I kinda hate when people point at the BSTc as a functional difference and as the one biological difference between transgender individuals and non-transgender individuals. The reason that I hate...
I kinda hate when people point at the BSTc as a functional difference and as the one biological difference between transgender individuals and non-transgender individuals. The reason that I hate this, is that it's based on extremely shoddy evidence with a horrendously low p, was a finding that they weren't even looking for, and the author never bothered to attempt to replicate it (as far as I know, no one has replicated this finding).
The two papers which all this evidence rests on are the following:
The first paper involves only 42 subjects, 6 of whom were transgender women. While they found that the BSTc was larger in males, for transgender women they failed to reach significance (p=0.13) for the assertion that their brains are more aligned with women. They also make an assertion about cross-hormone sex differences based on a single woman who had an adrenal tumor for a short period of time.
The second paper reviews the same subjects in the first paper, and attempts to further classify brain differences based on neuronal type and some other factors. Again, most assertions on transgender folks fail to reach a significant p. Of note, this particular study attempts to classify difference between homosexual and non-homosexual transgender individuals, a problematic framing which comes from a thoroughly discredited individual and is generally a red flag for poor quality research which is heavily influenced by bias.
Of additional note, studies since have proven a link between hormonal changes to brain organization 12, notably the BSTc appears to continue to differentiate and change far into adulthood 3, and brain morphology differences found in transgender individuals in the six individuals included in the original study may purely be a reflection of the age these individuals started hormones.
A final note on the original study by Zhou is that the study was not hypothesis driven and was purely exploratory. When you look at an unlimited number of data points and try to find the ones that differ, you will find differences due to pure chance. The BSTc was not even the region of interest they were exploring, suggesting that they examined additional areas just so they could have something interesting to publish. Given that no one has replicated their findings since and studies have even shown that the BSTc is more malleable in humans than originally thought (of note it's much less malleable into adulthood in rats), I wouldn't put any stock into these findings.
Just because I haven't had a chance to watch it yet, is this the generally stated idea that trans men have brains more similar to cis men's brains than to cis women's brains?
Just because I haven't had a chance to watch it yet, is this the generally stated idea that trans men have brains more similar to cis men's brains than to cis women's brains?
Sapolsky doesn't talk about what gender the transgender individuals he's talking about have. He generally refers to transgender and transsexual individuals (using the two terms interchangeably,...
Sapolsky doesn't talk about what gender the transgender individuals he's talking about have. He generally refers to transgender and transsexual individuals (using the two terms interchangeably, typically utilizing the latter) when talking about the research I criticized above, which only includes a grand total of 6 transgender women. He also talks briefly about phantom limb syndrome at the very end, but that's not exactly something we can pin down to brain structure or even brain activation (fMRI studies as a proxy for brain activity is itself quite problematic, but that's outside the scope of this reply). I'm not convinced that this is a true sexual dimorphism because nearly every study I've ever seen looking for sexual dimorphism in the brain is riddled full of problematic thinking, failure to adhere to the scientific method, or tainted by the file drawer effect. For more information on how male and female brains are probably not actually any different as well as general issues with science targeting gender, I highly recommend the book Delusions of Gender by Cordelia Fine.
Got it, I just wasn't sure if the research you referenced was that one that caused people to say that trans women's brains "look" more like cis women's brains on MRIs or what have you. Not that...
Got it, I just wasn't sure if the research you referenced was that one that caused people to say that trans women's brains "look" more like cis women's brains on MRIs or what have you. Not that this was necessarily considered accurate.
But yeah humans just don't have the level of sexual dimorphism that folks seem to look for, primary sexual characteristics aside, most everything else is on a bell curve that overlaps heavily IME. But I'm out of touch on the research. Thanks for the book rec, it'll get tossed on the TBR :-)
Sapolsky is referring to the two papers I linked in the top level reply when talking about the BSTc in the lecture. These papers do not use MRI data and are more targeted at measurements of brain...
Got it, I just wasn't sure if the research you referenced was that one that caused people to say that trans women's brains "look" more like cis women's brains on MRIs or what have you. Not that this was necessarily considered accurate.
Sapolsky is referring to the two papers I linked in the top level reply when talking about the BSTc in the lecture. These papers do not use MRI data and are more targeted at measurements of brain volume and subsequently counting receptor types. The BSTc is the portion of the brain he spends the majority of the talk highlighting, and he makes some claims with regards to how transgender brains resemble the brains of the gender with which they identify which I do not believe are justified.
Got it, thank you, and sorry for the confusion, I really should just watch the video but I ended up wanting to do the whole lecture which means it's a post-work task.
