A science writer who doesn’t understand the difference between binary and bimodal


Tom Chivers has dipped a tentative, timid toe into the arguments about trans issues to declare that of course biological sex exists, a statement I find utterly baffling. “Biological” sex? Is there some other kind? I look forward to hearing stories about abiological sex, or artificial sex, or machine sex. It’s very silly — next thing you know, the TERFs are going to start ranting about an equally silly term like “biological woman”, as if the non-biological women are running around made of plastic and aluminum. Uh-oh, I guess they already are. That’s another one I don’t get. Are they just sticking “biological” onto terms that they want to dignify with a sciencey label, contrary to what actual biologists say?

I’m still trying to wrap my head around “biological sex”. Is non-biological sex what you get when you stuff a Hitachi magic wand into a Fleshlight? Biology doesn’t have much to do with that.

Anyway, what triggered Timid Tom was a comment by a British politician, Jo Swinson (sorry, I’m American, I know nothing about politicians in the UK):

Swinson, on Radio 4’s Today programme, was asked by Justin Webb whether she believes that “biological sex exists”. She replied: “Not on a binary, from what I’ve read. I’m not going to pretend that I’m an expert in the subject but I don’t think that things are as binary as are often presented.”

That’s about as coherent and sensible a response as you can make to a silly question. She’s not going to pretend to be an expert, but she translates an absurdity into something as close to reality as she can, and answers that. She is correct. Sex is not binary. It’s a complicated mess of a subject with all kinds of variations.

Tentative Tom disagrees. He waffles about with a comparison to Pluto? Which used to be a planet? But “planet” was redefined so it isn’t anymore? Which he uses to somehow make an argument that objects in space are either planets or not-planets, a true binary, as long as you use the Correct Definition™, and that the fact that some objects are ambiguous does not affect the fact that Jupiter really is a planet.

OK.

I don’t see how arguing that there are artificial definitions that partition a continuum of object sizes supports his claim of unambiguous definitive binary states, but this is apparently Tom being Tom.

Then he launches into a discuss of intersex individuals, conceding that there are human intermediates in sexual differentiation.

With sex, just as with the concepts of “planet” or “species”, there do exist ambiguous cases. The intermediate cases in human sex are usually known as “intersex” people. There are various ways in which one can be intersex: the Intersex Society of North America (ISNA)’s FAQ site mentions genital ambiguity, such as girls with very large clitorises or boys with very small penises, or scrotums that have divided to form labia-like structures; external genitals that appear female, but with male-typical anatomy inside; chromosomal abnormalities, such as mosaicism, when some cells are XX and others XY, or having three sex chromosomes such as XXY; or having standard male XY chromosomes but a body that is insensitive to the androgenic hormones such as testosterone, which tell the embryo to start becoming male.

You’re losing me, Tom. These are all people exhibiting variation in sex-related traits. Are you trying to argue that these do not demonstrate that sex is nonbinary? They seem to me to show a clear range in the phenomena.

But then he says something that makes all clear. He doesn’t understand the difference between bimodal and binary distributions! Something can exhibit a bimodal distribution yet not be binary, so telling me that a phenomenon is bimodal does not imply that it’s binary.

…that doesn’t mean that sex doesn’t exist “on a binary”. If you did a graph, plotting human beings by height, you will see two clear peaks on that graph — average male height and average female height. If you plot weight, it would be even clearer. Foot size, hip-to-waist ratio. There would be significant overlap between men and women, but there would be very clear differences.

That’s a really good example. You’ve probably seen that kind of curves plotted to illustrate the differences in height of the different sexes. The trick is that they usually segregate the data into two categories first, and then plot two curves. Oh, look: two peaks!

Except for one little problem. He says if you “plot human beings by height”, then you will see “two clear peaks.” Let’s try that, without first biasing the interpretation.

Ooops, without the color coding, that looks like a bit of a smear; maybe with the right statistical analysis, you could extract a bimodal distribution out of that, but it would be pretty much impossible to turn that into a binary distribution.

