+With a _sufficiently_ detailed causal story, you could even dispense with the high-level categories altogether and directly talk about the consequences of different neurotransmitter counts or whatever—but lacking that supreme precise knowledge, it's useful to sum over the details into high-level categories, and meaningful to debate whether a one-type or two-type typology is a better statistical fit to the underlying reality whose full details we don't know yet.
+
+-----
+
+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. Many authors have noticed this clustering of traits, [while disagreeing about the underlying causality](/2021/Feb/you-are-right-and-i-was-wrong-reply-to-tailcalled-on-causality/).
+
+[Blanchard]
+
+[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.
+
+[Vitale] http://www.avitale.com/developmentalreview.htm
+
+[Serano 2020]
+
+Is a two type typology of male-to-female transsexualism a good theory? Is it "really" different conditions, or slightly different presentations of "the same" condition?
+
+
+I think I do have a pretty good guess at what's going on: https://en.wikipedia.org/wiki/Causal_graph ]