Thursday, June 22, 2017

Why are there so few Women in the Sciences?

That is, why are there so few women in the hard STEM fields that involve high-level mathematical and spatial-visual cognitive ability?

The Cultural Left, the Liberals and even some Conservatives have offered various explanations for this, but most of their theories are false or feeble, and some on the Cultural Left are basically unhinged conspiracy theories.

As it happens, there is a straight-forward scientific explanation, and backed up by a mountain of scientific evidence.

Unfortunately, it requires looking at the nature of IQ, or intelligence, in men and women, and, of course, this causes bilious, almost deranged howls of outrage in our culture, mostly from the Left.

But, if you bear with me, you can understand in this short post what the vast majority of people don’t understand (and even refuse to understand or believe if they are told the truth).

The explanation is as follows:
(1) Culturally unbiased, fair IQ tests measure a person’s general faculty of intelligence, or what is now called Spearman’s g (general intelligence), which is clearly a unified, single cognitive trait of human beings. It appears that IQ (which measures general intelligence) is about 70–85% heritable in adults. The heritability of IQ rises with age, so that by the time one is an adult perhaps as much as 80% of IQ is heritable (Plomin and Spinath 2004; Plomin and Deary 2015). Even the liberal/leftist American Psychological Association (APA) admits the overwhelming evidence for this (see Neisser et al. 1996: 96, which accepts the 0.75 figure), and the democratic socialist James R. Flynn (after whom the “Flynn Effect” is named) – the leading environmentalist on gaps in IQ between population groups – himself accepts that current evidence shows that the heritability of IQ in adults is probably about 0.75 (Dickens and Flynn 2001: 346).

(2) When the IQs of a representative sample of men and women are plotted on a graph, it has been discovered that the distribution of IQs is not the same. See the graph of male and female IQ distribution here. As we can see, the manner in which the IQs of men and women fall on the graph differs: the IQ scores of women tend to cluster around the average (with less distribution in upper and lower ranges), while male IQs tend to be distributed less around the average and more in the upper and lower ranges as compared with the IQ distribution of women (see Hedges and Nowell 1995; Lubs 1999; Roberts 1945; Deary et al. 2007).

The average IQ for European people is about 100. So, for example, more European women have IQs that tend to cluster around 100 than the IQs of men do. This means that, numerically, there are far more high IQ men than there are women (also, it means there are far more low IQ men than there are women). Furthermore, it means that, numerically, there are fewer men of about average IQ than there are women.

(3) in addition, there is probably a small difference between the average IQ of men as compared with that of women (Lubs 1999; Johnson and Bouchard 2007; Nyborg 2005). Men appear to have a slightly higher average IQ, with about a 3–5 point advantage over women – though, admittedly, that is not large. It is still correct to say that the average IQs of men and women are not greatly different.

(4) by examining the sub-tests of IQ tests, we have discovered that – in terms of sub-tests and specific cognitive abilities – men and women also differ. Women tend, on average, to be much better at verbal abilities and language, but men tend on average to outperform women on numerical/mathematical and spatial cognitive abilities (Neisser et al. 1996; Wechsler 1958: 144–149; Lubs 1999; Johnson and Bouchard 2007; Johnson et al. 2008; Halpern et al. 2007).
The fact that the intergenerational Flynn effect – which has been working for about a hundred years – hasn’t eliminated these IQ differences between men and women should alert us to the truth that the differences are mostly genetic, not environmental.

So why are there so few women in the sciences?

First, science requires a high IQ. But the IQs of women tend to cluster around the mean of 100. Because many more men have IQs well above 100 than women, numerically there are not enough women to compete with men in the sciences. The slightly higher average IQ of men also contributes to this.

Secondly, science also requires a high level of mathematical and visual-spatial cognitive abilities, and here on average men outperform women.

Thirdly, science tends to attract human beings with an interest and ability in mathematics, spatio-visual abilities, and propensity to do abstract, impersonal work, which is much less focussed on human beings, or on social/verbal interaction between human beings. There are also general psychological and behaviour differences between men and women that affect each gender’s educational choices and career choices. Women are better at verbal/language abilities, and have a general propensity to choose professions where they can use those abilities. Thus the hard sciences appeal to men far more than to women. Therefore, generally speaking, even high IQ women tend not to be interested in the hard sciences.

