Male vs Female Brains

Rationally Speaking | Official Podcast of New York City Skeptics - Current Episodes - RS 239 - Saloni Dattani on "The debate over whether male and female brains are different"

"'One claim that people make is that any sex differences that exist between males and females are the result of socialization, or gender roles and expectations that people have in society. And the opposing claim is that, no, instead, they are caused by genetic or sort of innate differences that emerge over time.

But, for some reason, sometimes people who claim the former, that gender differences in the brain are socialized, will also argue that there are no sex differences in the brain, or that there are very few of them. So, that's one thing that I find quite confusing'…

'She's arguing against the claim that there are structural differences in the brains of male and female babies, that the brains come out differently from birth. So, she's tackling that version of, "The differences are hard coded," right?'...

'It is actually an argument that people who claim gender differences are innate will use. A lot of brain development in humans takes place before birth. And so you would expect there to be sex differences present at birth if they were innate, for example.

But, you would also expect sex differences to emerge over age. So, if they do emerge over age, that doesn't necessarily mean that they're a result of socialization... when we think about innate causation ... if you think about, for example, somebody with Huntington's Disease, they will have a gene mutation in the Huntington Gene that doesn't emerge until they're in their mid 30s or so.

But, just because it's happened later on in their lifespan doesn't mean that it's not something that they're innately predisposed to. And in the same way, when we're talking about gender differences – like, puberty happens when kids are in their adolescence, and that clearly creates a divergence of physical traits.

So, you would expect that there are certain traits that will emerge over time in a predictable innate way because of genetics. And, I think that people might find that confusing because they have this impression that your DNA is sort of stable throughout your lifespan and that it doesn't change even in its expression.

But the reality is that even though your DNA is pretty much fixed, the expression of those genes and the timing of the expression is kind of also partly predetermined.'...

'She said, "The brain is no more gendered than the liver or kidneys or heart."'...

'In the book, she's actually very open to agreeing that there are lots of innate differences… she simply says that they've been exaggerated, or we're ignoring socialized differences.'

'This is what I mean. This is why this debate is so slippery to me.I read this claim, that seems very clear-cut, about the brain not being gendered just like the kidneys. And then, the actual details include all these allowances -- which seem like they're sort of treated as caveats or footnotes or something, but they seem extremely central.Like… Didn't you just concede the main point we're debating?'...

'It's very difficult to measure prenatal testosterone accurately, firstly. But, also, people tend to use proxies to sort of catch those things out. So, for example, people will look at your digit ratio, which is the length of your ring finger to the length of your index finger, and that supposedly correlates with the level of testosterone you had in the prenatal environment.But, it seems like a lot of that literature is very contradictory, and when you look at large meta analyses of the research, they don't find any differences, or they find very tiny effects'...

'The books that Cordelia Fines and Gina Rippons and [Eliot]'...

'Yeah, so, a lot of the claims that they make are for socialization, especially in Gina Rippon's book. She uses examples like stereotype threat or role models and she says that children respond differently to socialization and that's reflected in their brain activity, and that's how we know that cultural effects are responsible for any sex differences that we see.'

'There was a big leap in that last link… also, wasn't stereotype threat a victim of the replication crisis?'

'Right. I don't think she noticed that, or she didn't pick up on it in her book... she would place a very high standard of evidence that she would require from claims about innate causation. And she would not place any standard, any of the same rigor on claims about socialization.'"


Related:

Sex is a biological variable — in the brain too

"We are concerned that Lise Eliot’s review of Gina Rippon’s book The Gendered Brain (Nature 566, 453–454; 2019) undermines the premise that sex is a biological variable with respect to many medical conditions and drug responses (see J. A. Clayton and F. S. Collins Nature 509, 282–283; 2014).

As president-elect and president, respectively, of the Organization for the Study of Sex Differences, we disagree with Eliot’s claim that the brain is “no more gendered than the liver or kidneys or heart”. We also disagree that sex differences in behaviour are due to cultural effects on newborns, not to biological effects. In our view, these are not mutually exclusive. Sex disparities occur in animal models that are not subject to cultural bias.

The brain, like many organs, shows differences attributable to sex, both during health (see, for example, E. Luders et al. J. Neurosci. 29, 14265–14270; 2009) and during disease. Two-thirds of people with Alzheimer’s disease are women; twice as many men as women have Parkinson’s disease (see, for example, L. J. Young and D. W. Pfaff Front. Neuroendocrinol. 35, 253–254; 2014). And multiple sclerosis affects three times more women than men, although men with the condition develop neurological disability more quickly (see, for example, R. R. Voskuhl and S. M. Gold Nature Rev. Neurol. 8, 255–263; 2012). Sex is a modifier of disease risk and progression.

Studying the effects of sex differences in health and disease will lead to new treatments that target sex hormone and sex-chromosome effects. These will ultimately help people irrespective of their sex."


Testosterone Rex strikes again...