Sex Differences in Intelligence

What is Intelligence?

About a century ago, psychologists found that in tests designed to measure mental abilities—such as mathematical ability, verbal ability, or memory—people who did well on one kind of test tended to also do well on other tests. And those who did poorly, did so across the board. From this overlap, or inter-correlation, it was discovered that there exists a general factor underlying all mental abilities. This general factor is called general mental ability, or simply, general intelligence, abbreviated as g.

g is the single best predictor of how an individual performs in life at-large, and it is for this reason that g is of such profound importance in psychology. g is highly correlated with academic and professional achievement, proficiency in military training, and to a lesser extent, with longevity, prosocial and industrious behaviour.[1][2] Intelligence can thus be defined as the capacity to identify, understand and utilize resources in the environment.

Simply put, intelligence—to a certain extent—determines ‘destiny.’

g is a measure of neural processing efficiency. Nearly all mental abilities will therefore load on g to some extent, and the g loading increases with the complexity of information being processed. Neural processing power is determined by the architecture of the brain, such as the efficiency of connectivity within and across modules, and the efficiency of memory systems. g can thus be measured using processing tests that tap into these performance factors, and then graded in terms of ‘Intelligence Quotient (IQ)’ scores. Individuals with more efficient brain architecture will have higher g, or more “brain power,” and therefore greater IQ scores.

[g is broadly analogous to the processing power of the CPU in a computer, which acts as the general factor underlying all processing capabilities of that computer. CPU processing power is determined by the architecture of the CPU, such as the efficiency of connectivity within and across components, and the efficiency of its memory caching systems. CPUs can therefore be graded using processing tests that tap into these performance factors. Just as how high grade CPUs are necessary for complex computing tasks, high g is necessary for cognitively complex domains.]


Intelligence is one of the most heritable traits known: genetic influence accounts for about 80% of individual differences in g between adults. It is a highly polygenic trait controlled by small additive effects from a very large number of genes. However, the same large set of genes influence diverse mental abilities such as verbal and non-verbal abilities as well as learning abilities such as reading and mathematics. In other words, the same genes that influence one mental ability influence other mental abilities as well, indicating that there is a genetic general factor affecting neural processing efficiency.[3][4][5][6][7]

The genetic influence on g increases with age—from about 40% among preschoolers, 60% by adolescence and to 80% in late adulthood—whereas the influence of shared environment decreases with age, becoming negligible after adolescence. One reason for this is that individuals attain peak neural processing capacity only by late adulthood, and another is that individuals increasingly seek out environments that indulge their mental abilities as they grow older. Unique environmental influences have no predictable effects on g, because they are indistinguishable from random miscellaneous effects.

Sex Differences in g

Adult human males have a mean advantage in g of 7 IQ equivalent points, and greater variance in distribution, compared to adult human females. The combined effect of higher mean and greater variance results in an exponentially increasing male over-representation from average g (IQ=100) and up, amounting to 9 males for each female at g=3 SD (IQ=145).[8][9][10][11]

Figure 1, Nyborg 2005.

Alternate measures of g, such as Elementary Cognitive Tasks (ECT), also reveal similar sex differences. ECTs tap into basic mental processes to measure neural efficiency. As such, they have no specific intellectual content, and therefore have clear and correct outcomes that do not reflect differences in motivation, strategy, or personality traits.

  • Reaction Time (RT) is one such measure. RT is the time that elapses between a individual being presented with a stimulus and the individual initiating a response to that stimulus. RT tests are so easy to do that even 9-year-old children can perform them in a second. Not to be confused with “quick reflexes” in the realm of athletics, RT taps into the efficiency of the central nervous system. Simple RT measures correlate with g ∼ 0.20, while complex RT measures correlate ∼ 0.40. In aggregate, RTs can correlate ~ 0.70 with g.[12] Individuals with higher g have faster RTs, and males consistently have faster RTs than females.[13][14][15][16][17]
  • Temporal Processing (TP), which involves the perception of time, correlates ~ 0.45 with g.[18][19] There exists in the brain a unitary timing mechanism that synchronizes processing across modules to maintain neural efficiency. This is broadly analogous to the internal clock in a CPU which synchronizes the execution of instructions across components. TP measures tap into this internal neural clock. Individuals with higher g have a faster neural clock, reflecting faster updation of information, and so perceive time more accurately. From milliseconds, through seconds, to minutes, males perceive time more accurately than females do.[20][21][22][23][24][25]

ECTs reveal a male advantage of ~6 IQ equivalent points.[26]

Nerve Conduction Velocity (NCV) is the speed at which electrical signals propagate down a neural pathway. NCV measures correlate ~ 0.35 with g.[27][28] Individuals with higher g have faster NCVs due to more efficient brain architecture. Males have faster NCVs, increasing with age, than females.[29]

It should be noted that males have faster RT, TP and NCV despite also having larger brain volumes and body size. This necessarily means that there is a substantial increase in neural efficiency in males compared to females.

Brain Organization

Sex-related differences are found at every level of the brain.[30][31] The most important differences—related to intelligence—are found at the level of organization and may reveal the underlying mechanisms that contribute to the male advantage in general intelligence.

As a general rule, the brain’s structure is an expression of its function, where larger size translates to greater functional capacity. To illustrate this, I take ‘absolute brain size’ as the starting point. Absolute brain size has been established as the best predictor of individual differences in intelligence across species.[32][33] In humans, absolute brain size is moderately correlated with g ~ r=0.45.[34][35][36][37][38]

The absolute brain size in men is about 10–12% larger than in women. Males average larger brains from birth and across all age groups—even though girls tend to be taller from ages 10–14.[39][40][41][42][43][44][45][46][47][48][49][50] Results from autopsy studies and fMRI find only a weak brain size–body size correlation ~ r=0.20.[51][52][53][54][55][56][57] This means that even after correcting for body size, the brains of men are larger by 8–10%. When brain/body ratios of men and women of equal size are compared, at any given size, the ratio is much higher in men than in women.

Figure 2, Rushton & Ankney 2009.

Thus, men with their larger brains, have higher g.

Unfortunately, the simplistic presentation of this argument fails to capture its significance, which I will unpack.

Brains may enlarge by adding more neurons, by making existing neurons larger or some combination of both. The most common method of enlargement is by adding more neurons.[58] But, for this to work, the number of connections must increase much faster than the number of neurons in order to maintain connectivity.[59] White matter is known to increase faster than gray matter, but this is not quite fast enough to resolve the connectivity problem.[60][61][62][63] In addition to this design issue, a substantial increase in the ratio of glia–neurons is required to keep up with the increasing energy costs.[64][65] Given these constraints, brains cannot enlarge without undergoing changes to their organization. Thus, as brains enlarge, they become increasingly modular: larger functions are broken down into smaller processes and processes that handle overlapping tasks are clustered together, enhancing the connectivity within these localized regions.[66]

Then, there’s the other side of the coin: the increase in modularity is further exploited to increase the degree of hemispheric lateralization. ‘Hemispheric lateralization’ is the distribution of functions between the two hemispheres of the brain. The hemispheres have evolved qualitatively different biases in how they interact with each other: the right-hemisphere strongly interacts with both hemispheres whereas the left-hemisphere mostly interacts within itself.[67] This bias is also expressed in their functionality: the right-hemisphere is dominant for ‘global’ information, it operates spatially, intuitively and is concerned with the ‘whole’; the left-hemisphere is dominant for ‘local’ information, it operates verbally, sequentially and is concerned with the constituent ‘parts.’ By distributing functions between the two hemispheres, the brain is able to perform parallel processing. Therefore, as brains enlarge, they become more lateralized to take advantage of enhanced parallel processing.

However, for parallel processing to work, it is necessary to minimise potential conflicts between the hemispheres. The corpus callosum (CC)—the white matter tract connecting the two hemispheres of the brain—functions as the ‘bridge’ between the hemispheres. As brains enlarge, they are optimised for intra-hemispheric connectivity (within-hemisphere) and the CC is scaled down to minimise inter-hemispheric (between-hemisphere) interference.

Putting this all together: larger brains are more modular, more lateralized and consequently, optimised for intra-hemispheric connectivity. Absolute brain size is thus properly understood as a proxy for the brain’s organizational complexity. The end result is a substantial enhancement to parallel processing which leads to a systematic increase in cognitive capacity.

It follows that men’s larger brains are packed with 19% more neocortical neurons for processing, 16% more white matter for connectivity and 28% more neocortical glia to keep up with energy costs.[68][69][70][71][72] Consequently, men’s brains are more modular, more lateralized and optimised towards an intra-hemispheric configuration whereas women’s brains are more diffused and fall back to an inter-hemispheric configuration.[73][74][75][76][77][78][79][80][81][82][83][84] While there are certain benefits to both configurations, the mechanical advantages to men is apparent in task performance:

  • Language processing is represented bilaterally in women, but is left-lateralized in men. This necessitates a reliance on inter-hemispheric connectivity in women for processing language, resulting in slower performance and lower verbal intelligence.[85] The intra-hemispheric configuration in men prevents this kind of “traffic jam,” even though they have longer inter-hemispheric transmission times in the left–right direction.[86]
  • Women show greater reliance on inter-hemispheric connectivity for non-verbal intelligence as well. Correlations between bi-manual temporal measures, inter-hemispheric transfer times and non-verbal intelligence are significant for women, but not men.[87]
  • When adjusted for brain size, women have 3–5% more grey matter than men. This excess, found in the parietal lobe, is associated with a disadvantage in visuospatial processing for women. In contrast, the greater surface area of the parietal lobe in men translates to an advantage.[88]

The sex differences in brain organization manifest in preferred “cognitive styles”—i.e. men and women think differently—the most important aspect of sex differences in intelligence.

Cognitive Style

Men preferentially engage in a holistic, ‘global’ (“Gestalt”) style of processing taking advantage of their intra-hemispheric connectivity to integrate disparate streams of information into a coherent “whole,” whereas women preferentially engage in a decomposed, ‘local’ style of processing, assembling information piece-by-piece to optimise their reliance on inter-hemispheric connectivity. While there are certain advantages to both cognitive styles, the overall enhancement to cognitive capacity in men cannot be missed:

  • Visuospatial ability (VS) is the ability to generate, retain, retrieve, and transform well-structured mental images. VS is a unified trait in men—they are able to integrate complex mental images in a bottom-up, automatic and holistic fashion. For women, VS is a diffused trait—they put together mental images in a top-down, forced and piecemeal fashion. Thus, VS is more of a talent in men and a learned skill for women. Consequently, the more complex the task, the more apparent the male advantage.[89][90][91][92] Incredibly, the male advantage in VS can already be detected in 5-month-old infants.[93][94]
  • The male advantage in VS extends to spatial orientation. Here the global–local bias is immediately evident: when asked to navigate through maps, men focus primarily on global features, such as cardinal directions whereas women focus on local features, such as landmarks.[95] This global–local bias can also be detected in children.[96]
  • The male advantage in VS also extends to audiospatial tasks.[97] In binaural auditory processing tasks, the enhanced parallel processing in male brains contribute to a performance advantage.[98]
  • The male advantage in VS extends to visuospatial working memory (VSWM). When both object icons and words are presented together for VSWM processing, men outperform women even in the most demanding conditions.[99]
  • Mathematical ability is an enhanced trait in men, yet again extending from their advantage in VS. The global bias is also apparent here: the male advantage increases as the level of cognitive complexity increases and also as the content changes from arithmetic through algebra to geometry.[100][101][102]
  • Temporal Processing—perception of time—also reveals a male advantage. In tasks requiring temporal integration across a series of sensory events, men apply a holistic processing strategy to their advantage.[103]
  • Creative thinking is associated with ‘global’ right-hemispheric processing and selective parallel processing. Consequently, there exists a clear male superiority—found cross-culturally—in creativity.[104]
  • Men are also more ‘global’ when it comes to ‘social intelligence.’[105] The male social structure involves complex group-based interactions[106][107][108][109] set up by automatic rank-ordering[110] whereas the female social structure consists of triads, dyads and one-on-one interactions with related individuals. Consequently, men are more competitive, co-operative, collaborative, tolerant of and easily affiliate with genetically unrelated individuals.[111][112][113][114][115][116][117][118]

The sex difference in ‘cognitive style’ is clearly one of the most profound differences between the sexes, the full extent of which goes well beyond the mere numbers measured by IQ tests (and beyond the scope of this article). It is because IQ tests tap into some of these mechanical differences, that they reveal a higher g score for males.

Thus, men with their more complex brains, have higher g.

Women “Multitaskers”

Extrapolating from early findings of sex differences in the corpus callosum, it was claimed that because women had a differently shaped corpus callosum, they were better at “multitasking.”

