Testosterone may erode language skills in the female brain

This MRI study of brain changes in 18 women who are injecting testosterone to “transition” to male is getting a bit of traction in the press. (Apparently the researchers, from the European College of Neuropsychopharmacology, have only announced their findings; there is no published paper in the literature that I could find.)

Update: In response to several comments I’ve received, as well as some fruitful Twitter discussions with scientists and linguists, I would like to clarify a couple of points:

  • By itself, this study tells us nothing definitive about the possible impact of testosterone on the female brain. Particularly since the researchers did not couple the MRI with pre- and post-testosterone cognitive-linguistic testing, we don’t know whether the reduction in gray matter in the subjects’ brains correlates with reduced verbal fluency. Even more informative would be functional MRI studies (fMRI) while the subjects are performing linguistic tasks. Obviously, the results should spur researchers to do studies on more subjects, along with objective linguistic test measures to see whether results are replicated and whether they do indicate a decline in linguistic skills. I have found 3 studies in the research literature which point to a statistically significant decline in verbal fluency in women who have increased circulating testosterone.
  • Secondly, it is my opinion that the results of this study, along with a few others which assessed verbal fluency, should be shared with women who are contemplating testosterone “therapy.” It’s quite likely some of these women would go on to inject “T” anyway, but it’s also possible some would choose not to. Knowledge is power.
  • To discover whether testosterone-induced brain changes seen on MRI are permanent, another important line of research would be to longitudinally study women who want to inject “T” for only a limited time period. Multiple followup MRIs (and cognitive-linguistic testing) would provide insight into whether testosterone’s effects are permanent or temporary in these cases.

The big news is that “T” administered to women results in decreased volume of gray matter in the all-important zone of language in the brain, Broca and Wernicke’s areas. And these changes occurred after only 4 weeks of testosterone treatment.

According to one of the researchers, Dr. Andreas Hahn,

It has been known for some time that higher testosterone is linked to smaller vocabulary in children and that verbal fluency skills decrease in female-to-male transsexuals after testosterone treatment. This fits in well with our finding of decreased grey matter volume. However, the strengthening of the white matter in these areas was a surprise. We think that when it comes to certain language skills, the loss of grey matter outweighs the strengthened white matter connection.

Think about that. “It has been known for some time…that verbal fluency skills decrease in female-to-male transsexuals….when it comes to certain language skills, the loss of grey matter…” We are potentially talking about a loss of brain cells here.

Call me alarmist, but this is such major news that all the gender specialists should be sitting up and taking notice and–oh, I don’t know, maybe expressing a few doubts about the wisdom of injecting male sex hormones into females? Or asking the women about to start on “T” whether a potential loss of neurons is something they actually want for their future? Seems there might be some need to question whether a  reduction in gray matter of the cerebral cortex is an acceptable risk to take for women who wish they were men?

The press coverage I’ve seen so far hasn’t hinted at any medical ethics concerns raised by the study results. For instance, the venerable Washington Post treats the whole thing as just another ha-ha “Men are from Mars, Women are from Venus” fluff piece. Heck, the title of the Post article is “Why Men Get Tongue-Tied.” They could at least have called it “Why Women are So Verbally Adept.” You know, throw a tiny bone to the fact that the subjects of this study were women? 

Instead, it’s all about the differences in how men and women communicate–which admittedly, is an interesting corollary. But hang on a minute. How can they even draw those conclusions? This study didn’t compare men and women. The journalists are jabbering glibly about differences between men and women, but the study looked at 18 women who had been injecting themselves with testosterone for a month, not men.

But you can’t entirely blame the predictably shallow, politically correct press for ignoring the elephant in the room–or should I say, the guinea pigs. The researchers themselves only seem interested in how these results illuminate the differences between men and women–not on the rather sobering implications for “gender reassignment.” The opening paragraph of the press release says

Brain imaging shows that testosterone therapy given as part of sex reassignment changes the brain structures and the pathway associated with speech and verbal fluency. This result supports research that women in general may deal with speech and interaction differently than men.

So let me see if I follow. If endogenous hormones are largely responsible for some rather crucial brain and communication differences between ADULT men and women, how in the hell are transgender people “really” the opposite sex from birth (as the activists and specialists firmly believe), if it takes hormone treatment to actually differentiate their brains?

