+Sure, _in the limit of arbitrarily advanced technology_, everyone could be exactly where they wanted to be in sexpsace. Having said this, we have _not_ said all the facts relevant to decisionmaking in our world, where _we do not have arbitrarily advanced technology_. As Yudkowsky [acknowledges in the previous Tweet](https://twitter.com/ESYudkowsky/status/1067488844122021888), "Hormone therapy changes some things and leaves others constant." The existence of HRT does not itself take us into the Glorious Transhumanist Future where everyone is the sex they say they are.
+
+The _reason_ for having sex-segregated sports leagues is because the sport-relevant multivariate trait distributions of female bodies and male bodies are quite different. If you just had one integrated league, females wouldn't be competitive (in most sports, with some exceptions [like ultra-distance swimming](https://www.swimmingworldmagazine.com/news/why-women-have-beaten-men-in-marathon-swimming/)).
+
+It's not that females and males are exactly the same except males are 10% stronger on average (in which case, you might just shrug and accept unequal outcomes, the way we shrug and accept it that some competitors have better genes). Different traits have different relevance to different sports: women do better in ultraswimming _because_ that competition is sampling a corner of sportspace where body fat is an advantage. It really is an apples-to-oranges comparison, rather than "two populations of apples with different mean weight".
+
+Given the empirical reality of the different multivariate trait distributions, "Who are the best athletes _among females_" is a natural question for people to be interested in, and want separate sports leagues to determine. Including male people in female sports leagues undermines the point of having a separate female league, and [_empirically_, hormone replacement therapy after puberty](https://link.springer.com/article/10.1007/s40279-020-01389-3) [doesn't substantially change the picture here](https://bjsm.bmj.com/content/55/15/865).
+
+(Similarly, when conducting [automobile races](https://en.wikipedia.org/wiki/Auto_racing), you want there to be rules enforcing that all competitors have the same type of car for some common-sense-reasonable operationalization of "the same type", because a race between a sports car and a [moped](https://en.wikipedia.org/wiki/Moped) would be mostly measuring who has the sports car, rather than who's the better racer.)
+
+In light of these _empirical_ observations, Yudkowsky's suggestion that an ignorant comittment to an "Aristotelian binary" is the main reason someone might care about the integrity of women's sports, is revealed as an absurd strawman. This just isn't something any scientifically-literate person would write if they had actually thought about the issue _at all_, as contrasted to having _first_ decided (consciously or not) to bolster one's reputation among progressives by dunking on transphobes on Twitter, and wielding one's philosophy knowledge in the service of that political goal. The relevant empirical facts are _not subtle_, even if most people don't have the fancy vocabulary to talk about them in terms of "multivariate trait distributions".
+
+I spend a few paragraphs picking on the "sports segregated around an Aristotelian binary" remark because sports is a case where the relevant effect sizes are _so_ large as to make the point [hard for all but the most ardent gender-identity partisans to deny](/2017/Jun/questions-such-as-wtf-is-wrong-with-you-people/), but the point is very general. For example, the _function_ of sex-segrated bathrooms is to _protect females from males_, where "females" and "males" are natural clusters in configuration space that it makes sense to want words to refer to.
+
+Yudkowsky's claim to merely have been standing up for the distinction between facts and policy questions doesn't seem credible. It is, of course, true that pronoun and bathroom conventions are policy decisions rather than a matter of fact, but it's _bizarre_ to condescendingly point this out _as if it were the crux of contemporary trans-rights debates_. Conservatives and gender-critical feminists _know_ that trans-rights advocates aren't falsely claiming that trans women have XX chromosomes. If you _just_ wanted to point out that the organization of sports leagues is a policy question rather than a fact (as if anyone had doubted this), why would you throw in the "Aristotelian binary" strawman and belittle the matter as "humorous"? There are a lot of issues that I don't _personally_ care much about, but I don't see anything funny about the fact that other people _do_ care.
+
+If any concrete negative consequence of gender self-identity categories is going to be waved away with, "Oh, but that's a mere _policy_ decision that can be dealt with on some basis other than gender, and therefore doesn't count as an objection to the new definition of gender words", then it's not clear what the new definition is _for_. The policymaking categories we use to make decisions are _closely related_ to the epistemic categories we use to make predictions, and people need to be able to talk about them.
