed with it. But the societies did not poll their members before issuing a general statement in their name!
The statement is in fact is a prime but embarrassing example of societies being ideologically captured to the extent that they misrepresent science to cater to “progressive” liberalism. The object of course is not foxes, horses, or oak trees, but humans; this is meant to reassure people who feel that they are “nonbinary” in gender that nature is just like them. (For an excellent analysis of the issue, and a defense of the binary nature of sex, see Richard Dawkins’s article here.)
Luana Maroja of Williams College, my frequent partner in crime, was even more concerned, and so she penned a letter which she sent last night to the Presidents of the three societies. With a little help from me, she managed to get 23 biologists to sign the letter (as expected, many demurred and wouldn’t sign). I reproduce Luana’s letter below with permission; Except for Luana and me, I have left off the signers’ names because I didn’t ask them if they wanted to go public about such a touchy subject.
To wit:
Dear presidents of the Tri-societies: ASN, SSB and SSE,
We, Tri-society members and/or biologists, are deeply disappointed by your recent letter “Letter to the US President and Congress on the Scientific Understanding of Sex and Gender” issued last Wednesday, Feb 5, 2025, in response to Trump’s executive order “Defending Women From Gender Ideology Extremism And Restoring Biological Truth To The Federal Government”.
While we agree that Trump’s executive orders are misleading, we disagree with your statements about the sex binary and its definition. In animals and plants, binary sex is universally defined by gamete type, even though sexes vary in how they are developmentally determined and phenotypically identified across taxa. Thus, your letter misrepresents the scientific understanding of many members of the Tri-societies.
You state that: “Scientific consensus defines sex in humans as a biological construct that relies on a combination of chromosomes, hormonal balances, and the resulting expression of gonads, external genitalia, and secondary sex characteristics.”
However, we do not see sex as a “construct” and we do not see other mentioned human-specific characteristics, such as “lived experiences” or “[phenotypic] variation along the continuum of male to female”, as having anything to do with the biological definition of sex. While we humans might be unique in having gender identities and certain types of sexual dimorphism, sex applies to us just as it applies to dragonflies, butterflies, or fish – there is no human exceptionalism. Yes, there are developmental pathologies that cause sterility and there are variations in phenotypic traits related to sexual dimorphism. However, the existence of this variation does not make sex any less binary or more complex, because what defines sex is not a combination of chromosomes or hormonal balances or external genitalia and secondary sex characteristics. The universal biological definition of sex is gamete size.
If you and the signers of this letter do not agree on these points, then the Tri-societies were wrong to speak in our names and claim that there is a scientific consensus without even conducting a survey of society members to see if such a consensus exists. Distorting reality to comply with ideology and using a misleading claim of consensus to give a veneer of scientific authority to your statement does more harm than just misrepresenting our views: it also weakens public trust in science, which has declined rapidly in the last few years. Because of this, scientific societies should stay away from politics as much as possible, except for political issues that directly affect the mission of the society.
Respectfully,
Jerry Coyne, Professor Emeritus, Ecology and Evolution, University of Chicago
Luana S. Maroja, Professor of Biology, Williams College
THE NAMES OF 21 OTHER SIGNERS ARE REDACTED
I doubt the Societies will pay this letter any attention, as they seem to be doubling down on the sex-is-a-spectrum-in-all-species view. This is performative flaunting of virtue that will accomplish nothing. But we and the other signers want the public to know that this view of biological sex is not held by all biologists, and hardly represents a scientific consensus. (If there is a consensus, it is most likely the gametic definition described by Dawkins.) If you want to write your own letter rather than sign a group effort, the email addressed of two Presidents are given in their letter, and it’s easy to google that of the ASN President. And if you did sign the letter and want that to be public, simply say it in the comments below.
As a former President of the SSE, I am ashamed of what that society has done, and they should be ashamed of themselves for truckling to the latest ideology. They can of course issue statements bearing on issues of evolution, but this one simply distorts the facts. And, as I reported yesterday, the SSE has seen fit to make more general declarations about politics.
Bravo.
New Rule :
Whenever “gender” is written out and is of primacy in a piece, it needs a citation to literature – just like everyone has diligently been doing in extenso for “sex” the past so many years.