Unfortunately for this claim, the inter-hemispheric setup of the female brain is their primary disadvantage. Even worse for this claim, the human brain is not even capable of true “multitasking.” The closest we come to multitasking is parallel processing, which is an enhanced feature in the male brain. Still worse for this claim, it inadvertently reveals women’s inability to tune out information irrelevant to the task at hand, resulting in sub-optimal performance in certain tasks.[119][120]

Shell Games

Over the last few years, several publications have put forth claims such as “there are no sex differences in IQ” or that, “women and men are equally intelligent” and even “sex differences in cognitive abilities are small.”

Fully 100% of these publications manufacture their conclusions by either omitting or ignoring critical information regarding sex differences in mental abilities.

Sex Normalization

Most mental tests are constructed such that items that show a large advantage to one sex are removed, leaving behind a selection of sub-tests that cancel each other out. All popular IQ tests, including the many versions of the Wechsler Adult Intelligence Scales (WAIS), Raven’s Progressive Matrices (RPM) and the Wonderlic Cognitive Ability Test (WCAT) are ‘sex normalized’ in this manner.[121][122] Since the late ’80s, this treatment has been extended to national and international assessments including the SAT, the Cognitive Abilities Test (CAT), the Programme for International Student Assessment (PISA), the Trends in International Mathematics and Science Study (TIMSS) and even the armed forces’ standardized tests.[123]

[As Namae Nanka pointed out in the comments section, the practice of ‘sex normalization’ has been institutionalized at least since the time of the eminent educational psychologist Lewis Terman.]

It’s ridiculous to claim that sex differences in intelligence are small or non-existent when the tests themselves are constructed to render them invisible. One must look to other measures of intelligence to unveil sex differences in g, such as the ECTs mentioned in the previous section.

Dispersion Effects

It is well known that males tend to show 10–20% greater variance in measures of intellectual capacity, even when mean differences are small.[124][125][126][127][128] The sex difference in variance is found to emerge even before pre-school, and by age 10, boys have a mean advantage and greater variance.[129] Even among opposite-sex siblings, there are at least two times more males at the extremes.[130] The male tendency to be over-represented at the extremes and the female tendency to crowd around the center of the distribution is a fundamental aspect of sex differences in humans.[131]

Studies that claim there are no sex differences in intellectual capacity tend to ignore these dispersion effects altogether.[132] This is a serious omission which discounts the exponential increase in the proportion of males at higher levels of cognitive ability.

Developmental Trajectories

It is well known that boys mature several years after girls do. But the most conspicuous difference is the brain developmental lag seen in males compared to females. The ‘halfway’ point—the transitional point—in brain development for females is age 10.5, whereas the equivalent point for males is age 14.5. Females reach the end of their developmental trajectory at around age 22 and males at around age 30.[133][134] Furthermore, as I’ve already discussed earlier, the brains of men are organized differently from the brains of women and this results in a substantial difference in processing capacity. Given that brain organization is a function of age, differences in cognitive capacity may not be fully apparent until adulthood.

It is nonsensical to use samples of children in Grades 3–12 to generalize sex differences in intelligence, because it is guaranteed to underestimate the male advantage – by a substantial margin – as such samples contain a much greater proportion of immature males.


There exists a clear and significant male advantage in g that can be revealed by proper testing, but this is hidden through the use of outdated models and incorrect methodology.

One would think that even the most incompetent social scientist would have figured out the critical factors mentioned in the previous section. Indeed, it has now become clear that incompetence is not the problem here—academic fraud of this scale originate from radicals who, disguised as scholars, act in service to misguided ideology.

With the identity politics filtered out:

  • Measurable sex differences in general intelligence can largely explain the male dominance in the upper echelons of all known human societies, both in history and in the present day.
  • The ‘gender gap’ extends well beyond ‘general intelligence,’ and is most certainly not diminishing. If anything, the proportion of males at the extremes seems to have increased.
  • Contrary to various claims, women are not under-represented but over-represented in many domains. As a result of fixed quotas designed to bypass filters for ability, there is now an increasing number of mediocre women and a tragic paucity of gifted individuals in higher educational and S.T.E.M. spheres.

I intend to keep this post updated based on requests and any new data.


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162 thoughts on “Sex Differences in Intelligence

    1. Knew about the study before it was published, but the book I’ve not come across before. Also, the British Psychological Society needs to stop hiring imbeciles to write these types of articles.

  1. I regard this blog as one of the few sources that reliably go outside the mainstream narrative and whose author puts lots of effort in the articles. SO, could you please update the article including newer data and some of the thoughts that came out of the many comments to the post.
    P.S. it would be great if you could reduce your political right wing attitude and male chauvinism, since both take us further from truth and actually do a favour to feminism

  2. Ridiculous article. All the “sources” and “research” quoted here are, at best, outdated and cherry picked. There are thousands of recent, comprehensive, serious studies that prove that women have better brains and outperform men in several critical aspects.
    @NonControversy, do you have something to say?

  3. Wait, so are women dumber? I mean, with the way the sexes think, they are still smart, just in a different way. (Men are better at their thinking, while women are better at theirs.)

  4. What about sex differences in regional grey matter? I bet men have more grey matter on critical areas for intelligence regarding the parieto frontal integration theory. Those facts are interesting to add to this great article non-C.

      1. Why is it that you only state the advantages males have? There are also enough articles stating some obvious female advantages, like the language, the speed in which females can switch their attention. They tend to analyse a situation better than men? The amount in which you overstate the positives of the advantages of the male gender does make it seem that you are overly biased towards a preference of the male gender.
        In some terms men do outperform women but in others they do not.
        How about the continuous observations that man are more impulsive, are more emotionally volatile and more prone to prejudice? These are all attributes which interfere with overall intelligence.

        What are your thoughts on this?

  5. Here is some additional links on sex differences in intelligence. It seems likely that it is substantially an x linked trait which can explain the variability differences.

    podcast interview with Roderick Kaine, author of Smart and Sexy, which is on this topic.

    Additional article which provides a fairly good summary of the same book, lists a lot of the data that was in the book.

  6. Although I had heard of the supposed increase in human intelligence over time, I had my doubts. My Q is : is the increase in intelligence of humans over time totally explained by the increase in body size?[body size increase => larger brain => g increase]

    1. It’s called the Flynn Effect (or the Lynn-Flynn Effect), it’s a slow rise in mean IQ (i.e. 3 points per decade). More recently, it’s been slowing to a halt (much like the increase in height). The most likely cause is improved nutrition as this curious trend coincides almost perfectly with the industrial revolution.

      To put it simply we’re maxing out human height and intelligence, and both increases are stopping due to the fact that we’ve more or less reached our “genetic limit”, so to speak.

  7. Taking a look at “Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test”
    I’m surprised by the conclusion. An unpopular conclusion no doubt, but not as career killing as what seems to be the real conclusion “hidden” right up front, in the abstract. Over 100,000 students were tested, males came out ahead in the SAT. However assuming a balanced gender starting population 50:50, twelve years previously — something happened in between. Of the remaining students 45% males and 55% females, the males came out ahead. This alone does not indicate a difference in g, which may indeed exist. What it does show is that there’s a gender-based filtering process in primary and secondary education– only the smarter boys make it as far as taking the SAT.
    This is my conclusion, and it seems blindingly obvious.
    Am I right in guessing that the authors could say something unpopular; that there’s a gender difference in g favoring males, but they could not say something terribly politically incorrect? Something they were forbidden to say? But they managed to slip it into the abstract anyway.

    1. 1. The number of male and female asians taking the SAT is roughly equal yet males in this group again get higher SAT scores.

      2. Males taking the SAT have higher Standard Deviation than females – therefore lots of average and below average males take the test – in other words there is no evidence that “there’s a gender-based filtering process in primary and secondary education– only the smarter boys make it as far as taking the SAT.”

      3. Girls mature faster than boys. Mostly 17 – 18 year old teens take the SAT. Lynn found that differences between maes and females increase as they become adults. Greater performance of adult males was also confirmed by the GRE, GMAT, AFQT, and the PIAAC.

  8. While this article is certainly interesting and makes some valid points, it would be quite foolish of me and anyone really to trust a person with clear agenda to prove male superiority. You are running a blog titled “science vs feminism”. Trusting you would be about as sensible as trusting feminist “scientists” when it comes to sex differences in ability or achievement.

    Now I can’t refute all your points because I won’t bother to read all studies mentioned. But the fact that you deliberately misquoted from a study I am familiar with already makes you less trustworthy.

    “Creative thinking is associated with ‘global’ right-hemispheric processing and selective parallel processing. Consequently, there exists a clear male superiority—found cross-culturally—in creativity.”

    Your source for that statement is a study of creative thinking in China which I will grant you is titled “male superiority exists”. However anyone who actually bothers to investigate will find out that males show higher variability in creativity, meaning they score both higher and lower, while the average is about the same. Why you tried to omit that fact is beyond me.

    Finally I’m not an idiot. I don’t believe in equality of mental ability just because society tells me it’s politically correct. However I wonder how you could explain the fact that even when controversial researchers like Arthur Jensen, whom I have the utmost respect for, assessed sex differences they found nothing meaningful in general intelligence? Jensen assessed the relationship of sex differences to g in five different test batteries concluding that “the sex difference in psychometric g is either totally nonexistent or is of uncertain direction and of inconsequential magnitude”.

    Even Richard Lynn, the only scientist in this field still adamant about sex differences in favor of males, claims an IQ gap of just 4 points. And he hasn’t even managed to prove that as his own studies failed to replicate his findings on several occasions.

    I really appreciate the hard work you put into digging up all these studies but it’s clear as day that your conclusions are biased as fuck and shouldn’t be taken seriously.

    Good day dear Sir.

    1. As far as i know Jensen did not care too much about the issue of sex differences in intelligence and was not very interested in researching it.

      Jensen’s results were criticised because he included a test heavily packed with psyhomotor sub tests that favored women. Moreover, while psyhomotor abilities have some correlation with IQ they do not directly measure IQ. Traditionally, IQ tests very rarely use psyhomotor subtests.
      H. Nyborg The Scientific Study of General Intelligence page 205

      Since then, many new studies were done. If you take all the studies measuring G together you get 2-3 IQ points in favor of men. Moreover, most IQ tests are designed to show no sex differences so the real differences could be even larger.

      As far as Lynn is concerned, he consistenly found that men get higher IQ in Raven, DAT and WAIS tests. I do not see where his studies consistenly failed to replicate that. If you check all available WAIS and Raven studies you will find that in the vast majority of them men get higher IQ than women.

      For example there are at least 20 studies of older adults out there using Raven and men get higher IQ in 17 of them. Men get higher IQ in almost all available WAIS studies as well.

    2. “However anyone who actually bothers to investigate will find out that males show higher variability in creativity, meaning they score both higher and lower, while the average is about the same.”

      I read about the study before one year and it appears that they found greater differences in means scores in favor of males.

      “Results from an analysis of the means lent further support to the findings of male superiority.”

      If you look in the actual article you will find difference in the mean scores of around 0,2 SD in favor of men.

      A similar study found greater means for males as well.

      Page 91 Composite TCP-DP score 0,13 SD in favor of older adolescent males (19-23 old). Note that the difference increases with age and it could become even bigger later in life.

      1. Creativity is closely related to holistic processing of information (the kind that is characteristic of the male brain). Visuospatial abilities are closely related to creativity as well, and such abilities happen to be holistic in terms of information processing. Men also show greater philosophical intuition compared to women, and this is also closely related to holistic processing of information.

        Unfortunately, until we can figure out how exactly all of these pieces fit together, it’s going to be a challenge to quantify them. Understanding the biological underpinnings is key.

      2. Greater male variability is explained in my recent article:

        Males are designed to be the primary target of selection, and the brain is a large mutational target. Mutations that enhance brain efficiency will accumulate and also mutations that are deleterious to the brain’s functionality. This means more males at the bottom and much more at the top (because males at the bottom will fail to reproduce). It follows that the organization of the brain would be heavily sex-biased at every level:

        +Greater plasticity of the brain generally, at system level, circuit level and synaptic level in males: 1.Dachtler, J. & Fox, K. Do cortical plasticity mechanisms differ between males and females? J. Neurosci. Res. 95, 518–526 (2017).
        +Mottron, L. et al. Sex differences in brain plasticity: a new hypothesis for sex ratio bias in autism. Mol Autism 6, 33 (2015).

        +Direct effects of Sry on motor ability in the brain: Dewing, P. et al. Direct regulation of adult brain function by the male-specific factor SRY. Curr. Biol. 16, 415–420 (2006).

        +Epigenetic mechanisms are sex-biased: McCarthy, M. M., Nugent, B. M. & Lenz, K. M. Neuroimmunology and neuroepigenetics in the establishment of sex differences in the brain. Nature Reviews Neuroscience 18, 471–484 (2017).

        There is much more than this but it will take time to synthesize everything. Also, I will be rolling out the long-overdue update for this post next week.

