As I have often repeated here, I am from the Harry Benjamin school of genetic predisposition, but it’s important to note where the sociological aspects contribute in the development of the child.
Having a strong and controlling mother and caring, bookish and slightly distant father was probably not the best combination; neither was having two sisters immediately follow me in the birth order. I have a brother who is 5 years younger and he is as conventional a male as you can get. He was even dressed up by my sisters repeatedly with no ill effects on his gender identity.
Each person’s set of circumstances is entirely unique and, having read so many narratives over the years, I see no clear patterns emerge that would clearly point to why someone develops gender dysphoria. But there are likely some elements that carry more weight than others.
If a child over identifies with the mother rather than the father this could certainly cause some confusion and I suspect it must have been the case for me. For the longest time in my life, my mother was someone I could go to for guidance and I would favour her over my father especially if the issue was emotional in nature. My father became my source of guidance on more pragmatic questions.
Regardless, my psyche and hence my gender identity have been concreted. Now as I look back it was my inability to embrace that altered identity that created a problem since it did not coincide with a social norm which I was expected and to which I tried to live up to.
Now that our social roles are being relaxed, people can be who they are instead of worrying about measuring up to something artificial. It might also be that we end up reducing the number of surgical procedures for people who now really shouldn't need them to try and shoehorn themselves into a rigid binary they can't possibly fit into.