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+In the case of male-to-female transsexualism, we notice a pattern where androphilic and non-androphilic trans women seem to be different from each other—not just in their sexuality, but also in their age of dysphoria onset, interests, and personality.
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+This claim is most famously associated with the work of [Blanchard](/papers/blanchard-typology_of_mtf_transsexualism.pdf), [Bailey](https://en.wikipedia.org/wiki/The_Man_Who_Would_Be_Queen), and [Lawrence](http://www.annelawrence.com/autogynephilia_&_MtF_typology.html), who argue that there are two discrete types of male-to-female transsexualism: an autogynephilic type (basically, [men who love women and want to become what they love](/papers/lawrence-becoming_what_we_love.pdf)), and an androphilic/homosexual type (basically, the extreme right tail of feminine gay men).
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+But many authors have noticed the same bimodal clustering of traits under various names, [while disagreeing about the underlying causality](/2021/Feb/you-are-right-and-i-was-wrong-reply-to-tailcalled-on-causality/). [Veale, Clarke, and Lomax](/papers/veale-lomax-clarke-identity_defense_model.pdf) attribute the differences to whether defense mechanisms are used to suppress a gender-variant identity. [Anne Vitale](http://www.avitale.com/developmentalreview.htm) identifies distinct groups (Group One and Group Three, in her terminology), but hypothesizes that the difference is due to degree of prenatal androgenization. Julia Serano [concedes that "the correlations that Blanchard and other researchers prior to him described generally hold true"](/papers/serano-agp-a_scientific_review_feminist_analysis_and_alternative.pdf), but denies their causal or taxonometric significance.
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+Is a two type typology of male-to-female transsexualism a good theory? Is it "really" two different conditions (following Blanchard _et al._), or slightly different presentations of "the same" condition (following Veale _et al._)?
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+When the question is posed as such—if I have to choose between a one-type and a two-type theory—then I think the two-type theory is superior. But I also think we can do better and say more about the underlying causal structure that the simple two-types story is approximating, and hopefully explain anomalous cases that look like "noise" to the simple theory.
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+In the language of [causal graphs](https://en.wikipedia.org/wiki/Causal_graph) (where the arrows point from cause to effect), here's what I think is going on: