Deep learning models reveal replicable, generalizable, and behaviorally relevant sex differences in human functional brain organization - "Sex is an important biological factor that influences human behavior, impacting brain function and the manifestation of psychiatric and neurological disorders. However, previous research on how brain organization differs between males and females has been inconclusive. Leveraging recent advances in artificial intelligence and large multicohort fMRI (functional MRI) datasets, we identify highly replicable, generalizable, and behaviorally relevant sex differences in human functional brain organization localized to the default mode network, striatum, and limbic network. Our findings advance the understanding of sex-related differences in brain function and behavior. More generally, our approach provides AI–based tools for probing robust, generalizable, and interpretable neurobiological measures of sex differences in psychiatric and neurological disorders.
Sex plays a crucial role in human brain development, aging, and the manifestation of psychiatric and neurological disorders. However, our understanding of sex differences in human functional brain organization and their behavioral consequences has been hindered by inconsistent findings and a lack of replication. Here, we address these challenges using a spatiotemporal deep neural network (stDNN) model to uncover latent functional brain dynamics that distinguish male and female brains. Our stDNN model accurately differentiated male and female brains, demonstrating consistently high cross-validation accuracy (>90%), replicability, and generalizability across multisession data from the same individuals and three independent cohorts (N ~ 1,500 young adults aged 20 to 35). Explainable AI (XAI) analysis revealed that brain features associated with the default mode network, striatum, and limbic network consistently exhibited significant sex differences (effect sizes > 1.5) across sessions and independent cohorts. Furthermore, XAI-derived brain features accurately predicted sex-specific cognitive profiles, a finding that was also independently replicated. Our results demonstrate that sex differences in functional brain dynamics are not only highly replicable and generalizable but also behaviorally relevant, challenging the notion of a continuum in male-female brain organization. Our findings underscore the crucial role of sex as a biological determinant in human brain organization, have significant implications for developing personalized sex-specific biomarkers in psychiatric and neurological disorders, and provide innovative AI-based computational tools for future research."
Damn neurosexism! AI algorithms just amplify human bias, so they need to be trained to prevent "harm" by pretending that men and women are identical
Young teens at play: Girls are egalitarian, boys are generous - "Using the decisions of 2500 girls and boys in three mini dictator games, this paper investigates how the social preferences of five cohorts of students (aged 12 to 16) evolve throughout adolescence. We find that at early ages (12 years old, 7th grade), girls tend to be egalitarian, boys are more generous, and <10 % exhibit spiteful behavior - with equal representation of girls and boys. The gender gap in both strong egalitarianism (with girls showing more egalitarianism) and weak generosity (with boys being more generous) doesn't seem to fade as they grow older."
Thread by @SpencrGreenberg on Thread Reader App – Thread Reader App - "Important but often overlooked: when groups differ a small amount in their means, they may differ *dramatically* in their tails. For instance, in a personality study, we found males to have a little bit lower average compassion score than females (1.4 vs. 2) [tails thread] 𧡠Small differences like this in averages are typically not noticeable or important. Most people are not in the tails. If you knew only someone's compassion level and had to guess their sex from it, you'd be wrong more than one-third of the time (predicting optimally)! However, small differences in means can lead to much bigger differences in the tails. Among just the most compassionate people in our study, there were about 2x more females than males (right side of the chart). Moreover, the least compassionate people were almost all males! Similarly, on average, females usually test only a bit higher than males on peacefulness and forgiveness. But, if we look at the tails of behavior, we see extreme differences. Males accounted for 96% of U.S. mass shootings and 90% of homicide convictions. I suspect that one reason so many people believe that groups differ much more, on average, than they really do (and engage in dichotomizing and stereotyping) is that tail behavior is sometimes much more visible than typical behavior. When you meet most people, you don't really think about whether their compassion level is slightly above average or slightly below average (and then correlate it with sex). You just wouldn't even notice one way or the other. But when you see that the vast majority of serial killers are male, that stands out. Most males are not very low in compassion. But most people who are very low in compassion are males! For instance, ~4x more males than females have psychopathy/sociopathy."
Meme - Diana S. Fleischman @sentientist: "This woman weighs 47 kilos, meaning there are almost no grown men in her weight class. But she might be able to beat up the average 13 year old boy."
π¨ Katherine Brodsky @mysteriouskat: "The number of unfit, unskilled men claiming they can "take her" merely based on the fact that they are men... Yes, men are on average stronger. But take an unfit man in a somewhat similar weight class and she's winning."
Meme - i/o @eyeslasho: "14 and 15 year-old boys track and field records beat the world records set by adult women."
