There are two kinds of people: Those who think everything is binary, and those who don’t

Transcript below the fold.

About two weeks ago, I posted a video titled “There’s a lot more to it!” that pointed out that Richard Dawkins was wrong to claim that there are just two sexes, and that’s all there is to it. Of course I got pushback, I expected it. So today I’m going to respond to some of it.

First, I got a polite email asking for clarification.

Here’s the dilemma: I’m also a long time reader of Dr. Jerry Coyne’s blog. Quite a while ago, he wrote a piece about how gender is fluid, but sex, biologically speaking, can only be male and female—that in mammals, those are the only real choices and any variation from that is vanishingly small.

I gather from your writing you have a different opinion, a long with Hemant Mehta and others I respect. However, I haven’t found any good counter arguments to the arguments Dr. Coyne makes. I consider myself a trans-ally, and I feel like I need to better understand this issue.

So, if you’ve answered this on your blog and I’ve missed it, or if you have any links to articles that address it, I’d really appreciate the help.

OK, I can recognize that difference of opinion, but unfortunately, I’m not a reader of Coyne’s blog, so please don’t expect me to be familiar with his position. I had to go looking for his arguments. There’s only one, and here it is:

the sexes “are basically defined by the gametes they produce.” Big gametes = female, small gametes = male; these are, in our species, eggs and sperm, respectively.

He also says we should not discriminate against trans people, which is nice and I agree, but his one argument is seriously flawed: it is deeply, profoundly, fundamentally reductionist. It is so reductionist it ought to be taken as a reductio ad absurdum — it is a disproof of its own proposition by showing that it leads to absurd and untenable conclusions.

It should be obvious that you cannot define people by their gametes. If this were true, there would be no debate about trans participation in sports: the only effect of sex is to specify which of two flavors of gametes they produce, and the only sports where it would matter are those that are carried out in a petri dish between single cells. But no! Everyone is aware that sex contributes to all kinds of differences beyond their gametes. The whole problem is that we KNOW that there are far-reaching developmental changes that occur after fertilization and as a consequence of sex differences, which are both more subtle and more complex than the anti-trans contingent wants to allow.

So trans people are fully aware of what kinds of gametes they produce or don’t produce. They know about the basic biology. What they are doing is saying that while they might possess ovaries or testes, they are also aware that everything else about their biology, their behavior, and their psychology is rebelling and saying that that does not correspond with their sexual identity. Meanwhile, people like Beauvoir and Coyne are saying no, all sexual attributes should be in alignment with the phenotype of a few cells in your gonad. You must deny every other aspect of your self and bow down before the dictatorship of your gametes.

Somehow, the only difference that matters between the sexes is reduced to a single cell type. At the same time, though, we’re going to see absolutist arguments about what clothes you should wear, how long your hair should be, what sports you can play, what bathroom you’re allowed to use, about differences in rationality and emotion. It’s as if they already know the gamete argument is bullshit, because they’re going to insist on other gender norms after the fact. You know, if it really was about gametes and nothing but gametes, there would be no conflict over drag shows.

But why? Implicit in this argument is the idea that who you are is defined entirely by your reproductive abilities. It’s nonsense. We are a sophisticated social species, we live in a complex society that is built by a vast number of people making diverse contributions to the prosperity of the whole. Making babies can be a valued part of the repertoire, but so is building bridges or writing songs or farming, contributions independent of gonads. You can’t build a civilization out of overly simplistic notions about only two kinds of people. Especially not if you are going to oppress any divergence from a narrow set of norms.

I also got a fair number of comments on YouTube about my video, but I’m not going to dwell on all the people who disagree with me. Instead, I’ll pick on just one scapegoat who represents all the problems with sex as a binary. This guy is so reductionist he needs to adopt a life as a sessile protochordate.

“We are not our gametes, we are a complex multicellular organism” … not even wrong, just irrelevant. You could carry on and say many more things about what we are – philosophers! mathematicians! diabetics! cynics! the kitchen sink! – but if the aren’t relevant to the conversation of the biology of sexual reproduction, they will continue to be irrelevant.

Everything about our morphology, behavior, endocrinology, physiology, genetics…IRRELEVANT. So what if there are philosophers and mathematicians, all that matters is the “biology of sexual reproduction,” which only involves sperm bumping into ova.

