[Serious] Please convince me gender is binary

[Jehanne]

The idea is that brains produce minds, not souls or spirits:

Are the Brains of Transgender People Different from Those of Cisgender People?

All feelings and their behaviors come down to brain function, and most chronic differences must surely come down to brain structure.

You are arguing that the seat of the self is in the brain, so if the brain has structures typical of females, then the self is functionally female without regard to the form of much courser organs located far from that center.  Do I read you correctly?

I am no expert, but it is at least certain that gender is not purely black/white.  Some biological men, such as myself, are effeminate; some women (some women cops, for sure) are masculine.  I have traits that are female; I know this to be so, because, over the last 50 years of my life, I have had other women look and even make fun of me when I was acting "feminine" around my children.  My two youngest children, now age 20 and 21, used to call me "Moddy", when they were toddlers.  And, my "list" goes on and on.  As such, I am comfortable with the label "transgender".