"100m 200m 400m 800m 1000m 1500m Mile 5000m 400m Hurdles
High Jump Pole Vault Long Jump Triple Jump Shot Put Discus Hammer Throw Javelin"
Keeping it Casual - "men and women’s sexual behavior since the 1960s actually fits better with the evolutionary psychologists’ narrative than with its sociocultural rival. The pill removes one of the main risks of casual sex for women: the risk of getting pregnant and having to raise an unplanned child without the help of the father. Despite this, more than a half century after it first appeared, women are still less willing than men to engage in casual sex. This doesn’t prove that the Nurture Only theory is false; it’s no doubt possible to come up with a non-evolutionary explanation for the tenacity of the sex difference. But the tenacity of the sex difference isn’t what we would have predicted on the basis of the Nurture Only theory. That should make us wary of any post hoc explanation for the persistence of the casual sex gender gap. Other evidence presents a similar challenge to the Nurture Only view. Consider, for instance, the sexual behavior of lesbians. Unlike straight women, lesbians don’t have to worry about getting pregnant or about being alone with a more physically powerful partner. If these worries were all that kept women from jumping into bed with every good-looking stranger, then lesbians would have more sexual partners than their straight female counterparts. As various studies have demonstrated, however, they don’t; they have fewer partners... the social pressures don’t all point in the direction presupposed by the Nurture Only theory. Research has generally failed to demonstrate a consistent or pervasive sexual double standard in the modern Western world. Although the belief in the sexual double standard is still widespread, the double standard itself is much less so. Indeed, some people these days hold a reverse double standard, such that they judge men who sleep around more harshly than they judge women. Certainly, “slut” is an insulting term. But so is “prude,” and women who don’t engage in casual sex are sometimes called that – by men who want to sleep with them, for a start. And while “slut” is usually reserved for women, there are plenty of pejorative terms for men who sleep around: womanizer, dirty old man, letch, sleaze, “worthless, lazy, good-for-nothing, womanizing asshole” – and so on... the difference persists even when society pushes against it. As Donald Symons points out, men’s stronger interest in casual sex and sexual novelty has survived society’s best efforts to eradicate it... Arguably, though, the most persuasive argument against the Nurture Only view is that sex differences in sexual inclinations and choosiness can be found in many individuals who have no gender norms, no socialization, and little in the way of culture: that rather sizeable group, so often overlooked by psychologists, known as other animals. The differences aren’t found in all other species, but they are found in many, including most birds, mammals, and reptiles. And when we find the differences in other animals, evolution is the only reasonable explanation. Why should humans be different?... what the Nurture Only theory asks us to believe is that, in our lineage and ours alone, natural selection eliminated the normal sex differences, despite the fact that the selection pressure that initially created them was still operative. Why would it do that? It’s particularly perplexing given that, when we look around the world, we still find the sex differences that selection supposedly eliminated. Thus, the Nurture Only theory asks us to believe not only that selection eliminated the differences for reasons unknown, but that learning and culture then coincidentally reproduced exactly the same differences in every culture on record. This is not a compelling thesis."
As usual, the nurture squad believes in nurture only, while the "nature squad" believes both are important, and the nurture squad pretend that just because culture influences things means that nature cannot play a role at all
Patriarchy is so powerful it affects animals, once again
Paulo F. on X - "Why are there > men in leadership positions? Because it is men who have the most to gain from these positions. They guarantee more income, status & above all more sex. As for sex, it is men who, in reproductive terms, gain the most from it the more they practice it. That's all"
Dryborer on X - "Men are more interested in the status symbols of leadership and less vulnerable to the costs. Some men will neglect their wife and kids to get status. Very few women think it's worth it."
Bachman on X - "A weird result of 60 years of sexual egalitarian whitewashing is that every adult learns about gender differences via a series of private relationship crises--more or less excruciating--rather than that knowledge being embodied in institutions, ritual, and prejudice"
Four-foot-tall dwarf beats female pornstar in MMA fight before sparking brawl - "A four-foot-tall dwarf defeated two female MMA fighters including a pornstar during the latest instalment of Epic Fighting Championship. Majit Suleymanov, who is a blogger and social media influencer, was fighting on the Russian label's latest bizarre MMA card. He was facing pornstar Alexandra Piskun who has previously fought with the promotion against a reality-TV star."
Meme - "The well-known sex difference in brain size is not explained by men being taller than women."
