Article on sex-related brain differences

[Mermoose]

Kevin Mitchell (@WiringTheBrain) has written a good article about sex-related brain differences. He says that while neuroimaging can show physical differences that make it possible to identify a brain as female or male, we can't relate physical aspects of the brain to behaviours.
aeon.co/essays/the-gender-wars-will-end-only-with-a-synthesis-of-research
It's also good to see that Mitchell uses the word 'sex' when he means sex and 'gendered' when he means gendered.

Good article, really explores both sides. Quite clear though that that TRA assertion that TW's brains are 'female' is nonsense given our current knowledge.

But even if, so what? We have sex segregation. Not personality/characteristic segregation.

It was always silly of TRAs to promote the idea of girl brains in male bodies and vice versa.

That always ran the risk of someone offering a test, be it DNA test of one or more brain scans, to determine if a person really, truly did have the brain of the other sex.

Such a test would only ever show that the person did indeed have the brain of their own sex, and so could not be trans.

Ifonly gender identity clinics did away with diagnoses of gender dysphoria, and relied on brain imaging, no child or adolescent would be transed ever again.

brain scans, to determine if a person really, truly did have the brain of the other sex

But they can't, by definition! They can only show that the range of brain characteristics has more overlap.

Regardless of mapping structure to behaviour, I'm not really convinced that it is possible to determine the sex of someone from their brain, at least not definitively.
You can say it is more likely that person X is male, or female, from looking at their brain, but having a "male brain" does not mean someone is male.

Just like lots of other physical characteristics...
If you looked at my height, and no other part of me, you would probably conclude I was a man. I am bang on the average height for a man, and am an outlier in terms of height for women.
For other people, you could say the same about their hand size, their facial hair, their hair pattern on their head, their shoe size, the amount of breast tissue they have, etc etc. I don't understand why anyone would expect brains to magically correlate perfectly with sex, when almost nothing else does.

I'm not really convinced that it is possible to determine the sex of someone from their brain, at least not definitively.

Well, apart from extracting a few cells and checking the chromosomes. That'll do it.

Well obviously

*From imaging someones brain, or looking at structural differences

I would not say that body parts don't correlate with sex. Yes there is some overlap, but it's possible to sex a skeleton, for example, with a pretty good degree of accuracy. Even things like bone density, muscle density, the way some muscles are attached, facial structure, hormone levels, etc, will give an indication.

If the brain correlated to the level the body did you could tell with good accuracy most of the time.

I'm doing a really terrible job of explaining myself here.
There are obviously lots of physical indicators of what sex someone is.
My point is that failing one, or any combination, of these, does not define your sex.
Having a 'male brain' does not make you male, having dense bones does not make you male, having male proportions does not make you male. Having all of these does not make you male, though of course there is a very strong correlation. Male and female are defined by the reproductive class you fall into, obviously this results from your chromosomes.

Someone may be more likely to have a male brain because their sex is male, but having a 'male brain' is not enough to definitively prove someone is male. Just like many other individual physical characteristics. That's all I meant to say.

bingoitsadingo

I think it gets all topsy-turvey because the language is so weird. In the most straightforward sense, if you are a male, you have a male brain, you have male bones, etc. They might just look atypical, more like a typical female body part. But it's not, by definition, a female bone or brain.

That's speaking too from the POV of trying to figure out the sex of someone who you don't know the sex of. You can also say, the brain is that way, the bone is that way, because it is a male brain or male bone which has developed normally. Or sometimes, the brain or bone looks a different way, because it is a male bone that has developed abnormally.

It only gets weird if you presuppose that there might be a 'female brain' in any other sense than a female's brain.

bingoitsadingo
Regardless of mapping structure to behaviour, I'm not really convinced that it is possible to determine the sex of someone from their brain, at least not definitively.
You can say it is more likely that person X is male, or female, from looking at their brain, but having a "male brain" does not mean someone is male.

Yes, I agree, a female brain is a brain that grew in a female body and a male brain is one that grew in a male body. It's just that you can predict whether a brain is male (part of a male body) or female (part of a female body) and as I understand it you can do this with a high rate of success, if you look at the whole brain, not just isolated parts. Mitchell describes it as similar to the way male and female faces differ.
This is a quote from one of his blog posts:
"An analogy with faces makes this clear. Male and female faces differ on a wide range of parameters – size of the jaw, prominence of the ridge over the eyebrows, fullness of the lips, size of the bridge of the nose, and others (think Jason Momoa versus Natalie Portman). For each of these parameters, there is not a male form and a female form – there is a distribution, which is shifted one way in males and the other way in females. None of these markers by itself provides the means to accurately classify faces as either male or female. But taking all of them together certainly does. We are all very good at telling whether a face is male or female and computer programs can also very successfully perform this classification. So, “male” faces and “female” faces are clearly real things, even though the differences in specific parameters between them are not dimorphic."
www.wiringthebrain.com/2017/08/debunking-male-female-brain-mosaic.html

Absolutely fantastic article. Thanks for sharing! It is great to read a balanced explanation of the brain debate and I'm glad that both nature and nurture have a role to play as I would have expected.

