This study also found differences in transgender and cisgender brains.
Nevertheless, even though findings are not immediately comparable, all existing structural MRI classifier studies—as well as a recent resting-state functional MRI classifier study [38]—seem to support the notion of a “shift” away from the biological sex towards the gender identity in transgender people.
It was also specifically carried out on participants that has not undergone any hormone therapy yet so the results cannot be explained away as the effects of hormones.
The observed shift away from a male-typical brain anatomy towards a female-typical one in people who identify as transgender women suggests a possible underlying neuroanatomical correlate for a female gender identity. That is, all transgender women included in this study were confirmed to be genetic males who had not undergone any gender-affirming hormone therapy. Thus, these transgender women have been subject to the influence of androgens and grown up (at least up until a certain age) in an environment that presumably treated them as males. The combination of male genes, androgens, and (to some degree) male upbringing should ordinarily be expected to result in a male-typical brain [39,40,41,42,43,44,45], making a female-typical brain anatomy extremely unlikely. Yet, the brain anatomy in the current sample of transgender women is shifted towards their gender identity
So, what is it again that you feel makes a person truly transgender vs not transgender at all? Taking hormones to make their brains shrink? Because that then puts your other claims about "It is not transphobic to point out that men who are clearly exploiting self ID laws by only pretending to be transgender for the duration of their prison sentence, are not genuinely transgender." in significant doubt too.
In fact, if a male person is taking hormones to exploit the laws as you describe, they are exactly the same in brain as all other male people taking the treatment.
No it doesn't, because the the men falsely claiming to be transgender to exploit laws do not take hormones, they declare themselves transgender women after being convicted, then continue living their lives as men after they are released. They are clearly not making any effort to transition, obtaining a GRC or taking hormones, because they are clearly not transgender, they just pluck it out of the air post conviction for an easier life, because the poor legislation we have allows them to do that. All of this together makes it clear they are not transgender individual, they are liars. A person who is genuinely transgender will be doing things like having a GRC, taking hormones and will have transitioned socially, or if they are not fully transitioned yet, they will have at least mentioned it to someone before being convicted, not just plucked it from the air. It is blindingly obvious to anyone not trying to be deliberately obtuse that there is a clear difference between these two groups of people. And I do not believe for a minute that any transgender person would find it transphobic that people point out the first group are liars that make them look bad and are not transgender individuals.