  9. Thoroughly enjoyed the read. Even as a young woman myself, I believe understanding natural dichotomy without being up in arms (like some of these people commenting) is somewhat indicative of one’s capacity–or at maturity, if nothing else LOL. Which is to say, I wish we could accept facts without being so obsessed with the political correctness; the commonality of people prioritizing feelings over knowledge is…unsettling. Anyway, again, great piece.

  10. Hello,

    This is a great article. There are indeed a lot of sex differences in intelligence. I recently had the privilege of reading the book “Smart and SeXy” by Roderick Kaine. That book echos a lot of your findings in this article. For example, it also had a section on brain size differences. However, it provides evidence that the X chromosome is the most important factor in causing these differences. Basically, since men on have one X chromosome, recessive brain genes on the X are always expressed. That is what causes the much greater male variability. In other words, why there is more male morons and more male genuises. I highly suggest you check out this fascinating read:

  11. No idea why, but a long comment of mine was marked as spam.
    WIsh the admin will retrieve it, I didn’t think it was very spammy, lol.

    I just said:

    1) the subjective nature of arts and philosophy makes it all too easy to deny reality and self-feed on illusions of being adept. The male-female gap in these fields, the real gap, is at the very least as wide as that in “hard sciences”.
    Other reasons why it looks invisible: educational standards have been dropped many a decade earlier in liberal arts and philosophy than “hard sciences” (the last bastion to resist the assault of the anti-intelligence ideology-fuelled mob).
    Nobody, not even the very intelligent, knows much of what real philosophy, and real art would be about.

    2) IQ/g are the best approximations of cognitive ability we have. But thinking they tell us all about a mind is as silly — although in no way as intellectually cowardly — as denying their carrying any meaning.
    They carry a lot of meaning, and are of much use, but they are tools, approximations.
    Your average 130-IQ Chinaman, Chinawoman, Scandinavian, Western male and Western female brain and mind are still going to have different skills and lines of thought.
    This is why “multiculturalism”, that is multiracialism, putting all races together, is a crime against culture, intelligence, and the richness of human biodiversity.

    If all are put together, a single culture, civilization, and type of brain will result, after a certain time.

  12. Some additional data: Smart men have more children than smart women. The smartest women are also those women more likely to be childless.

    In other words, intelligence appears to be a relatively good (or neutral) trait for men, but negative trait for women, therefore you can not expect to have many female geniuses, nobel laureats, professors, or inventors, as they will be dysgenic and genetically/evolutionary unsuccessful. And this is exactly what we observe.

    In biology, this contradictory relation between intelligence and fertility would be described as a sexually antagonistic trait because it increases reproductive fitness of one sex (males) and decreases it in the other (females). As such, these genes are under conflicting selection pressures as they pass between genders over the course of multiple generations. This creates a large incentive to evolve sexually dimorphic expression patterns which can silence or diminish expression of intelligence genes in females while allowing the same genes to be turned on in males.

    Intelligence and childlessness: “Analyses of the National Child Development Study show that more intelligent men and women express preference to remain childless early in their reproductive careers, but only more intelligent women (not more intelligent men) are more likely to remain childless by the end of their reproductive careers. Controlling for education and earnings does not at all attenuate the association between childhood general intelligence and lifetime childlessness among women. One-standard-deviation increase in childhood general intelligence (15 IQ points) decreases women’s odds of parenthood by 21–25%”

    “Offspring number increased with wealth and educational level in men, whereas an inverse pattern emerged in women: fewer offspring as income and education increased.”

    “Further analysis showed that dysgenic fertility is present only in females.”

    “We found that IQ had a small but statistically significant negative effect on subsequent family size. This negative effect was considerably larger for women than for men.”

    1. That’s a way of taking notice of how high-IQ men are more natural, and make more sense evolutionarily speaking, than high-IQ women.

      However, the technological progress we are living and going to see in the incoming century is so large it’ll alter humans evolution-wise.
      Children will be produced in laboratories, and bought online like we buy media and other goods. Everybody I tell this to seem intimidated and react, at best, with anxiety.
      But it’s going to be possible, and, no matter the resistance opposed by society, what’s possible is going to be done after some time.

      This, + being discharged from domestic chores (which is in effect as regards Western women already: when you don’t have to do housework your personality changes, a lot. And that’s why Whites and Browns/Blacks are so different, also.), + eventual wars being no more fought by hundred-thousand-strong armies, is already making females and males less different.
      Humanity is headed to be a monogender life form. The most intelligent share of it is, at least.

      See how less and less sex is being had in the more intelligent countries, by the more intelligent people. There are statistics as concerns the sexual conduct of Japanese youth, Chinese metropolitan youth, Swedish youth, American White youth. All of them are talking of sex more than ever, and banging less than ever (the chatter being a form of compensation, certainly).

      As sex is no more needed… sex urges will gradually wane.
      As physical fights are no more joined, inborn sinewy will gradually wane (look at the muscular structure of Ashkenazi Jews and Tokyomen).

    1. I checked carefully the Wikipedia article and to me, it looks like it is highly biased. For example it mentions a few studies showing male advantage, and then a lot more showing no difference in intelligence. Actually the vast majority of studies show a male advantage in IQ and in G. As far as i’m aware there are at least 130 studies showing male advantage in IQ, around 40-50 studies showing no differences, and around 10 studies showing a female advantage (among adults). There are at least 15 studies among adults showing that males have greater G, 8 showing no differences in G, and 1 showing a female advantage in G. All the studies, taken together, show that males have slightly higher mean IQ, maybe 2-3 IQ points more than women. Now this is all measured with sex normalized tests. Since most tests are sex normalized, the difference could be even higher. Then Wiki cites lots of studies of children and adolescents. People who look for what is really going on look at adult performance, not at teen performance, since girls mature faster than boys and actually have higher IQ at 14, but later, among adults, the table turns.

      Plus there are some inaccuracies, and even studies that i can refute, but that will take me a long time. For example it mentions 3 studies by Colom, showing no difference in G. But according to Nyborg, Colom actually found sex difference in favor of men, but decided not to investigate further. The third study by Colom claims that there is no difference in G, if you look at the actual study, he actually found a difference between 1,8 and 3 IQ points. It mentions a study by Wendy Johnson and Thomas J. Bouchard that supposedly found no sex differences in G. The study actually found 2,1 IQ points in favor of men, but the result was not statistically significant, because it was a small difference, combined with a small sample. In other words, the study can not prove if there are differences in intelligence or not, and even if such small differences (2-3 IQ points) exist, they can not be reliably detected due to the small sample. Being incapable of finding a sex difference due to study limitations (small sample, making the reliable detection of small differences impossible) is different than explicitly and clearly finding no sex difference in intelligence, and therefore that study should not be placed together with other studies showing null sex differences in intelligence.

      Note that if men and women had equal IQ, you should be also seeing lots of studies where women perform better than men, due to sample fluctuations. Yet such studies are extremely rare. Which shows, indirectly, that there is difference in favor of men. If there was no difference in intelligence, you should be seeing lots of studies showing no difference (maybe 40 – 50 percent of them, the majority), lots of studies showing a small difference in favor of males (around 25 – 30 percent), and lots of studies showing a small difference in favor of females (around 25 – 30 percent). Yet this is not what is going on.

      What is going on is that the majority of IQ studies show male advantage among adults (around 70 percent of all studies), a good number also shows no sex difference (around 25 percent), and only a very small number shows women performing better than men (around 5 percent). What this means is that there is small advantage in favor of males, which is close to 2-3 IQ points, which causes the majority of studies to show a male advantage, but also causes some studies to show no differences in IQ, as well as a very small amount of studies showing a female advantage.

      Then there is the fact that males perform better at the SAT, ACT, LSAT, MCAT, GRE, GMAT, the Advanced Placement, and the Bar Exam (that are already sex normalized). Or the fact that male scientists publish more papers per capita even compared to childless or unmarried female scientists. Or the fact that 95 percent of new things are invented by men – see patent holders.

      ECTs are already mentioned in the article. Men have faster reaction time, faster NCV, and better time perception, all of them correlate with IQ.

      Men also perform better on the majority of subtests in exams and IQ tests. For example adult men perform better at verbal reasoning, math, spatial ability, science reasoning, social sciences, biological science, general knowledge, mechanical reasoning, etc. Women are better at writing, emotional intelligence (the reading of other people’s emotions), and some perception tasks (clerical speed and coding). Men are better at timed (harder) tests and exams compared to women.

      Then, when comparing the abilities of men and women, it should be mentioned that the biggest differences in subtests favor men. For example the difference in writing is only 0,1 sd in favor of women (among adults).
      But the difference in mental rotation and mechanical reasoning is large (1 sd). The difference between men and women on mental rotation and mechanical reasoning is similar to the IQ difference between US whites and blacks – around 15 IQ points. Which explains why so few women are engineers and why only 5 percent of civilian pilots are women.

      Moreover, men have more variable IQ, as well as greater variablility than women in math, spatial ability, science reasoning, social sciences, biological science, general knowledge, and mechanical reasoning, which leads to a situation where men are the vast majority of geniuses, nobel laureats, top chess players, professors, surgeons, inventors, people who start high growth businesses, people who earn more than 1 million per year, etc.

      Other indirect ways to understand who will have more intelligence is to compare the “fertility rate” of smart men and smart women (see my post above). Smart men have more children compared to smart women (women are more dysgenic than men), plus the children of high status people are more likely to be boys (the Trivers-Willard effect, as Non Controversy mentioned below). Then studies show that men are not very interested in intelligent women, and prefer looks over intelligence. All of this leads to certain amounts of sexual dimorphism in intelligence, because intelligence has better effect on the reproductive fitness of one sex (males) and decreases it in the other (females).

      1. You do realize that 2-3 points difference in intelligence means nothing right? It would only show up at very extremely tasks. I don’t think you understand how intelligence research works. Colom’s studies summarized “no significant difference” or “negligible difference” because 2-3 points is not big. There are bigger difference in IQ between races then there are between genders.

        1. 1. It is actually very important difference because combined with greater male variability it leads to total male domination at the top and male ruled societies.

          “Small mean differences combined with modest differences in variance can
          have a surprisingly large effect on the number of individuals who excel. It has been shown that if scores are normally distributed in two populations and if one population has both a higher mean score and a larger variance than the other, then the ratio of the number of individuals in the population with the higher mean to that of the other population (the tail ratio) increases at higher percentiles in the upper tails of the distribution. This pattern
          held for the tests that had sufficiently high ceilings to accommodate the estimation of percentiles above 95. For example,in the Project Talent mathematics (total) scale, the sex ratio was 1.3 for scores in the top 10%, 1.5 in the top 5%, 2.1 in the top 3%, and 7.0 in the top 1% of the overall
          distribution. For several of the science and vocational aptitude tests, the sex ratio became infinite in the top 3% or 1% of the overall distribution because no females scored in this range.”

          “LG: It seems that there is an insignificant difference separating men and women.

          P: That depends on the context.

          LG: Wouldn’t you call a difference of less than 2.5 IQ points small?

          P: Again, that depends on the context. For example, suppose we ask what the chances are that a randomly selected woman is smarter than a randomly selected man. Based on their g distributions, I calculate that the woman has better than a 45 percent chance of being smarter than the man.

          LG: I’d say that difference is barely noticeable.

          P: I agree. Based on this criterion male-female cognitive differences would mostly go unnoticed

          LG: What other criteria are there?

          P: The marketplace provides good examples. Linda Gottfredson has studied cognitive demands of various occupations. In her paper, Why g Matters (Intelligence, 24(1), 79–132) she estimates a minimum IQ of 120 is needed to be competitive in moderately “high-level” jobs such as research analyst or advertising manager. A gender gap of 0.162 SD with a variance ratio 0.916 tells us that of the workforce segment meeting this requirement only 37% will be female. The g distributions will impose not a glass but rather a statistical ceiling on women in the high end of the workforce. According to EEOC, in 2003, 35.2% of “officials and managers” in the private sector were women — a number suspiciously close to 37%.”

          Moreover, Lynn found even bigger mean differences of 4-5 IQ points. According to Nyborg some Colom studies found 5 IQ points mean difference in favor of males but Colom decided not to investigate further or to downplay the differences.

          2. Most IQ tests are sex normalized to show minimal differences and so the difference could be even larger, with even more serious implications for the top.

          “According to the 1994 report “Intelligence: Knowns and Unknowns” by the American Psychological Association, “Most standard tests of intelligence have been constructed so that there are no overall score differences between females and males.”

          “When standardized IQ tests were first developed in the early 20th century, girls typically scored higher than boys until age 14, at which time the curve for girls dropped below that for boys. As testing methodology was revised, efforts were made to equalize gender performance.”

