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I need to bring up something that's been bugging me.

We talk all the time about how sex isn't just genitals, it's every piece of our being. If you look into it, even our non-sexual organs are genetically dimorphic between men and women.

The inconsistency to me though is when we say there's no such thing as a female brain. All of a sudden, all of the femaleness that is intrinsic to every other part of who we are becomes invisible. I understand that we don't want to lend credibility to the idea that TIMs can have a "female brain," but even the research that exhibits sexual dimorphism in brains doesn't show that--in fact, while "trans brains" are mildly shifted towards their "preferred gender," they are still well-within normal ranges for their sex, and still outside the average range for their "identity." It's not a gotcha, and I don't think we need to be afraid of it.

The graphic on this study (under Results) is especially good to look at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8955456/

If anything, I think admitting that female brains do exist (with some variance within the sex, of course) and that TIMs do not have them is perfectly good evidence for being gender critical. (And for those who criticize lesbians for not sleeping with TIMs because we're genital fetishists, well, no, the brain plays a part too. Suck on that, "hearts, not parts.")

Some might call it sexist to say there are differences between male and female brains, but I think the it's more that the sexist conclusions that people come to as a result of the difference existing are problematic--ie: because "female brains" exist, women must be more predisposed to doing housework, or some other nonsense.

Also, when we talk about puberty blockers being harmful because of the importance of sex hormones in adolescent brain development, I think it's a bit willfully ignorant to not assume that estrogen and testosterone might have different effects on the brain.

Prove me wrong, please, or give me another way to think about it! I just think it's something worth tackling head on, rather than brushing aside.

I need to bring up something that's been bugging me. We talk all the time about how sex isn't just genitals, it's every piece of our being. If you look into it, even our non-sexual organs are genetically dimorphic between men and women. The inconsistency to me though is when we say there's no such thing as a female brain. All of a sudden, all of the femaleness that is intrinsic to every other part of who we are becomes invisible. I understand that we don't want to lend credibility to the idea that TIMs can have a "female brain," but even the research that exhibits sexual dimorphism in brains *doesn't show that*--in fact, while "trans brains" are mildly shifted towards their "preferred gender," they are still well-within normal ranges for their sex, and still outside the average range for their "identity." It's not a gotcha, and I don't think we need to be afraid of it. The graphic on this study (under Results) is especially good to look at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8955456/ If anything, I think admitting that female brains do exist (with some variance within the sex, of course) and that TIMs do not have them is perfectly good evidence *for* being gender critical. (And for those who criticize lesbians for not sleeping with TIMs because we're genital fetishists, well, no, the brain plays a part too. Suck on that, "hearts, not parts.") Some might call it sexist to say there are differences between male and female brains, but I think the it's more that the sexist conclusions that people come to as a result of the difference existing are problematic--ie: because "female brains" exist, women must be more predisposed to doing housework, or some other nonsense. Also, when we talk about puberty blockers being harmful because of the importance of sex hormones in adolescent brain development, I think it's a bit willfully ignorant to not assume that estrogen and testosterone might have different effects on the brain. Prove me wrong, please, or give me another way to think about it! I just think it's something worth tackling head on, rather than brushing aside.

43 comments

I mean, there is such a thing as a female brain: it's a brain in which all the neurons have XX chromosomes, and which has been bathing in female levels of estrogen from the time it was in utero.

What there is NOT is a brain structure or organization that is found in all non-trans women, and in trans-identified men.

Yes, of course there is a female brain. It is a brain that belongs to a female. Every cell is XX. Strogen induces more neuroplasticity and vasodilation. That's what we know.

There isn't however a statistical significance in morphological and structural analysis between female and male brains. There is no gender center in our brains.

Thus there is no material reality to the claim "born in the wrong body". It is purely a belief on "female essence", same old misogyny you can find criticized extensely by Simone B, with the addition of the idea that this essence can exist on poor men's bodies, as well, so we better let them pee into our bathrooms. It's in their essence.

I have been saying for years that while man's and women intellectual habilities are not the same, it doesn't mean that woman are less intelligent. There are different strength ON AVERAGE like for height and such and those strength are all valid: we just need to judge differently. However, lots of people found it was sexist of me to say brains were different 🤯

And the trans's lady brain are just ridiculous... That's something else, and THAT is sexist.