Got it, thank you, and sorry for the confusion, I really should just watch the video but I ended up wanting to do the whole lecture which means it's a post-work task.
As a brief aside, Sapolsky is perhaps best known in his rejection in the idea of free will. For someone so heavily invested in determinism, I'm not so certain he's the best person to be talking...
As a brief aside, Sapolsky is perhaps best known in his rejection in the idea of free will. For someone so heavily invested in determinism, I'm not so certain he's the best person to be talking about what essentially is biological determinism - he is perhaps more likely than others to suffer from confirmation bias when looking for differences in brain morphology. Even if some individuals are more likely than others to have a primarily nature based reason (such as by differences in brain morphology, as proposed) for being transgender, he doesn't seem to even confront the idea that nurture could effect whether someone goes to their deathbed insisting they were born the wrong gender but never pursuing hormonal intervention as compared to someone who pursues medical intervention at an earlier age (this premise assumes that hormones or other biological processes do not effect brain morphology as it is developing, for which there is ample evidence it does) and it doesn't even begin to confront gender non-conformity or situations which are more complex than folks who are transgender but conform to the gender binary.
In theory, being a determinist shouldn't impact the nature/nurture debate. On determinism, an individual's future is uniquely and necessarily determined by all of the causal factors in that...
In theory, being a determinist shouldn't impact the nature/nurture debate. On determinism, an individual's future is uniquely and necessarily determined by all of the causal factors in that individual's past. All of them. That includes environmental factors, because nobody is a bag of biology devoid of context. It's like the statement "that die roll was always going to come up six" could be because you rigged the die and table with magnets or it could be because the ten trillion different things leading up to that moment caused you to throw the die at such an angle that it would land on a six. Both would be a kind of determinism, but only one of them simplifies the entire phenomenon under study into a singular, mechanistic explanation.
It shouldn't, and to his credit Sapolsky does recognize this, but having listened to Sapolsky make his case about the lack of free will I harbor doubts about his ability to entertain ideas which...
It shouldn't, and to his credit Sapolsky does recognize this, but having listened to Sapolsky make his case about the lack of free will I harbor doubts about his ability to entertain ideas which are outside of his frame of reference. In particular, as I noted, the lack of understanding or familiarity with the diversity amongst transgender individuals and the focus on sexual dimorphism with no mention of hormones and other factors which might shape it, let alone the fact that dimorphism and even brain activation patterns are not precise models of thought... in short I just wonder if he's the right person to be talking about this. He is without a doubt an important professor in the biological sciences, but that doesn't necessarily give him authority to talk on this specific biological field.
Video Description: This is a snippet from 'Lecture 15: Human Sexual Behavior I' of Stanford's 'Introduction to Behavioral Biology' given by prof. Robert Sapolsky. The link to the entire lecture:...
Video Description:
This is a snippet from 'Lecture 15: Human Sexual Behavior I' of Stanford's 'Introduction to Behavioral Biology' given by prof. Robert Sapolsky.
I kinda hate when people point at the BSTc as a functional difference and as the one biological difference between transgender individuals and non-transgender individuals. The reason that I hate this, is that it's based on extremely shoddy evidence with a horrendously low p, was a finding that they weren't even looking for, and the author never bothered to attempt to replicate it (as far as I know, no one has replicated this finding).
The two papers which all this evidence rests on are the following:
https://pubmed.ncbi.nlm.nih.gov/7477289/
https://pubmed.ncbi.nlm.nih.gov/10843193/
The first paper involves only 42 subjects, 6 of whom were transgender women. While they found that the BSTc was larger in males, for transgender women they failed to reach significance (p=0.13) for the assertion that their brains are more aligned with women. They also make an assertion about cross-hormone sex differences based on a single woman who had an adrenal tumor for a short period of time.
The second paper reviews the same subjects in the first paper, and attempts to further classify brain differences based on neuronal type and some other factors. Again, most assertions on transgender folks fail to reach a significant p. Of note, this particular study attempts to classify difference between homosexual and non-homosexual transgender individuals, a problematic framing which comes from a thoroughly discredited individual and is generally a red flag for poor quality research which is heavily influenced by bias.
Of additional note, studies since have proven a link between hormonal changes to brain organization 1 2, notably the BSTc appears to continue to differentiate and change far into adulthood 3, and brain morphology differences found in transgender individuals in the six individuals included in the original study may purely be a reflection of the age these individuals started hormones.