Other small problems with these data is that height varies in history and geographic location. The average height of men 150 years ago was equivalent to the average height of women today; South Asian men tend to be shorter than American women. Were all those workers in the industrial revolution women, as are the majority of people in South Asia? Belgians are significantly taller than the French…are they more manly?

This is not to claim that biological differences are non-existent — individual traits do vary significantly between sexes. Even height! This kind of growth curve is really interesting.

It’s almost as if exposure to differing hormone concentrations at puberty elicits a differing pattern of growth, an observation that isn’t at all surprising to all those biologists who will tell you that there is a spectrum of variation that tends to be biased by sex, but still insist that sex is not binary.

But you still wouldn’t argue that a solution to the terrible transgender bathroom problem is that all you have to do is put a stick across the restroom door 170cm from the floor with a sign that says “You must be shorter than this to enter”. That wouldn’t work at all. My wife would have to use the men’s room, and Tom Cruise would have to use the ladies’. So why is Tom Chivers using this argument?

I think Timorous Tom is well aware that this won’t work, so he unslings a fresh battery of “facts.”

And those are not really sexual characteristics. If you were to plot, say, volume of mammary tissue, or number of ovaries, or number of sperm cells produced, you would see a far, far clearer picture of two enormous spikes with almost no overlap at all. Sex is about as binary as any biological or natural classification gets. It’s certainly a lot more binary than planetary status, and we’re happy to teach kids that Mercury is a planet but Pluto isn’t. There is a twilight, but it’s tiny compared to the size of day and night.

Whoa. I think if you plotted the volume of mammary tissue it most definitely produce a non-binary distribution within women and within men, and there would be overlap. You wouldn’t see two enormous spikes, you’d see two rounded mounds, which would remind me of something, I can’t quite think what. Similarly, if you plotted sperm counts, there’d be a broad distribution, admittedly floored at near zero for many women and some men, so there’d be a strong, tall rod at 0 and a rounded hemisphere subsequently. But again, it’s a poor way to distinguish men and women. I can’t quite see the bathroom police cupping breasts or getting a sperm sample before allowing you to enter.

It also brings up another problem: there are so darned many traits with differential expression. Trembling Tom brings them up one at a time to try to make the case that everything is binary, and he’s failing at even that, but what about the combos? A person is short, has large breasts, a Y chromosome, and a sperm count of 0; man or woman? Another person is tall, is flat-chested, had a hysterectomy, and identifies as a woman; will you tell her no? We don’t just have a graded distribution, we have combinatorial variation.

Oh, and he also trots out that familiar excuse, that it’s a tiny minority. So what? You don’t get to ignore their existence, and they still wreck your imaginary binary distribution.

But wait, one more absurdity from poor Torn Tom.

Male suspects in domestic homicides outnumbered female ones by more than seven to one in England and Wales from 2016 to 2018. Men — male-bodied people — are simply much more violent than women, and it’s silly to pretend otherwise.

No one is pretending otherwise, it’s a disgraceful statistic. But why? That’s a real concern — is it something about masculine nature, or is it something about masculine roles in our society? Also, is it binary? Are all males violent, and all women passive victims? Tom — honest question here, I’m just trying to discern your sex — how often do you beat your wife? If the majority of men are not violent, doesn’t this make violence a poor criterion? We’re only going to allow you to use this public restroom if you present a copy of your arrest record for domestic violence.

It should also go without saying that transgender women are by far the victims of violence. I guess that makes them Biological Women™ by definition, then.

Comments

  1. says

    Curiously enough, I think you could have recycled one of your recent headlines for this post as well:

    How much longer must we put up with this?

    So many geniuses out there terribly insistent that saying things that are factually true is so harmful to society that they must man-/het-/cis-/condesplain for hours about how ACKSHULLY the true facts are false because stupid people might draw wrong conclusions from true facts so we have to go with poorly informed opinion to save the world from descending into madness. And they never seem to run out of time or words to use defending idiocy.