          1. This is a horrifying question for me to ask but i need you to address every point in that wiki page point by point. There are a number that you missed in this complex issue, including but not limited to lynns exclusions and broken methodology (alleged) , criticism of lynns research that he failed to rectify, the presence or absense of studies that deal with the psychology of tests ( controlls for environmental factors, variance likelyhood among men selected to do tests compared to actual expected variance), the assertion of female efficiency that counters your assertions of male efficiency for neural activity (both cannot be right afaik), the assertion of g factor being normalized in tests that specifically only test for g factor ( in depth explination needed as you spend most of your time targetting iq tests in general here )

            I understand if i come off as cunty as i have a horse in this race but I really favor scientific explination and want you to break me if needed
            I however may question as there have been a number of harsh examples of male supremacists who claim supremacy and fail consistantly to avoid rookie mistakes, fall for clickbait or anything that confirms their belief despite nothing so muh as resembling the intimidating body of evidence youve provided.

            Its not much consolation to be called inferior by people who consistantly fail to act any wiser and i dont forsee myself as unable to do anything but critically examine and needle for information and high standards of rigor. I know at minimum you have provided an intimidating ammount of arguements for this topic yet have been silent on key points addressed in the wiki link for example as well as the topics above. Whether you reply in blog post format or comment, I wouldnt mind talking to you in hangouts or another direct messaging of your choosing if you find the idea of guessing at what the hell im talking about daunting if any of its unclear,

            More importantly and TL;DR if you find any of this inane and not worth your time please use my email so that i can see if i can make it worth your time somehow. Authenticity in this topic is very important to me and my friend and your post represents the first thing ive run across that approaches even if it falls short in some respects to a legitimately dominant position for male supremacy in scientific study as opposed to a simple parroting of lynns study and neuron counts without addressing or in some cases presuming the complete absence of countering evidence.

            Thankyou for your time. I may mail you directly if i dont recoeve any kind of reply.

          2. It occurs to me that despite the fields offering it there is no link to email accounts provided so here is mine via post


            I cant understate how much i hope to get into contact with you to talk about this

            1. It’s intentional that the emails don’t appear to anyone who randomly waltz into this blog, because I fear such information will be abused. I’m approving this comment only because you posted your email of your own accord.

      2. Excellent and well documented article. I read that page on Wikipedia too and found it fundamentally biased. Since such topic requires someone competent, could you please consider to update the page? It would be misleading for many readers. You might be thinking to add a section or correct throughout. Thank you

        1. Thanks for the offer, James, but i do not know if it will work. From what i hear there is plenty of bias in Wiki. There are whole teams who work on editing Wikipedia pages, including feminist organisations who team up to edit Wiki pages. Whatever i do it will be “fixed” in no time.

          Btw just recently a new study came up refuting the assertions at the Wiki page that greater brain size in men (compared to women) does not lead to higher G.


          1. I see your point but if someone never tries the bias would never be amended. Besides I made few corrections on the Wiki page and they still stand so please let’s not indulge in the feminist theory of complot! That page must be rewritten

            1. I’ve attempted to edit some of the pages, but it doesn’t stick because Wikipedia moderation is carried out by progressive crackpots. You may have heard of “edit-a-thon” programs by feminist groups in Universities. If you look at the timing of these programs, you’ll see that it corresponds to the huge infusion of progressive propaganda into pages that deal with sex differences.

  13. On G

    “Bruce Bracken, a psychologist at the College of William and Mary in Williamsburg, Virginia, who was not involved in the new study, said he thinks Rushton and Jackson make a convincing argument for the sample they used.

    “The difference appears to be real,” Bracken said.

    But he questions the team’s conclusions. “I believe that the differences probably lie in the variables they hadn’t considered,” Bracken said.

    One plausible explanation is that more females than males decide to go to college and thus take the SAT test. The study did in fact include about 10,000 more females than males.

    “This suggests that more males are deciding to do something else,” Bracken said. “It may be that the males who would not have scored as high on the SAT chose not to take it, and they chose another route.”

    A more reliable study, he said, would be to match each male with a very similar female and then compare the results. “

    1. On the other hand, Rushton studied the performance of 17-18 olds. It is known that the younger the girls are, the better they perform, compared to boys. Later the tables turn.

      Females mature faster that males, so i bet that if a bunch of 30 year olds take the SAT, the performance gap between males and females will be even larger.

      Moreover, while the SAT does include Verbal and Math components, it does not include a spatial component, where males have large advantage over females.

      A recent study that quantified male advantages found that older adolescent men out-performed women on average by 6 IQ points on items involving numerical reasoning and 13 IQ points on items involving mechanical reasoning. A full standard deviation advantage on spatial reasoning tasks is a LOT and goes a very long way in explaining the dearth of women in STEM and the low numbers of female electricians or mechanics. Having a high spatial reasoning has been shown to be essential to the pursuit of the inorganic sciences among the smartest people.

      Performance on image rotation tasks is known to predict success in fields such as airplane piloting, engineering, physical sciences, and fine arts. Studying SAT or GRE scores can not predict the fact that women are only 5 percent of civilian and only 2 percent of combat pilots, studying sex differences in spatial ability can.

      And it is not only the SAT where males perform better, but also the American College Testing Program Assessment (ACT), the Graduate Record Exam (GSE), the Graduate Management Admissions Test, used by most business schools in the United States (GMAT), and the Medical College Admissions Test (MCAT).

      1. References:

        Note that the number of male and female MCAT test takers is roughly the same, so Bracken’s argument does not apply in this case. If anything, real male scores should become even higher, since the number of men is a bit bigger than the number of women.

        And among US GMAT test takers, where males again outperform females, there are far more men than women, so following Bracken’s argument the gender gap favoring males should become even larger.

        1. Note that the SAT has been sex-normalized for some time now. The main “problem” was SAT-M.

          Previously, the SAT-M had been a surprisingly accurate predictor of success in STEM fields. Complex mathematical items were removed from the SAT altogether, or shuffled across to the optional tests, for the simple reason that they favoured males. They knew exactly what to do because the data was clear-cut: the more cognitively complex the item, the higher the male advantage, which means increasing male advantage from arithmetic through algebra to geometry. But it wasn’t a one-shot change—that would make it too obvious—rolled out to the SAT slowly probably as part of its “revisions.”

          I think they managed to bring down the male:female ratio at the top from 13:1 to 2:1. The consequence, as usual, is the opposite of what they probably intended. It was one of the few tests that made a lot of progress in seeking out gifted girls/women in the past, now it’s obsolete and nobody is interested in female test-takers.

          I’m pretty sure many other tests have been put through the same process.

    2. “One plausible explanation is that more females than males decide to go to college and thus take the SAT test. The study did in fact include about 10,000 more females than males.

      “This suggests that more males are deciding to do something else,” Bracken said. “It may be that the males who would not have scored as high on the SAT chose not to take it, and they chose another route.”

      Recently i had a look at SAT data, and i found another reason why Bracken is wrong. If lots of average and below average males decided not to take the SAT, then this should lead to clustering of high IQ males, more similar male scores, and, therefore, to lower standart deviation for males. Yet males taking the SAT have larger standart deviation than females, therefore lots of average and below average males decided to take the SAT.

      In other words: Bracken’s explanation does not sound that plausible to me.

  14. While you were writing this article, women were out…

    Discovering elements

    Designing atom bombs

    Developing new drugs

    Running for president


    Of course, there are plenty of studies out there that may support your theories, and I agree that men and women have different strengths, in terms of intelligence as well. But also consider who is driving and paying for these studies. Not too many women, I’m guessing.


    Especially considering the increased obstacles that women face in their endeavors that men do not, their lack of access to formal education and established professional networks that men have, plus their ability to balance work with the demands of child rearing from which men often shirk, women’s accomplishments are even more astonishing.

    I feel sad for the women in your life who must live with your limiting, small beliefs. I don’t judge a man’s abilities, as I am not a man and have not walked a mile in his shoes.

    1. Woman are having very, very poor performance in Science, as far as invention of new things is concerned, so you shouldn’t be talking about this, because it is really embarrassing. Women invent only 5 – 10 percent of new things (see patent holders). Do you know what this extremely poor performance means?

      It means that women, if left to their own devices, will be living in the Middle Ages, not to say the Stone Age. Feminist Cammile Paglia herself mentioned that women, if left to themselves, will be living in grass huts.

      Just look at the verbal intelligence area, a place where women are supposedly at their best. Yet even there, the vast majority of the best writers, poets, philosophers, or movie makers, are men.

      It is useless to really talk about this. More women than men reproduce, while mostly the best men reproduce, so this causes a situation where men (generally speaking) have better qualities than women. The greater variability among males (males are more unique, while females are more similar to each other) is also connected with this.

      And it isn’t even men who are causing this, it is women and their hypergamy. As long as women are trying to mate only with the best men, men will have better qualities than women.

      1. References:

        Women have played a proportionally tiny part in the history of the arts and sciences. Even in the 20th century, women got only 2 percent of the Nobel Prizes in the sciences—a proportion constant for both halves of the century—and 10 percent of the prizes in literature. The Fields Medal, the most prestigious award in mathematics, has been given to 44 people since it originated in 1936. All have been men.

        Where are all the female inventors?

        Just 8% of primary patent-holders for 2010 are women. Their patents are most often for technologies associated with “traditional” female roles, such as jewelry and apparel.

        Why Don’t Women Patent? American women patent at only 8% of the male rate, according to the National Survey of College Graduates

        1. @Mestre

          One woman per 50 men is extremely poor performance. At top levels men and women are basically different species.

    2. Your delusional “hurting people’s feelings changes the biomechanical basis of intelligence” is no longer working

    3. Ingrid, I understand that you’re a woman and abstract thought is not your strength, but when you make a comment you should be sure that the arguments displayed aren’t self-contradictory.
      If your point is that women are equal you can’t say then that womyn face obstacles like discrimination from male networking(including education, a knowledge and training distribution network). Because if womyn are equal why they haven’t their own functioning networks? Why they need to parasitize male social spaces? I mean if women weren’t stupid they would have their own philosophers, scientist, etc independently of male networks, obviously if such female only, functioning networks were real or possible, women wouldn’t whining about face obstacles due to their women condition.
      Imagine monkeys, are they regarded as dumb because they face obstacles in white men networking that white men not, or because they fail to establish a successful networking in first time?? Whatever being could claim the same you claim for womyn and the response would be the same.
      Forget about kids, men have to care for BOTH womyn and kids, going to war, unsafe work, and several other dismembering related activities. Housekeeping is leisure time.

      1. Housekeeping is leisure time, and historically leisure time has been great for geniuses. Think about Greeks, Galileo, Kepler and several others. Uhh, what that says about womyn?? After all they have more “opportunities,” and still perform poorer!!!

  15. Don’t you think that the difference in intelligence said here is too little?
    Creativity is problem solving and problem solving is intelligence. Creativity occurs in the long run because a person needs to take and process much information usually temporarily distant. Creativity is a indeed a punctual expression of systematising. Systematizing can be defined as the skill to realize that there are patterns, identify the small variables that modify it, and relating the abstract concepts to create ”the one pattern”. Systematizing also takes place in the long term due to the complexity of the task and the massive data processing. My point here is, systematizing isn’t measured by Nyborg. Baron-Cohen has a test but isn’t very complex and more tests are needed to measure well. Most IQ tests are exclusively focused on fluid intelligence and the so called crystal IQ which by its definition could be systematizing,but is measured merely via general knowledge and vocabulary. So in no moment is measured the full scope of the skill. Because that’s the main intellectual void of women the more deeply is measured the main skill underlying creativity (also scientific creativity) the greater will be the differences in scores.
    I also want your opinion on the “social pressure model of selection of better language skills in women against spatial in men”. This is idiotic, you need less spech to do what women do than to make a plan to hunt dangerous animals. Hunt is also a social activity no matter how much they say otherwise. This is part of the mainstream: if men obviously have that that and that we need to find some to balance the thing for women so we can force anti human rights policy on every sphere! I let you one of this mainstream articles here: The Evolution of Sex Differences in Language, Sexuality, and Visual–Spatial Skills

    1. I agree with some of your points. Yes, this article does underestimate the intelligence differences between men and women because I’m more interested in unraveling the mechanisms behind the difference than the actual difference itself. This article awaits a major content update but I haven’t yet found the time to do it. I’ll also be posting the last part of this series on sex differences, which will deal with ‘social intelligence.’

  16. How come you didn’t mention the male advantage in mechanical reasoning? which is the biggest intelligence gap between men and women.

  17. Until I know sex standardisation takes place on three levels:
    -Statistical weighing: less difficult and less g loaded subtests are artificially skewed in score importance to favour women.
    -Set of subtests: subtests that aren’t fine for women (usually the most complex) are excluded, making inaccurate g measuring.
    -Subtest: for example, in Raven, test slides that don’t favour women are automatically ruled out.There are two types of those slides, ones contains subtract type patterns, and the other type more than one pattern per slide(i.e. more complex slides)
    Is a complete miracle that men still score higher in IQ.