ZUBY: on X - "The social media fuelled 'gender war' is stupid. But it's also interesting. I think an overlooked reason for it is despite all the "men and women are the same" claptrap, men think and talk like men, and women think and talk like women. And online, these styles constantly clash. In real life, men typically soften our speech and manner when women are present. It happens instantaneously and perhaps unconsciously in most cases. But on the internet, detached from being able to physically SEE (let alone cater to) every potential viewer or listener, this calibration is less likely to occur. Online, men default to speaking as if their audience is other men (it predominantly is). Women hear or see this and think the tone is too 'harsh', broad, and 'insensitive'. And it often is. But that's how men speak when you're not around. For the first time in human history, we have billions of men and women of all different backgrounds, all communicating and cross-pollinating ideas and communication styles. People are privvy to more conversations than ever, and don't always like it because their particularly sensitivities are not catered to. They are often outright ignored. Very few men actually hate women. But we aren't women and technology has its limitations. Real world conversations are superior because there is more empathy and humanity. And fewer algorithms :)"
Feminists claim that treating men and women differently is sexist. But they can't walk the walk and get upset when men treat women like they treat men (see also: treating women like you'd treat Dwayne "The Rock" Johnson - they'd be upset at that too)
Girls' under-10s football team lost every game last season beats boys to claim league trophy - "A girl’s under-10 football team which lost every single game last season has now triumphed in a league of all-boys squads to win a cup trophy. The team from Woodlanders FC won the Huddersfield Junior Football League Vase trophy by beating rivals Howden Clough FC 3-2... The girls had a difficult start last season as an all-girl team in a league of boys’ teams and lost every game."
Clearly, this shows that women are equally physically capable as men, because puberty isn't a thing
Steve Stewart-Williams on X - "Sex differences in suicide rates by age (UK; 2017)
Note that a lot of sex differences follow a similar trajectory: They start growing in adolescence then shrink in later life. This applies, for instance, to fireworks-related hospitalizations, alcohol consumption, road deaths, and homicide rates."
Meme - CrΓ©mieux @cremieuxrecueil: "I still haven't seen a satisfactory explanation for the finding that men are much stronger than women even when they're equally muscular."
Damn socialisation!
This Mixed-Gender Wrestling Match Ended In Tears… π€Ό♂️
Instagram - Mens Media: "Bro ain't playing no games"
High school (?) girl wrestles guy from "BTWC" and epically loses and cries, with her hairband down over her mouthBTWC" and epically loses and cries, with her hairband down over her mouth
mark normand on X - "Me: Are women as horny as men?
Lady Friend: Definitely.
Me: Well I’d have sex with you, would you have sex with me?
LF: No way.
Me: Well there ya go.
LF: But I’m not attracted to you.
Me: Yeah, I’m not attracted to you either."
Left wing logic: if person A says he's starving and he will eat anything and person B says he's staving but refuses to eat most things you give him but loves burgers, person A and person B are equally hungrystaving but refuses to eat most things you give him but loves burgers, person A and person B are equally hungry
Defiant L’s on X - "Democrat Lindsey Williams: "Female bodies are just as strong and fast and capable as male bodies.""
︎ ︎venom on X - "YouTuber Jesse James West held a competition to see who’s stronger between tall, strong bodybuilder women and strong dwarf men.
> Dwarf men easily crushed them
> Women were very egoistic, serious, and competitive
> While men were just having fun
Why is gender equality forced when the difference in ability is pretty clear?"
Damn structural sexism and misogyny!
Gender stereotypes are often accurate but vary in magnitude depending on the criterion - "Research published in the Journal of Experimental Social Psychology found that while gender stereotypes are often viewed as misleading, they are surprisingly accurate. People correctly guess whether men or women are higher on a given trait about 85% of the time... People tended to underestimate gender differences in areas such as cognitive abilities, occupational distributions, and academic performance (e.g., GPA in different college majors). In contrast, they overestimated differences in personality traits, behaviors, and social attitudes. The sensitivity correlations further supported the conclusion that gender stereotypes are largely accurate. When averaging across all participants in a given study, the mean consensual sensitivity correlation was .77, indicating a strong relationship between stereotypical beliefs and actual gender differences."
Most stereotypes are true
Rob Henderson on X - "Interesting: women carry a large reproductive cost (pregnancy). But men carry 20% more active metabolic tissue to aid in reproductive efforts (boosts competitiveness, attractiveness, and ability to provide) and is ultimately just as costly as pregnancy."
