Males showed 6.16% larger total brain volume and 5.64% larger intracranial volume (total space inside the skull) compared to females, even after accounting for birth weight. Females showed relatively larger gray matter volumes, while males had relatively larger white matter volumes when controlling for overall brain size.
Accessible discussion of the results can be found here:
> Males showed 6.16% larger total brain volume and 5.64% larger intracranial volume (total space inside the skull) compared to females, even after accounting for birth weight.
One can have 100% total brain volume or intracranial volume. If it is not used, it's useles.
I thought the differences in grey/white matter in male/female brains were known. I remember hearing about this all the way back in 2005.
Edit:
Well I feel like a fool. I opened up and read past the headline. This article is specifically about the differences in babies and acknowledges known differences in adults.
> Sex differences in human brain anatomy have been well-documented, though remain significantly underexplored during early development.
It's fascinating to see figure 1 and figure 3 where there's a huge amount of overlap between the groups. To get to a place on each graph where there are no men you also have almost no women either. It's only the extreme outliers who are definitively inside a single gender part of the results.
Yes, you'd see the same thing with height, for example. On average, men are several inches taller than women, but there's a ton of overlap, and plenty of men are shorter than the taller women.
In a professional sport, the top 1000 athletes on Earth are almost certainly going to be men. But at the recreational level, the genders can be very competitive, and a lot of women will kick your butt.
Not too surprising, that's true for many single axes for adult humans as well, for example there's lots of tall women and short men. Multi-dimensional analyses are very different though
> It makes it harder to accept the statement "Trans women are women", for example.
This is a statement about social identity rather than biology. Transgender people have little or no interest in opening their gray matter or genitals to public scrutiny. It's about respecting the feelings and choices of the individual.
Consider this analogy: suppose that we refused to call people "Christians" who self-identify as Christian but nonetheless ignore or even act in contraction to the teachings of Jesus Christ? As far as I can tell, this would apply to the majority of so-called Christians in the United States. (I personally refer to these people as "Old Testament Christians".)
The statement is a motte and bailey. "Trans women are women" meaning "this person wants to wear a dress so you should accept their social identity" is the motte. "Trans women are women" meaning "this person with the advantage of male puberty must be allowed to punch women in the face in boxing or else you're transphobic" is the bailey.
Your analogy fails because there aren't biological differences between people of different faiths. There are real biological differences between males and females, now detectable to the earliest life stages. Surgery and hormones won't change that, so we should drop the "Trans women are women" rhetoric, because the statement is false. It also enables bad behavior like trying to force lesbians to like dick, lest they be called transphobic.
It would be much more productive to come up with a new pithy statement meaning "be nice to people even if you think they're weird".
Note that these are both social issues, not biological issues, and it's possible to have different opinions about the two. There's certainly no biological imperative to have separate sports for men and women; that's simply a social convention. If we look only at men, those who are taller typically have a huge athletic advantage over those who are shorter. Why don't we have separate pro basketball leagues for tall guys and short guys? Even the "shorter" NBA players, usually guards, are almost always taller than the average male. As a shorter than average male myself, I'm dwarfed not only by NBA players but also by WNBA players. Where do I get my fair shot? ;-)
> Your analogy fails because there aren't biological differences between people of different faiths.
As I already said in my previous comment, this is a social issue, not a biological issue. I also elaborated on this in another comment in this same thread: https://news.ycombinator.com/item?id=42674247
> It also enables bad behavior like trying to force lesbians to like dick, lest they be called transphobic.
I have no idea what you're talking about or where you're getting this stuff.
The biological issue is that men competing against women will cause very real biological injuries.
Saying that women shouldn't get to compete in the Olympics is fine, you should just be honest about it. Eliminating the division between the sexes in sports will inevitably lead to that.
> I have no idea what you're talking about or where you're getting this stuff.
I admire your innocence. Search for "genital preference transphobic" or the like to see an example
> The biological issue is that men competing against women will cause very real biological injuries.
Uh... this is quite a bizarre statement, given that you previously brought up boxing, in which the entire point is to cause very real biological injuries to your opponent. If you hadn't noticed, in all sports, men competing against men causes very real biological injuries, as does women competing against women.
> Saying that women shouldn't get to compete in the Olympics is fine, you should just be honest about it.
I wasn't making any suggestions, merely pointing out that the current divisions are arbitrary social conventions that could be changed. I honestly have no strong opinions about sporting rules, and I was joking about the need for a basketball league to accommodate me. I've played tennis but not basketball.
> I admire your innocence. Search for "genital preference transphobic" or the like to see an example
You can always find examples of any opinion in the world on any subject, but if they're not commonly propounded or representative of the public debate, then they're largely irrelevant. You can't validly repudiate a position by pointing out the most extreme advocates of the position, otherwise you would repudiate every position.