That should be fun to see – what would be cited? Hmmm…
During her confirmation when Ketanji Jackson was asked to define the word “woman”, she said she couldn’t because she wasn’t a biologist. Apparently biologists aren’t able to define it either.
Very good
Here in Europe, the situation is not as insane as in USA and Canada, but in the largest newspaper, here in Norway there’s been an intense discussion about “sex as a spectrum”.
First one neuro/developmental biologist, then one medical doctor dealing with DSD.
The typical stuff : DSD , brain scan studiers, ….everything is so complex, and gender identity …bla, bla…so ergo: sex is a spectrum
We have one prominent evolutionary biologist here whom does a great job speaking against gender ideology nonsense who wrote against and even said it all this was embarrassingly bad from these two “sex is a spectrum” guys.
Fortunately, cancel culture is not as bad here as in USA so it is not risky for this prof. to talk about this stuff openly and in public
Anyway, lots of people participate in the online discussion (me too) and more and more professionals, biologist, medical doctor and other scientist and non-scientist definitely side with the sane side: that sex is not a spectrum, but rather a binary (except for the 0.018%)
Anyway, at least here in Europe I feel the tide has already turned against this pseudoscience. Hopefully, USA will follow shortly
Get ready for more “DSD, brain scan studiers, ….everything is so complex, and gender identity …bla, bla…so ergo: sex is a spectrum”:
To appear on May 6, 2025:
Get this people: Within the categories male and female there is variation. Not all men are the same. Ditto for women. This blows my mind! And it’s all endorsed by Anne Fausto-Sterling !
Bjorn, please, never ever forget about the fishes! Never ever. I beseech you … Some of them can change sex!
I hope this is meant to be ironic (it is hard to tell sometimes in print). Of course some fishes change sex, but when that is done they are still either biological males or females.
I have read a lot of Fuentes stuff. I mean, as a developmental biologist (MSc) with minors in social anthropology and philosophy I could learn something. But no. Totally bonkers this guy.
As a Norwegian, I can’t understand how a uni like Princeton pay this guy to do anything. And that student pay thousand of dollars a year in tuition to go to his classes. We have these types in Norway too, but mostly in department of gender studies.
And here unis are free. I may take a course in gender studies just to annoy woke professor in class, fail on purpose and not pay a penny. (actually about 120 USD a year, for registration, but that all)
Don’t you want to leave the MAGA madness in USA and rather live here?
“It’s complex” … a reason that experts are required. It’s woke ideology grifting.
“Experts say” and “It’s complex” are trigger phrases for me. When I see those in articles, I know the author probably can’t explain the material properly, or their pushing an agenda.
I wish I could share your optimism. In Sweden we introduced a gender self recognition law last fall (and this from a center right government) and there is currently a new proposal to remove the word woman from the abortion law and replace it with sex neutral words (whatever those may be). In academia, at least in the humanities and social sciences, there it is still little open dissent from the gender mantras and the word “transphobe” gets thrown about a lot. In huge parts of the humanities gender ideology is accepted as received knowledge (or those dissenting do not dare/cannot be bothered to voice their dissent). We have not seen as much outright bullshit from the biological sciences as in the anglophone world but judging by the recent introduction of a DEI program at Chalmers (school of engineering) we seem to be a tad behind on the dogmatic stuff. Schools however diligently do teach pseudoscience in regards to the sex binary and there is a lot of gingerbread men and the like being tossed around. All in all I do not see much of an improvement, rather it seems that a whole generation is immersed in this and genuinely do believe it to be true rather than dogmatic. It is Sweden after all and the “be kind” attitude often trumps science and reason.
We have had gender self ID since 2016, one of the most liberal in the wourd. Most people except TERF’s like me don’t think about this, but when it comes to public opinion about gender care the tide seem to have shifted. Also in Sweden I believe (after Uppdrag Granskning Transtoget)
But of course, a lot of politician here try to do the same as in Sweden (removing woman and replace with the one that give birth) I believe Sweden is still more woke than Norway. and know that tehre been some woke/DEI stuff there that would probably not be a problem in Norway
Since you are Swedish and can read Norwegian. The debate started here:
https://www.aftenposten.no/meninger/debatt/i/xmdLkB/desinformasjon-fra-kjoennsforvirret-professor
More articles below this one. Our local Coyne/Dawkins type is name Glenn-Peter Sætre.
