New Research Finds Differences Between Male and Female Brains

https://www.psychologytoday.com/us/blog/sax-on-sex/202405/ai-finds-astonishing-malefemale-differences-in-human-brain

by janandonly • 2 years ago

44 49 2 years ago

mouse_• 2 years ago

Interesting. Would also like to see a similar study conducted among non-binary and gender nonconforming people.

Looks like they _might_ have been in the study set, but weren't separated out and focused on? At any rate, the author is hoping for the same:

"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."

liveoneggs2• 2 years ago

the sample was "roughly 1,500 young adults 20 to 35 years of age" so, in today's environment, I don't think it's possible that there were not at least a few who self-identify as non-binary and nonconforming.

riskable• 2 years ago

Transgender folks are represent about half a percent of any given population. So if the study had 1500 participants that would mean ~7 were transgender.

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.

astromaniak• 2 years ago

The difference has two components: genetic, personal. Genetic does not depend on self identification. Personal is very similar these days. Same families, same schools.

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.

logicprog6• 2 years ago

So a [gigantic meta analysis](https://www.sciencedirect.com/science/article/pii/S014976342...) of thirty years of studies on sexed structural and functional differences in human brains found zero evidence of any differences, a completely overlapping distribution, but as soon as "big data AI" is used suddenly not only are there differences, there's literally zero overlap? Count me suspicious. I think I'm going to trust the meta-analysis of 30 years worth of wide-ranging scientific study over the brand new study that's just throwing whatever fad is currently in the vogue at the problem to see what happens.

im3w1l• 2 years ago

Sounds like a case of "Old measuring instrument cannot tell two things apart. New more precise instrument can tell them apart"

logicprog6• 2 years ago

They're using the same measuring instruments, though. They're just feeding them through AI. Maybe, though. Let's see if it replicates.

courseofaction• 2 years ago

Without making any claims about gender or non-binary people (not my wheelhouse, I simply don't know), there's ample evidence to suggest statistically significant population-level differences between males and females on a many cognitive measures.

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.

derbOac• 2 years ago

I think the linked news article is a little misleading, although I share your skepticism. I'd like to see these results replicated rigorously on still new sets of data by independent researchers; I wouldn't be surprised either way, if the results did or did not replicate.

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.

RoyalHenOil• 2 years ago

It seems to me that in order for male and female brains to be functionally the same, they would need to be physically different to account for the extreme hormonal differences.

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.)

cmcaleer• 2 years ago

I have to assume you haven’t bothered reading this, because section 2.3 points out flaws in the methodology of the studies looked at which the methodology in this study kind of tries to address (whether or not it’s a good job of it is left for everyone else to figure out). You shouldn’t dismiss a result out of hand because it doesn’t fit preconceived notions, but it’s absolutely a reason to try to dig in to the methodology of the new study and make sure it’s not flawed.

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.

logicprog6• 2 years ago

Update: had a friend with access send me a PDF of the study and looked through it. It seems that the big breakthrough is only half AI — the other half being looking directly at time series of fMRIs instead of static images with features in them manually selected for relevance, because how the various circuits in the brain operate and circulate over time is important information. Also they got this to replicate well with the same people at different times, and also generalize to two other cohorts, consistently, and also used XAI to check what the AI was keying off, to make sure it wasn't going off something nonsensical, and directly used those features with success as well. It seems like an extremely carefully controlled and designed study tbh.

ars3• 2 years ago

When your study contradicts reality, your study is wrong. That there are major mental difference between men and women is obvious to anyone who interacts with both.

If your study can't find those differences it's your study that's wrong, not that the differences don't exist.

logicprog6• 2 years ago

That's interesting. So if a study is counter intuitive to "common sense," it's the study that's wrong? Especially since they're talking about structural and functional neurological differences, whereas the "everyday common sense" differences you're gesturing at could be due to other things, so they aren't necessarily in contradiction.

LudwigNagasena• 2 years ago

It’s not the first study to find differences. And that’s not the only meta study in existence. I don’t see why one would be surprised given other literature around the subject.

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”.

aappleby• 2 years ago

"Male and female brains are so similar that it takes a dedicated AI to distinguish between the two."

hpen2• 2 years ago

Turns out AI is good at separating noisy signals

dopylitty• 2 years ago

The article seems to conflate sex and gender while the study is paywalled so I can't tell how they defined male and female. The study does seem specific to sex and doesn't mention gender at all in the abstract.

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.

elzbardico3• 2 years ago

Really, I understand the human rights aspect of calling people whatever they feel they are and I am all for it. I think we should call people by their pronouns and whatever. Sex is one thing and gender is another.

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.

AndrewKemendo2• 2 years ago

That’s making a pretty big assumption that external factors are non-causal in the expression of genes that impact gender

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

Flemiklo• 2 years ago

I would assume that the hormonal effect on a brain is a lot more relevant when looking for brain forms than like social constructs.

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

Supermancho3• 2 years ago

This may be of interest. https://youtu.be/8QScpDGqwsQ?si=mTXWvzZKJO0RsAiA

Neuro-biology of trans-sexuality : Prof. Robert Sapolsky

dryanau• 2 years ago

This is a lazy take.

hpen2• 2 years ago

Says the guy who leaves a one liner explaining his take

grugagag• 2 years ago

Im surprised they didn’t find any differences between brains of various men. Or women.

New Research Finds Differences Between Male and Female Brains

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