[EDIT:] It was probably a mistake for me to get sidetracked arguing about sports. The weirdest thing about your "motte and bailey" argument is the implication that the worst thing about acknowledging the self-identity of transgender women would be its effect on sporting competition. Whereas transgender people themselves appear to be much more worried about things like violence against them, discrimination against them in the workplace, housing, and health care, and general social disrespect, refusal to accept their very existence. I think that sports is largely a red herring.
> That entirely depends on whether one considers "woman" and "man" to be social identities that anyone of either sex can choose to adopt.
Yes, but debates over the meaning or usage of words are social/philosophical/political issues, not biological issues.
> Many people don't accept that belief, for a variety of reasons, such as viewing that belief as being based upon sexist stereotyping of women and men.
This claim seems questionable. As far as I can tell, the origin of the opposition is mainly religious, and it has come to be political as a consequence of the religious leanings of political parties.
> Instead, they understand "woman" and "man" to be the words used to describe, respectively, female and male people who have reached adulthood.
Yes, but it's unclear how a study of brain matter would change anyone's mind. After all, their definition of female and male always depended on genitals rather than brain composition.
The fixation on genitals in this discourse is weird. It's an argument that tries to say "if you don't agree with me, you're a pervert that just thinks about genitals".
Men vs women can be clearly distinguished in many different ways while keeping their clothes on. Why bother trying to push a narrative that is obviously false? Is it an Emperor's New Clothes situation?
> The fixation on genitals in this discourse is weird.
It doesn't come from me. It comes from the people who demand purely biological definitions of "man" and "woman".
> It's an argument that tries to say "if you don't agree with me, you're a pervert that just thinks about genitals".
I didn't say anything about perversion.
> Men vs women can be clearly distinguished in many different ways while keeping their clothes on.
Highly inaccurately. For some damn reason, I've been called "ma'am" way too often, for example by grocery and retail store employees. I guess it's because of my height, which is shorter than average. (I don't have long hair, in case you're wondering.) Anyway, it really pisses me off, massive disrespect.
Or maybe it may be related to trans people having a brain structure more similar to the other sex at birth. The article talks about the median results, it doesn't state that all new born male brains have those features, but that the median brain have them.
Having some brain measurements that are more similar to the opposite sex correlates with homosexuality, not trans.
The initial studies on this didn't control for sexuality and mostly used subjects who were both homosexual and transsexual. In later studies that also measured sexuality, no correlation of sex atypical brain measurements with trans was found, only with homosexuality.
Could you link to these studies, please? I made a quick Google search and I found quite the opposite, two studies from 2021 and 2022 supporting brain differences on trans people from their biological sex brain. I find quite hard to believe that correlation between sexual attraction and brain structures.
I think maybe you've understood. The study doesn't say that all birth-assigned male brains are larger than all birth-assigned female brains. There's still variety within the group, with lots of girls with larger brains than lots of boys.
Actually in recent years, there are many people who argue exactly that.
Their claim being that taking medication to suppress testosterone and boost estrogen, as well as having various cosmetic surgeries (castration, inversion of penis, bone/cartilage/soft tissue reshaping of facial features), gives these males a "female body".
Some of these males even claim to no longer be trans as a result of these surgical and pharmaceutical interventions, referring to themselves as "cis women".
This is a tech website, most people here have no relevant expertise to say or think anything meaningful about this.
I don't think this is constructive at all to post something like this, without any context, people will point to these differences and jump to conclusions as why we should consider men 'better' than women or probably more precise: to keep the status quo (pay gap).
The skull measuring people will try to justify yet again, abusing this result, to make claims about how suitable women are to tech jobs.
I think we should probably just let people discuss it, and study it, and find out what the truth is, whatever that might be. A conclusion reached before considering the evidence isn’t really a conclusion.
Edit: but now I see that this thread has disappeared from the front page, so I guess letting people discuss it is off the table…
Why would anyone need to have expertise in a topic to be allowed to say anything? Sounds like a very dark path to walk to just ban discussion on a topic.
Non-experts can chime in and can often glean insights experts miss. I conjecture -- as a non-expert -- for this article, most laymen will probably come to wackier conclusions than the research really permits. There is a common (and I believe fallacious) conflation between brain size and intelligence. There is also a common (and I believe fallacious) conflation between quick early development and lifelong intelligence.
If brain size alone meant anything, sperm whales and elephants would be rulers of the world. If brain-body proportion alone meant anything, ants would be rulers of the world.
Also, brains at birth and speedy early development can be misleading. Pigeons develop physically and mentally very quickly when born, while crows take much longer to become self-sufficient. Once fully developed, crows are much more intelligent than pigeons. If anything, there may generally be an inverse correlation between taking longer to develop and smarts. Humans take years to start walking and feed themselves, while giraffes take less than a minute to take their first steps.
The research linked in this thread is probably useful to experts in the field. Without further expert interpretation, I am not sure what value laymen could glean from this study other than a factoid or two. However, I think my comment and a couple of others may be insightful, so sharing the article to start a conversation is not meritless.
Accessible discussion of the results can be found here:
https://studyfinds.org/how-male-and-female-brains-differ-at-...
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