Sex neutral: expressions like “pregnant people” is example.
They’re awful.
Hurray — and thank you to Jerry and Luana. It is regrettable that this kind of letter even needs to be written but it does need to be!
You and Luana keep up the good work! Always counter nonsense.
Damn. I wish I were a biologist so I could sign.
Nobody ever asks me to sign anything! And it isn’t like I don’t have opinions and know facts.
Damn. 😉
D.A.
NYC
Good letter. They’ll pay attention, but they may or may not issue a response. They know that they were using sleight of hand in implying that the 3,500 members endorse the sex-as-a-spectrum narrative. Their clever wording in the original letter proves it.
“Our three scientific societies represent over 3500 scientists, many of whom are experts on the variability that is found in sexual expression throughout the plant and animal kingdoms.”
Note that they said that the societies represent over 3500 scientists, not that the letter reflects the consensus of the 3500 scientists. And note that they said that many are experts on the variability in sexual expression throughout the plant and animal kingdoms. Variability in sexual expression does not imply that sex itself is a spectrum, nor does it impact the definition of sex in terms of anisogamy. The presidents knew that they were doing the wrong thing here and they tried to obfuscate it.
Yes, but the notion that there is huge support in the societies for this palaver is buttressed by another statement in their letter:
Maybe the societies would direct inquiries only to those scientists who think that sex is a spectrum. But that would be dishonest.
Indeed, it would be dishonest.
I of course look forward to declarations from Presidents of learned societies that
species are not discrete categories at all, noting the existence of lion-tiger hybrids and the terrible complexity of the whole matter. In the next step, the discreteness of atomic theory will be revealed as a colonial imposition, “atoms” as a social construct, and consultants from the gender theory department will be tasked with revising all our physics and chemistry curricula, with editorial advice from the Scientific American.
LOL@”atoms” as a social construct
Good one!
I remember from a History of Science class that Ernst Mach among others was very doubtful of the then new “atomic theory”, because the alleged atoms could not be seen (in the usual phenomenological sense): “I don’t believe that atoms exist!” (1897). So for him at that time it was definitely a “social construct”.
Oh dear! What type of professor do you identify as?!
Ah, the liger. Per Napoleon Dynamite: “It’s pretty much my favorite animal. It’s like a lion and a tiger mixed… bred for its skills in magic.”
Nice!
I think it’s time for a list of scientists named Steve who believe sex is binary!
Jerry, could this letter remain open online to gather yet more signatures? There are cases where this has been done, most famously from Project Steve which gathers signatures from scientists named Steve who support evolutionary theory.
Right now, there is hesitancy to sign Marojas’ letter, but over time I’d bet more and more would participate as the feeling for safety in numbers begins to take hold. Hell, as a biologist and academic I’d sign although I am nobody in particular.
You should also sign Emma Hilton’s Project Nettie at https://projectnettie.substack.com/p/project-nettie-scientists-and-academics
Good idea! I will look into it.
Done! It was easy. This is a good letter to sign, and so thank you!
Another thanks for the tip, have signed up with PN. I also would love to sign an online version of the Coyne/Maroja letter. Happy to be public about it, too.
I’m drafting my own letter explaining why I plan to resign from SSE (after being a member for 40 years), but the more biologists we can get behind a single group letter the better.
Kudos for standing up and defending science from ideology!
A problem with these kinds of statements is that they make the authors look like idiotic, virtue signaling buffoons, which then leads to reduction in trust for the overall scientific community among laypeople.
Ordinary people know that sex is binary. The primary way they know this is via experience with how it works. They understand that there are some special cases but that the end result is still binary in terms of biology.
When supposedly esteemed “experts” put out such statements, it becomes very easy to doubt everything else that comes out of their mouths. “This guy who thinks that men can become women by putting on lipstick and prancing around is obviously a loon, so why should I believe him when he tells me to get a vaccine?” This would be doubly so in the case of biologists and others who need to sort by sex to do research.