Evolution and Social Cognition: Contrast Effects as a Function of Sex, Dominance, and Physical Attractiveness - "Previous research indicates that males, compared with females, evaluate their relationships less favorably after exposure to physically attractive members of the other sex. An evolutionary model predicts a converse effect after exposure to opposite-sex individuals high in dominance, which should lead females to evaluate their current relationships less favorably than males. Women and men rated their current relationships after being exposed to opposite-sex targets varying in both dominance and physical attractiveness. Consistent with earlier research, males exposed to physically attractive, as compared with average, targets rated their current relationships less favorably. Males' relationship evaluations were not directly influenced by the targets' dominance, although the effect of physical attractiveness was significant only for men exposed to women low in dominance. However; females' evaluations of their relationships were unaffected by exposure to physically attractive males but were lower after exposure to targets high in dominance. These data support predictions derived from an evolutionary model and suggest that such models can be used to generate testable hypotheses about ongoing social cognition."
John Rain on X - "Men consistently score higher than women on measures of political knowledge. A 2018 study found that this difference cannot be explained by stereotype threat. (More generally, men tend to have broader general knowledge than women on average.)"
Time to demonize men and their politics because deferring to stances supported by people with greater knowledge is only good when it pushes the left wing agenda
Covfefe Anon on X - "Women having significantly less general knowledge than men is a real phenomenon and shows up in multiple areas - in this case a female PhD student in the field doesn't know basic underlying facts about the field - this is only surprising in that you can't predict where her knowledge will be lacking Part of the reason our society is destroying itself is that it's decided upon a religious dogma of group equality across all domains which it then enforces by making it taboo to look at and think about the implications of the fact that groups are *not* all equally capable How many people know about the general knowledge gap between men and women? Few How many studies are there on it? Few - no one wants to try to publish a paper that has a "controversial" result when the result contradicts progressive religious dogma Millions and millions of "little" things like this add up and only disagreeable, knowledgeable people can actually fit it all into a coherent framework"
Men are better at trivia than women
Covfefe Anon on X - "The general knowledge gap between men and women is huge and replicates across many studies"
Bryan Caplan on X - "I found that being male changes beliefs about economics by roughly 16% as much as a PhD in economics."
Rob Henderson on X - ""social scientists are more likely than civilians to chalk up sex differences to nurture rather than nature...even extends to differences between hens and roosters...this one area where laypeople have a firmer grasp on reality than many alleged experts""
Eve Keneinan π☦️Ω on X - "There are many such areas because "experts" are usually educated academics, and academic fields are highly susceptible to ideologies. Once an academic in field A has been captured by an ideological lens, it is not only possible, but common, that all his judgments in his own area of expertise are distorted to the point that laypeople make sounder judgments. Not because they know more, but because their ability to see the realities on the ground are not systematically distorted or corrupted by extraneous ideological incentives. Hence the key conclusion here "Academia seems to impair people's understanding of the world rather than improving it.""
Trust the Experts! Even when they are wrong
π»ππ πΊπππ πΆπ π»ππ π¬ππππ on X - "When selling to a woman, show her that other women have it. Because women want what other women have. Explains their dating lifestyle - why they are attracted to players and married men
• Women value preselection
When selling to a man, show him that no other man has it. Because men want what what other men don't have. Explains their dating lifestyle - why they are more likely to commit to virgins
• Men value exclusivity"
Sex Differences in Mathematics and Reading Achievement Are Inversely Related: Within- and Across-Nation Assessment of 10 Years of PISA Data - "We analyzed one decade of data collected by the Programme for International Student Assessment (PISA), including the mathematics and reading performance of nearly 1.5 million 15 year olds in 75 countries. Across nations, boys scored higher than girls in mathematics, but lower than girls in reading. The sex difference in reading was three times as large as in mathematics. There was considerable variation in the extent of the sex differences between nations. There are countries without a sex difference in mathematics performance, and in some countries girls scored higher than boys. Boys scored lower in reading in all nations in all four PISA assessments (2000, 2003, 2006, 2009). Contrary to several previous studies, we found no evidence that the sex differences were related to nations’ gender equality indicators. Further, paradoxically, sex differences in mathematics were consistently and strongly inversely correlated with sex differences in reading: Countries with a smaller sex difference in mathematics had a larger sex difference in reading and vice versa. We demonstrate that this was not merely a between-nation, but also a within-nation effect. This effect is related to relative changes in these sex differences across the performance continuum: We did not find a sex difference in mathematics among the lowest performing students, but this is where the sex difference in reading was largest. In contrast, the sex difference in mathematics was largest among the higher performing students, and this is where the sex difference in reading was smallest. The implication is that if policy makers decide that changes in these sex differences are desired, different approaches will be needed to achieve this for reading and mathematics. Interventions that focus on high-achieving girls in mathematics and on low achieving boys in reading are likely to yield the strongest educational benefits."
