I'd always been under the impression that the brain's spacial differences developed more according to how we used it, not necessarily by biology. Have we separated genetic brain development from what is environmental/individually ingrained...
And the way I see it, some people have higher aptitude in certain areas, so perhaps more connections are made... but for example, if you have never developed a certain skill or trait, then that part lays in atrophy... and developing, encouraging new habits, it takes a lot of repetition, I guess to map learn new behavioral patterns....
But our personalities are a complex thing. They're likely dependent on several dependencies, and some areas may strongly reinforce certain aspects, so different to remap in that sense....
As far as biology, yes, they've seen differences between brains, but I was under the impression that was individualized and didn't necessarily mean there was a cause, it could be instead be a symptom...
For example, if I have an addiction, my pleasure centers are going to look different than other folk.
If someone is suffering from dysphoria and is constantly dealing with the discomfort of their identity, then why would it not make sense they may align or develop their behaviors according to chosen sex... and as such, that those brain characteristics may grow accordingly.
I sometimes sound like a Latina, and have certain characteristic of that speech as those were the female peers I associated with... but then I don't think that because my speech patterns show in brain images that that suddenly means I'm full Mexican.
It just means my environment shaped my thinking, my mannerisms and the way I feel comfortable communicating with others...
The thing is, when many people transitions, it doesn't end the dysphoria. It helps to alleviate it, but it doesn't end the symptoms. That's why I err on the side of caution when it comes to "brain scans" as being the proof in the pudding. I think more research needs to be done into why there is a dysphoria in the first place... not simply, oh, there's more female centers and thus female... there's a lot we still don't really understand about the human brain... and if it down to mental illness, then we need to know what it is, so we can treat it better actually and improve the livelihood of those who are suffering with it... but when these discussions are had, they are treated as "transphobic" by activists for not falling in line with their subscribed thought processes...
I think on SD in particular, it feels like an inquisition sometimes... and I think Nom and Vicky, maybe they were like me, did their own research in their own time in an attempt to understand why there are so many difficult feelings there when simply having a discussion... and what I've found does not necessarily paint a pretty picture of where we are going as a society, when discussions about science are labeled as counter-productive, anti-insert thing, pro-male white supremacy, etc... there's an uglier side to this activism, and I think--because these issues are so close to home to them--some folk would rather ignore that this exists and fosters a looming sense of anxiety when it comes to these discussions... because there are political ideologies trying to entrench themselves with this activist... and for better or worse, they have hijacked the discussion which I think has distracted from what is actually helpful to those suffering versus what they'd like to accomplish instead... but yes, that is the short version, and I think people who are talking about what they think is evidence, would not like to be straw-manned into one of those side conversations about what is decency, what is socially acceptable in discussion and so on...