If these people truly believe this then they are mad. If they know better and are only publishing these kinds of statements to appease others then they are cowards. In either case they should not be leading scientific organizations.
This is a very important point. This sex spectrum stuff is undermining many people’s faith in science in general.
I’ve had this happen to me: I argued that the there was a scientific consensus that AIDS was caused by HIV and got the retort: are those the same people who say a man can become a woman?
Given that HIV was named almost forty years ago it’s a good bet those people aren’t the same. But a single rebuttal to a multitude of distrustful retorts can hardly be comforting.
He figured that if scientists were stupid now they were stupid then.
I tried every argument I could think of but nothing worked. He insisted I must first read a book by HIV denier Peter Duesberg, from the 1990s.
These same people are now great believers in RFK Jr.
We’re doomed.
I heard the same with masking during COVID – paraphrasing: “why do I need to wear a mask and socially distance to visit my family in their home when medical professionals and epidemiologists said its OK for thousands of BLM rioters to yell and march in the streets without taking the same precautions”. The lack of concern with a more severe situation removed all trust in the recommendation for the less risky condition.
I’ve seen that examples dozens of times. People will be talking about that for years.
Marchers moving in the open air under breezes. A family sitting together in crowded rooms in a weatherproof house with the windows closed. Air quality? What’s that?
Sure, when the aerosol transmission of SARS-Cov2 was worked out, then it made sense in retrospect that outdoor riots and arson were safe and indoor family dinners were gravely dangerous. But at the time of the George Floyd ructions we were still being told to keep 2 metres apart and not congregate indoors or out because droplets of snot laden with Covid could jump off you and land on someone just from passing by on the sidewalk, and swamp the ICU. Playground equipment was embargoed with police tape. Remember all the screaming? “TOO CLOSE!! TOO CLOSE!!”
Was George Floyd’s one contribution to humanity all his short troubled life to be the raising of skepticism about the outdoor danger of Covid? Not only was arson a form of laudable community engagement and looting a down payment on reparations, both got the physicists and the doctors talking the same language about aerosols. Being inside jewelry stores in gangs was OK as long as you wore masks and broke all the windows first. Air quality you know.
When the Trump administration posted its definition of sex, a friend of mine posted about it on Facebook. She thought it was a “bizarre” definition and several of her friends posted comments to the effect that it was scientifically illiterate, typical of the Trump administrations ignorance etc etc
I posted a comment that, regardless of what Trump might be planning to do around transgender issues, the definition was pretty close to the long-accepted biological definition of sex. I was then challenged to provide a reference to scientists using such a definition today; on googling her, the challenger turned out to be a history professor who had published on gender issues.
So my question is: who do I reference? Especially when she can point to a statement from the Society for the Study of Evolution and other biological societies. I suspect that she would dismiss Richard Dawkins, Jerry etc; there is the letter above but 23 doesn’t sound like very many signatures; and a quick glance at Emma Hilton’s letter reveals a couple of psychologists, a nurse, and a high school astronomy teacher among the first few signatures, which I also suspect won’t fly.
I don’t expect to change her mind, and I doubt that I will bother going back to comment further now, but if I wanted to try to persuade other commenters to think again, who do I reference?
It’s not easy when a (presumably otherwise) respected society does this.
I wrote my own response to this to the three presidents before I saw this post, and haven’t received a reply, though I’m not really expecting one.
For a nice paper on the topic, I like this one in BioEssays:
Biological sex is binary, even though there is a rainbow of sex roles
Denying biological sex is anthropocentric and promotes species chauvinism
Wolfgang Goymann, Henrik Brumm, Peter M. Kappeler
First published: 21 December 2022 https://doi.org/10.1002/bies.202200173
All of those authors are biologists.
Paul Griffiths is a philosopher of science whose paper Sex is Real is also excellent.
The article by Goymann et al. is excellent! Thank you for the link.
The article was written only 3 years ago, so I hope that the three societies critiqued above are indeed misrepresenting the opinion of their members and that this statement from the article is still true:
Email me and I will given you tons of references –all the way back to 194–defining sex as binary and using gamete type or the apparatus to make gametes as the criterion. In fact, I gave a recent definition from Futuymas (sorry no apostrophes) just the other day; apparently you didnt see it. I have also given a reference to a list of gamete-based definitions.