When women do go into the sciences, it tends to be in biology or medicine, where they can use their superior verbal skills, while women tend to avoid other STEM fields that require a more intense mathematical and spatial cognitive ability.

By contrast, men excel at physics, chemistry and engineering, where greater numerical and spatial cognitive abilities are required (see Johnson et al. 2004).

The reality of few women in the hard sciences, then, has a mainly biological explanation, which is grounded in genetics and Darwinian evolution. In short, it is explained by the biological and genetic differences between men and women.

This is precisely why not only in the past but also to this day modern Western science and scientific discovery is driven mostly by high-IQ men, not women.

Of course, this biological explanation does not rule out influences from culture, institutional factors, discrimination, and government policy either. But these are likely to be minor or even trivial factors, while the major factor is biology.

Crucially, while none of this necessarily rules out the moral case for equality of opportunity for women, it totally destroys the feminist aim of total gender equality of outcome in all employment, professions and intellectual life. Moreover, it follows logically that the conventional explanation for the failure of women to attain a 50% presence in all higher professions because of some evil institutional gender discrimination and sexism in Western societies is manifestly absurd.

And nobody scientifically literate even in a layman’s sense should be surprised by any of this.

There are also other significant biological differences between men and women, as follows:
(1) on average, men are taller than women;

(2) on average, men have greater upper and lower body strength (with greater muscle mass, thicker tendons, and greater bone density) than women;

(3) on average, oxygen is better circulated around the male body because of higher haemoglobin levels so that, physiologically, men are better at physical activity than women;

(4) on average, men have greater stamina (with higher levels of anabolic steroids);

(5) on average, men have greater maximal oxygen uptake capacity than women;

(6) on average, men are more competitive (because of higher levels of testosterone) and more aggressive than women.
This is also why women, on average, simply cannot work at certain jobs that require hard, strenuous, extended physical labour in the way that men can.

Once again, these facts of human social life are explained largely by biology and genetics.

But try saying this in public, or in academia, or in the media. The response will be a hysterical, vicious, witch-hunting wave of public abuse, persecution and, if the person in question is of high-profile or status, probably the ruin of that person’s career.

This is how anti-scientific and insane our civilisation has become. The fault lies mostly with the Cultural Left and feminists too. But the mainstream Conservatives aren’t any better either.

Modern conservatives – who are rightly derided as “Cuckservatives” (from “cuckold conservatives”) by their own enemies on the right – are so useless that they cannot even defend basic scientific truths about the biological differences between men and women.

Bouchard, Thomas J., Lykken, David T., McGue, Matthew, Segal, Nancy L. and Auke Tellegen. 1990. “Sources of Human Psychological Differences: The Minnesota Study of Twins Reared Apart,” Science n.s. 250.4978: 223–228.

Deary, Ian J., Irwing, Paul, Der, Geoff, and Timothy C. Bates. 2007. “Brother–Sister Differences in the g Factor in Intelligence: Analysis of Full, Opposite-Sex Siblings from the NLSY1979,” Intelligence 35.5: 451–456.

Dickens, William T. and James R. Flynn. 2001. “Heritability Estimates Versus Large Environmental Effects: The IQ Paradox Resolved,” Psychological Review 108.2: 346–369.

Halpern, Diane F., Benbow, Camilla P., Geary, David C., Gur, Ruben C., Hyde, Janet Shibley and Morton Ann Gernsbacher. 2007. “The Science of Sex Differences in Science and Mathematics,” Psychological Science in the Public Interest 8.1: 1–51.

Hedges, Larry V. and Amy Nowell. 1995. “Sex Differences in Mental Test Scores, Variability, and Numbers of High-Scoring Individuals,” Science n.s. 269.5220: 41–45.

Johnson, W., Bouchard, T. J., Krueger, R. F., McGue, M. and I. I. Gottesman. 2004. “Just one g: Consistent Results from Three Test Batteries,” Intelligence 32.1: 95–107.

Johnson, Wendy and Thomas J. Bouchard Jr. 2007. “Sex Differences in Mental Abilities: g masks the Dimensions on which they lie,” Intelligence 35.1: 23–39.

