+So imagine having something like the transporter in _Star Trek_, but you re-materialize with the body of someone else, rather than your original body—a little booth I could walk in, dissolve in a tingly glowy special effect for a few seconds, and walk out looking like (say) [Nana Visitor (circa 1998)](https://memory-alpha.fandom.com/wiki/Kay_Eaton?file=Kay_Eaton.jpg). (In the folklore of [female-transformation erotica](/2016/Oct/exactly-what-it-says-on-the-tin/), this machine is often called the ["morphic adaptation unit"](https://www.cyoc.net/interactives/chapter_115321.html).)
+
+This high-level description of a hypothetical fantasy technology leaves some details unspecified—not just the _how_, but the _what_. What would the indistinguishable-from-magical transformation booth do to my brain? [As a preference-revealing thought experiment](https://www.lesswrong.com/posts/DdEKcS6JcW7ordZqQ/not-taking-over-the-world), what would I _want_ it to do, if I can't change [the basic nature of reality](https://www.lesswrong.com/posts/tPqQdLCuxanjhoaNs/reductionism), but if engineering practicalities weren't a constraint? (That is, I'm allowed to posit any atom-configuration without having to worry about how you would get all the atoms in the right place, but I'm not allowed to posit tethering my immortal soul to a new body, because [souls](https://www.lesswrong.com/posts/u6JzcFtPGiznFgDxP/excluding-the-supernatural) [aren't](https://www.lesswrong.com/posts/7Au7kvRAPREm3ADcK/psychic-powers) [real](https://www.lesswrong.com/posts/fdEWWr8St59bXLbQr/zombies-zombies).)
+
+The anti-plug-and-play argument makes me confident that it would have to change _something_ about my mind in order to integrate it with a new female body—if nothing else, my unmodified brain doesn't physically _fit_ inside Nana Visitor's skull. ([One meta-analysis puts the sex difference in intracranial volume and brain volume at](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3969295/) a gaping [Cohen's _d_](/2019/Sep/does-general-intelligence-deflate-standardized-effect-sizes-of-cognitive-sex-differences/) ≈ 3.0 and 2.1, respectively, and Visitor doesn't look like she has an unusually large head.)
+
+Fine—we're assuming that difficulty away and stipulating that the magical transformation booth can make the _minimal_ changes necessary to put my brain in a female body, and have it fit, and have all the motor-connection/body-mapping stuff line up so that I can move and talk normally in a body that feels like mine.
+
+I want this more than I can say. But is that _all_ I want? What about all the _other_ sex differences in the brain? Male brains are more lateralized—doing [relatively more communication within hemispheres rather than between](https://www.pnas.org/content/111/2/823); there are language tasks that women and men perform equally well on, but [men's brains use only the _left_ inferior frontal gyrus, whereas women's use both](/papers/shaywitz-et_al-sex_differences_in_the_functional_organization_of_the_brain_for_language.pdf). Women have a relatively thicker corpus callosum; men have a relatively larger amygdala. Fetal testosterone levels [increase the amount of gray matter in posterior lateral orbitofrontal cortex, but decrease the gray matter in Wernicke's area](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306238/) ...
+
+Do I want the magical transformation technology to fix all that, too?
+
+Do I have _any idea_ what it would even _mean_ to fix all that, without spending multiple lifetimes studying neuroscience?
+
+I think I have just enough language to _start_ to talk about what it would mean. What makes it hard to think about is that humans don't really _know_ how our own minds work. Evolution endowed us with certain capacities for making sense of the world, in our own way, when making sense of the world increased fitness in the environment of evolutionary adaptedness, but this mostly doesn't extend to making sense of the _mechanisms by which_ we can make sense of the world.
+
+People are [verifiably very good at recognizing sex from (hair covered, males clean-shaven) photographs of people's faces](/papers/bruce_et_al-sex_discrimination_how_do_we_tell.pdf) (96% accuracy, which is the equivalent of _d_ ≈ 3.5), but we don't have direct introspective access into what _specific_ features our brains are using to do it; we just look, and _somehow_ know. The differences are real, but it's not a matter of any single measurement: [covering up the nose makes people slower and slightly worse at sexing faces, but people don't do better than chance at guessing sex from photos of noses alone](/papers/roberts-bruce-feature_saliency_in_judging_the_sex_and_familiarity_of_faces.pdf).
+
+[TODO: Mathematically,
+Joel et al. and response—maybe in next paragraph
+http://zackmdavis.net/blog/2019/05/the-typical-set/
+> once you draw a boundary around a group, the mind starts trying to harvest similarities from the group. And unfortunately the human pattern-detectors seem to operate in such overdrive that we see patterns whether they're there or not; a weakly negative correlation can be mistaken for a strong positive one with a bit of selective memory.
+https://www.lesswrong.com/posts/veN86cBhoe7mBxXLk/categorizing-has-consequences
+[a higher-dimensional statistical regularity in the _conjunction_ of many variables](https://www.lesswrong.com/posts/cu7YY7WdgJBs3DpmJ/the-univariate-fallacy-1)
+96.8% classification from MRI https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6374327/
+]
+
+The same moral applies to sex differences in psychology. I'm a pretty weird guy, in more ways than one. I am not prototypically masculine. Most men are not like me. If I'm allowed to cherry-pick what measurements to take, I can name ways in which I'm more female-typical than male-typical. (For example, I'm _sure_ I'm above the female mean in [Big Five Neuroticism](https://en.wikipedia.org/wiki/Big_Five_personality_traits).) But "weird" represents a much larger space of possibilities than "normal", much as [_nonapples_ are a less cohesive category than _apples_](https://www.lesswrong.com/posts/2mLZiWxWKZyaRgcn7/selling-nonapples).