This degree of reductionism is simply gross and denies all aspects of biology and culture other than the one he (yeah, pretty sure this is a “he”) wants to use to make his argument. OK, fine, if everything but this one thing is irrelevant, just lie down in a gutter, masturbating, and wait for an ovum to find your puddle of semen.

He continues…

The maturation process after fusion? Really? Yes it takes years, no it is not relevant to the biology of reproduction.

Wait, wait, wait. So puberty, the development of secondary sexual characteristics, gonad development, mental maturation, and sexual orientation are NOT relevant to the biology of reproduction? Seriously, dude? All this fancy non-gonadal equipment we evolved has nothing at all to do with making babies, which is, of course, the only criterion we’ll use for classifying sex?

“You might think you can peek in the baby’s diapers and predict with absolute certainty their future role as a biological organism in society” – your usual mistake, conflating sex with societal role. Yes the sexes are surrounded by many stereotypes, yes many people place expectations of behaviour / personality / profession / hobby / sexual preference / favourite colour / taste in movies and all sorts of other silly things on people on the basis of their sex. Still only two sexes though.

So, after briefly lising a small sample of the panoply of possibilities for human individuals, he just dismisses at all as “silly” because there are “only two sexes”. Because all that matters is whether you produce sperm or egg. But nobody, let alone any biologists, is arguing that there is some alternative mechanisms for reproduction in humans than the fusion of sperm and ovum; what I’m saying is sex is immensely more complex than that, that there are many other factors that define the sex of individuals. What they’re doing is restricting their definition of sex very narrowly, to just the sex of gametes, to avoid all the other features found in multicellular animals that might complicate their limited understanding.

It’s distressing how much of our humanity these people will throw away, all in the name of preserving the purity and simplicity of the binary. Not only is it wrong, it’s a bad argument that leads to pain and suffering and oppression. All you need to do is look at a newspaper to see the chilling consequences of thinking human beings are just gametes.

I hope that clarifies things. I’m not a reductionist so arguing with me by discarding all the phenomena that discredit your position by asserting a flawed and incomplete definition isn’t at all convincing.


  1. chrislawson says

    Neat variation on the barber’s paradox! But seriously, thank you for your tireless battle against transphobic bigotry.

  2. doctorworm says

    What gets me is the people who acknowledge intersex people as falling outside the strict binary, but claim that it doesn’t invalidate the binary model. When you’re trying to determine the laws of physical reality, you don’t get to set aside outliers as if they were just statistical noise. If your model doesn’t cover 100% of known cases, then your model is wrong!

  3. DanDare says

    There are multiple layers of context to this discussion. Each layer applies different meanings to the term sex.
    The anti trans play a game of defining things at the absurd reductionist layer and then drawing “logical” conclusions from that at the societal layer.
    Even at the pure biological layer what is a human who produces no gametes? Or broken ones? Or who has both sets?
    What about the development of genital organs, or lack thereof?
    How is the discussion furthered if used appropriately except to show that even biological sex is not actually a binary proposition.

  4. chrislawson says

    I would accept people saying something like ‘historically, biology has defined sex by the size of gametes, a handy shortcut for the purposes of categorisation that was developed long before modern molecular tools that show how limited this model is, and has only trivial relevance to sex, gender, orientation, identity, and other complex psychosocial traits in humans.’ Using a cellular model derived in the years immediately after the invention of the microscope as a definitive guide to sexual development isn’t just socially regressive, it’s biologically wrong. Scientifically, it’s about as tenable as insisting that galaxies are just local clusters.

    And there is a deep, deep flaw in that gamete-size argument. We define the ‘female’ gamete as the larger and the ‘male’ gamete as the smaller, but the usual sex-determining features in mammals are in the sperm. So, any ‘male’ gamete that fertilises an ovum, if it carries an X, would in most cases lead to the development of a ‘female’ embryo. So why exactly is that sperm cell ‘male’ instead of ‘female’? Why are we imposing a gender identity on a mindless cell that is a ‘male’ gamete by cell size but a ‘female’ gamete by standard reproductive outcome?

    (And yes, this is the simplistic model of sex assignment that I have argued against vociferously in recent comments. But it’s the model the biological essentialists insist on using despite truckloads of contrary evidence. It’s also worth noting that even this system fails completely for the many species that are isogamous, i.e. the gametes are the same size. So, again, even from a crude biological essentialist perspective, this classification system is terribly incomplete.)