Johnson, Wendy, Carothers, Andrew and Ian J. Deary. 2008. “Sex Differences in Variability in General Intelligence: A New Look at the Old Question,” Perspectives on Psychological Science 3.6: 518–531.

Lubs, H. A. 1999. “The Other Side of the Coin: A Hypothesis Concerning the Importance of Genes for High Intelligence and Evolution of the X chromosome,” American Journal of Medical Genetics 85.3: 206–208.

Neisser, Ulric, Boodoo, Gwyneth, Bouchard Jr., Thomas J., Boykin, A. Wade, Brody, Nathan, Ceci, Stephen J., Halpern, Diane F., Loehlin, John C., Perloff, Robert, Sternberg, Robert J., and Susana Urbina. 1996. “Intelligence: Knowns and Unknowns,” American Psychologist 51.2: 77–101.

Nyborg, H. 2005. “Sex Related Differences in General Intelligence g, Brain Size, and Social Status,” Personality and Individual Differences 39.3: 497–509.

Plomin, R. and F. M. Spinath. 2004. “Intelligence: Genetics, Genes, and Genomics,” Journal of Personality and Social Psychology 86.1: 112–129.

Plomin, R. and I. J. Deary. 2015. “Genetics and Intelligence Differences: Five Special Findings,” Molecular Psychiatry 20.1: 98–108.

Roberts, J. A. Fraser. 1945. “On the Difference between the Sexes in Dispersion of Intelligence,” The British Medical Journal 1.4403: 727–730.

Schmidt, F. L. and J. E. Hunter. 2004. “General Mental Ability in the World of Work: Occupational Attainment and Job Performance,” Journal of Personality and Social Psychology 86.1: 162–173.

Wechsler D. 1958. The Measurement of Appraisal of Adult Intelligence (4th edn.). Williams & Wilkins Company, Baltimore.


  1. It is basic male vs. female physiology. Even if a female has the required IQ she will not likely have the physiological based drive and physical endurance to enter a competitive or concentration based field.

    The reason women don't make good engineers is the same reason even the best female athlete can't beat even the top 800 male players in tennis or Starcraft players.

    Men evolved to keep focus under high level of stress and lack of food during high endurance hunting. Women evolved under gathering conditions which is much less stressful and doesn't require much focus or strategic thinking. Women are not physical built for long intense concentration on complex problem solving while working in teams under extreme stress, lack of sleep and food. Men are.


    Hopefully, we can move and understand that women voting and even most men voting was a mistake and that no one with I.Q. under 120 and no children should vote.

    Take a look at leaders destroying Europe. All Childless. They have no future stake in their nation's future and that is why they anti-nationalist internationalist/globalist.

    The childless especially females think that all people are interchangeable like cats whereas we know women become xenophobic during pregnancy because having children dramatically changes a person's brain.

    People are only equal in death. Pursuit of equality is pursuit of death.

    1. What the heck is a "competitive or concentration based field"? Talk about loose terminology.

      Even the fields women traditionally dominate require concentration and involve competition. If hairdressers could never concentrate we'd all be walking around with abominable haircuts or the industry would go out of business.

    2. It's perfectly sensible. Evergreen College in Washington accepts over 98% of applicants. Berkeley accepts under 18% (and noticeably lowe for Asians btw). Admission to Berkeley is highly competitive, admission to Evergreen is not.

      The same holds true of some subjects and advanced programs. It's much easier to get accepted for Social Work than for physics or math.

      Some fields are "concentrated" meaning that it takes a longer time and more work to reach the point where a PhD can be an effective independent researcher. You need to do a doctorate and then a post doc if you want to extend results about Fermat's Last Theorem for example. Again, this is perfectly comprehensible to anyone not a deliberate obscurantist like you.

  2. You can expect a firestorm of name-calling from many of the regulars LK. Maybe not as bad as when you suggested killing babies with Down's is wrong, but one can already imagine Kevin boiling with rage that you would dare use a standard deviation that way (don't you know arithmetic is socially constructed?)

    Anyway, an excellent post, and an obvious one to those who bother to pay attention. This is the same argument that got Larry Summers in trouble a decade ago.

  3. "But these are likely to be minor or even trivial factors, while the major factor is biology."

