New Research Finds Differences Between Male and Female Brains
psychologytoday.com
psychologytoday.com
I don't see how it's surprising that an new generation of signal-detection tool finds population-level differences in the brains that produce these cognitions.
However, the news article seems to spin this as "male and female brains are totally different entities that bear no relationship with one another." Although I haven't reread it carefully, it seems like the article is saying something more like "you can identify gender-specific patterns, and those gender-specific components relate to things like cognitive ability gender-specifically". It's not that you can't find overlap — that that wasn't the focus of the study — it's that if you go looking for differences, you can find them.
When you give a man a female dose of hormones or a woman a male dose of hormones, it has a very big effect on their mood, behavior, and mental wellbeing. This change is much, much bigger than the average diffences we see between men and women. For example, an average man with an average woman's level of testosterone will experience a MUCH higher level depression, listlessness, and sexual disinterest than the average woman experiences.
This strongly implies that human brains must correct for these huge hormonal differences. Basically, in order for male and female behavior to be similar, their brains must differ. If their brains are the same, then hormones will have a much, much bigger influence on male and female behavior than what we actually see in reality.
Hormone-correcting brain differences would also imply that it's possible for people to be born with some type of intersex brain condition, and that these individuals would benefit greatly from receiving hormone therapy to bring their hormone levels in line with their brains. And this, indeed, seems to be something we see occasionally.
(In case anyone cares or thinks it is relevant, I wish to note that I am a cisgender woman and I do not think that there are huge innate differences in men's and women's mentality — certainly nothing like on the level that testosterone/estrogen/etc levels would predict. I think most of the differences we do see are environmental, which is why these gaps have been closing in recent history — or widening in some cases/locations. Based on these trajectories, I suspect that men and women are actually FAR more similar than anyone natively groks, and that we exaggerate or invent small differences due to a biological hyperfixation with sex. Note that we don't obsess about the mental differences between, say, male and female cats, even though they have much greater sexual dimorphism than humans do.)
Is this true even if they were to have an average woman's level of estrogen? It may be that the brain needs either set of hormones to work effectively, and doesn't work well when lacking both (of course, gender transition HRT aims for this, but pretty much all undergoing it are trans and so aren't a good indication of average reaction to hormones for their chromosomal sex. And a cis person undergoing the same HRT isn't likely to enjoy the process)
They do. They have the average 60-year-old woman's level of estrogen.
That said, this meta-analysis is also filled with some crazy statements. It seems to imply sexual dimorphism is only really visible in repro organs but women necessarily need to have wider hips to facilitate child birth among other differences.
This obvious point should have also been noted when comparing differences in organ mass, since mothers of babies with larger heads are more likely to die so this is selected against. Not an issue with lungs, heart etc., hence larger % differences in sexes there.
These aren’t egregious omissions in and of themselves, but it’s certainly useful context I’d like to have were I not familiar with sexual dimorphism.
The dismissiveness of a 1.6 fold increase in SDN size of human males compared to human women is bad. That’s enormous! Not something I would prepend with “only” and repeatedly call “small”, even when not comparing the differences between M/F humans and M/F rodents.
Bizarre that none of the authors objected to this phrasing, because it’s poisoned reading the rest of this paper for me. How am I meant to trust the authors’ opinion of what a “small” difference is?
Some of the points are a bit more compelling, like in section 5.1 where they point out that a difference attributed to M/F was replicated in much smaller size by concentrating on volume instead, or in 5.2 where they point out a few papers that missed crucial nuance.
But overall after reading a few thousand words of this, the nicest thing I can say about it is that I agree that it is indeed gigantic.
If your study can't find those differences it's your study that's wrong, not that the differences don't exist.
Possibly, yes. But "common sense" is a very weak way of describing things here, because common sense is usually used to describe intuition, not knowledge. We are talking here about knowledge - men and women are different mentally, this isn't something unknown, or something requiring a study.
> since they're talking about structural and functional neurological differences
Given that there are obvious mental differences, and that most people don't believe in duality, that would imply there have to be neurological differences, if your study didn't find them, your study is faulty. Either that, or it's evidence for dualism.
The whole point of science is to double-check this sort of thing, the stuff "everyone knows" that seems obvious to casual observation, like that the earth is flat. Plus you're simply asserting and re-asserting that this is capital-K Knowledge, without providing any reasons, just banging the podium. That's not very convincing. This is anti-intellectualism.
> Given that there are obvious mental differences, and that most people don't believe in duality, that would imply there have to be neurological differences, if your study didn't find them, your study is faulty. Either that, or it's evidence for dualism.
Or maybe the differences are very social and contextual — men and women's brains largely operate the same way and are structured the same, but give different outputs because they're given different inputs — and the impacts of those social and contextual inputs are simply too fine-grained to show up.
