+ * *Claim*: [brain intersex theory]
+ * *Claim*: [transition actually works]
+ * *Claim*: [social gender is determined by secondary sex characteristics anyway; you don't usually see someone's genetalia, let alone chromosomes, _&c_.]
+ * *Conclusion*: [they actually are of their target gender]
+
+Notice that this is an _empirical_ argument for why trans people fit into _existing_ concepts of (social) gender, not a redefinition of words by fiat in order to avoid hurting someone's feelings. To the extent that any of the claims _fail_ to be true of self-identified trans people or some subset thereof, the conclusion is correspondingly weakened. Note that these can change over time (_e.g._, if transition technology improves).
+
+[explain two-type taxonomy; [single paper rec](http://unremediatedgender.space/papers/lawrence-agp_and_typology.pdf)]
+
+[caveats: take care to note that it's possible to believe in a weaker form of it: maybe you argree to the bimodality in the data, but don't think it's two discrete etiological types; or, maybe you [agree that there are two etiologies, but](https://thingofthings.wordpress.com/2017/04/18/against-blanchardianism/) don't buy that AGP is the cause]
+
+[note that I'm focusing on MtF because of reasons; analyzing the situation with trans men is left as an exercise to the interested reader]
+
+In less tolerant places and decades, where trans women were very rare and had to try very hard to pass as cis women out of dire necessity, the impact on the social order and how people think about gender was minimal—there were just too few trans people to make much of a difference.
+
+Nowadays, in progressive enclaves of Western countries, this is no longer true, and in communities that form around [non-sex-balanced interests](http://slatestarcodex.com/2017/08/07/contra-grant-on-exaggerated-differences/), the numbers can be quite dramatic. For example, on the 2017 _Slate Star Codex_ reader survey, 9.4% responded _F (cisgender)_ to the gender question, compared to 1.4% responding _F (transgender m -> f)_. So, if trans women are women, _13.4%_ (!!) of female _Slate Star Codex_ readers are trans.
+
+A (cis) female friend of the blog, a member of the Berkeley, California rationalist community reports on recent changes in local social norms—
+
+> There have been "all women" things, like clothing swaps or groups, that then pre-transitioned trans women show up to. And it's hard, because it's weird and uncomfortable once three or four participants of twelve are trans women. I think the reality that's happening is women are having those spaces less—instead doing private things "for friends," with specific invite lists that are implicitly understood not to include men or trans women. This sucks because then we can't include women who aren't _already_ in our social circle, and we all know it but no one wants to say it.
+
+Depending on your values, of course, you might be in favor of making it socially unacceptable to have sex-segregated spaces that are actually segregated by biological sex; the methods of rationality themselves have nothing to say on the matter.