    1. Yup, exactly.

      However, male/female differences in mental aptitude are a direct consequence of differential brain “design.” No matter how hard they try, it’s going to be difficult to conceal it.

  18. Are you going to write another post on height making up for sex differences in intelligence? You said that there was a lot wrong with the study but you didn’t explain what. I would be curious to know.

  19. While reading I thought…

    does it make sense that less masculine men (physically and characterially speaking) may have
    brains which are more female-brain-like?

    You can see how a man with a talent for poetry is much less likely to have a masculine body and personality than a man inclined to sciences.
    And I think, imaginative language skills will be better in someone whose verbal outputs from a more inter-hemispheric than intra-hemispheric activity.
    The same goes for music composers, and all artists, and, I say, wherever phantasy, creativity are involved.

    Yet, the best music composers, painters, poets, have no doubt been males, and, frankly, the male-female gap in humanities and liberal arts, contrary to the vulgata, is not less wide than the gap in scientific areas, not at all.

    I guess that, global brain size unchanged, some brains, even excellent brains, have more an inter-hemispheric organizations than others.
    (You can say: well, no, they just have a bigger right hemisphere (and a less big left). But if we speak of top-grade art, it’s evident it comes from left-hemisphere excellency as well as right-hemisphere.)

  20. Next time you’re running cognitive tests with a PET scanner, play the sound of a baby crying in the distance. Notice how the male brains register a slight irritation but proceed with the test (and probably won’t remember the baby if you ask about it later), while the female brains cease all other activity to focus on this child in distress.

    Men sleep while babies cry, so they can be well-rested for tomorrow’s hunt. If women did this, a lot more babies would die. My 10-yo daughter is capable of highly intelligent conversation, but her brain instantly turns to mush if there’s a baby in the room or crying outside.

  21. otherwise you show me aright path for all women
    tell me what should she dream of
    tell me something that can benefit

    most probably you are a male and will always be happy to take your side

  22. Also …I am a feminist ..Yes males and females have differences and similarities
    I think that death is better for all women than living a world which tells us often that males as you have described ….what meaning can i derive from your this article for my life..whats the use when a woman cant contribute anything intelligent to society as if she was born only to talk and men to think always

      1. Ever heard of the Taliban? Or that women weren’t allowed to vote and were considered property? Or when hitting women was commonplace in the past, along with the prevalence of spousal rape in developing nations from the past to future?

        Not saying men had it easy by any means in human history, given the prevalence of wars, flawed ideologies, illnesses, etc.; but it is a far cry to say there’s no place or time anywhere in human history where men have lived better than women.

  23. So are you sayiing that women should not be mathematicians and scientists
    Also are you saying that women are born to be dumb
    And men are born to rule dominate with their brains
    and women are idiot and not suffering problems
    pls tell me

    1. @shani

      Women aren’t dumb, but hopefully as differently gifted from men as possible. That would mean our species has access to two large brains if minimal cognitive overlap, instead of just one type of brain.

      There are other cognitive realms than science or math, we need to cover as many as possible, optimally.

    1. Very interesting! I’ve heard of the PIAAC but was under the impression that the assessment results would not be published until 2018—I’ll study it and add it to the article. Thank you for bringing this to my attention (I should keep better track of this stuff).

      (P.S – I bet it’s only a matter of time before the PC police arrive and demand it be normalized.)

  24. What do you think about this study?

    >He appears to have learned his lesson, and
    on this occasion has made no attempt to invite a range of
    opinions: indeed, the only paper that is omitted here from those
    that appeared in the original journal is one by Emily SavageMcGlynn,
    which reported that the British standardization sample
    of the latest revision of Raven’s Standard Progressive Matrices
    (the SMP+) shows, contrary to Lynn’s prediction, absolutely no
    evidence of male superiority in 16- or 17-year olds (this is
    achieved by the simple expedient of changing the items in Set E
    that in the original SPM had revealed a significant male

    >As a result, this book consists of a rather relentless paean of
    praise, which, from what I know of him, Lynn himself would be
    the first to question. Even the final chapter, by James Thompson,
    described as ‘a critical evaluation’ lets him off quite lightly. This
    seems absurd. Whatever else one can say of them, Lynn’s views
    have been controversial, and have not commanded universal
    assent. For example, although he believes that the viewthat ‘men
    have a higher IQ than women … is now accepted by all serious
    scholars’, this is simply untrue. Neither Diane Halpern (2012) nor
    James Flynn and Rossi-Case (2011) appear to accept it, nor for
    what it is worth, do I.

    1. “The one chapter on sex differences in IQ in the present book concentrates exclusively on the American standardization of the WAIS III. Yes indeed, there is an verall male advantage here, as earlier versions of theWAIS had shown.The critical question is whether this finding has been consistently replicated with other test batteries or in other countries. I do not think that it has (for example both the DAT and theW-JIII find an overall female advantage.”

      Apparently Mackintosh is too lazy to check for himself and has no idea what he is talking about. I’m aware of at least 30 studies using the WAIS, and men performed better on almost all of them. Here are some of them, from all kinds of countries.

      As for other test batteries, men perform better not only on WAIS, but also on Raven, DAT, IST, AFQT, ASVAB, Wonderlic, etc. Here is what Mackintosh himself says about the Differential Aptitude Test.

      “Although Lynn (1994) has reported data from other countries’ standardisations, suggesting that males out-score females, the difference over all age groups in the most recent American DAT standardisation sample was 0-3 points on the verbal, and 0-6 points on the abstract reasoning test—both in favour of women; in the oldest age group (18-year-olds) there was no difference at all on verbal reasoning and one of 0-3 points in favour of males on abstract reasoning”

      In other words, females were better among children, and males were better among 18 year olds, then he sums them all and claims no dif in intelligence. A classic mistake – you don’t mix data from children and adults because among children, females perform better, and among adults, males perform better. Another mistake – he calls female teens “women”, and makes assumptions from their performance about adult female performance. Moreover, the gender gap among 25 – 30 year olds is even larger than the one among 18 year olds.

      Here is data where adult males perform better than adult females on the Differential Aptitude Test, plus there is one more study in the Lynn compilation above.

      Then Mackintosh says that Halpern and Flynn did not agree with Lynn.
      Halpern did not do anything great in the field. Flynn’s study is concerned mostly with teen performance on Raven’s Matrices, and he makes series of wrong assumptions:

      1. Claims that females from third world countries should perform worse than males due to lack of gender equality. Actually two recent studies contradict that assertion. Curiously, data from PISA shows that girls from muslim countries perform better than muslim males, and girls from western countries perform worse than western males. Also see the comment about Saudi Arabia below. From nowhere it follows that gender equality should decrease the gender gap in IQ, because if smart women have less children than smart men, this is going to cause gender differences in intelligence no matter the level of equality in the country.

      2. Uses reading comprehension data from 15 year olds, where girls perform significantly better than boys, to make assumptions about adult female performance. Actually numerous studies show that among adults, males become equal or slightly better at reading and verbal reasoning.

      3. Uses wrong values in several cases (makes wrong assumption for the percent of male high school dropouts, uses wrong standard deviation for 2 studies, and does not comment on two studies in his own data that contradict his assumptions).

      4. In his limited analysis of adults, uses only student data (only several studies) and not the more numerous general population data. So he missed, i suppose intentionally, lots of data, at least 20 studies dealing with sex differences on Raven. The vast majority of those studies show adult males performing better than females on Raven’s Matrices, i think around 20 studies show males performing better, 2 show no difference, and one (from Saudi Arabia, of all countries), shows females performing better. Flynn never comments about that, and focuses mostly on younger populations, makes mistakes there too (see above), therefore his conclusion about women matching men on Raven is wrong.

      5. Finally, Flynn does not make comments about tests other than Raven, such as WAIS, IST, DAT or AFQT, where males again perform better.

      Back to Mackintosh.
      He also mentions one study using the W-JIII where females performed better and had greater G. And that’s ok, but as far as i’m aware that’s the only one. There are at least 15 other studies where males performed better and had greater G. Its entirely normal to get one result like this, due to sample fluctuations. The point remains though that the majority of studies show otherwise.

      In closing, Mackintosh and his sources did not refute the fact that adult men perform better on the majority of tests (even with the sex normalisation of these tests) and in the majoritiy of studies. While he claims that Lynn can not be taken seriously, it is he who can not be taken seriously, as he makes incredible amateur mistakes, such as making assumptions about adult women based on childen’s performance on IQ tests.

    1. Such hyphotesis is dismissed in the post — and it is clearly explained why it is to be dismissed, though body size/height is correlated with g.

    1. I came across her talk at TED and then picked up the book. It was exactly what I expected it to be: a retelling of gender theory and feminist theory. Neither are valid “theories” as they’ve been debunked and discredited for over two decades now. The “Delusions of Gender” reminded me of the “Myths of Gender” by Anne Fausto-Sterling.

  25. I have nothing intelligent to add here but merely wish to subscribe to further posts. Apparently, my feeble brain isn’t capable of determining how to subscribe by email, independent of branded, feminine-centric web-interfaces such as Facebook, other than to leave a comment and check the appropriate box beneath it.

    Since I’m here, I have to agree with the observations of this article, except as pertains to language processing in terms of the ability to frame, appeal to emotions, and appeal to the subconscious of the reader; as opposed to efficiency of communication. It would appear to be what even teenaged girls do all the f-ing time. This skill of women tends to cloud men’s minds, regardless of the archetypes expressed by either party. To that end I agree with Angry Harry’s comment, even if I’m the exception.

    I’d be delighted to submit to brain size and weight measurement and otherwise a determination as to why I’m past two standard deviations from the mean and how well that’s worked for me in terms of my ability to influence people. Not so much.

    I suspect that a self-perception of helplessness causes small-brain types to seek power and influence over knowledge, and that this self-perception halts brain development. It is my belief and observation that female writers of the past had less self-perception of helplessness and thereby superior vocabulary and language ability compared to the modern, female, Westerner. Of course, I could be wrong.

    Meanwhile, testosterone, which provides risk tolerance, might cause a resistance to fear-based propaganda, thereby mitigating any youthful sense of helplessness. I appreciate the good example which may be why I’d rather learn from it than try to compete with it unless I perceive danger from it.

    1. The subscription box is hidden away in the side-bar (button at the top-right corner).

      >This skill of women tends to cloud men’s minds

      Not a skill but an inbuilt bias that goes all the way back to the origin of sexes: men—by design—show chivalrous deference to women. Consider the dynamic of human sexual relationships: women oversee the relationship, while men agree/give in. There even exists a neural pathway—found only in males—which produces a near-elimination of aggression, triggered by close physical contact of any kind with a female.

    2. I think the socially intelligent crowd are drawn from a “sweet spot” in the superior IQ range—but not from the extremes. At the extremes, you have geniuses who seem to have no interest in social life because they have this unyielding focus on some particular domain.

      >Meanwhile, testosterone, which provides risk tolerance, might cause a resistance to fear-based propaganda, thereby mitigating any youthful sense of helplessness.

      Yes, while testosterone can reduce unconscious fear and startle, it actually has more direct influence over cognitive abilities. Pre-natal testosterone exerts powerful organizational effects on the brain. Simon Baron-Cohen has found that women with high levels of cognitive ability have higher pre-natal T and a more male-like brain configuration.

      1. “Simon Baron-Cohen has found that women with high levels of cognitive ability have higher pre-natal T and a more male-like brain configuration.” Mind if I see a source on that? I see that claim wafting about online a lot but without a proper citation.

        1. You can start with “The Essential Difference” and related publications by Simon Baron-Cohen and his team. It can’t be reduced to a single citation because it’s a pattern observed from series of studies across disciplines.

    3. Caprizchka wrote

      >…as pertains to language processing in terms of the ability to frame, appeal to emotions, and appeal to the subconscious of the reader; as opposed to efficiency of communication. … This skill of women tends to cloud men’s minds…

      Yeah, the brain scrambler! It’s kind of fun until a feminized society as a whole starts scrambling peoples brains…

  26. Re, Nick012000’s “Your whole premise is based on Lamarkian thought.”

    First, your assertions would benefit from the qualifier “I think”. Second, I think you’ll find the work of Conrad Waddington to be a good introduction for some serious thinking about genetic logic, which permits the dynamics described.

    If you don’t want to do the genetic logic, there is a simpler argument: “There is nothing in the universe that operates solely in a one directional fashion. Everything is related to everything else.”

  27. Determining what is important and worthy of ones attention seems to be a rather important faculty, which you have omitted from your definition of intelligence. Instead of the misleading term “general intelligence”, you might be better off with a description such as “ability at analysing uninteresting data”.

  28. Good to see the site back up. You have a plethora of good sources here but I am interested in more recently published analyses consisting of data collected from large, representative modern samples, so scouring the literature I found a couple of studies that I would very much like to get your opinion on that I didn’t see mentioned here.