    It’s times like these that I really appreciate sports ball, y’know? If we could just get Toddler Tom to refocus on Cricketfoot Polo, he could still indulge his best skills and true passions, yet the world would be substantially better off.

  2. Jazzlet says

    Just FYI as I’m sure you are really fascinated /s Jo Swinson was the leader of the Liberal Democrats our theoretically centerist party, she resigned after their appaliing performance in the election just gone.

    So many people have a conflicting view of biology, on the one hand ‘natural = good’ and therefore explains everthing about us, on the other we are above all that ‘because of our brains’, and they flipflop between the two according to which best supports the argument they are making at that moment.

  3. Hj Hornbeck says

    That’s a real concern — is it something about masculine nature, or is it something about masculine roles in our society? Also, is it binary? Are all males violent, and all women passive victims?

    This is another weird part of so-called “gender critical” thought: gender is a social construct learned from culture, but your tendency towards violence is biologically innate and cannot be changed. If you were raised as a boy, you were taught to be violent by a culture that promoted violence, but no amount of education would ever be able to reverse that. It’s an extreme form of imprinting that denies human complexity.

    TERFs and transphobes are so invested in the “only males are violent” narrative that they cover up sexual assaults committed by women against women. Six months ago I ran across a collective of TERFs claiming there was no evidence for women-on-women violence, which is quite obviously false. Emphasis mine:

    Even though there are a few studies on Same-Sex Intimate Partner Violence (SSIPV), they highlight that the phenomenon occurs at a rate that is comparable (Turell, 2000) or even higher than heterosexual IPV (Messinger, 2011; Kelley et al., 2012; Barrett and St.Pierre, 2013). It can be difficult to identify LGB IPV prevalence rates due to the different methodologies used in the researches. However, according to one of the most recent and representative study reports, almost one-third of sexual minority males and one-half of sexual minority women in the United States affirmed they were victims of physical or psychological abuse in a romantic relationship. …
    Life-time prevalence of IPV in LGB couples appeared to be similar to or higher than in heterosexual ones: 61.1% of bisexual women, 43.8% of lesbian women, 37.3% of bisexual men, and 26.0% of homosexual men experienced IPV during their life, while 5.0% of heterosexual women and 29.0% of heterosexual men experienced IPV. When episodes of severe violence were considered, prevalence was similar or higher for LGB adults (bisexual women: 49.3%; lesbian women: 29.4%; homosexual men: 16.4%) compared to heterosexual adults (heterosexual women: 23.6%; heterosexual men: 13.9%) (Breiding et al., 2013).

    Rollè, Luca, Giulia Giardina, Angela M. Caldarera, Eva Gerino, and Piera Brustia. “When Intimate Partner Violence Meets Same Sex Couples: A Review of Same Sex Intimate Partner Violence.” Frontiers in Psychology 9 (August 21, 2018). https://doi.org/10.3389/fpsyg.2018.01506.

    While the evidence is incomplete, it argues that there is no sexual dimorphism when it comes to violence. The whole “protecting women” trope is just promoting stereotypes that, at best, reflect a culture we can change.

  4. numerobis says

    Biological women are the ones that you don’t spray with synthetic fertilizer and pesticides, duh.

  5. numerobis says

    Hj Hornbeck: those numbers for lifetime interpersonal violence don’t quite make sense. Only 5% of heterosexual women experience violence in a relationship, but 23.6% experience severe violence?

  6. wzrd1 says

    @4, I thought that was orgasmic.
    What? Oh, my bad, damned hearing loss. Read the reference without my glasses, that should be organic.
    As opposed to inorganic humans, which we see in many clothier’s windows…

    More seriously, whatinhell does a planet vs minor or dwarf planet have to do with biology? Is one not biological if one is not entirely bound by one’s own gravity and to qualify as a planet, clear one’s orbit? Or does one need to be in any kind of solar orbit in order to qualify as biological?