+
+An illustrative example: like many gender-dysphoric males, I [cosplay](/2016/Dec/joined/) [female](/2017/Oct/a-leaf-in-the-crosswind/) [characters](/2019/Aug/a-love-that-is-out-of-anyones-control/) at fandom conventions sometimes. And, unfortunately, like many gender-dysphoric males, I'm _not very good at it_. I think someone looking at some of my cosplay photos and trying to describe their content in clear language—not trying to be nice to anyone or make a point, but just trying to use language as a map that reflects the territory—would say something like, "This is a photo of a man and he's wearing a dress." The word _man_ in that sentence is expressing _cognitive work_: it's a summary of the [lawful cause-and-effect evidential entanglement](https://www.lesswrong.com/posts/6s3xABaXKPdFwA3FS/what-is-evidence) whereby the photons reflecting off the photograph are correlated with photons reflecting off my body at the time the photo was taken, which are correlated with my externally-observable secondary sex characteristics (facial structure, beard shadow, _&c._), from which evidence an agent using an [efficient naïve-Bayes-like model](http://lesswrong.com/lw/o8/conditional_independence_and_naive_bayes/) can assign me to its "man" category and thereby make probabilistic predictions about some of my traits that aren't directly observable from the photo, and achieve a better [score on those predictions](http://yudkowsky.net/rational/technical/) than if the agent had assigned me to its "woman" category, where by "traits" I mean not (just) particularly sex chromosomes ([as Yudkowsky suggested on Twitter](https://twitter.com/ESYudkowsky/status/1067291243728650243)), but the _conjunction_ of dozens or hundreds of observable measurements that are [_causally downstream_ of sex chromosomes](/2021/Sep/link-blood-is-thicker-than-water/): reproductive organs _and_ muscle mass (sex difference effect size of [Cohen's _d_](https://en.wikipedia.org/wiki/Effect_size#Cohen's_d)≈2.6) _and_ Big Five Agreeableness (_d_≈0.5) _and_ Big Five Neuroticism (_d_≈0.4) _and_ short-term memory (_d_≈0.2, favoring women) _and_ white-to-gray-matter ratios in the brain _and_ probable socialization history _and_ [any number of other things](https://en.wikipedia.org/wiki/Sex_differences_in_human_physiology)—including differences we might not necessarily currently know about, but have prior reasons to suspect exist: no one _knew_ about sex chromosomes before 1905, but given all the other systematic differences between women and men, it would have been a reasonable guess (that turned out to be correct!) to suspect the existence of some sort of molecular mechanism of sex determination.
+
+Forcing a speaker to say "trans woman" instead of "man" in that sentence depending on my verbally self-reported self-identity may not be forcing them to _lie_, exactly. (Because it's understood, "openly and explicitly and with public focus on the language and its meaning", what _trans women_ are; no one is making a false-to-fact claim about them having ovaries, for example.) But it _is_ forcing the speaker to obfuscate the probabilistic inference they were trying to communicate with the original sentence (about modeling the person in the photograph as being sampled from the "men" [cluster in configuration space](https://www.lesswrong.com/posts/WBw8dDkAWohFjWQSk/the-cluster-structure-of-thingspace)), and instead use language that suggests a different cluster-structure ("trans women", two words, are presumably a subcluster within the "women" cluster). Crowing in the public square about how people who object to be forced to "lie" must be ontologically confused is _ignoring the interesting part of the problem_. Gender identity's [claim to be non-disprovable](https://www.lesswrong.com/posts/fAuWLS7RKWD2npBFR/religion-s-claim-to-be-non-disprovable) mostly functions as a way to [avoid the belief's real weak points](https://www.lesswrong.com/posts/dHQkDNMhj692ayx78/avoiding-your-belief-s-real-weak-points).
+
+To this one might reply that I'm giving too much credit to the "anti-trans" coalition for how stupid they're not being: that _my_ careful dissection of the hidden probabilistic inferences implied by pronoun choices is all well and good, but that calling pronouns "lies" is not something you do when you know how to use words.