> This is anti-intellectualism.
And what epithet would you give to those who pretend there is no difference?
> Or maybe the differences are very social and contextual
This is certainly an interesting idea (and one I've heard before). But you have to prove it. You can't just declare "I found no differences, therefor it must be a social difference".
The standard of evidence to declare this is very high, it requires actual proof not just a well reasoned argument.
And you will have to somehow explain all the evidence against this - for example in nordic countries they found that if they give the household enough money the wife prefers to stop working, and stay home. This went against their idea that men and women should be paid the same, and supported identically, because then women will want to work. Instead they found women actually preferred to be home, and they only wanted to work if they had to (i.e. not enough money). Men however had the opposite result.
So their goal of equal employment would require them to reduce support. I'm not sure what the government chose to do.
> are simply too fine-grained to show up.
Then your study is faulty and you should declare "invalid study", not "valid study we found nothing".
BTW, note how the article you cited doesn’t argue against differences between male and female brains but makes a rather pedantic point about “dimorphism”.
Without those definitions it's basically saying "things we grouped a certain way ended up grouped that way" which isn't really a useful result.
But definitely, pretending that innate differences between sexes are influenced by the social construct of gender is going to far into a rabbit hole.
Let's just accept that we can still have medical research based on sex, and understand that it doesn't invalidade the idea of gender. It is just a different matter.
We know for a absolute fact that genetic expression is environmentally impacted - To the extent that even eukaryotic organisms can change sex based on environmental factors
So it’s not implausible that environmental factors actually do affect human genetic expression of characteristics that we typically consider gendered
It is a simple variable, we can start from it and then try to see whether gender self-identity has any effect.
We can be pretty sure of the sex-at-birth of any human being given some simple tests. It is a simple variable that we can trust have been correctly recorded the vast majority of time. Gender identity? not so simple.
And given a correct understanding of the differences, if any, between sex-at-birth individuals, we will have a good framework from which we can investigate if those differences follow gender identity, and if so, what is their causal relationship with gender, etc. etc. etc...
What I am questioning, is that if every time a scientist do a sex-at-birth based study we question implicitly if they are not being bigots, we will end up censoring scientific inquiry for no good reason at all. (yeah, I do believe that not all scientific inquiry is allowable, for example, I oppose research on chemical and biological weapons)
In a culture without such polarized ideals of how males and females should behave and present themselves, the concept probably wouldn't exist at all.
You’re supposing that the binary classifier is the most accurate starting point.
I’m suggesting that you should assume that this is a biased starting point and shouldn’t have any power as a benchmark or reference frame in any dimension
The same way we don’t use ideas like humors anymore because they are based on bad assumptions
So, I am no medical doctor, but I was a pretty diligent student, and given the few things I studied about human physiology, I can assure you that biological sex is a pretty much fundamental fact for species that propagate via sexual reproduction, something that I can provide some anedoctal evidence being an homo sapiens, and being one of the parents of a certain number of other homo sapiens.
Maybe it is not as fundamental as the measurement of whether someone have a pulse or not at the present moment, or if their core temperature is around 36C, but it is still really consequential. Indeed, sex is far more consequential than something like race, which basically is mostly irrelevant for medicine.
You see, the problem with your analogy, is that humours was not a theory really based on the systematic observation of reality. Once we could measure more and more things empirically, it was pretty clear that it was a crackpot theory.
And while in a sense, you may be right and someday we could come up with new scientific facts that showed that the whole edifice of sexual reproduction would be superceded by new, better scientific concepts, the fact is that this has not happened, and frankly, it doesn't look even remotely likely to happen.
Until the day we have an alternative scientific theory, with predictions that can be reliably reproduced on experiments, and that explain such foundational biological issues such as human reproduction and secondary sexual characteristics, sex continues to be a very useful category of study.
Indeed, even the medical field of gender reassignment treatment relies heavily on the corpus of knowledge based on the concept of sex in things like hormonal treatment and puberty blockers.
We are not able to tell if someone is a logical person or a cool dude or whatever just by looking at it.
And apparently hormones don't make a brain look different either
Neuro-biology of trans-sexuality : Prof. Robert Sapolsky
Has there? Following studies have shown more differentiation than in the earlier studies. Reviews of the data resulted in some additional commonalities, accoring to: https://en.wikipedia.org/wiki/Causes_of_gender_incongruence
Which research are you referring to?
"In the first edition of my book Why Gender Matters, published by Doubleday in 2005, I devoted a chapter to kids who are psychologically “gender-atypical.” I suggested that these kids are somewhere in between male and female. But the Stanford study provides little support for that claim. I am hopeful that the researchers will do follow-up studies specifically looking at individuals who are gender-nonconforming, gender-atypical, and who have gender dysphoria, to see whether and how those characteristics influence these findings."
