This is very interesting. I don't doubt that gender identity is biological. I agree with the current thinking that gender dysphoria is not mental illness. It is just apparent to me in my very small sample size of three (two transfem for more than 50 years and one transmasc for 10 years) that mental illness and gender dysphoria are, at least in my sample, adjacent to each other in 100% of trans people I know. I am also of the mind that mental illness is a biological issue so having biological gender dysphoria and biological mental illness adjacent to each other raises questions.

I have been thinking as I've been puttering around this evening and you just hit the nail on the head. It is the secondary sexual characteristics of cis women that I find attractive. I like a feminine face, natural breasts, and wide hips. I have a copy of The Big Butt Book 3D that a friend gave me in my nightstand. I don't find men's bodies attractive. When I look at a fit man I think, that's a great body but I don't feel any attration to him. I just appreciate that it is a good body. I have never encountered a transfem whose body I found attractive. In all cases I found their faces and bodies masculine which I don't find attractive. To be honest, I don't find supermodels attractive, either. They're too skinny, with no behinds and often very chiseled, masculine faces. I think Scarlett Johansson is gorgeous and I find her body very attractive. I think Anna Kendrick if stunning but I don't find her body attractive. She's too light in the pants for my tastes. I don't find most social media personalities at all attractive because I don't like heavy makeup and fakeness. I like no makeup, hair pulled up into a ponytail, and ... I dunno, plain?

Saying that I have an exclusive sexual preference for cis women is a very good starting point. I'm not interested in penises at all and every single person that I've ever been attracted to sexually has been a cis woman with the secondary sexual characterists of a cis woman. I don't hate or fear trans women, I'm just never been attracted to any that I've met.