I am never convinced by the extremely popular ideological angle that all the differences between women and men is down to socialisation and environment. And that we can socially engineer certain problems away by creating the perfect environment or socialisation. Primitive instincts for sexuality, aggression and certain personality traits are definitely part of our evolutionary heritage and I dislike it when people try to downplay or ignore such aspects. Of course behaviour like aggression can be exacerbated by the environment or how the individual is socialised from a young age, but there are marked differences between men and women.

Cultural and social factors do have a big role to play in many aspects of our development though and that does impact on the 'macro' level.

It's a reasonable summary, but I have to say I'm so fed up with hearing this same meaningless line over again: "In psychometric analyses of interests, females consistently show a greater interest in people, on average, while males show a greater interest in things." What are "things"? Do people not come into the category of "things"? If not, what are they, ideas?

I do question the utility of research which attempts to assign observed differences to a biological cause: if this is true, is it not going to be fuel for the argument that a woman's rightful place is in the home because of her lady brain?

StereochemPurist I think Mitchell addresses that when he says that we simply don't know, when it gets to things like interest in STEM, how much is down to biology and socialisation.

Anyway, I don't think it follows that because we may have a tendency one way, that that should be encouraged. We have a tendency to crave fatty sugary foods but we don't think it's healthy to always give in to that tendency. A biological basis for male aggression doesn't mean men should be encouraged to be aggressive, and a biological basis for a nurturing instinct in women doesn't necessarily mean women should be consigned to home-making.

Spencer Greenberg talks about a meta-analysis of studies on sex-related personality differences here and he says that most people sit in the overlap area. Where you find a marked difference is in extremes - for example, it is rare to find a man who's a psychopath but it's practically nonexistent among women. Also, he found that men will express interest in people depending on how the question is asked. So I think you're right when you ask what exactly is meant by 'things'. I'd also like to know what's meant by a nurturing instinct - is it the feeling of responsibility, or the enjoyment of looking after others (which, after all, is often tiring and unpleasant). Do women end up with care work because they feel it has to be done, or do they do it because it actually makes them happy? My guess is that both men and women are happy hugging their well-behaved kids and neither men nor women particularly cherish dragging screaming kids around a shop or cleaning toilets.

It's also interesting that when a stereotypical woman's job like cooking becomes prestigious and well-paid, it becomes a job more likely to be held by men. It's true that being a chef involves martialling kitchen staff and maybe that draws on stereotypical 'male' skills, but it still undermines the idea that, because a task tends to be carried out by one sex in most cultures, it is somehow biologically tied to that sex.

is it not going to be fuel for the argument that a woman's rightful place is in the home because of her lady brain?

There's two rather different aspects to that. One is that if there are some genuine differences at a population level which give rise to different inherent aptitudes, then we might expect to see differences in what men and women do at a population level. This has nothing to do with what any individual man or woman can do. About a century ago people were still saying that women didn't have the type of brains necessary to be lawyers or politicians - we now have abundant evidence that this is untrue.

I'm not sure that this piece adds much to the debate, other than a useful reminder that anyone engaged in this field - researchers but also commentators such as Petersen - should be mindful of their own biases and endeavour not to fall into the confirmation trap.

Yes, in a number of areas and social issues, there is no way to reliably determine how much of it is down to biology and how much of it is down to socialisation. Yet proponents of either camp try to interpret results to reflect better on their own position and deeply held assumptions. It's a human trait.
And as Mermoose mentioned, the answers can vary depending on how the question is asked, which is another set of variables to factor in.

For me, science is about figuring out how things work and why things are the way they are. The pursuit of truth, facts etc and broadening our understanding. Deliberately avoiding topics because of worry that the research findings might challenge our assumptions and beliefs isn't how we should be approaching social issues, in my opinion.

People are still responsible for their actions and as a society we are responsible for confronting inequalities and striving for the best outcomes.

For me, science is about figuring out how things work and why things are the way they are. The pursuit of truth, facts etc and broadening our understanding. Deliberately avoiding topics because of worry that the research findings might challenge our assumptions and beliefs isn't how we should be approaching social issues, in my opinion.

Yes, I think it's really important that science is kept as free from the influence of ideology as possible, and that goes for any ideology, even ones we agree with. I've noticed that some scientists who made nice noises about there being no difference (even at population level) between men and women, are now happy to make misleading comments in the trans debate.