comment: An interesting fact about categories is that the way that the human brain works is not by matching definitions but rather by archetypes. 
  A lot of people think we put things in categories by comparing an item to a list of properties and then if and only if the item has the properties on the list does it go in the category. That’s not how brains or languages work. 
  Is a hotdog a sandwich?
  The reason people have inane category fight like this is that they keep making that definition basis error. I.e. “a sandwich has bread outside and a meat filling…”
  Instead, this is how categorization works:
  In your mind instead of a list of criteria, there exists a prototype sandwich. Close your eyes and say the word sandwich. If you’re like me, you’re now picturing that prototype sandwich. Mine looks like this 🥪. 
  It has two slices of white bread some lettuce and definitely some meat and cheese. That’s the center of the bullseye. The archetype. And it lights up a particular cluster of neurons that we can “recognition of a sandwich”. 
  Now when you open your eyes and see something that might be a sandwich, what you’re doing is comparing the new object to the archetype. If I see one without lettuce and on a club roll, my mind says “close enough” to the archetype and I call it a sandwich. Personally, when I see a taco, it’s too far from the bullseye to hit the recognition circuit cluster of neurons for “sandwich” so I don’t use that word. But if everyone else started to, probably my dart board would grow. It’s not like there’s some kind of objective meaning for the category. 
  Now, the exact same is true of social categories like gender. The word “woman” refers to the archetype you see when you close your eyes. That archetype is based on a platonic ideal of a woman. In my minds eye she looks like this 🙋‍♀️💃. In real life, when someone has long hair but isn’t wearing a dress, yeah, she land a hair off center from the bullseye — but is just as much a “woman” as a club roll with meat and cheese is a sandwich. Other things can vary too. Maybe she is wearing a dress but doesn’t have long hair. Maybe she has un expressed Y chromosomes. Maybe she’s physiologically male but expresses gender as a woman. 
  All of these things are somewhere on my dartboard for woman. 
  All social categorizations work this way. Things that fit a right definition based category rather than an archetype are the rare exception and gender has never been one of them.