I think it was speculated that certain parts of the brain do look and react differently depending on if one is male or female, but that every individual brain is so different that you can tell the sex of the brain in one go. I suppose that means everyone is a bit non-binary, a bit feminine, and a bit masculine
There are statistical differences, sure, but nothing big enough to really work with other than in those same statistical terms (more/less likely). But I think it's key to point out that this attacks gender norms and not identity. It doesn't even attempt to discuss how identity comes about and research into intersex conditions (and other situations that occur shortly after birth, such as a botched circumcision) are interesting to show that identity does have some innate component. But what it does show is that the concept around ideas like "boys are better at math" and "girls are better at communication" is at best, a statistical difference, and not even close to a blanket statement. And are possibly total BS.
Yes to all the above! I'm at the point where I'm so confused about what's expected of me, sometimes forget which gender I was assigned at birth and then painfully remember. I.e., driving a tractor with a giant construction trailer attached. Squealing in my highest voice: "Oh my gosh, will you look at me! I'm doing it!!!" Remembering that this is ruining my perfect dudely moment. Remembering that thinking this is stupid, especially considering the person teaching me to drive is a transwoman. Getting angry when everybody around's talking to her about the technical stuff, but not to me, even though she desperately wants to get away from that image. Every day, being pushed back into boxes we don't fit in, but still somehow alive and kicking.