I think you're right. As I commented elsewhere (and others have brought up more eloquently), the issue is when the female brain is shorthand for women not being as intelligent or capable as men.

But there likely are differences, if only in the chromosomal makeup of brain cells. Apparently pregnancy also changes the brain quite seriously (they compare it to the changes brought about during adolescence) and permanently, though I don't know the full extent or indeed if the full ramifications are fully understood yet by researchers (I listen to a lot of podcasts, so have no sources to hand, and tend to be multitasking while listening so foggy on the details - an ironic case of mum brain!). So maybe in addition to male and female brains, we should be thinking in terms of child, adolescent and adult brains, and nulliparous and mother brains (and possibly post-menopausal brains?). I hasten to add that given how plastic and adaptable the brain is, I would be surprised to see major differences in function between adult brains (neurodiverse aside). Just because I had a baby doesn't mean I have forgotten how to read, eg. In fact now I can read and respond while making sure my toddler doesn't set the house on fire.

Trans brains aren't skewed towards their preferred gender, the paper got it wrong, the correlation was with sexual orientation, not "gender identity". So far there have been no trans brain markers observed. Basically on average, but not always, certain structures are enlarged in gay men and women (who are mainly straight), and that first trans study was done with all HSTS TIMs, aka gay men, so obviously some of their brains looked like that. Straight TIMs don't have anything like it. Obviously hormones impact the brain, I think people saying there is no female brain were railing against the idea that men and women are diametrically opposed with no overlap, which makes sexism easier to defend (for example, "all women are incapable of math", or "all men are incapable of communicating their feelings in a calm manner"). Also the brain isn't just formed through genetics and hormones, life experience wires the brain. The trauma from growing up female in this dangerous world certainly impacted how our brains function. In any case, even if they do find a trains brain marker some day, it still wouldn't justify the erosion of women's rights.

Re: "hearts not parts", the straight TIMs fail on that front too. I've had the misfortune of interacting with a ton of them since I'm a lesbian in a big city with "queer" friends who bring them around (also have read my friend's dating app messages from many of them). Not a single one of them acts like a woman! Not even slightly! They are selfish and feel entitled to women's time, attention, and bodies in a way that is fully male. They corner women and go into graphic detail about disturbing sex topics, either unaware of her discomfort or enjoying it. They threaten stalking and rape when someone politely turns them down. Not only that, but the libfem women don't treat TIMs like women either, they defer to them like they defer to men. If a lesbian acted how they act no one would think twice about kicking her out of a friend group.

[–] BlackCirce 🔮🐖🐖🐖 2 points

It was recently established that human brains are monomorphic. There are no significant sex differences in brain structures that hold up across diverse populations.

GCs have become obsessed with demonstrating sexual dimorphism in humans (which is moderate at best), to the point where it almost comes across as a belief in female as a separate species. Humans are not extremely, severely, dramatically dimorphic, but we aren’t monomorphic either, and that’s that.

There are over 6500+ genetic differences between men and women. Sex codes over a 3rd of our genes differently.

So our bodies are drastically dimorphic. Our brains aren’t, outside of chromosomes and other biological differences that don’t relate to functionality.

What you're suggesting makes sense to me, OP. I am not an expert in the area, but I know evolutionary biologists Heather Heying and Bret Weinstein have discussed sex difference in the brain--I think they've discussed how males start out relatively more focused on objects and females are more interested in faces.

IIRC trans brains aren’t “shifted” at all because that study didn’t control for homosexuality.

that was a point i forgot to add! i wonder how studies will look with more AGPs than HSTSs...

Also, when we talk about puberty blockers being harmful because of the importance of sex hormones in adolescent brain development, I think it's a bit willfully ignorant to not assume that estrogen and testosterone might have different effects on the brain.

Yes, I am sure the different hormones have an effect. But's important to keep in mind that estrogen is only one of several sex hormones we make and that affect us females.