    This one finds a male advantage (.19-.22d) of 3 IQ points in ages 16-69:

    Irwing, Paul (2012). Sex differences in g: An analysis of the US standardization sample of the WAIS-III. Personality and Individual Differences 53 (2): 126–31.

    This study finds no meaningful sex differences (perhaps a marginal female advantage of 0.7 points):

    Flynn, James R, & Rossi-Casé, Lilia (2011). Modern women match men on Raven’s Progressive Matrices. Personality and Individual Differences 50 (6): 799.

    ^(This is the Flynn study, if you remember, that was mentioned heavily in the news in 2012.)

    Your thoughts on these are appreciated.

    *edit: fixed links

    1. I have omitted some studies that use excessively sex normalized tests and also those that ignore age and dispersion effects.

      + The first study you cite administered the WAIS-III which is a fully sex normalized test. It’s been cut down so much that it has insufficient sub-test diversity to properly detect any group differences at all. In order to detect sex differences, you’ll need around 10 or more diverse subtests.
      + The Flynn study was misrepresented in the news. What Flynn actually found was that the ‘Lynn-Flynn effect’ (gains in IQ over time) may have been stronger for women than for men by about 1 IQ point. The ‘Lynn-Flynn’ effect is an environmental effect on raw IQ points, it is not concerned with the genetic g. Also, Raven’s Progressive Matrices is a sex normalized test.

      I think the only IQ test that is currently diverse enough to detect sex differences is the german IST 2000 (but don’t quote me on that). Either way, sex difference in g is eclipsed by the profound differences in brain connectivity and organization.

      For the record, I’ve also omitted about half a dozen studies reporting larger male means for the same reasons. For example, the following studies report a male advantage of 11.5 IQ points and 9.7 IQ points respectively in samples of 16-year-olds:

      * Steinmayr R, Beauducel A and Spinath B (2010). Do sex differences in a faceted model of fluid and crystallized intelligence depend on the method applied? Intelligence. 38(1):101–110.
      * Steinmayr R and Spinath B (2008). Sex differences in school achievement: what are the roles of personality and achievement motivation? European Journal of Personality. 22(3):185–209.

      Nyborg uses a ruthless criteria, which is why I’ve cited him as the main source.

  29. Actually the definition of “intelligence”is person by person ,some people think intelligence is “the obedience for political power”…

    If they design the test ,the “smarter”gender would be very different.

    1. >Actually the definition of “intelligence”is person by person ,some people think intelligence is “the obedience for political power”…
      There is no need for complicated definitions of intelligence invented by “some people.” This is why I use the simplest, long-standing definition here: “intelligence is the individual’s capacity to process information efficiently.”

      >If they design the test ,the “smarter”gender would be very different.
      +Nothing in this article hinges on a single test or even one kind of test. In fact, many tests here were not even designed as intelligence tests in the first place—but because they all tap into a person’s information processing capacity in some way, we can use them to measure intelligence even though they were not designed specifically for that purpose.
      +Since the early 1900s, most intelligence tests are normalized to favour females, not the other way around. Despite the rigging, test constructors could not eliminate the male advantage—this is the only reason why the topic is considered controversial.

      1. You can’t make people “who count”use a same standard as you.(Yao Ming face)

        >“intelligence is the individual’s capacity to process information efficiently”.
        Which kind of information?Even computers have and CPU and GPU.If you count the face analysis calculation speed…

        >Despite the rigging, test constructors could not eliminate the male advantage
        Did they count the male mentally retarded group data as well?

        1. >Which kind of information?Even computers have and CPU and GPU.If you count the face analysis calculation speed…
          Most of your questions have already been answered in the article itself. You haven’t read the article properly, nor have you looked through the references. If you were looking for an actual answer instead of trolling, you would have found it by now.

          >Did they count the male mentally retarded group data as well?
          Intelligence tests serve as diagnostic and clinical tools, so data on mental retardation is obviously taken into account wherever appropriate. However, as I mentioned before, this is irrelevant here. The existence of mentally-retarded males does not magically nullify or reverse the fact that males have higher mean IQs or that there are 10 times more intellectually exceptional men than women. Don’t forget that many males who are retarded are organically retarded—malfunctioning to the point that they cannot even write IQ tests.

          1. >Most of your questions have already been answered in the article itself. You haven’t read the article properly, nor have you looked through the references. If you were looking for an actual answer instead of trolling, you would have found it by now.

            I just want to make a joke about how these experiment could be controlled.

            >However, as I mentioned before, this is irrelevant here. The existence of mentally-retarded males does not magically nullify or reverse the fact that males have higher mean IQs or that there are 10 times more intellectually exceptional men than women.

            How could you know did they count the retarded group data?You keeping say I didn’t read your article well.I think you just don’t want to think something outside of the data.(But you keeping to believe feminist fake the test)If feminist can fake the test for their own purpose,why I should not believe some people let males being better in the test for their own purpose?So I think don’t believe everything 100% is my right choice.But your article still be valuable for argue with feminist.Although believe male have higher intelligence overall is your belief.You can’t say people who don’t want to believe your faith is troll.

            I can’t find the words in your article and references like “even count the mentally retarded male group,male still well higher intelligence overall”.

      2. “Since the early 1900s, most intelligence tests are normalized to favour females, not the other way around. Despite the rigging”

        I have never heard about this, and by this I don’t express doubtfulness, but surprise at how well-hidden it’s been kept.
        I also didn’t think politics and ideology had invaded science since the beginning of 20th century.

        May you give details on the rigging? At this point, one must think there is rigging to favour other “minorities” as well (while more and more “scientists” are advancing more and more claims that tests are biased against them, opposition to truth growing to seemingly no end).

        By the way, let me say your article is very useful, and written with the reader’s needs in mind.

  30. I don’t really believe those test you mentioned.
    “It’s Not the People Who Vote that Count; It’s the People. Who Count the Votes. ” Joseph Stalin
    To be fair ,you didn’t mentioned the gender differences of intellectual disability .
    Clearly ,male easier to become outliers.

    1. >I don’t really believe those test you mentioned.
      Facts don’t change according to one’s beliefs. I too would have preferred that such sex differences didn’t exist but, unfortunately, they do.

      >To be fair ,you didn’t mentioned the gender differences of intellectual disability .
      That information doesn’t add anything to this article, that’s why I didn’t bother. Fyi, the sex ratio at the bottom 2% (the mentally retarded group) is around 2:1.

      1. Again :

        “It’s Not the People Who Vote that Count; It’s the People. Who Count the Votes. ” Joseph Stalin

        Did you join into the test?I just keep my skepticism to any kind of test.My skepticism tell me many feminists are lying.

        I am not want to trust the world is no sex/gender differences,the only thing I know is I should not trust most of these test as I don’t trust those evidence quoted from feminist.

    1. Apologies for the delayed response. I’ve been out of station. I’ll have a look at the study and get back to you in a bit.

        1. Odd article but good find.

          + The first study they link to is a 2-decade old rehash from ‘The Journal of Neuroscience’. It’s true that women have about 3–5% more grey matter (GM) than men but this is only after ‘correcting’ for brain size. The articles try to portray this as some sort of advantage, but this slight excess in grey matter (which is found in the parietal lobe region) is actually associated with a disadvantage in spatial ability:

          The study goes on to suggest that this 3–5% excess grey matter “could compensate for smaller intracranial space in women.” I can’t follow their reasoning behind this at all. The absolute size of the brain and all structures in the brain (including GM and WM volumes) are larger in men than in women, indicating greater cognitive capacity.

          + The findings from the second study have been replicated by others, but the conclusions drawn contradict their findings. The reliance on interhemispheric connectivity in the female brain results in a disadvantage in language processing:

          This is because an interhemispheric (between-hemispheres) setup is not an ‘optimization’ at all: too much bidirectional “traffic” will cause interference between the hemispheres of the brain. The intrahemispheric (within-hemisphere) optimization in the male brain solves this problem by rearranging relevant processing areas within each hemisphere, diminishing the need to bounce to and fro across hemispheres. The end result is a better organized and more efficient brain but it’s a trade-off: even minor damage may result in a serious loss of function. With respect to the aforementioned example, the language processing areas are generally spread across both hemispheres in women, but in men, they have been mostly clubbed together in the left hemisphere.

          + It seems to me that both these studies want to play the ‘balancing game’: if men have A ability, then women must magically possess B ability and somehow A and B are of equal value. As you probably noticed, in both cases, they actually betray their own findings to do this. A clear example of this is the “women have an advantage in social cognition and language” thing that I’ve run into quite a bit recently. This seems to be a distortion of the fact that men prefer group activity/working together to bond with others, while women bond through verbal mediation. In its original form, what this actually means is that men are the ‘socially intelligent’ sex; not the other way around.

          I forgot to mention something very important in the second study. The study finds no age-by-sex interactions despite the large sex differences in brain connectivity, which pretty much rules out all “environmental” explanations for these differences.

  31. I also found this snippet by a modern day Leta Hollingsworth in the comments amusing:

    “Correct me if I am wrong. The status quo does not imply that if more women develop those skills, they will not transmit them to future generations, and eventually sex differences will be smaller.”

    One look at the fertility rates of these skilled women compared to unskilled ones and hilarity ensues.

    1. There is also the “Trivers-Willard” effect. Females of higher quality/status/condition will have more sons than daughters.

  32. From Barbara Kerr’s Gender and Genius, on Lewis Terman, the pioneer of studies of gifted children and the creator of the first widely used IQ test during WWI:

    ” Terman made efforts to correct item bias in the Stanford Binet so that as many girls as boys would be identified, and he went so far as to obscure the drop in girls’ IQ scores between 11 and 17 by collapsing their means scores with the boys, yielding a nonsignificant decline in IQ for the entire group.”

    He didn’t get equal numbers.

  33. Fascinating article, props for how ludicrously heavily sourced it is. Provides a firm bulwark against the inevitable waves of criticism that will follow (and is already happening) as this gains popularity.

    Something that caught me, and my friend who is a Biology major, off guard was that you(r sources) dismiss what we thought was a well accepted theory on brain size and intelligence. We have always been taught that, while imperfect of course, relative brain size to body mass (Encephalization Quotient) was a better indicator of overall intelligence.

    Otherwise, whales would be super geniuses.

    As someone who a bit more of a layman when it comes to neuroscience could you lay this out for me? I’m sure there are others, like me, caught in this awkward zone of ‘knowing just enough to scratch our heads’ on this issue. I’ve checked your sources, and they do indeed make the same conclusions that you’re drawing.. But given you’re the author of the article and clearly a knowledgeable individual on the subject it would help to make an inquiry to you personally.

    1. Yes, I’m aware of the brain size (non-) debate. I was taught the exact same thing. There are some issues underlying the claims related to encephalization quotient (EQ) as the best predictor.

      Comparing the brain size of animals between widely irrelevant taxa is nonsensical, as different classes of animals have different body/brain size scaling ratios. The ‘rules’ or constraints governing brain organization (which I outline in this post) must be taken into account. This is why even the massive African Elephant brain weighing 5kg has less than half the neocortical neuronal number of the human brain. Also, the point made here is that absolute brain size is a better predictor of intelligence than EQ and most relevant for individual differences in intelligence. There are some studies here that test this in mice (Anderson, 1993) and 24 primate species (Deaner et al, 2007).

      Looking backwards, it’s a bit embarrassing to point out that a strong political rather than any scientific motive played behind the dismissal of absolute brain size measures. With relation to sex and brain size, this sprung from the use of brain mass/body size ratios instead of the appropriate use analysis of covariance (ANCOVA).

      Ankney (1992) demonstrates how the use of improper statistical techniques to correct for sex differences in body size makes the brain size difference “disappear.” When comparing brain mass to body size ratios of men and women of equal size, at any given size, the ratio is much higher in men than in women. Please see Figure 2 in Rushton and Ankney (2009) which clearly demonstrates this.

      Of course, the advent of fMRI rendered the brain size debate obsolete. Anyway, I’ll add a section to the post on this. Thanks.

  34. “the ‘halfway’ point in brain development for females is age 11, whereas the equivalent point for males is age 15 and females are fully mature at around age 22, males at around age 30”

    Skimmed both sources and this doesn’t seem to be in either of them. The only source seems to be where he doesn’t specify how he got it. Defend or remove.

    The data on mean differences is mixed, you don’t cite the contrary evidence and the relationship with brain size is not nearly as straightforward as you make it out to be. I’ll have a lot more to say at another time. You should also do one on differences in non-g abilities between the sexes.

    1. What a remarkably pointless comment.

      You obviously didn’t even check a single source. See (Figure 2a) in Lenroot et al 2007—freely available on PMC: [] Also, (Figure 2b) shows grey matter peaking and (Figure 2c) white matter peaking.