What we see is a real quantitative difference in brain structure after prolonged exposure to testosterone. This would have been impossible to understand without looking at a transsexual population. In more general terms, these findings may suggest that the genuine difference between the brains of women and men is substantially attributable to the effects of circulating sex hormones. Moreover, the hormonal influence on human brain structure goes beyond early developmental phases and is still present in adulthood.

Right. “Circulating sex hormones” make the man (or woman). So, aren’t the researchers then pretty much stating that people who claim to have brains “born in the wrong body” don’t actually have the brains of the opposite sex until they undergo cross-sex hormone treatment? 

This intriguing neuroimaging study of transsexuals before and after their female-to-male gender reassignment suggests that even adult men and women differ in brain structure within regions involved in language and speech. In particular, female-to-male gender reassignment resulted in local brain matter decrease within language processing regions, which may explain why verbal abilities are often stronger in women.

Here’s an idea. How about we start doing some pre-treatment studies and surveys of young women who are considering “transition.” Hell, let’s ask the prepubescent girls and teens too, since the activists and gender docs seem to think the earlier they get on “T”, the better. Let’s ask them how they feel about a “brain matter decrease” that potentially could make them less adept with language. (We don’t know this but it’s a possibility).

Just a suggestion. Just a few words from the zone of language in this female brain, which has not been marinated in extra androgens, thank you very much.

Some other press coverage of this research. None mention that loss of gray matter in the zone of language might be cause for concern in “transitioning” females. In fact, they are all essentially rewrites of the press release provided by the researchers. I’d expect more from well established news outlets with high circulation, but that’s just me. (Tangentially, I did happen upon an interesting study showing higher circulating testosterone in children who stutter, inspiring me to look more deeply into the effects of testosterone on communication skills in the future.)







29 thoughts on “Testosterone may erode language skills in the female brain

  1. so are post menopausal women men now? this is really disturbing that the medical field is finding evidence that testosterone causes brain damage to women and are just excusing it as acceptable because it’s ok to cause brain damage in women or something, the whole business is bizarre.

    Liked by 3 people

    • This is the first research study I’ve ever seen where there is zero concern voiced about the possible negative effects of the treatment the subjects received. Significant gray matter loss is a huge effect after only a month on testosterone. And the media coverage is even more strange. I guess their attitude is, these women are on “T” because they want to be, so who cares if their brains shrink?

      Liked by 4 people

      • Im terribly skeptical that transition is medically ethical but I am completely convinced that the medical community treats trans people like garbage.

        Liked by 3 people

      • I would not be at all surprised if injecting especially large amounts of any hormone have a negative effect on the body including the brain. But brain research is notoriously awful. I want to see this crazy fake sex change mass experiment end. Poor research showing problems is not going to help us get there.

        “Loss of gray matter volume” is not brain damage. No one knows what it is. It really is just the brain is, or looks like, it is a little bit smaller. Raising the question ‘Smaller than what?’ there aren’t standard sizes for different areas of the brain anymore than there’s a standard size for foot length or calf circumference. The way MRI technology works if the person’s head is at a slightly different angle then the brain or a particular area of it will look smaller. And saying there is “loss of gray matter volume” in the “language area” is just meaningless. “The” language area is spread over the whole of the forward half of the temporal lobe. Where different language functions are varies from person to person. Hugely. Studies like this one really don’t tell you anything. Which is unfortunate because at the same time it’s good that someone is actually trying to look at does taking these hormones damage the body. Looking for it in the language area of the brain though is very weird. All hormones have a thing called their ‘target organ’. For Luteinizing Hormone Releasing Factor the target organ is the ovary. Looking for damage in the target organs makes a lot more sense to me. If the person takes hormone blockers as I’ve heard MtoF do then there’s possible impaired functioning from not having that hormone. So the question would be what else does testosterone do? It does like whiskers, muscle building and so forth but is it involved in say, metabolism? This is just off the top of my head. (I’m a scientist and science critic. My field is brain science.) And of course any weird disease like cancers of the tissues that make up the target organ or some big ass all body disease like leukemia, are the things that if they turned up in higher than usual numbers in people taking these drugs that would be how that kind of an effect would be discovered in the normal way that we do science and public health. Because this is all totally INSANE off-label use. No testing has been done. And we have heard haven’t we about men on estrogen getting breast cancer, right? That’s a target organ effect.

        Sorry to be so long-winded and pedantic.

