+[If a category seems to come into types, you can reify those as separate sub-categories, like bipolar I and II. The idea that there's something to the idea that bipolar I and II are "different", is s]
+
+[In the case of male-to-female transsexualism, straight and gay trans women seem different. Many authors agree to this simple story! e.g., Veale, Vitale, possibly Serano 2020 —but they have different detailed theories as to how the two clusters come about—the simple story is a useful approximation even if you don't know how to pin down the more detailed story]
+
+[I think I do have a pretty good guess at what's going on: https://en.wikipedia.org/wiki/Causal_graph ]