+
+But I'm _not_ giving them credit for _for understanding the lessons of "A Human's Guide to Words"_; I just think there's a useful sense of "know how to use words" that embodies a lower standard of philosophical rigor. If a person-in-the-street says of my cosplay photos, "That's a man! I _have eyes_ and I can _see_ that that's a man! Men aren't women!"—well, I _probably_ wouldn't want to invite such a person-in-the-street to a _Less Wrong_ meetup. But I do think the person-in-the-street is _performing useful cognitive work_. Because _I_ have the hidden-Bayesian-structure-of-language-and-cognition-sight (thanks to Yudkowsky's writings back in the 'aughts), _I_ know how to sketch out the reduction of "Men aren't women" to something more like "This [cognitive algorithm](https://www.lesswrong.com/posts/HcCpvYLoSFP4iAqSz/rationality-appreciating-cognitive-algorithms) detects secondary sex characteristics and uses it as a classifier for a binary female/male 'sex' category, which it uses to make predictions about not-yet-observed features ..."
+
+But having _done_ the reduction-to-cognitive-algorithms, it still looks like the person-in-the-street _has a point_ that I shouldn't be allowed to ignore just because I have 30 more IQ points and better philosophy-of-language skills? As it is written: "intelligence, to be useful, must be used for something other than defeating itself."
+
+I bring up my bad cosplay photos as an edge case that helps illustrate the problem I'm trying to point out, much like how people love to bring up [complete androgen insensitivity syndrome](https://en.wikipedia.org/wiki/Complete_androgen_insensitivity_syndrome) to illustrate why "But chromosomes!" isn't the correct reduction of sex classification. But to differentiate what I'm saying from mere blind transphobia, let me note that I predict that most people-in-the-street would be comfortable using feminine pronouns for someone like [Blaire White](http://msblairewhite.com/). That's evidence about the kind of cognitive work people's brains are doing when they use English language singular third-person pronouns! Certainly, English is not the only language; ours is not the only culture; maybe there is a way to do gender categories that would be more accurate and better for everyone! But to _find_ what that better way is, I think we need to be able to _talk_ about these kinds of details in public. And _in practice_, the attitude evinced in Yudkowsky's Tweets seemed to function as a [semantic stopsign](https://www.lesswrong.com/posts/FWMfQKG3RpZx6irjm/semantic-stopsigns) to get people to stop talking about the details.
+
+If you were actually interested in having a real discussion (instead of a fake discussion that makes you look good to progressives), why would you slap down the "But, but, chromosomes" idiocy and then not engage with the _drop-dead obvious_ "But, but, clusters in high-dimensional configuration space that [aren't actually changeable with contemporary technology](https://www.lesswrong.com/posts/QZs4vkC7cbyjL9XA9/changing-emotions)" steelman, [which was, in fact, brought up in the replies](https://twitter.com/EnyeWord/status/1068983389716385792)?
+
+Satire is a very weak form of argument: the one who wishes to doubt will always be able to find some aspect in which the obviously-absurd satirical situation differs from the real-world situation being satirized, and claim that that difference destroys the relevence of the joke. But on the off-chance that it might help _illustrate_ my concern, imagine you lived in a so-called "rationalist" subculture where conversations like this happened—
+
+<div class="dialogue">
+<p><span class="dialogue-character-label">Bob</span>: "Look at this [adorable cat picture](https://twitter.com/mydogiscutest/status/1079125652282822656)!"</p>
+<p><span class="dialogue-character-label">Alice</span>: "Um, that looks like a dog to me, actually."</p>
+<p><span class="dialogue-character-label">Bob</span>: "[You're not standing](https://twitter.com/ESYudkowsky/status/1067198993485058048) in defense of truth if you insist on a word, brought explicitly into question, being used with some particular meaning. [Now, maybe as a matter of policy](https://twitter.com/ESYudkowsky/status/1067294823000887297), you want to make a case for language being used a certain way. Well, that's a separate debate then."</p>
+</div>
+
+If you were Alice, and a _solid supermajority_ of your incredibly smart, incredibly philosophically sophisticated friend group _including Eliezer Yudkowsky_ (!!!) seemed to behave like Bob (and reaped microhedonic social rewards for it in the form of, _e.g._, hundreds of Twitter likes), that would be a _pretty worrying_ sign about your friends' ability to accomplish intellectually hard things (_e.g._, AI alignment), right? Even if there isn't any pressing practical need to discriminate between dogs and cats, the _problem_ is that Bob is [_selectively_](http://slatestarcodex.com/2014/08/14/beware-isolated-demands-for-rigor/) using his sophisticated philosophy-of-language insight to try to _undermine Alice's ability to use language to make sense of the world_, even though Bob obviously knows goddamned well what Alice was trying to say; it's _incredibly_ obfuscatory in a way that people would not tolerate in almost _any_ other context.