        Liked by 2 people

      • The fact that they saw a measurable decrease in certain brain regions after only one month of testosterone is not “meaningless.” It isn’t a matter of the total size of the area. It’s the fact that there was shrinkage compared to what was there 4 weeks prior. In my comment, I used the word “damage” loosely and somewhat facetiously. But speaking only for myself, if I learned that a drug I was taking reduced gray matter volume in my brain’s left cerebral hemisphere that quickly, I’d consider it “damage.”

        There was a loss of brain matter in an important region of the brain, and that’s a big deal. And experienced research MRI technicians and brain scientists are not going to be tripped up by head positioning errors. Much of what is currently known (including, recently, from MRI and fMRI studies) about this part of the brain comes from decades of study of people who have brain damage–via stroke, traumatic brain injury, etc. Verbal fluency, grammatical knowledge, semantics, comprehension, and all the other remarkable language skills we take for granted emanate from the zone of language. Anyone who has known someone with a severe left hemisphere injury can attest to that. That testosterone affected a part of this region in women’s brains so quickly is cause for more study of FTMs, not flippant articles about “men being tongue tied.” Of keen interest to me is the researchers’ passing comment that it has been known for “some time” that FTMs lose language facility. On what are they basing that assertion? As scientists, they are likely not just talking about anecdotal evidence, but I plan to find out.

        Liked by 3 people

  2. This study is loaded with biases. A sample size of 18 cannot be taken seriously, especially when pre-selected without any effort at establishing controls. I read this article a few days ago and was aghast that anybody took this begging the question sort of work seriously.

    Liked by 2 people

    • Agree that an “n” of 18 is way too small, but what it should stimulate is a much bigger study to see if the results are replicable. If all 18 of these women had the same brain effect, it is cause for concern. Loss of brain volume is such a screamingly serious effect it needs to be studied widely. But no one cares, because the assumption is that these women want this to happen. They want EVERYTHING that “T” brings, and that is an insane assumption. I have read so many accounts written by young detransitioned women wherein they said they simply were not informed about all the possible dangers of androgen treatment. We sure as hell know that “brain damage” is not mentioned on the package insert for testosterone…

      Liked by 3 people

      • I don’t know how one studies hormone abuse without enabling hormone abuse. Hormones are powerful chemicals the body produces that serve specific purposes. We evolved a couple three million years and became this. But also our culture exposes us to hormone mimickers. It’s all wrong up from the bottom falling out.

        Liked by 1 person

      • Agreed about hormones and how screwed up this is. But the study wasn’t unethical. These were adults who volunteered, who were already voluntarily injecting testosterone. What they could do is a study looking at women who are willing to go off “T” for a while (or forever) and see what happens to those same brain regions. Is there any neural regeneration in Broca’s and Wernicke’s areas, or are the changes permanent? There are many detransitioned women who would be quite interested in that avenue of research. And asking subjects to go OFF “T” would not be unethical at all…

        Liked by 1 person

  3. ‘Seems there might be some need to question whether a significant reduction in gray matter of the cerebral cortex is an acceptable risk to take for women who wish they were men?’

    While I went along with much of your argument, you have inserted the word ‘significant’ into your question where it does not appear in the original quotes. Nowhere is it stated how much grey matter is lost or how much it might matter.


    • Good point. Corrected. How much it might matter needs testing, obviously. What the authors do assert is that an evidence base already exists that female-to-male transsexuals lose some verbal facility. They even say that has “been known for some time.” I’m curious what they base that assertion on.

      Liked by 2 people

      • Wouldn’t it be helpful if they’d included citations? That’s sort of the point of peer review–letting people review the basis of your assertions. Perhaps I’m cynical, but I suspect this was never fully published because it couldn’t be “spun” in the right way. As you’ve said, it cuts against the brain-body disconnect narrative, that “trans” women are a male brain trapped in a female body and need T to bring their body in line with their male brain. That logic falls apart the second someone finds that T is changing the brain.


  4. I so admire your (4thwave and commenters) ability to write clearly on this press release and its media coverage. I’m still in the furious / spluttering / screaming / throwing things stage.

    Liked by 2 people

  5. It would be nice if someone studied what happens to the brains of women who take estrogen for all the various reasons it’s prescribed. A while back, someone finally noticed that high levels of estrogen can cause aggression — who’da thunk it? t wouldn’t surprise me if excessive amounts of any sex hormone turned out to cause foul moods and/or neurological changes in ways that aren’t obviously sex-differentiated.

    Anecdotally, I have seen zero evidence that one sex is more verbally gifted than the other.