A final note on the original study by Zhou is that the study was not hypothesis driven and was purely exploratory. When you look at an unlimited number of data points and try to find the ones that differ, you will find differences due to pure chance. The BSTc was not even the region of interest they were exploring, suggesting that they examined additional areas just so they could have something interesting to publish. Given that no one has replicated their findings since and studies have even shown that the BSTc is more malleable in humans than originally thought (of note it's much less malleable into adulthood in rats), I wouldn't put any stock into these findings.
Just because I haven't had a chance to watch it yet, is this the generally stated idea that trans men have brains more similar to cis men's brains than to cis women's brains?
Sapolsky doesn't talk about what gender the transgender individuals he's talking about have. He generally refers to transgender and transsexual individuals (using the two terms interchangeably, typically utilizing the latter) when talking about the research I criticized above, which only includes a grand total of 6 transgender women. He also talks briefly about phantom limb syndrome at the very end, but that's not exactly something we can pin down to brain structure or even brain activation (fMRI studies as a proxy for brain activity is itself quite problematic, but that's outside the scope of this reply). I'm not convinced that this is a true sexual dimorphism because nearly every study I've ever seen looking for sexual dimorphism in the brain is riddled full of problematic thinking, failure to adhere to the scientific method, or tainted by the file drawer effect. For more information on how male and female brains are probably not actually any different as well as general issues with science targeting gender, I highly recommend the book Delusions of Gender by Cordelia Fine.
Got it, I just wasn't sure if the research you referenced was that one that caused people to say that trans women's brains "look" more like cis women's brains on MRIs or what have you. Not that this was necessarily considered accurate.
But yeah humans just don't have the level of sexual dimorphism that folks seem to look for, primary sexual characteristics aside, most everything else is on a bell curve that overlaps heavily IME. But I'm out of touch on the research. Thanks for the book rec, it'll get tossed on the TBR :-)
Sapolsky is referring to the two papers I linked in the top level reply when talking about the BSTc in the lecture. These papers do not use MRI data and are more targeted at measurements of brain volume and subsequently counting receptor types. The BSTc is the portion of the brain he spends the majority of the talk highlighting, and he makes some claims with regards to how transgender brains resemble the brains of the gender with which they identify which I do not believe are justified.
Got it, thank you, and sorry for the confusion, I really should just watch the video but I ended up wanting to do the whole lecture which means it's a post-work task.
As a brief aside, Sapolsky is perhaps best known in his rejection in the idea of free will. For someone so heavily invested in determinism, I'm not so certain he's the best person to be talking about what essentially is biological determinism - he is perhaps more likely than others to suffer from confirmation bias when looking for differences in brain morphology. Even if some individuals are more likely than others to have a primarily nature based reason (such as by differences in brain morphology, as proposed) for being transgender, he doesn't seem to even confront the idea that nurture could effect whether someone goes to their deathbed insisting they were born the wrong gender but never pursuing hormonal intervention as compared to someone who pursues medical intervention at an earlier age (this premise assumes that hormones or other biological processes do not effect brain morphology as it is developing, for which there is ample evidence it does) and it doesn't even begin to confront gender non-conformity or situations which are more complex than folks who are transgender but conform to the gender binary.
In theory, being a determinist shouldn't impact the nature/nurture debate. On determinism, an individual's future is uniquely and necessarily determined by all of the causal factors in that individual's past. All of them. That includes environmental factors, because nobody is a bag of biology devoid of context. It's like the statement "that die roll was always going to come up six" could be because you rigged the die and table with magnets or it could be because the ten trillion different things leading up to that moment caused you to throw the die at such an angle that it would land on a six. Both would be a kind of determinism, but only one of them simplifies the entire phenomenon under study into a singular, mechanistic explanation.
It shouldn't, and to his credit Sapolsky does recognize this, but having listened to Sapolsky make his case about the lack of free will I harbor doubts about his ability to entertain ideas which are outside of his frame of reference. In particular, as I noted, the lack of understanding or familiarity with the diversity amongst transgender individuals and the focus on sexual dimorphism with no mention of hormones and other factors which might shape it, let alone the fact that dimorphism and even brain activation patterns are not precise models of thought... in short I just wonder if he's the right person to be talking about this. He is without a doubt an important professor in the biological sciences, but that doesn't necessarily give him authority to talk on this specific biological field.
Video Description:
This is a snippet from 'Lecture 15: Human Sexual Behavior I' of Stanford's 'Introduction to Behavioral Biology' given by prof. Robert Sapolsky.
The link to the entire lecture: https://www.youtube.com/watch?v=LOY3QH_jOtE
The link to one of the studies mentioned: https://www.nature.com/articles/378068a0
Some outdated language but it is a very interesting segment if you ask me.
Saved for later, ty :)