      Studies of mean differences don’t look so mixed once you eliminate the confounds mentioned in the 2nd section. I also offer a section with various uncontaminated g measures which you also apparently “skimmed” through. I might add a section later with a list of studies eliminated.

      This post only examines the relationship between *absolute brain size* and cognitive complexity. I point out that far from being a simple or straightforward relationship, it can only be understood by determining the brain’s organizational mechanisms.

      Follow up posts on domain intelligence and non-g abilities will show up in a week or two.

      1. Where do any of those figures show that females fully mature at 22 and males at 30 and 11 and 15 are “halfway” points. The study doesn’t even include many subjects past ~20 years of age. Remarkable, did you even read it?
        And you didn’t even specify what you mean by maturity. The figures are for cerebral volume, grey matter, white matter etc. trajectories at younger ages.

          1. Copying what appears to be made up trash off of a blog without bothering to read the actual cited article and then refusing to correct yourself when proven wrong. His logic of regarding the peak as the halfway point is nonsense. Lmao nice job showing you are nothing but an agenda driven hack with zero intellectual honesty

            1. If you can’t interpret data, that’s not my problem. One more chance before I ignore you:

              Brain development involves two processes: 1) overproduction of brain cells and connections & 2) elimination or “pruning” of excess connections.

              The inflection point (mathematically, the change in curve), the arrow on the graph(s) in question, marks the transition from overproduction (increasing until peak) to elimination (falling from peak). The graphs show a clear lag in this transition for males as compared to females.

              The second citation is a follow-up review by some members of the same team which extends upon these findings.

              The link that you posted refers to an article written by someone who has published several books on the development of boys and girls. As such, he probably doesn’t see the need to elaborate what can clearly be seen in the graphs.

  35. Interesting. Lots of information here. There was a big media fiasco a few years ago about a Flynn study on women catching up and surpassing men in IQ claiming that they were “smarter”, but I think it turned out to be greatly exaggerated and distorted, and only focused on young ages.

    1. Yup, and it was a crazy misrepresentation of the results from his study. What Flynn was actually saying was that the ‘Lynn-Flynn effect’ (gains in IQ over time) may have been stronger for women than for men by about 1 IQ point.

      The ‘Lynn-Flynn’ effect is an environmental effect affect raw IQ points, it is not concerned with the general factor of intelligence itself.

      [Hmm, I should add definitions to this post so people know the concepts better.]

      1. Yeah, I think it’s an important point that an “IQ score” on some metric isn’t exactly or necessarily the same as the general factor (g). Two groups can certainly be equal on mean IQ but there can still be a difference in g because not all IQ items load the same on it. So men and women having equal IQ scores doesn’t necessarily mean that there’s no difference in general intelligence, especially since the tests are rigged when it comes to sex differences.

        1. That and the heritability of g too. I didn’t think I’d bother with these because the post was intended to be a sort of review but now I think I should. Thanks for your input.

    1. Read up on Machiavellianism and learn to counter their manipulation. Good start: Sun Tzu – The art of war, the prince by Niccolo Machiavelli. What’s your point though? Their manipulation tendency is usually not a concious effort, but a hardwired function of their brains. Women have been and always will be the weaker sex, hence they required techniques of securing protection of the Alpha (i.e. strong) male. Manipulation was the ideal tool: Whereas women couldn’t dominate men on the physical level, they were now able to dominate men on the mental level. Only the top 20% of men weren’t sufficiently influenced by that. Those were the men that gave them the vagina tingles, so they allowed them access to their reproductive organs. The other 80% were then manipulated into taking care of another man’s child (the beta males) and took on a provider role. Sorry, I think I’ve written this in a rather shitty way, but I’m tired and I can’t be bothered to write it more eloquently.

    2. Angry Harry when you have something that people desire irrationally is really easy to manipulate them. Just imagine that I have water and you’re thirsty. Their water is sex, pretty obvious it isn’t??

    3. 1) The less progressed a society is, the more women will be in a position of subordination, the more they’ll develop and perfect the arts and practices of indirectness.
      Thereby, Mongolid females are more skilled at feigning and exercising influence through it than Western females. And so are Arab females (aside from the rather relevant IQ difference).

      2) But, you say, Western males are swayed by females way more than their Eastern counterparts.
      Yes. This is owing to a process some have called betaization, that is, the femininization of males. Women are masculinizing, also.
      They have more power, but that’s not because they feign and influence indirectly more than past; they are more outspoken and dominant, that’s what it is.

    1. [Edit: Some more references for you]

      I’ve cited Nyborg as the primary source because he has revisited various studies by other researchers using correct methodology. The most recently published studies deliberately ignore the important factors I’ve outlined. For example, here is a large study using Grade 3-12 children on a ‘sex normalized’ test, the CAT, claiming that mean differences are ‘very small’ :
      * Lohman DF & Lakin JM.(2009) Consistencies in sex differences on the Cognitive Abilities Test across countries, grades, test forms, and cohorts. Br J Educ Psychol.79(2):389-407.

      More references in the variance section; can also compute a higher male mean g from a battery of elementary cognitive tasks (which is why there is a section dedicated to it).

      Richard Lynn finds higher adult male means of 4-6 IQ points cross-culturally but he uses ‘sex normalized’ tests so I haven’t included his work here. It seems the test constructors didn’t expect the function of age to so easily betray them.

      There are also studies using the German Intelligence-Structure-Test 2000-R, which is a very diverse battery of tests, that find higher male means of 9-12 IQ but these have not been included in this post:
      * Steinmayr R, Beauducel A & Spinath B (2010). Do sex differences in a faceted model of fluid and crystallized intelligence depend on the method applied? Intelligence. 38(1):101–110.
      * Steinmayr R & Spinath B (2008). Sex differences in school achievement: what are the roles of personality and achievement motivation? European Journal of Personality. 22(3):185–209.

      Some other, also not included in the post:
      * Đapo N and Kolenović-Đapo J (2012). Sex differences in fluid intelligence: Some findings from Bosnia and Herzegovina. Personality and Individual Differences. 53(7):811–815.

  36. I did not infer anything about myself, I was only responding to the point made the article about the difference in average levels of general intelligence. As a person who is in the 99th percentile I’d say I am probably biased towards viewing issues which relate to intelligence as more personally relevant, than others. IQ is probably not the only way to measure intelligence btw. My point was not about self-worth, it was about access to education and knowledge, which we all should have right to access, regardless of iq, or race or ability, and we should not use such differences to discriminate against people when it comes to executing that right.

    1. No it isn’t, if Aristotle, Pythagoras or anybody exclude women or whoever of their schools is a perfect legitimate action. Everyone has the right to choose the people whom they maintain relationships of any kind. Just as rape is unlawful because implies a relation by the force. So if Y people doesn’t want to admit X people is Y people choice. If that doesn’t like to X people they can do what Y people do by their own side, but they would need to be competent to do so in first place.

  37. I agree with you on issues of physical difference, but I disagree on points of intelligence, because it is used in this text as some sort of proof of inferiority, which can be further used to reduce access to education for females, so you are making an ideological point here, disguised as science.
    Aspects which contribute to intelligence, such as brain size are heritable, and it follows that the reason why male brains are bigger, or why males often have a better average ability in math, is because if mostly males had to develop a faster response time due to working in dangerous jobs, or because mostly males were involved in mathematics related jobs, then they would be only transmitted mostly to males genetically, no?
    Correct me if I am wrong. The status quo does not imply that if more women develop those skills, they will not transmit them to future generations, and eventually sex differences will be smaller.

    Evolution takes care of incorporating traits which are deemed beneficial for the organism in question: a recent experiment showed that mice transmit associations of smell and danger from one generation to another.
    Existing differences between sexes do not justify a gendered approach to education because this hinders human evolutionary progress: saying that females should not try to succeed in traditionally male-oriented disciplines because on average less females are capable of it, is precisely the opposite of what we should be saying: that we should be working on increasing that capacity. It is essentially saying that dumb people should stay dumb, exactly the opposite that anyone who genuinely cares about general levels of intelligence in population should say.

    Rise standards for everyone, and include everyone in encouraging to meet them, and work to eradicate cultural bias which mean that people don’t believe they can be good at something.

    Mathematics is a language, humans invented it, humans communicate through it. You practice it, you’ll be able to use it. If you don’t practice it, you will not be able to use it. Saying that because historically women did not practice math much it means that they are less capable of learning it, means that they don’t try to learn it, which keeps them from getting any good at it. The argument in your conclusion “In the male advantage in g largely explain why men greatly outnumber women among exceptional people in history and in present-day society.” is circular and contains the seed of its own contradiction: the male advantage developed genetically through evolution because the activities which give the advantage were practiced by men.
    If you don’t allow women to practice them, they will not develop the skill. Seeing biological advantages as innate and not subject to evolution is a way to maintain the status quo and the circumstances which create that disadvantage and difference. This is an ideological point, which actually sounds almost religious: ‘god made us that way, therefore we have to stay that way’, rather than ‘we are a product of our circumstances, and we ought to work change the circumstances to improve the product.’ It is unscientific, and anti-progress.

    I am human because I reason. I have the right to think for myself and to access knowledge and so does everybody else. People should access knowledge and learn skill such as math, even if they’ll never be brilliant at it, because they have the right to know what they want to know, it is not for you to decide what I am capable of understanding and what not. Using biological arguments about average capacity for assimilating knowledge as somehow proving that access to knowledge should be limited is simply morally abhorrent and undemocratic.

    1. Nope. You yourself have inferred that you are considered inferior. Since when is IQ the only measure of value among humans?

    2. * I take the world as it is, not how some people wish it were. This post puts together findings from a wide range of studies in a coherent framework for the purpose of investigating something very specific.

      * This is not a men vs. women website. To claim one sex is superior to the other is a nonsensical apples-to-oranges comparison. This is why sex differences are only examined in context, in this case: ‘general intelligence.’

      * All extrinsic inheritance is a consequence of intrinsic design: the environment isn’t “out there,” we select environments (=extrinsic inheritance) as a consequence of our innate predispositions/traits (=intrinsic design). There are no biologically-independent cultural processes.

      This is clearly the case with sex, which stems from a dichotomy of function in root biology. The genomes of sexual species are structured such that males will have high genetic variance compared to females. As they evolve rapidly, males will continue to exhibit more extreme traits compared to females. There are various biological mechanisms that come in to play on top of this. For example, females of higher condition/rank/quality automatically bias their litters towards more male offspring.

      Long story short, sexual selection and related mechanisms ensure that there will always be more males than females at the top. It’s not about “working in dangerous jobs.”

      * There is no untapped pool of talent among women waiting to be revealed. The increasing female representation in various domains over the last century is mainly due to progress in science (particularly medicine) and technology. The next largest effect arrived in the latter half of the 20th century in the form of quota systems enforcing female representation without any filters for ability.

      Sex-discrimination does not even come up as a large effect that prevented women’s ‘advance’ in history. The stratification of the sexes is mostly explained by their differential physical abilities and social behaviour. There is no need to invoke sex differences in general intelligence except to study the sex ratios at the extremes.

      * Since the 1970s, standards across the entire western academic realm have fallen so low that it’s debatable if we’ll ever recover.

      * Obvious double-standard on your part. I show here that it’s men, not women, who are being denied access to knowledge and advanced education despite their talents. There is nothing in this post that endorses “gendered approaches to education.” The only endorsement here is to uplift those with ability.

      * I’m not a political activist—of any kind.

      1. *” All extrinsic inheritance is a consequence of intrinsic design: the environment isn’t “out there”, we select environments (=extrinsic inheritance) as a consequence of our innate predispositions/traits (=intrinsic design). ”

        >Yes, but this does not imply that we need to keep selecting the same environments, which keep reinforcing some intrinsic traits.
        Some people will have different intrinsic traits to what the average, or most common trait for that group is, and that trait might actually be more beneficial, but this it will not be allowed to be expressed in a person due to cultural restrictions, which will extinguish it in the long term from the pool.
        In that sense culture will influence biological change in the interest of preserving itself (culture).

        *”There are no biologically-independent cultural processes.”
        >Yes, but there are also some culturally-dependent biological processes.

        It means that we can shape biology through encouraging some traits, or through controlling the environment.

        There is no reason why we should not choose to foster some traits in humans, which would be good for humans to have.
        Eg. foxes bread for docility became more docile as a group. It would make sense to foster traits which lead to an increase in general intelligence in the general population for example.

        >There is no reason why should not do it to humans in a way that benefits humanity as a whole, or in a way that benefits human, individual liberty.

        >Animals live in environments which they cannot control, but we MAKE our environments, therefore we should not treat them as if they are completely out of our control.