Time to do more about "patriarchy"
It seems that countries which are more feminist boost girls and/or suppress boys in maths, and feminism also generally demonises males, so that would increase the sex differences in reading
Boys behave differently to girls within hours of birth, Cambridge study finds - "Girls and boys exhibit sex differences within a few hours of birth, a University of Cambridge study has found. For decades, biologists and sociologists have noticed that boys and girls show different behaviours and preferences growing up, but have been unsure whether nature or nurture was responsible. Cambridge scientists have shown that, on average, infant girls show a natural preference for looking at faces within a few hours of birth, while boys would rather gaze at objects... There are major differences between boys and girls during childhood. Girls typically develop language earlier, speak in longer sentences and often have larger vocabularies than boys growing up. Girls are also better at picking up non-verbal signals, such as facial expressions and tone of voice, and have fine motor coordination and more self-control. In contrast, boys display higher levels of physical activity and are more adept at large motor movements such as running, jumping and climbing. When playing, girls tend to lean towards co-operative, verbal and fantasy play, sometimes focusing on domestic make-believe scenarios, while boys gravitate towards sports, outdoor activities, construction sets and toy vehicles... For the study, 130 infants were presented with side-by-side videos containing either a social stimulus – a human face with natural movement – or a non-social object, in this case a popular desk toy or a set of swinging metallic balls known as a Newton’s cradle. Researchers who analysed the videos of the babies eyes were unaware of their sex or what video a child was looking at, which ensured that they could not bias the results. The team found that, regardless of sex, newborn infants generally preferred to look at the social stimulus. But on average, female infants spent a greater proportion of the time looking at the social stimulus compared with male infants, while male infants spent a greater proportion of time looking at the non-social stimulus compared with female infants. Since the differences could be seen within hours of birth, it was likely that prenatal biological factors such as hormone levels and genetics contributed to the observed on-average sex differences, the researchers concluded... The team is interested in finding out whether these early sex differences contribute to later differences in children’s minds, brains and behaviour. To test this requires a longitudinal study design, which is under way. The researchers hope that by understanding the origins of the earliest sex differences, scientists can better understand neurodiversity and conditions such as autism, which is diagnosed about twice as often in boys than in girls."
This shows the power of patriarchy - it's capable of socialising infants within hours of birth! If you disagree, that's neurosexism because male and female brains are almost the same
Compared to men, women view professional advancement as equally attainable, but less desirable - "We identify a profound and consistent gender gap in people’s core life goals. Across nine studies using diverse sample populations (executives in high-power positions, recent graduates of a top MBA program, undergraduate students, and online panels of working adults) and over 4,000 participants, we find that, compared to men, women have a higher number of life goals, place less importance on power-related goals, associate more negative outcomes (e.g., time constraints and tradeoffs) with high-power positions, perceive power as less desirable, and are less likely to take advantage of opportunities for professional advancement. Women view high-level positions as equally attainable as men do, but less desirable. Our findings advance the science of gender, goals, organizational behavior, and decision making."
The gender wage gap is proof that women are discriminated against
Paul Graham on X - "In England, students choose just a few subjects (usually 3) to study in the last 2 years of high school, so gender differences in their interests become more visible than in the US."
John Papola on X - "Read another way, this is a smooth sliding scale from rigorous reality-based studies to complete groupthink bullshit. Men and women need each other. Women help us be kind. We help them be rational. It’s grand pop wisdom and it’s reflect in every clear revealed preference."
Do women talk more than men? It might depend on their age - "The stereotype that women are much more talkative than men is pervasive across many cultures, but a widely reported study by University of Arizona researchers in 2007 refuted the claim, finding that men and women speak roughly the same number of words per day – around 16,000. A new, larger follow-up to that study paints a more nuanced picture, suggesting that women may be the chattier gender, but only during a certain period of life. "There is a strong cross-cultural assumption that women talk a lot more than men," said co-lead study author Colin Tidwell, a clinical psychology doctoral candidate at the U of A. "We wanted to see whether or not this assumption holds when empirically tested." Researchers found that women between the ages of 25 and 64 – the life stages of early and middle adulthood – spoke on average about 3,000 more words per day than their male counterparts. Significant gender differences did not appear in the study's other age groups: adolescence (ages 10 to 17), emerging adulthood (ages 18 to 24) and older adulthood (65 and up). The researchers also discovered that people in general might be becoming less talkative, a finding they suspect is linked to an increasing reliance on digital communication."
Women talk more than men after all. This is more robust than Mehl's previous study of college students finding they talked the same, too
Amusingly, a September 2026 Psychology Today article written by a PhD and reviewed by someone else misrepresented the study and dismissed its findings. Anything to protect the narrative