Moreover, research on humans and other animals considered similar show that males not only make estrogen directly in their testes and other parts of the male reproductive tract, just as females make testosterone in our ovaries - but that males also convert some of the testosterone and other androgens they make into estrogens - estradiol and estrone - in some of their body parts/tissues through the process of aromatization due to the enzyme aromatase. Aromatization is a process that only occurs one way, turning androgens into estrogens. Aromatization does not convert estrogen into androgens.

Interestingly, one of the main sites where males appear to convert quite a lof of their T into E through aromatization is the male brain.

Aromatase is the enzyme responsible for converting testosterone to estradiol. In mammals, aromatase is expressed in the testes, ovaries, brain, and other tissues. While estrogen is traditionally associated with reproduction and sexual behavior in females, our current understanding broadens this perspective to include such biological functions as metabolism and cognition. It is now well-recognized that aromatase plays a vital lifetime role in brain development and neurobehavioral function in both sexes.

https://www.frontiersin.org/articles/10.3389/fnmol.2018.00374/full

Estrogen masculinizes neural pathways and sex-specific behaviors:

Male behaviors require both testosterone and estrogen. Circulating testosterone activates the androgen receptor (AR) and is also converted into estrogen in the brain via aromatase. This conversion is the primary source of estrogen to the male brain. It is unclear whether testosterone and estrogen signaling interact to masculinize neural circuits. Using a genetic approach, we show extensive sexual dimorphism in the number and projections of aromatase expressing neurons. The masculinization of these cells is independent of AR but can be induced by either testosterone or estrogen, indicating a role for aromatase in sexual differentiation of these neurons. We provide evidence suggesting that aromatase is also important in activating male aggression and urine marking as these behaviors can be elicited by testosterone in males mutant for AR. Taken together with additional findings, our results suggest that aromatization of testosterone into estrogen is important for the development and activation of neural circuits that control male territorial behaviors.

Estrogen is also essential for male behaviors. The requirement for estrogen to masculinize behavior seems counter-intuitive as this ovarian hormone is essentially undetectable in the male circulation. All estrogenic steroids are synthesized in vivo from testosterone or related androgens in a reaction catalyzed by aromatase. Aromatase expressing cells in the brain convert circulating testosterone into estrogen, and it is this local estrogen that is thought to control dimorphic behaviors in males (Figure 1A) (MacLusky and Naftolin, 1981; Naftolin and Ryan, 1975). Consistent with a requirement for estrogen in male behaviors, aromatase activity is essential for male behaviors.

Estrogen mediates many of its effects by signaling through the estrogen receptors ERα and ERβ, which exhibit overlapping expression patterns, and regulate masculinization of the brain and behavior in a complex, redundant manner (Bodo et al., 2006; Ogawa et al., 1999; Ogawa et al., 2000; Ogawa et al., 2004; Perez et al., 2003; Rissman et al., 1997).

The role of a third estrogen receptor, GPR30, in male behaviors is presently unknown (Revankar et al., 2005).

The dual requirement for testosterone and estrogen signaling in male behaviors suggests that these two pathways may interact genetically to control these dimorphic displays. One potential site of interaction is the control of aromatase expression.

We find extensive, previously uncharacterized sexual dimorphisms in both the number and projections of neurons expressing aromatase. The masculinization of these neural pathways is independent of AR but can be induced in neonatal females by testosterone or estrogen, indicating that aromatase plays an important role in the sexual differentiation of these neurons. Moreover, testosterone activates male typical fighting and urine marking independent of AR, demonstrating that the differentiation and function of the neural circuits underlying these behaviors are governed by testosterone, at least in part, after its conversion into estrogen. Finally, our results show that adult gonadal hormones of either sex can support male territorial marking and fighting provided estrogen has neonatally masculinized the underlying neural circuitry.