        >Viewing everything from an evolutionary-biology perspective is limiting.
        Aspects which improve reproductive success, are not necessarily also beneficial for individuals or society.
        Those aspects are often in contradiction with each other. If we let ourselves be controlled by biology, we’d not have science, or music, or internet, and we’d not have this conversation, instead we’d be running away from wolves, or trying to not freeze our butt off catching fish in a stream. The fact that we control biology and use our reason to do so, means that we are more secure as a species.
        To propagate the species we need to both ensure individual reproductive success, but also ensure the maintenance of a working society. It is beneficial for society when each individual does what they have the most aptitude for.

        > with advances in the species humans evolved an ability to reason at high levels, and also developed an individual and high level of consciousness, and a shared sense of culture and language. These ‘higher’ abilities distinguish us from other primates. It is a matter now of not just species well being, but also of individual liberty to be able for an individual to do what they have the most aptitude for, as well as partaking in culture in general.

        *” There is no untapped pool of talent among women waiting to be revealed.”
        No, but neither is there in males, talent and high intelligence are sporadic, and rare, and therefore it makes sense to include the whole of society in the search for it, rather than only assuming that it can be found in one group and excluding other groups from the chance. We all have reason, we are all human and we all have a right to knowledge and education.
        Using average distribution of intelligence according to gender to claim that there is no untapped pool of talent in women, lets able women down.

        *”I’m not a political activist — of any kind.”
        >Historically scientific arguments based on biology have been used to justify racial discrimination for example, so science itself can be used for political aims. Science is not apolitical by any means.
        It is fine to show differences between sexes, but it can be used to justify policies which exclude people from certain spheres based on gender difference.
        You say that statistics are now used to define quotas for entry into certain institutions: that is an example of using science for a political aim. But your compilation of facts could also be used for a political aim.
        And lastly: you construct your arguments in relation to feminism. There are many feminisms, but a lot of them would fall under the name of ideology, so if you construct arguments against it, then you are engaging in arguments on an ideological plane.

        *”In conclusion, the male advantage in g largely explain why men greatly outnumber women among exceptional people in history and in present-day society” (from the original article)

        >This, assuming it is true, only shows why there is an inequality of outcome, and it can be used to deny an equality of opportunity, since it can be interpreted as a general inferiority of the sex.
        If very few people in Russia swim, I will assume that you must be bad at swimming, if you are a Russian, because there is a higher chance that you are. It is incorrect reasoning of course, but this is how generalisations work, and this how they are used to deny people opportunities.

        We ought to assume that ability is everywhere, and not omit any social group from that assumption, and base our policies on that.

        >Personally I think generally focusing on ‘sex’ and ‘gender’ only is counterproductive, because social class and race is often a far bigger advantage in accessing good education. I don’t see a middle class white woman struggling to be a scientist if she wants to, but I certainly see a Black boy in a poor neighbourhood never actually considering being a scientist.

        1. Wrong end of the tunnel. Culture is manifest from evolved psychology, which is a product of the brain—the brain being a biological construction. In other words, culture is biology.

          Back to: “All extrinsic inheritance is a consequence of intrinsic design.” The environment doesn’t impose itself on the brain, instead, the brain applies a model on to the environment seeking to capture anything that is relevant to its design. This is why we’re only conscious of very, very few things—just enough to make sure there’s some flexibility to our information processing capacity. This is also inherent in the brain’s design: it’s not top-down, it’s bottom-up.

          Gotta start from root biology and then work our way up. My next post is centered around this, let’s see how that goes.

      2. Anna, you are self contradictory. You first appeal freedom and then denied it.
        Discrimination is freedom, every human has the right to share or not what s/he wants with anyone. If I don’t want to give you a site in my university or business is a personal freedom. The same for a group of people who possess whatever.
        And what has hindered women historically aren’t men, but that horrible thing that’s pregnancy. Without it there would be no difference.

    3. There’s a couple problems I see with your idea about how to reduce the disparity in g between men and women, if there is one. One of them is that if more women practice something (your example is math), they’ll get better at it and pass it to their offspring. That sounds like a great idea in theory, but the problem is actually getting women to go ahead and do it. Women have gotten an insane amount of support in academia in the last fifty years and haven’t done much in the way of mathematics at all, opting instead to go for softer sciences like psychology.

      The other problem is that men aren’t interested in a woman’s mathematical ability for mate selection. It’s not sexist, it’s just a fact of life. Men in general don’t care what their partner’s GPA was in college, or how high their IQ is, or whether or not they have their masters or PhD yet. Your man is not going to buy you flowers if you stare lovingly into his eyes and recite Euler’s equation.

      A bigger problem than that even is the example of math. As a species, we have not changed much in the last 10,000 years, a time before math. If men are better at math, then that means that the “evolutionary bedrock” for a higher average general intelligence likely goes back much, much further than that.

      “Existing differences between sexes do not justify a gendered approach to education because this hinders human evolutionary progress: saying that females should not try to succeed in traditionally male-oriented disciplines because on average less females are capable of it, is precisely the opposite of what we should be saying: that we should be working on increasing that capacity.”

      I believe that the existing differences stem more from a lack of motivation than any kind of hindrance in academia. We have more information at our fingertips now than we ever had in any period of time (the majority of it for free), yet our society is no legion of self educated wizards.

      An anecdotal aside, in every math class I ever took, the women dominated any and all time spent with the professor before, during, and after class. What that led me to do was, instead of ask for help for every little thing, was to figure things out for myself. Men feel shame and inadequacy when they have to ask for help, the only way we buck our own disposability is by getting good at something. That’s literally wired in our brains, being great at anything will increase chances for reproductive success.

      Also, why is it so important to get more females in traditionally male-oriented disciplines? If women don’t want to go into disciplines like engineering, welding, fixing cars, business, or construction, then shouldn’t we as a society respect that collective decision? Why don’t we let those with aptitude do whatever they want, regardless of their gender? Pushing women towards career paths that they don’t want to go sounds like a form of oppression to me.

      1. I will reply to your points made in each paragraph.

        1) I don’t think there is any reason to make anyone and go ahead and do anything, the responsibility lies only in making sure people are free to go ahead and do what ever they are interested in, and to include them in the first phases of education in which ability is fostered.

        I am sure younger women have easier access to math now. In my case as a child I simply did not have access to it due to social channelling into ‘feminine’ disciplines, I had to fight later to get into what I am interested, but it gave me a 7 year disadvantage. The same might go for boys, who are more interested in languages, etc. My argument is one and simple: don’t channel children into various types of education, based on their sex, and assume that aptitude for welding or dance can be in either sex, despite it statistically occurring more in one or the other.

        If we really adopt a completely gender-neutral attitude towards education, and people naturally prefer one discipline over another, then so be it, but so far as I am aware, education is by no means gender-neutral at the moment, and we assume that a child is automatically less capable of one thing or another because of their sex to the point where we don’t even let them try things outside of their gender.

        My point is really only in relation to the article and the claim about the assumed differences in general intelligence: that those assumed differences, regardless if they exist, or not, can be used to limit peoples access to education in certain areas through a gender- based approach.

        2) yes, men are not interested in mathematical ability for mate selection, but why should that matter in terms of what a person finds interesting to do in her life for herself? Isn’t that a terribly biologically reductionist approach to take, to limit a persons purpose of life solely to biology? or mate selection?
        Its like saying that all the inventions made by men in history, were only so they can get money and be attractive to women, that they never had any true intellectual curiosity about the world.
        People get satisfaction from all sort of aspects of life, and one of them is partnership, but it is not the only one. I need to be mentally creative and engage with the sphere of ideas to feel fully human, I need to engage with math to feel fully human, because I have a mind and keeping it passive makes me dead inside, whilst using it gives me pleasure.
        What you are saying is that women and men only need sexual validation from a sex partner to feel human, which is a terribly reductionist approach, because you are essentially saying that the mind does not matter in itself, that intelligence is there only to serve the needs of the penis and vagina, and that to use intelligence in any other way as to serve the needs of biology is excessive.
        Why do people pursue sciences such as physics then? Nobody really needs to know what is at the other end of the universe, do they, they do it just to get laid? it will not help them to win a war, nor to get laid, why bother with the whole science circus, if the only objective of life is to get a mate? There are also people, also men who identify as ‘sapiosexual’, so your view also invalidates their sexuality.
        If I wanted to interpret your words in the worst way I’d say that you view that is woman’s sense of worth can only come from her vagina and she is not entitled to draw it from intellectual pursuits, and only men can truly be interested in the life of the mind, but I will not draw that conclusion, since it is unfair to you, and I don’t presume somebody on a site devoted to scientific approach would be anti-humanist.

        3) you have a point there, and I think with the advance of open-source learning more people will take their learning outside of institutions, so institutional bias will have less of a role to play.
        I am not even sure institutional bias as such plays a big role: it is more of a general social anti-intellectualism, combined with elitism, which views science and math as this incredibly special discipline, only for the ‘genius’, and as such almost everybody, including teachers, treats interests in it as beyond reach of ‘ordinary’ people, and in this context, belonging to a group which traditionally is seen as less inclined to pursue it will be a further hinderance.

        I only got interested in math after I realised it is all BS and I COULD be good at it.
        Boys are generally socialised, or maybe naturally more inclined to transgress such social messages, so they might disregard any such messages and try things out for themselves regardless, but still people say “I am just not good at math”, even though they could be if they tried, because they have internalised this message of special talent needed for it.

        As somebody who studied math on an academic level for a while, I can say that there definitely is an element of judging people if they need a bit of time to figure out something, I witnessed people being a bit weary of admitting that they did not understand something, but maybe that was just German culture. The disciplines themselves also have a culture which is tough psychologically, and male socialisation helps to cope with it.
        In general I’d say boys and men are better able to cope with the psychological pressures of pursuing these disciplines because of their socialisation, so I think the best solution would be to create an educational system where boys and girls are equally socialised and encouraged to try hard things.

        4) I don’t have much to say to that point, other than again you view reproductive success and biology as the primary drive for personality and character, which I disagree with, it influences it, but other drives and forces are also at play, such as the desire to know the world, for example.
        Little boys do ask a lot of questions actually, they are curious and so are girls. We all get it crushed out of us at some point in life. I don’t view the lack of willingness to ask questions in adult males, as ‘hardwired’, but more an effect of socialisation which tells boys to shut up and do things for themselves, whilst being more permissive towards girls, because they don’t risk losing their face if the admit to not knowing something.

        5) I don’t argue for ‘getting more females into traditionally male oriented disciplines’, and I agree with ‘letting those with aptitude do whatever they want, regardless of gender’, completely , but I think that concentrating on what happens in a group on average, and designing policies solely based on that, lets down those who have more aptitude.

        I argue AGAINST channeling children into educational paths according to their sex and gender. I argue that the role of education is to nourish talent in people who have it, because it is important to create conditions in the world where people can fulfil their true potential.
        If they don’t do that, it is their choice, but they must have had the conditions to do it first, to say that it is their choice. However cultural aspects, such as gender and race, often prohibit people from believing that they can succeed in an area that is outside of what is considered the ‘norm’ for their group, and so they never even try to be good at what they they have a talent for, so despite having aptitude, they themselves don’t believe that, and don’t work based on that.
        It is not getting about ‘getting more women’ into science, but about not letting down those people who are talented, but who don’t believe that they can do it, because their interest or talent is different from what is common in that particular group, so they are presumed not to have it due to gender and race stereotyping. Using average statistics for a group in certain occupations, or using arguments about general intelligence can legitimise policies which let down those people who are not average for that group.

        It goes the same for boys and disciplines which are perceived as not traditionally male, they should be free to pursue them, should they choose them. So I believe policies should be designed around making sure people can fulfil their potential and are not hindered by culture and what is considered average for the group they belong to.

        I guess the point that I am making is that we should not aim to get more women into any discipline as such, but we should make sure that we don’t treat women as a group who is intrinsically not interested or capable of joining certain disciplines, because it lets those down who have a genuine aptitude for them.

        Using averages, such as intelligence etc. for women or any other group, legitimises the position that this group should be excluded from fostering talents for disciplines which on average are less popular in that group. It’s about adopting mind sent which says: ‘talent could be everywhere, so we need to look and foster it everywhere” as opposed to “we need to exclude those social areas in which talent appears less frequently’. It just does not make sense, because it excludes those able people based on accidents of birth, just because they share some characteristics such as sex with others.

        Does it make sense?

    4. >Correct me if I am wrong. The status quo does not imply that if more women develop those skills, they will not transmit them to future generations, and eventually sex differences will be smaller.

      Your whole premise is based on Lamarkian thought. Evolution doesn’t work that way, and Lamarkianism has been disproven for over a century.

    5. “Correct me if I am wrong. The status quo does not imply that if more women develop those skills, they will not transmit them to future generations, and eventually sex differences will be smaller.”

      This is not how evolution works.

      If women with higher IQ would be more likely to have larger and more surviving offspring, then the allele will be more common. However, men select for physical attractiveness rather than IQ.

      Epigenetics is complex and unlikely to account for intelligence, especially consider the vast role of hormones in guiding the development of brain structure.

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