    Liked by 2 people

  6. This is really disturbing information. And it was reported in a fluff piece! The medical field does truly treat those who seek to “transition” as less than animals. There is more outrage against testing cosmetics on rabbits.

    Liked by 5 people

    • No, this blog is focused on the current trend to diagnose kids and teens as transgender. We do talk about aspects of transition as it pertains to adult women. But our primary concern is protecting young people, who are being encouraged to undergo medical transition before they have the cognitive wherewithal to sign off on permanent changes to their bodies and minds. In case you haven’t noticed, there are very few people actually discussing the possible down side of “transition.” Luckily we have free speech in the US so we are providing a place for that here. Adults who have reached the age of medical majority will do what they want. Doesn’t mean they can’t benefit from more information. That’s a bit different from “telling other women what to do with their bodys” [sic]

      Liked by 6 people

  7. For further insight on this, I refer you to an MD/brain scientist who comments frequently on research like this in one of the gender critical subReddits. (URL at bottom of this comment)

    She says:
    A decrease in gray matter means one of two things: dendrites were pruned away, as in neuroplasticity, or there was an actual loss of cell bodies of neurons. The former isn’t a huge deal because those connections can be rebuilt. The latter is a bigger deal because neurons don’t regenerate and the brain has to work harder to overcome those deficits. My hypothesis with the white matter connections becoming “stronger” is that it’s an attempt to compensate for the loss of gray matter.
    What’s more distressing is that this happened after only four weeks of testosterone administration in women. What happens after a year? Two years? Furthermore, what happens in girls, these “trans kids,” whose brains haven’t yet finished developing?
    Truly, I’m seriously puzzled by the conclusions of the researchers in this study. You can’t take a normal female brain, bathe it in male hormones, and then say that this is how a normal male brain develops. All you can come away with from such a study is that this is what happens when you take a normal female brain and bathe it in male hormones abnormally. And the results aren’t good.
    This should seriously give anyone considering transition pause, but I’m afraid that it will just encourage them. “Hey, look, the more T I inject, the more manbrain I’ll develop!” No, the more gray matter you’ll destroy, and the more cognitive impairment you’ll develop. Are we going to see a whole generation of transitioned women with early-onset dementia?

    Liked by 2 people

  8. Replying to petuniacat00
    on September 5, 2015 at 4:11 am:

    Re: “brain research is notoriously awful,” brain research is all over the map from excellent to dismal. What is notoriously awful is the way neuroscience research is reported, as Cordelia Fine and others have documented so well.

    I agree with 4thwave’s comments at 12:12 PM on the implications of the study, given what little information we have on it.

    Testosterone, and other hormones, have wide-ranging and complex effects on the body, including the brain. You cannot think of them as having a single target organ. A major reason to be concerned about treating kids with hormone blockers and cross-sex hormones is the well-known fact that hormones are crucial for the normal maturation of the brain in adolescence, in particular the frontal cortices. We have not investigated how the current standard of care for so-called trans kids affects their brains.

    I Googled “consent forms transgender.” The forms I’ve read so far closely resemble each other, and none of them make any mention of any possible effects on brains.

    Liked by 1 person

    • Excellent comment. Many gender-critical feminists tend to throw the baby out with the bathwater when it comes to neuroscientific brain research, because too much of it (as Fine points out) has been used to justify the man brain/lady brain meme trans-activists love to promote. But nature-nurture is a false dichotomy, and if we really want the truth, we should look at ALL facets, all evidence. To me, the man brain/lady brain justification for this whole transgenderist trend CAN be thrown out, because, regardless of how a particular person’s brain looks on MRI, that brain is a priori part of the rest of the body. In other words, if a particular woman’s brain has an anatomy/physiology more closely resembling that of the majority of men, so what? That just shows the diversity of humanity, and should not be a reason to see that woman’s body as foreign or “wrong” and in need of drugging and amputation/augmentation. However, research like that discussed in this post, showing a RAPID change (and 4 weeks is very rapid) in a brain region after administration of “T” is cause for MORE research, and, at a minimum, an effort to inform patients about to embark on hormone “treatment” about such research and its implications. Like a direct question: “How would you feel about a measurable reduction in the brain region responsible for speech and language? These studies [cited] indicate this may be a side effect of testosterone treatment.”

      Liked by 2 people

  9. Hello, new here. Do you have a post or can you direct me to where various permanent effects of even short-term doses of testosterone on FTM trans are fully explained? Thank you.


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