Circulating testosterone and locally derived estrogen in the brain are critical for the expression of male behaviors. It has been difficult to determine the individual contributions of these two hormones to masculinization of the brain and behavior. Our gene targeting strategy has allowed us to identify at cellular resolution the small population of aromatase expressing neurons that can synthesize estrogen from testosterone. Testosterone appears to serve, at least in part, as a pro-hormone for estrogen for the male typical differentiation of aromatase positive neurons and for masculinization of territorial behaviors.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2851224/#:~:text=Male%20behaviors%20require%20both%20testosterone,estrogen%20to%20the%20male%20brain.

https://pubmed.ncbi.nlm.nih.gov/33621637/

With the explosion of neuroimaging, differences between male and female brains have been exhaustively analyzed. Here we synthesize three decades of human MRI and postmortem data, emphasizing meta-analyses and other large studies, which collectively reveal few reliable sex/gender differences and a history of unreplicated claims. Males' brains are larger than females' from birth, stabilizing around 11 % in adults. This size difference accounts for other reproducible findings: higher white/gray matter ratio, intra- versus interhemispheric connectivity, and regional cortical and subcortical volumes in males. But when structural and lateralization differences are present independent of size, sex/gender explains only about 1% of total variance. Connectome differences and multivariate sex/gender prediction are largely based on brain size, and perform poorly across diverse populations. Task-based fMRI has especially failed to find reproducible activation differences between men and women in verbal, spatial or emotion processing due to high rates of false discovery. Overall, male/female brain differences appear trivial and population-specific. The human brain is not "sexually dimorphic."

[–] kelltoid [OP] 1 points Edited

Interestingly, Lise Eliot (one of the names on the study you provided) has a pretty extensive history of trying to provide "research evidence" for transgenderism... Click on her name and one of the first articles I saw says, "Preliminary evidence suggests pubertal suppression improves mental health functioning." Not sure I'd trust anything her name is attached to.

[–] SecondSkin 1 points Edited

Her original work was about how there’s no functional difference between boy and girls brains.

Then we were all on twitter a decade back using her work to shut down TRAs and she back tracked a bunch iirc. Same with the lead on the massive Swedish cohort study that shows transitioning doesn’t reduce male violence/increases suicide etc. she got all huffy we used her own valid research conclusions to shut down the trans zealots and got all but transys are so sweet and just want to peeeeee herself.

You shouldn’t accept any persons findings, you should read through the individual research yourself. It isn’t she said this it’s this specific research says this.

Maybe she's given up on chasing the impossible in the face of overwhelming evidence or the other three have basically told her to stop chatting shit.

When people are making the argument that "female brains" don't exist, it is because it is a response to the idea of a "female brain" as demonstrated by this graphic. The idea that gender, sex role stereotypes and roles, are innate and result from different brain structures between men and women is what this idea of a "female brain" comes from. Female brains, brains developed as a part of a female body, exist, but "female brains", a sexist idea, does not.

Absolutely this. Female brains definitely exist but the assumption that they can't do everything male brains can do, just as well (or better), is the problem.

OH! That makes sense... I can see how I misunderstood then, I thought they were trying to say that sexual dimorphism just doesn't exist when it comes to the brain. Thank you for clearing that up~

I've seen it abused by TIMs who say "the brain scans of some males show patterns more similar to those of females, not other males, therefore this proves they are women in mens' bodies."

Men are, on average, taller than women. Yet many individual women are taller than many individual men. So this is the rhetorical equivalent of saying "this man if 5'4, and the average height of a woman is 5'6, while for a man is 5'9. Therefore, this man is actually a woman because SHE is 5'4."

Yes, sexual dimorphism is real - and one facet of this is that, since most health benchmarks and therapies are normed for men, we are under/misdiagnosed and not as well treated. The problem is when it's turned into a scientistic factoid by TIMs to 'prove' their point.

I increasingly think the lesson is just not to argue with people incapable of good faith, rather than try and either explain or oversimplify reality, which is complicated but still doesn't prove you can be "born in the wrong body."

Theoretically even if there were blue and pink brains, and the pink brain was born in a male body, it doesn’t mean born in wrong body. If this hypothetical situation was real it could just mean that human species has developed to the extent female brains can be in male bodies and vice versa. Like x men shit. Even if it were real it doesn’t mean they need to mutilate their bodies or use spaces for the opposite sexed body. We don’t pee from our brains, a female brain in a male body doesn’t need the female toilets.

If it were hypothetically even possible.

When they say 'female brain" they mean a stereotypically "feminine" mind/psyche/personality - which they assume, mistakenly, is innate and physical in origin.

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