    I also wonder, if one is genetically and self-identified as male, has gynecomastia and low testosterone, while also having elevated SHBG, with elevated free estrogen, what is that individual?
    Clinically confusing, perhaps. Right until a physician follows up with a more in depth analysis and finds calcium is high, other electrolytes confusing and TSH is nearly absent, free T3 and free T4 are extremely high, dangerously high and total cholesterol extremely low.
    Trust me, don’t get me into a discussion about sex hormones and sterol levels!
    With a resting pulse of 130, BP 210/130, rapidly dwindling weight.
    Oh, that person has fairly longstanding hyperthyroidism, but also confounds the idiot’s description.
    That person is also in danger for their life, due to the pulse rate and BP.
    But, that wouldn’t count with such willful idiots, who never look into finer details, let alone comprehend that every mammal on the planet, not to mention a significant number of avian species show a spectrum of sexual behavior that are excellent analogs to humans. Oddly, because humans happen to be mammals.

  7. says

    @numerobis:

    Something got corrupted in cut/paste. This was my professional field for a long time and I recognized that the 5% number could not be correct. So I went back to the source and here’s the original paragraph:

    Life-time prevalence of IPV in LGB couples appeared to be similar to or higher than in heterosexual ones: 61.1% of bisexual women, 43.8% of lesbian women, 37.3% of bisexual men, and 26.0% of homosexual men experienced IPV during their life, while 35.0% of heterosexual women and 29.0% of heterosexual men experienced IPV. When episodes of severe violence were considered, prevalence was similar or higher for LGB adults (bisexual women: 49.3%; lesbian women: 29.4%; homosexual men: 16.4%) compared to heterosexual adults (heterosexual women: 23.6%; heterosexual men: 13.9%) (Breiding et al., 2013).

    Note my bolding. Clearly the initial 3 from the “35.0%” figure just got accidentally deleted.

  8. Hj Hornbeck says

    I had a boo at the cited report, and that’s a typo. The real number is 35%, not 5%. The HTML version of the report I’m quoting from also lists 35%, so that typo may be my bad.

  9. Hj Hornbeck says

    Ack, too slow! If I had to guess, for the original blog post I copy-pasted from a PDF, and that can sometimes garble the underlying text. Either way, the original post was just corrected.

  10. leerudolph says

    PZ:

    I can’t quite see the bathroom police cupping breasts or getting a sperm sample before allowing you to enter.

    Actually, given the general run of people who seem to want to volunteer to be “bathroom police”, I can quite easily see that…indulging themselves in groping that’s not only non-consensual but (in their fevered dreams!) under color of law, what could be better???

  11. leerudolph says

    wzrd1: “Read the reference without my glasses, that should be organic.” I don’t know (or don’t recollect) where numerobis posts from and/or lives, nor you for that matter, but at least in France, “biologique” is the standard word to convey what American English calls “organic” when applied to produce (vegetable or animal). (Excuse me, either or both of you, if I’ve missed a joke and/or mistakenly attributed either joking or not joking to you.)

  12. Grace says

    Y’know, we’re a minority, but I’m starting to quibble about “tiny”, especially since that modifier is only used to emphasize how we’re worth disregarding. The latest Williams Institute data, published almost three years ago, says 0.7% of youth. Earlier adult data said about 0.6% for adults. I expect that as we gain visibility, we’re surviving more and coming out younger, so I expect both of those numbers to rise over time. I will not be at all shocked if we end up being 1% of the population.

    A minority? Certainly. But if we’re 1%, then statistically, any time you’re at a supermarket, you can shout and be heard by one or more trans people. When you go to a movie theater, with 200-300 seats, there are 2 or 3 trans people in there with you. If an average traffic jam contains 4000 cars and the average car contains 1.6 people, there are 60 or so trans people in that traffic jam with you.