194+
It’s really not clear to me how the presidents of these societies think about genealogy and DNA. In some sense they must agree that their grandfathers were male and their grandmothers female, and ditto for THEIR grandparents etc.
I am very glad you’ve been able to put together a group letter this quickly, although it’s too bad the list of signatories isn’t public. Getting more senior people in the field openly pushing back against this sort of nonsense might inspire some courage among those who are surely quietly nodding along, but have been too cowed to speak out. What I’ve found immensely depressing in this saga is the silence from so many evolutionary biologists who made their careers working on the evolution of anisogamy, sex allocation, the evolution of sex determination systems, sexual selection, etc. They must all see this ideological rubbish for what it is, yet they say nothing. Meanwhile, the loud activist clique gets to promote the dodgy work of barely a handful of usual suspects as the new “scientific consensus”.
There is manmade “fog” over difference between social self identification of people (which should be legal, protected and never persecuted) and biological basis of it.
I think, in medicine as in social life, mixing definition for ideological reasons does not help anybody, just fuel conflicts.
Non binary people should never try to dominate the over binary majority using soviet style demagogy, as it will always backfire.
Personally I think society owes “non binary” a lot in art (ex. Michaelangelo Buonarotti), music (ex. Tchaikovsky), military (ex. Pulaski) and even in science (ex. Harari). But it is something else to “live and let live” as opposed to “adjusting basic theories by force for political reasons”.
This is purposeful “postmodernist” confusion of a “culture movement” which out of wishing to be seen attacked even Kościuszko (!!!) as a colonial slaveowner. What a shame!
Thank you for your effort to popularise easy to understand explanations.
Happy Valentine for everyone!
Tchaikovsky was (famously) homosexual but who is claiming that he was in any sense sexually non-binary? He married one woman who presumably knew he was a man. No one refers to him in musical history as “her” or “them”, not even in a pejorative sense against his homosexuality. All of us know many homosexual men as they are no longer in the closet. None of them I know express any public doubt that they are men or present as women, not even the ones who call themselves effeminate.
I am comfortable with that theory that, at least among men and excluding the dissemblers and the autogynephiles, trans-identification as women is simply a variant of male homosexual identity, perhaps rooted in misogyny. (Everyone knows that “transwomen” are really men. Forcing women to pretend they are women and welcome them into their spaces is an act of intimidation against women, sometimes with violence.). But just because A is a wholly contained subset of B doesn’t mean all elements of B are also A.
Being homosexual is living who you are. Being trans or non-binary is living a lie. A man does not become a woman or discover he really was one all along. Society has a right to discriminate against people who hold beliefs, however sincerely, that are untrue. RFK Jr. believes things that aren’t true, which will compromise his ability to do his job. He should have been discriminated against for those beliefs by not being hired. If “being trans” communicates a sense of entitlement based on a falsehood, then an employer should be free to discriminate against such belief-holders in hiring.
The establishment (medical, scientific, etc.) has burned down its credibility. Has anyone ever heard the acronyms AFAB and AMAB? Sex is observed at birth (mostly accurately), it is not assigned. For example, C. Semenya and I. Khelif were thought to be female at birth. Both are male (5-ARD with high probability). Of course, we also have ‘pregnant people’.
We know for certain that Semenya is 46,XY 5-ARD from the Court of Arbitration for Sport’s investigation report. Khelif declined to appeal the International Boxing Association’s sex verification tests, so we don’t know that he is too, but you’re right it is highly likely.
How much trouble could we have avoided by overworking the word “gender,” which used to be a grammatical term, and using it as a substitute for “sex,” as in, for example, labor economics research, where worker types might have been broken down by sex, age, and experience. And I’ll let grammarians fuss over whether “sex” is also overworked, as people were getting worked up about its use as an adjective when constructing Divisia indices while it also served as a verb when referring to the gentlemens’ club or the adult movies.
Put briefly, isn’t your post arguing the same thing. Sex is binary and you look at gametes to determine it, whilst personality can be on multiple continuua in Euclidean space?