+
+It makes sense that Yudkowsky might perceive political constraints on what he might want to say in public. (Despite my misgivings, and the fact that it's basically a running joke at this point, this blog is still published under a pseudonym; it would be hypocritical of me to accuse someone of cowardice about what they're willing to attach their real name to, especially when you look at what happened to the _other_ Harry Potter author.)
+
+But if Yudkowsky didn't want to get into a distracting political fight about a topic, then maybe the responsible thing to do would have been to just not say anything about the topic, rather than engaging with the _stupid_ version of the opposition and stonewalling with "That's a policy question" when people try to point out the problem?!
+
+------
+
+... I didn't have all of that criticism collected so legibly on 28 November 2018. But that, basically, is why I _flipped the fuck out_ when I saw that Twitter thread. If the "rationalists" didn't [click](https://www.lesswrong.com/posts/R3ATEWWmBhMhbY2AL/that-magical-click) on the autogynephilia thing, that was disappointing, but forgivable. If the "rationalists", on Scott Alexander's authority, were furthermore going to get our own philosophy of language wrong over this, that was—I don't want to say _forgivable_ exactly, but it was—tolerable. I had learned from my misadventures the previous year that I had been wrong to trust "the community" as a reified collective and put it on a pedastal—that had never been a reasonable mental stance in the first place.
+
+But trusting Eliezer Yudkowsky—whose writings, more than any other single influence, had made me who I am—_did_ seem reasonable. If I put him on a pedastal, it was because he had earned the pedastal, for supplying me with my criteria for how to think—including, as a trivial special case, how to think about what things to put on pedastals.
+
+So if the rationalists were going to get our own philosophy of language wrong over this _and Eliezer Yudkowsky was in on it_ (!!!), that was intolerable. I remember going downstairs to impulsively confide in a senior engineer, an older bald guy who exuded masculinity, who you could tell by his entire manner and being was not infected by the Berkeley mind-virus, no matter how loyally he voted Democrat—not just about the immediate impetus of this Twitter thread, but this whole _thing_ of the past couple years where my entire social circle just suddenly decided that guys like me could be women by means of saying so. He was sympathetic.
+
+I had to do _something_. But if Yudkowsky was _already_ stonewalling his Twitter followers, entering the thread myself didn't seem likely to help. (And I hadn't intended to talk about gender on that account yet, although that seemed unimportant in light of the present cause for _flipping the fuck out_.)
+
+It seemed better to try to clear this up in private. I still had Yudkowsky's email address. I felt bad bidding for his attention over my gender thing _again_—but I had to do _something_. Hands trembling, I sent him an email asking him to read my ["The Categories Were Made for Man to Make Predictions"](/2018/Feb/the-categories-were-made-for-man-to-make-predictions/), suggesting that it may qualify as an answer to his question about ["a page [he] could read to find a non-confused exclamation of how there's scientific truth at stake"](https://twitter.com/ESYudkowsky/status/1067482047126495232)—and that, because I cared very much about correcting what I claim are confusions in my rationalist subculture, that I would be happy to pay up to $1000 for his time—and that, if he liked the post, he might consider Tweeting a link—and that I was cc'ing my friends Anna Salamon and Michael Vassar as a character reference (Subject: "another offer, $1000 to read a ~6500 word blog post about (was: Re: Happy Price offer for a 2 hour conversation)"). Then I texted Anna and Michael begging them to chime in.