    In other words, in every aspect of daily life, we are there. We are a minority. But “tiny”? Depends on how you define your terms.

  13. Susan Montgomery says

    @13 The way I look at it is we’re too large to ignore but too small to fight back. Perfect for anyone looking for an easy target.

  14. says

    Hj Hornbeck @#3

    The whole “protecting women” trope is just promoting stereotypes that, at best, reflect a culture we can change.

    This trope also erases the existence of adult male victims of violence or sexual abuse. It makes it so much harder for them to seek help.

  15. says

    I remember that aweful “why men don’t listen and women can’t read maps” book*. At the end there was a “test” which promised to reveal your sex? gender? (German only has one word for both) to you, in case you made it to adulthood without ever noticing.
    By the end of it Mr. and I were still a heterosexual couple, just not the way we thought…

    *Interestingly, in the German version women can’t park cars. You’d think that if these were some universal biological truths about men and women we’d be universally bad at the same thing in Germany and the Anglosphere…

  16. chrislawson says

    Grace@13, Susan M@14–

    Too true. “Tiny” is being used, scientifically speaking, to exclude the outliers. Excluding data is bad enough in science, but when it means excluding real people from consideration it becomes directly harmful.

    Besides, “tiny” is a stupid defence. The difference between special relativity and Galiliean relativity is so tiny that it took decades to confirm with experimentation. And yet most scientists regard relativity as one of the most important developments in the history of physics. Getting back to biology, the Y chromosome is the smallest of all human chromosomes and weighs only 0.015 picograms. I think that’s pretty tiny. And yet the gender essentialists insist that this particular tiny thing is of paramount importance.,,and yet the Y chromosome makes up 1/1800 of the average human cell mass — much less than the proportion of trans people in the population. “Tiny” apparently is not a physical or statistical measure; what it really means is “below the limit where I will be personally disadvantaged if I refuse to extend empathy.”

  17. Grace says

    “Tiny” apparently is not a physical or statistical measure; what it really means is “below the limit where I will be personally disadvantaged if I refuse to extend empathy.”

    This is incisive. Thank you.

    Grace

  18. ColeYote says

    “Biological” sex? Is there some other kind? I look forward to hearing stories about abiological sex, or artificial sex, or MACHINE SEX.

    Er… that’s kind of a thing. Which I may or may not be into.

  19. unclefrogy says

    I do find it interesting that when ever simple ideas about the nature of reality or nature are examined to see if the assumptions on which they are based are actually true they answer is at best kind of true but not actually 100% true.
    It is not surprising that there are sometimes a large portion of population that are uncomfortable with the results of really honest inquiry They have forgotten that feeling of wondrous mystery when they first saw things as a child. The longer I live the more mysterious and wondrous it remains, each question just leads to more wonders. The definitive absolute simple answers I was given as a child by often fearful people when I was given any answer at all just fade away leaving me in the same place I started out
    does not it seem that those who are the most sure about things who question the least are the ones in control and also happen to be unafraid to use violence.

    uncle frogy

  20. lochaber says

    Grace @ 13>

    I expect those numbers to continue to increase. Not an expert, and all that, but I suspect there are lots of individuals who aren’t dysphoric, and can survive as their assigned gender, but would be more comfortable and happy transitioning. And, as society is slowly getting better at understanding and accepting, those individuals may be more likely to transition, and do so earlier in their life than they would in a more repressive society.

    I mean, things are still pretty bad, but in some places they are a lot better than they were 20, or even 10 years ago. But we still need to make things better.

  21. M Smith says

    so there’d be a strong, tall rod at 0 and a rounded hemisphere subsequently

    For the stats nerds, that would be a Tweedie Distribution with a p factor between 1 and 2. It’s pretty commonly in general insurance claims analysis (many people make no claims, and those that do tend to fit a gamma distribution on cost).

    I will now be calling it the “sperm-count” distribution.