    This is an unsubstantiated assumption on your part, and the research you cite on IQ does not prove this. Indeed, the Flynn effect suggests the opposite--human biology has changed very slightly since we started measuring IQ, while human culture has changed massively. Cultural change is really all that can explain the Flynn effect, which in and of itself undermines biologically determinist arguments about IQ and intelligence, though even Flynn himself is loathe to admit it.

  4. It's neither unsubstantiated nor an assumption since he discusses the reasons for thinking so in the post.

    1. well specifically I would argue that sex differences in g are not large enough to account for the disparity in STEM fields. See eg this chart from the most representative sample we have

      It's data of children and that might be a problem but I would argue that overall adult samples provide a similar picture.

      The average IQ in engineering, IT and other fields would have to be unrealistically high to account for female underrepresentation in these fields. However the commonly noted difference in variance may lead to more extremely high achievers being male rather than female

    2. Huh? The whole post is saying "it's the variance".

      Imagine the blue people all have an IQ of either 135 or 65, evenly split. The red people all have an IQ of either 100 or 102, evenly split. To be a frabulator you need an IQ over 112.

      Which group has higher average IQ? The reds.
      Which group will all frabulators belong to? The blues.

    3. The hypothesis is plausible, but no more than that. What is not substantiated is that "these [cultural effects] are likely to be minor or even trivial factors, while the major factor is biology."

      That is conjecture.

      The Flynn effect shows that variance between generations is as great as variance between sexes and between races. We know that intergenerational variance is not genetic. That raises questions about IQ testing.

      We can not say with certainty that women's IQ is on average lower than men's. So we have variance as an explanation. The reference Johnson et al 2008 says in the abstract "Though present at the high end of the distribution, sex differences in variability did not appear to account for sex differences in high-level achievement." This is not a ringing endorsement of the hypothesis. It says variance did not account for performance differences.

      We also know that cultural factors affect the number of different sexes going into different jobs. The number of female astronauts has risen dramatically over the last twenty years or so. This is not due to women changing but due to cultural factors, both in women wanting to apply, women having the necessary priors to apply and men (mostly) accepting these applications.

      Men are very under-represents as nurses, but that is rising significantly. That is not because men have become more able to do nursing, nor probably they have become more caring. The reasons are cultural, not biological.

      Men and women do perform differently on different axes of "intelligence", but it has not been demonstrated in this article that women's mix should lead to inferior performance in science generally. The characterisation that "Women tend, on average, to be much better at verbal abilities and language, but men tend on average to outperform women on numerical/mathematical and spatial cognitive abilities" is a little "pop science", I think. The Johnson and Bouchard reference phases is as "Substantial sex differences appeared to lie along all three dimensions, with men more likely to be positioned towards the rotation and focus poles of those dimensions, and women displaying generally greater memory."

      It is certain that both biological and cultural factors are at play. What this article does not do is demonstrated that biological ones are dominant and cultural ones are minor or insignificant.

    4. Harold@June 26, 2017 at 9:01 AM

      (1) "What this article does not do is demonstrated that biological ones are dominant and cultural ones are minor or insignificant."

      That is because you lazily cite just 1 article from the large number I have listed, and in the process demonstrate your own confirmation bias.

      (2) "The Flynn effect shows that variance between generations is as great as variance between sexes and between races."

      The Flynn effect has been working for probably 100 years, but has not eliminated the differences in male versus female performance in various specific cognitive abilities. It has not eliminated the differences in the distribution of IQ either between males-females, which were reported even in 1945 by J. A. Fraser Roberts (Roberts 1945).

      Nor is it true that the Flynn effect must be totally environmental in the sense you want it to be: probably, the improvements in the environment have allowed individuals to reach *their full potential genetic/genotypic IQ*.

    5. Ken B, were you replying to me? My point was that differences in variance were insufficient to account for the disparity in STEM. To substantiate this I cited a graph from Deary et al (2003). Unless the average IQ required for participation in STEM is significantly above 140 (therefore unrealistically high) I don't see how sex differences in overall IQ can account for the disparity

      also regarding the Flynn effect it ought to be pointed out that it has in fact been slightly larger for women than for men at least regarding episodic memory and "category fluency"