+> But I'm kinda getting the impression that when you do normalize transgender generally and MtF particularly, like not "I support that in theory!" normalize but "Oh hey a few of my friends are transitioning and nothing bad happened to them", there's a _hell_ of a lot of people who come out as trans.
+
+> If that starts to scale up, we might see a really, really interesting moral panic in 5-10 years or so. I mean, if you thought gay marriage was causing a moral panic, you just wait and see what comes next ...
+
+Indeed—here we are five years later, and _I am panicking_. (As 2007–9 Sequences-era Yudkowsky [taught me](https://www.yudkowsky.net/other/fiction/the-sword-of-good), and 2016 Facebook-shitposting-era Yudkowsky seemed to ignore, the thing that makes a moral panic really interesting is how hard it is to know you're on the right side of it—and the importance of [panicking sideways](https://www.lesswrong.com/posts/erGipespbbzdG5zYb/the-third-alternative) [in policyspace](https://www.overcomingbias.com/2007/05/policy_tugowar.html) when the "maximize the number of trans people" and "minimize the number of trans people" coalitions are both wrong.)
+
+At the time, this was merely _very confusing_. I left a careful comment in the Facebook thread (with the obligatory "speaking only for myself; I obviously know that I can't say anything about anyone else's experience" [disclaimer](https://www.overcomingbias.com/2008/06/against-disclai.html)), quietly puzzled at what Yudkowsky could _possibly_ be thinking ...
+
+A month later, I moved out of my mom's house in [Walnut Creek](https://en.wikipedia.org/wiki/Walnut_Creek,_California) to go live with a new roommate in an apartment on the correct side of the [Caldecott tunnel](https://en.wikipedia.org/wiki/Caldecott_Tunnel), in [Berkeley](https://en.wikipedia.org/wiki/Berkeley,_California): closer to other people in the robot-cult scene and with a shorter train ride to my coding dayjob in San Francisco.
+
+(I would later change my mind about which side of the tunnel is the correct one.)
+
+In Berkeley, I met a number of really interesting people who seemed quite similar to me along a lot of dimensions, but also very different along some other dimensions having to do with how they were currently living their life! (I see where the pattern-matching facilities in Yudkowsky's brain got that 20% figure from.) This prompted me to do a little bit more reading in some corners of the literature that I had certainly _heard of_, but hadn't already mastered and taken seriously in the previous twelve years of reading everything I could about sex and gender and transgender and feminism and evopsych. (Kay Brown's blog, [_On the Science of Changing Sex_](https://sillyolme.wordpress.com/), was especially helpful.)
+
+Between the reading, and a series of increasingly frustrating private conversations, I gradually became persuaded that Blanchard _wasn't_ dumb and wrong, that his taxonomy is _basically_ correct, at least as a first approximation. So far this post has just been about _my_ experience, and not anyone's theory of transsexualism (which I had assumed for years couldn't possibly apply to me), so let me take a moment to explain the theory now.
+
+(With the caveated understanding that psychology is complicated and there's more to be said about what "as a first approximation" is even supposed to mean, but I need a few paragraphs to talk about the _simple_ version of the theory that makes _pretty good_ predictions on _average_, before I can elaborate on more complicated theories that might make even better predictions including on cases that diverge from average.)
+
+(And with the caveated understanding that [pinning down the specific causal relationships is a much harder scientific feat](/2021/Feb/you-are-right-and-i-was-wrong-reply-to-tailcalled-on-causality/) than merely showcasing observations that cast doubt on the "internal sense of their own gender does not match their assigned sex at birth" story.)
+
+The idea is that male-to-female transsexualism isn't actually one phenomenon; it's two completely different phenomena that don't actually have anything to do with each other, except for the (perhaps) indicated treatment of HRT, surgery, and social transition. (Compare to how different bacterial or viral diseases might happen to respond to the same drug.)
+
+In one taxon, the "early-onset" type, you have same-sex-attracted males who have just been extremely feminine (in social behavior, interests, _&c._) their entire lives, in a way that causes huge social problems for them—the far tail of effeminate gay men who end up fitting into the world better as straight women. _That's_ where the "woman trapped inside a man's body" trope comes from. [This one probably _is_ a brain-intersex condition.](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3180619/)
+
+That story is pretty intuitive. Were an alien AI to be informed of the fact that, among humans, some fraction of males elect to undergo medical interventions to resememble females and aspire to be perceived as females socially, "brain-intersex condition such that they already behave like females" would probably be its top hypothesis for the cause of such behavior, just on priors.