  22. Silentbob says

    From the link:

    I will note that when Swinson said that women commit domestic violence as well as men and so keeping men out of rape shelters isn’t the whole answer, it’s saying something technically true but kind of asinine. Male suspects in domestic homicides outnumbered female ones by more than seven to one in England and Wales from 2016 to 2018. Men – male-bodied people – are simply much more violent than women, and it’s silly to pretend otherwise.

    This is in reference to transgender women, and I hope the slight-of-hand is obvious here. It’s assumed that “male-bodies” are the relevant factor rather than male identity. Consider the following adaptation:

    When X said that straight women commit domestic violence as well as lesbians and so keeping lesbians out of rape shelters isn’t the whole answer, it’s saying something technically true but kind of asinine. Gynephilic suspects in domestic homicides outnumbered androphilic ones by more than seven to one in England and Wales from 2016 to 2018. Gynephiles – people sexually attracted to women – are simply much more violent than androphiles, and it’s silly to pretend otherwise.

    So I guess we need to ban lesbians (not). The flaw is, of course that it’s not just any old gynephiles who are prone to violence, it’s straight men – and likewise it’s not just any old male-bodied people assigned male, it’s cis men. Cis-het men are overwhelmingly responsible for sexual violence. Stop trying to use that as an excuse to demonise and ostracize transgender women who are much, much more likely to be victims than perps.

  23. dianne says

    f you were to plot, say, volume of mammary tissue, or number of ovaries, or number of sperm cells produced, you would see a far, far clearer picture of two enormous spikes with almost no overlap at all.

    Um…okay, there are going to be some skew at zero for sperm and ovaries, but mammary tissue? Cis-men and other people with typical XY development have mammary tissue and in various circumstances it can hypertrophy quite far into the “normal female” range.

  24. says

    … boys with… scrotums that have divided to form labia-like structures…

    Your patriarchal bias is showing there, Tom, buddy. You mean “tissue that has not fully fused to form a scrotum”.

  25. says

    Also, “Chivers” is the name of a brand of jam here in Ireland, and when you mentioned him “dipping a tentative, timid toe”, it has formed a resulting permanent connection in my mind between this guy and toe jam. Which I’m perfectly fine with, to be honest.

  26. says

    Tiny minority? That’ll never work in the long run.

    0.5/100 sounds like reasonable rates for biological minorities with disproportionate affect or benefit on or for the group. That’s my rate, I’ve yet to find the individual extended social confrontation that I couldn’t power through if I really wanted to. There’s only one other person with tourette syndrome that I’ve told about my ideas regarding tourette syndrome and repeated social behavior like social conflict, and she seems to have taken to to the idea.
    I wonder what these transphobes would make of the idea of taking a minority into account when the minority has different politics and can’t be readily driven off.

    There’s similar stories for lots of other ways of being, autism, ADHD… if gender identity breaks their minds they’re going to fall apart when the rest of us make use of what’s being established. Dichotomous thinking is a current political flaw.

  27. packbat says

    Re: the size of the trans minority: that 0.6% is actually on the low end of recent estimates – GLAAD commissioned an online survey that found ~3% of respondents self-identifying as trans in 2016 and when the Youth Risk Behavior Survey of high school students in 2017 tested out a transgender item in several states and large urban school districts, ~1.8% of students said they were trans and another ~1.6% said they were unsure. And from my experience, I would frankly not be surprised if those numbers were still low.

    Also, the intersex population is definitely part of this conversation, too – and while these groups overlap, the popular estimate there is something like 1.7% and doesn’t even include PCOS, which is literally associated with higher androgen levels in people the binary would classify as women.

  28. KG says

    Just FYI as I’m sure you are really fascinated /s Jo Swinson was the leader of the Liberal Democrats our theoretically centerist party, she resigned after their appaliing performance in the election just gone.

    It wasn’t just the party performance – she lost her own seat to the SNP, after making ridiculous claims she was going to become Prime Minister. Nice to see she is capable of saying something sensible!

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