I can’t confidently make claims about all brain imaging studies as I haven’t read enough of them, but as a general rule studies that claim to find links between neurology and psychological traits are fake (same problem as candidate gene studies, plus maybe also the problem of “it’s not clear we’re looking at the right variables”) unless the trait in question is g (IQ).
This applies not just to the trans brain studies, but also to the studies claiming to find the sex differences in brain structure (while large sex differences in brain structure do exist, the ones that have been found so far appear to be completely uncorrelated with psychological traits that have sex differences once you control for sex, so they do not mediate the relationship between sex and those psychological traits).
Oh and I guess I should add, if we do insist on talking about brain neurology in the context of transness, there is one set of studies I expect to replicate, because it is conceptually very simple. The idea is to take a bunch of cis men and cis women, train a predictor to classify people’s sex from their brain structure, and then apply that brain structure to trans women. This is essentially a multivariate approach, which I’d expect Zack to like because he talks a lot about multivariate approaches.
The general pattern from the studies I’ve read is that prior to transitioning, trans women have male brains, and after having been on HRT for a while, trans women’s brain structure shifts to be in the middle between cis women and cis men (on the sex-separating axis). I don’t know if trans women’s brains change even more given even longer time; it seems conceivable that they do.
But anyway most noteworthy about these studies is that this applies to both HSTSs and AGPTSs. I.e. HSTS MtFs (who Zack sees as “true transsexuals”) have male brains prior to transitioning. (See the second of my links for more info on this.) This illustrates why I am not enthusiastic about arguments based on multivariate group-separating axes: HSTSs are clearly feminine in some sense, but this isn’t the sense which gets emphasized when taking the neurological sex-separating axis. I’m not sure why Zack still regularly makes appeals to multivariate groups differences though. My best guess is that he doesn’t pay attention to this but he should be encouraged to answer for himself.
I can’t confidently make claims about all brain imaging studies as I haven’t read enough of them, but as a general rule studies that claim to find links between neurology and psychological traits are fake (same problem as candidate gene studies, plus maybe also the problem of “it’s not clear we’re looking at the right variables”) unless the trait in question is g (IQ).
This applies not just to the trans brain studies, but also to the studies claiming to find the sex differences in brain structure (while large sex differences in brain structure do exist, the ones that have been found so far appear to be completely uncorrelated with psychological traits that have sex differences once you control for sex, so they do not mediate the relationship between sex and those psychological traits).
Oh and I guess I should add, if we do insist on talking about brain neurology in the context of transness, there is one set of studies I expect to replicate, because it is conceptually very simple. The idea is to take a bunch of cis men and cis women, train a predictor to classify people’s sex from their brain structure, and then apply that brain structure to trans women. This is essentially a multivariate approach, which I’d expect Zack to like because he talks a lot about multivariate approaches.
I think I’ve seen three or four studies that do this, but the two I have at hand right now are Sex Matters: A Multivariate Pattern Analysis of Sex- and Gender-Related Neuroanatomical Differences in Cis- and Transgender Individuals Using Structural Magnetic Resonance Imaging and Regional volumes and spatial volumetric distribution of gray matter in the gender dysphoric brain.
The general pattern from the studies I’ve read is that prior to transitioning, trans women have male brains, and after having been on HRT for a while, trans women’s brain structure shifts to be in the middle between cis women and cis men (on the sex-separating axis). I don’t know if trans women’s brains change even more given even longer time; it seems conceivable that they do.
But anyway most noteworthy about these studies is that this applies to both HSTSs and AGPTSs. I.e. HSTS MtFs (who Zack sees as “true transsexuals”) have male brains prior to transitioning. (See the second of my links for more info on this.) This illustrates why I am not enthusiastic about arguments based on multivariate group-separating axes: HSTSs are clearly feminine in some sense, but this isn’t the sense which gets emphasized when taking the neurological sex-separating axis. I’m not sure why Zack still regularly makes appeals to multivariate groups differences though. My best guess is that he doesn’t pay attention to this but he should be encouraged to answer for himself.