If you look at the graphs from the study those people could be the outliers but no matter what, it's not really enough people to glean anything useful.
This is not accurate for the cohort under study. 5% of people under age 30 identify as transgender or nonbinary. I would personally be unsurprised if well over 100 individuals in the study identified that way.
https://www.pewresearch.org/short-reads/2022/06/07/about-5-o...
(As an aside, this is one of the things that makes the data on the effectiveness of transition care more remarkable than it even looks. Given the very high probability that a random person is cisgender, even moderate false-positive rates would swamp true-positives. The fact that they don't suggests false-positives are very rare indeed.)
> The American Trends Panel (ATP), created by Pew Research Center, is a nationally representative panel of randomly selected U.S. adults. Panelists participate via self-administered web surveys.
[1] https://www.pewresearch.org/wp-content/uploads/2022/06/trans...
My point is that it is reasonable to expect between 3% and 8% of the MRI study participants to have been trans. It is not reasonable to think that 0.5% or less would have been trans.
I'm not dismissing the claim as false, I'm saying that surveys like this are poor evidence that it is true because they are not very good at making precise statements about rare subgroups.
Should I doubt that there are really around 5 million religious Jews in the US, because the Pew survey used to estimate this could have had "people randomly selecting the wrong button?" Should I hold it equally likely that there are a mere 500,000 religious Jews? This subgroup is far more rare than the subgroup of 20-35 year olds that identify as transgender or nonbinary. How can we know anything about this subgroup at all, since (according to you) surveys cannot constitute good evidence for anything for a group with such rarity?
If the only source we had for the percentage of the population that was religiously Jewish was a poll, then yes, I would say you should take that number with a hefty grain of salt. But that isn't the only data we have. We have data from many polls, the census, back-of-the-napkin estimates based on the number of places of worship and average attendance, past demographic knowledge, fertility rates and immigration, and so on.
Even then, there's substantial error in those estimates - the US Census Bureau itself, arguably the most sophisticated demographic operation in the history of mankind, estimates that they double-counted ("erroneous enumeration") roughly ten million Americans, shrugged and went "yeah someone probably lives there" ("whole-person imputation") for another eight million, and missed eighteen million [1]. And that's just for total population (they think the error is larger among subgroups).
And numbers for trans people are highly variable (by as much as 1.5 orders of magnitude) among major sources I'm aware of. For example, the Williams Institute [2] finds ~1.5% trans ID among young people (a third of Pew's number), and binary trans people outnumbering nonbinary ones 2:1 (inverting Pew's ratio). The Canadian census shows <1% [3] among young people.
And corroborating sources are harder to get, both because there's a lot of disagreement about who exactly "counts" (Pew uses "transgender" and "nonbinary" as separate categories, the Williams Institute considers the latter a subset of the former) and because corroborating evidence is often only available for subsets of the population (like people who sought medical care related to their identity).
So yeah, I stand by what I said: a single survey does not tell you very much about a rare subgroup, in this or any other context. It is data, but it should be taken with a substantial grain of salt, especially when it comes to a group like trans people whose boundaries are fuzzy and highly controversial even internally. Certainly I don't think the statistical MOE tells even close to the full story, since it doesn't even for MUCH simpler questions (typical polling error in elections is ~twice the MOE on a much more clearly-defined question, for example).
[1] https://www.prb.org/resources/how-accurate-was-the-2020-cens....
[2] https://williamsinstitute.law.ucla.edu/wp-content/uploads/Tr...
[3] https://www150.statcan.gc.ca/n1/daily-quotidien/220427/dq220...
As for trans. Humans, unlike most animals, cannot even have sex without being taught. The reason is humans for many generations, million years probably, lived in groups and learned how to do it. Those who didn't have genetically hardcoded knowledge how to make kids by the time they grew up they knew it any way. It wasn't necessary and with the time it was almost lost. The same with gender identification. Everywhere boys and girls where brought up differently. So, we lost hadcoded self identification. Today human kids may grow up thinking they are dogs, or wolfs, or sheep. If they happened to grow up with animals.
Conclusion is it's parents responsibility to give kids the right identity. Failure to do it, some brainwashed wokes don't do it intentionally, results in miss self-identification. Add to that 'doctors' multi-billon industry preying on them and some schools playing along to keep parents uninformed. There was a couple of months back interesting article about navy seal who had mental problems. He was brainwashed into believing he was a woman, and needs treatment and surgeries, payed by government. Later he realized he was just used to make money, and became a man again. The same happens to kids en mass. Because they are easy targets.