  5. chrislawson says


    Indeed. Incomplete models can be very useful, but when people stubbornly apply them to situations that are clearly incompatible with reality, well it’s a sign that a heavy dose of motivated reasoning is at play.

  6. chrislawson says


    That is an excellent comment. The same people insisting we define human sex by the size of the gametes they produce cannot account for the many people who don’t produce gametes.

  7. StevoR says

    Aren’t there meant to be three kinds of people – those who can count and those who can’t? ;-)

    Sorry, couldn’t resist the opportunity for that bad joke.

  8. says

    What makes the gamete argument even more absurd is when it gets paired with the mantra “it’s biologically impossible for humans to change sex.”

    On the day I was born, someone wrote “male” down on a piece of paper. What criteria did they use to decide on my True Biological Sex? It can’t be “gametes,” because AMAB babies don’t produce gametes. If gametes were the only thing that defined sex, then no one with be assigned male at birth.

    Later on, I gained the ability to produce gametes. Later still, I lost all my gametes. Following the gamete definition of sex, I have “changed sex” twice.

    Of course, if you point that out to a transphobe, they will move the goalposts from gametes to “intelligent design hypothetical gametes.” They insist your body is “designed” to produce either large gametes or small gametes, and that the “true” definition of sex is whatever gametes the Intelligent Designer intended you to produce.

  9. Pierce R. Butler says

    … the sexes “are basically defined by the gametes they produce.”

    Will each member of the “boys” team have to produce an on-site semen sample? Will the rest need an (inaccurately named) egg retrieval procedure? How much of each examination goes onto the stadium Jumbotron?

    So many questions, doubtless all bound for the Supreme Court.

  10. John Morales says

    StevoR, what?

    No, that’s the joke. Two kinds of people, those who do and those who don’t.

    (Or: mock the binary with a binary)

    On topic, this is one of those cases where definitions matter.


  11. beholder says

    I hate to quibble, John (oh, who am I kidding, I love it), but: “There are 10 kinds of people, those who understand binary and those who do not” is the more accurate rendition.

  12. says

    I’m always perplexed by people who insist on conflating the map with the terrain. Definitions and classifications are useful tools, but they don’t prevent reality from existing.

  13. moonslicer says

    This is an argument that I steer clear of. Given that I myself have no grounding whatsoever in biology, I leave the biological side of the question to those who do. There are plenty of people with the expertise to handle the issue very capably. They don’t need my ignorance.

    But it’s also because in my view there’s another fundamental issue that the anti-transers don’t begin to understand, and that is what we call “gender identity” (which I personally consider a very poor name for the thing, and I really wish we could find something else). I have found in my contact with anti-transers that they will unfailingly bring the argument around to sex because this notion of gender identity is a total mystery to them. If they engage with the notion at all, it’s only to trivialize and erase it, thereby erasing transgenderism and transgender people.

    But if I have to justify myself, gender identity is all I need. My gender identity has always been with me, it’s always been a part of me. My “transgender memories” (as I call them) go back to my very earliest years. There’s never been a time when my gender identity wasn’t with me.

    Which is why, in a way, I get a bit impatient with the biological arguments about sex. I regard them as a distraction, a way of indulging the anti-transers’ wish to dismiss gender identity altogether. I recently came across a statement to the effect that neurologists figured they were still decades away from being able to explain why transpeople are trans. This sounds right to me. It seems to me that virtually nobody outside the trans world has really come to grips with this aspect of us.

  14. John Morales says


    Which is why, in a way, I get a bit impatient with the biological arguments about sex. I regard them as a distraction, a way of indulging the anti-transers’ wish to dismiss gender identity altogether.

    Basically, they pay lip service to the sex-gender distinction, but functionally equate gender with sex, and furthermore equivocate about it until pinned down.

    It seems to me that virtually nobody outside the trans world has really come to grips with this [why transpeople are trans] aspect of us.

    How could one? It’s about a sense of self.
    Anyway. Me, I don’t care why. Or even how.
    I can see it’s a real, empirical thing, don’t need an explanation to determine it’s a real thing. That’s enough.

  15. chrislawson says


    One of the great things about Guardian’s Australian edition is that the editors have repeatedly opted not to reprint most of the UK’s transphobic op-eds.

