(Posted in thanks to Saanvi’s help)
We’ve addressed this argument in the past:
Gender and Biology – The Council (spirited-tech.com)
There are a few different points I wish to make.
If these studies are correct, then it implies a trans person is merely a percentage of the other gender. This is because they have a certain percentage of their brain similar to their biological sex. What’s the threshold of brain distribution of tissues or gland sizes that entails you have passed from one gender to another?
There’s also an issue of whether this proves there’s any relevant similarity. It may very well be the case that such is true but has nothing to do with gender. For example, suppose toenail length in women and trans women were closer than trans women were to cis men. Does that show the distribution of toenails is causal of gender?
It also turns out that if the view was true, then homosexual men don’t exist. That is because their brains are closer to cis women’s brains rather than cis male brains. Or does it imply women don’t exist and are just homosexuals in disguise?
Study Says Brains of Gay Men and Women Are Similar – Scientific American
It also appears that females to males are less male than males to females are female:
“The Brain Sex of transgender women was estimated as 0.75 ± 0.39, thus hovering between cisgender men and cisgender women, albeit closer to cisgender men (see also Figure 1). The follow-up post hoc tests revealed that transgender women were significantly more female than cisgender men (Cohen’s d = 0.64, t(46) = 2.20, p = 0.016), but significantly less female than cisgender women (Cohen’s d = 1.87, t(46) = 6.48, p < 0.001).”
Brain Sex in Transgender Women Is Shifted towards Gender Identity – PMC (nih.gov)
By this standard, trans women are just mixes of the two rather than distinctly the other. I haven’t found a study calculating this for transgender men in comparison to female brains. I suspect that is most likely because transgender men’s brains are probably not that different than cis female brains. This would imply that transgender women are more women than a transgender man could ever be a man, given this view.
“It is important to note that CW and TM did not differentiate in any FC dynamical measure.”
There’s also the issue that these studies purposely didn’t study the non-binary genders. But aren’t those equally real supposed genders? I suspect just like the tested folks will range like transgender men and women in terms of their brain structure and matter distribution. What should we expect a non-binary brain to look like?
Furthermore, various other factors for such brain structural differences:
“Men and women’s brains do differ slightly, but the key finding is that these distinctions are due to brain size, not sex or gender,” Dr. Eliot said. “Sex differences in the brain are tiny and inconsistent, once individuals’ head size is accounted for.”
The unusually large study of studies, “Dump the ‘dimorphism’: Comprehensive synthesis of human brain studies reveals few male-female differences beyond size,” published in Neuroscience and Biobehavioral Reviews, finds that size is the only clear-cut difference between male and female brains. Women’s brains are about 11% smaller than men’s, in proportion to their body size. Smaller brains allow certain features, such as a slightly higher ratio of gray matter to white matter, and a higher ratio of connections between, versus within, cerebral hemispheres. …
A last focus of the new study is on functional MRI. This method allows neuroscientists to see areas that “light up” during particular mental tasks and has been widely used to look for male-female differences during language, spatial, and emotional tasks.
Across hundreds of such studies, Dr. Eliot’s team found extremely poor reliability in sex difference findings — nearly all specific brain areas that differed in activity between men and women were not repeated across studies. Such poor reproducibility agrees with recent research out of Stanford University demonstrating “false discovery,” or the over-publication of false-positive findings in the scientific literature on functional MRI sex difference.
“Sex comparisons are super easy for researchers to conduct after an experiment is already done. If they find something, it gets another publication. If not, it gets ignored,” Dr. Eliot said. Publication bias is common in sex-difference research, she added, because the topic garners high interest.
“Sex differences are sexy, but this false impression that there is such a thing as a ‘male brain’ and a ‘female brain’ has had wide impact on how we treat boys and girls, men and women,” Dr. Eliot said.
“The truth is that there are no universal, species-wide brain features that differ between the sexes. Rather, the brain is like other organs, such as the heart and kidneys, which are similar enough to be transplanted between women and men quite successfully.”
The Council 