I've just been allied with "outmoded science and prejudiced social attitudes" for holding the view that human (and all mammalian) biology is sexually dimorphic. The person is now refusing to engage further with me, despite having encouraged the discussion after I politely said we would never convince each other to change sides. Partly very angry right now and partly feeling like I have played a small part in demonstrating the weakness of the "sex is a spectrum" argument. Bringing it out into the light, for discussion in the mainstream.