  16. rietpluim says

    Binary absolutists are a lot like the various Christian denominations. They can’t even agree on the most basic thing like the definition of the sexes (be it XX-XY, penis-vulva, or egg-sperm) but they must agree it’s the non-absolutists who have it all wrong.

  17. rietpluim says

    the sexes “are basically defined by the gametes they produce.” Big gametes = female, small gametes = male; these are, in our species, eggs and sperm, respectively.

    Strictly speaking, this is not even an argument. It is just a definition, one of multiple possible definitions, one which may be useful in some contexts and less useful in others. An argument would be why this should be the definition of biological sex. I have never heard or read such an argument ever.

  18. says

    @moonslicer #13

    …this notion of gender identity is a total mystery to them.

    Indeed. I suspect a lot of cis people don’t even realize that they have a gender identity, too.
    It’s one of those things where you can actually go through your entire life blissfully unaware of what’s happening in your own brain. Trans people figure it out quickly because they constantly run their face into the societal wall, but if you don’t have that experience, there’s no reason to ever think about it. So, most people just don’t. They’ll even get upset if you try to point it out to them.

  19. imback says

    rietplum wrote at #17:

    Binary absolutists are a lot like the various Christian denominations. They can’t even agree on the most basic thing like the definition of the sexes (be it XX-XY, penis-vulva, or egg-sperm) but they must agree it’s the non-absolutists who have it all wrong.

    Ha ha, this is my favorite comment, showing the silliness of it all in a nutshell. It’s like the Judean People’s Front insisting sex is identified in chromosomes while the People’s Front of Judea say it’s identified in gametes, and they never get around to the important part that people are much more complex than one single factor. I’m still waiting for the blood type essentialists to start segregating people, with one sect insisting ABO makes the essential difference but the splitters insisting Rh does.

  20. StevoR says

    OK, fine, if everything but this one thing is irrelevant, just lie down in a gutter, masturbating, and wait for an ovum to find your puddle of semen.

    I don’t recommend following that advice – first its likely going to be uncomfortable and all the passing cars will be off-putting and a danger. Second, while waiting you’re going to be seen by neighbours or passers-by and shortly afterwards probly arrested by police for public indecency.. Depending on the specifics of which gutter you lie down masturbating in, natch.

    Tangential but via PBS Newshour :

    A rule change the Biden administration is proposing could make broad bans on competition by transgender athletes illegal, but would still allow restrictions in some cases. The proposal would affect Title IX, which prohibits sex-based discrimination by schools that receive government funding. William Brangham spoke with LGBTQ+ reporter Orion Rummler of The 19th News about the restrictions.

    Source :

  21. christoph says

    @ John Morales, # 10: Shouldn’t that be 10 kinds of people? Those who understand binary, and those who don’t.

  22. Samuel Vimes says


    Since the universe is 98% hydrogen and helium, all the other elements are statistically irrelevant. There, I just solved every problem that ever was, is, and will be.

  23. imback says

    @Samuel Vimes #26, in fact you are quoting percent by mass, and we don’t do people percent by mass but by individual. In our solar system (according to wikipedia), hydrogen and helium make up 99.87% of the atoms, so the nonbinary population of our solar system is truly tiny.

  24. fishy says

    I suppose this is unrelated, but I have a little annoyance I would like to share.
    There are two kinds of people.
    There are those who put the pencil into the cup with the lead pointed down and then there are the people who understand that it is a pencil! No one I work with understands that it is a pencil.
    I feel so alone.

  25. says

    I want to second rietpluim @17, because I think it’s the core of the matter. Beyond whatever biological absolutism and general ignorance the binarists bring to the table, they never make the case for why their preferred definition of sex is the Only Correct One. They rarely seem to be aware that they are choosing one definition out of many options, and doing so arbitrarily (and as PZ pointed out in these videos, doing so inconsistently). There are similarities to Pascal’s Wager, an argument that assumes only one concept of god can be the correct one. One might hope that atheists would be able to take the same logic they use to debunk religious claims and apply them in other contexts, but as we have all been thoroughly lectured, the only requirement to be considered an atheist is lack of belief in gods. Adding on anything else, like an ability to use logic or think critically, is hijacking the movement for atheism plus social justice warrior feminism something something.