+
+Suppose our alien AI were to be informed that many of the human males seeking to become female (as far as the technology can manage, anyway) do _not_ fit the clinical profile of the early-onset type—it looks like there's a separate "late-onset" type or types. If you [didn't have enough data to _prove_ anything, but you had to guess](https://www.lesswrong.com/posts/xTyuQ3cgsPjifr7oj/faster-than-science), what would be your _second_ hypothesis for how this behavior might arise?
+
+What's the _usual_ reason for males to be obsessed with female bodies?
+
+So, yeah. Basically, I think a _substantial majority_ of trans women under modern conditions in Western countries are, essentially, guys like me who were _less self-aware about what the thing actually is_.
+
+So, I realize this is an inflamatory and (far more importantly) _surprising_ claim. Obviously, I don't have introspective access into other people's minds. If someone claims to have an internal sense of her own gender that doesn't match her assigned sex at birth, on what evidence could I _possibly_ have the _astounding_ arrogance to reply, "No, I think you're really just a perverted male like me"?
+
+Actually, lots. To arbitrarily pick one particularly vivid exhibition, in April 2018, the [/r/MtF subreddit](https://www.reddit.com/r/MtF/) (which currently has 100,000 subscribers) [posted a link to a poll: "Did you have a gender/body swap/transformation "fetish" (or similar) before you realised you were trans?"](https://archive.is/uswsz). The [results of the poll](https://strawpoll.com/5p7y96x2/r): [_82%_ said Yes](/images/did_you_have-reddit_poll.png). [Top comment in the thread](https://archive.is/c7YFG), with 232 karma: "I spent a long time in the 'it's probably just a fetish' camp".
+
+Certainly, 82% is not 100%. Certainly, you could argue that Reddit has a sampling bias such that poll results and karma scores from /r/MtF fail to match the distribution of opinion among real-world MtFs. But if you don't take the gender-identity story as a _axiom_ and [_actually look_](https://www.lesswrong.com/posts/SA79JMXKWke32A3hG/original-seeing) at the _details_ of what people say and do, these kinds of observations are _not hard to find_.
+
+Informal Reddit poll isn't "scientific" enough for you? Fine. The scientific literature says the same thing.
+
+[TODO: one sentence summary from each of—
+
+Blanchard 1985 /papers/blanchard-typology_of_mtf_transsexualism.pdf
+Lawrence 2005 /papers/lawrence-sexuality_before_and_after_mtf_srs.pdf
+Smith _et al._ 2005 /papers/smith_et_al-transsexual_subtypes_clinical_and_theoretical_significance.pdf
+Nuttbrock _et al._ 2011 /papers/nuttbrock_et_al-a_further_assessment.pdf
+Zavlin _et al._ 2018 /papers/zavlin_et_al-age_related_differences_for_mtf_transgender_patients.pdf
+the social desireability responding paper?
+]
+
+Peer-reviewed scientific papers aren't enough for you? (They could be cherry-picked; there are lots of scientific journals, and no doubt a lot of bad science slips through the cracks of the review process.) Want something more indicative of a consensus among practitioners? Fine. The [_Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition_](https://en.wikipedia.org/wiki/DSM-5) (the definitive taxonomic handbook of the American Psychiatric Association) [says the same thing](https://sillyolme.wordpress.com/2021/02/06/american-psychiatric-association-supports-the-two-type-transsexual-taxonomy/) in [its section on gender dysphoria](/papers/DSM-V-gender_dysphoria_section.pdf) ([ICD-10-CM codes](https://en.wikipedia.org/wiki/ICD-10-CM) F64.1 and F64.2):
+
+> In both adolescent and adult natal males, there are two broad trajectories for development of gender dysphoria: early onset and late onset. _Early-onset gender dysphoria_ starts in childhood and continues into adolescence and adulthood; or, there is an intermittent period in which the gender dysphoria desists and these individuals self-identify as gay or homosexual, followed by recurrence of gender dysphoria. _Late-onset gender dysphoria_ occurs around puberty or much later in life. Some of these individuals report having had a desire to be of the other gender in childhood that was not expressed verbally to others. Others do not recall any signs of childhood gender dysphoria. For adolescent males with late-onset gender dysphoria, parents often report surprise because they did not see signs of gender dysphoria in childhood. Adolescent and adult natal males with early-onset gender dysphoria are almost always sexually attracted to men (androphilic). Adolescents and adults with late-onset gender dysphoria **frequently engage in transvestic behavior with sexual excitement.**
+
+(Bolding mine.)
+
+Don't trust scientists or clinicians? Me too! Want more detailed (if not standardizable and quantifiable) accounts? Me too! And there's lots!