+We don't typically _think_ of it as the same issue here in America on Earth. People do sometimes complain about inappropriate reliance on "individual trait" proxies: that holding a college degree isn't the same thing as being educated, that IQ is not intelligence, that job interviews aren't the same thing as job performance, but the objection doesn't pack the same moral force in our culture:
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+oftentimes, the objection to
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+[
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+[](/2020/Apr/book-review-human-diversity/#schelling-point-for-preventing-group-conflicts)
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+]
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+But if you take probability and expected utility seriously—and everything we've been told about dath ilan says that that's what their Civilization is _all about_—then the quantitative extent to which the statement "It's wrong to make _X_ decision about me just because I'm _Y_" makes sense, depends quantitatively on how strongly _Y_ predicts the outcomes of _X_. Whether _Y_ is an "individual trait" like having Intelligence 18 or a demographic category like being female _does not matter_.
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+[TODO: we talk about Keltham being different "because" he's a dath ilani]
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+As far as principles are concerned, anyway. But pragmatically, might it not be the case in practice, that statistical group differences are small enough, and that individual trait measurements are cheap and reliable enough, such that "don't discriminate by race or sex" is a useful _heuristic_?
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+It's an empirical issue—but sure, very often, yes. For most jobs—especially most jobs in an industrialized Society like dath ilan—"always test the individual's aptitude, never use sex as a proxy" is a fine rule, because most jobs primarily rely on human general intelligence: there was no _dentistry_ in the environment of evolutionary adaptedness, and thus there's no reason why women or men should make better dentists. In domains where sex differences are small, using sex as a proxy would just be _dumb_, not _unjust_.
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+But then it's _bizarre_ that Keltham persists in his no-legal-sex-discrimination stance when his interlocutor brings up _military conscription_ as a potential counterexample. Because, well, as unpleasant as it is for modern folk to think about ... there _was_ war in the environment of evolutionary adaptedness. Men's bodies are built for war. Men's _emotions_ are built for war. [(Males have more reproductive fitness to gain and less to lose by the prospect of risking death in a war where the victors gain mating opportunities.)](https://www.cep.ucsb.edu/papers/EvolutionofWar.pdf) The sex difference in muscle mass is [_2.6 standard deviations_](/papers/janssen_et_al-skeletal_muscle_mass_and_distribution.pdf). That means a woman as strong as the average man is at _the 99.5th percentile_ for women. That means if you just select everyone whose strength is greater than one standard deviation _below_ the male mean, you end up excluding 94.5% of women.
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+Notwithstanding that Keltham grew up in a peaceful Society that [screened off its history](https://www.glowfic.com/replies/1612939#reply-1612939) (such that he wouldn't have read histories of some analogue of Genghis Khan), it seems like Keltham should know this stuff? We're told that dath ilan [has very advanced evolutionary psychology](https://www.glowfic.com/replies/1801140#reply-1801140), and there's no apparent reason for them to have spent any of their eugenics bandwidth selecting for reduced sexual dimorphism (which is [slower to evolve than monomorphic traits, anyway](/papers/rogers-mukherjee-quantitative_genetics_of_sexual_dimorphism.pdf)). We're told that [ordinary dath ilani are good at reasoning about effect sizes](https://www.glowfic.com/replies/1783037#reply-1783037).
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+But if Keltham _does_ know this stuff, why is he talking like a UC Berkeley graduate?