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Explaining male predominance in chess

by Robert Howard
6/19/2014 – There are two theories to explain male predominance at the apex of intellectual achievement: some attribute it to some innate evolutionary ability differences, others to social factors of present-day society. Robert Howard of Sydney, Australia, has sent us the most profound and well-researched article we have seen on this subject – we urge everyone to read and ...
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Males predominate at the top in chess. Almost all grandmasters are male, there never has been a female world champion and only one female, Judit Polgar, ever has reached the top ten in the FIDE rating list (eighth spot in 2005 with a peak rating of 2735).

The male predominance in chess parallels that in domains such as mathematics, physics and engineering, which may tap some similar abilities and propensities. Carrying out research in high-level, competitive areas of physics and mathematics or playing a grandmaster-level game can greatly tax physical stamina and ability to concentrate and can strain the processing limits of our monkey brains, which evolved to carry out much simpler tasks. These areas also all rely partly on spatial ability, the power to visualize objects in space and to mentally manipulate the images. This ability is important in chess calculation, for instance. In the endgame, players may calculate variations 20 moves deep, relying on spatial ability to visualize the changes. Players may picture a position some moves down the line, analyse it extensively, and then work out how to reach it.

This painting by Dutch artist Lucas van Leyden (1494–1533) very aptly illustrates our subject

Various explanations have been proposed for the female under-representation at the top in chess and in science and technology areas. Some researchers say that it is all due to social factors. There are no ability or personality differences between the sexes. Instead, social pressures discourage women from being competitive and from outdoing men, women face “stereotype threats” that males have more talent, and old boys networks downplay female achievement and limit female opportunity.

Evolutionary psychologists counter that natural selection pressures on the sexes of a species may differ and may create some differences in abilities and propensities. Consider a battle-scarred male beach master sea lion on a sub-Antarctic island in mating season, guarding a harem of 20 females. He continually must fend off other males sneaking in to try to mate and there is natural selection for beach master size, ferocity, stamina, and competitiveness. Female sea lions do not need to compete for mates in the same way and so sex differences arise over time. For instance, male sea lions became much physically larger and more ferocious than females.

The argument goes that in hunter-gatherer times, there were natural selection pressures on human males for better spatial ability, competitiveness and related factors. Females also are more important in evolution because few males are needed to produce the next generation. Nature can experiment more with them and males show more variability in many traits. There are more males at both extremes of the IQ distribution, for example.

Chess talent may consist of a mix of ability and personality traits at which males on average may excel or there may be more males at the top extreme due to greater male variability. These factors may include high IQ (to learn chess material quickly and to understand complex concepts such as opposite colored bishops endgame and tactically unbalanced position), and spatial ability, ability to concentrate, and competitiveness. Stars in chess and in physical sports often have the famed “killer instinct”, the desire to win at all costs.

In 2005, I published a study which aimed to quantify the male/female FIDE rating difference at the top and to see if the gap had diminished with all the societal changes in the role of women over the period and with the increasing number of female grandmasters (31 in January, 2014). I looked at the top 50 male players and top 50 female players in the first FIDE rating list each year from 1975 to 2004. I have extended the resulting graph for an additional ten years and the results are shown below. The sex difference averages nearly 250 rating points (about a hefty one standard deviation for the statistically minded) and has remained roughly constant over the four decades.

But the 2005 study had two interpretation problems. I found that women typically play many fewer FIDE-rated games than males, only about one third of the number on average. Now, the usual learning curve for chess players is a progressive ascent to a peak at around 750 FIDE-rated games. Most players who persist to 900 rated games become grandmasters but few play so many games. Women tend to drop out much earlier and perhaps most would have become grandmasters if they had persisted to 900 games. Comparing modestly- and highly-practiced individuals can be misleading. Studies should control for differences in number of games played, either by equating males and females on this or by examining differences at the typical rating peak at around 750 games.

But when this is done, the male predominance remains. The figure below illustrates this. As noted, for some traits males show more variability. There are more males at both IQ extremes. In other traits, such as height and spatial ability, the male mean also is higher. I examined the rating distributions for males and females at about 750 FIDE-rated games played, looking at all males and females who had played 750 games by January 2012. With differences in games played thus controlled for and with players near their performance limits, the male distribution still shows a higher mean and more variability, exactly as with spatial ability and height.

The other interpretation problem is that many fewer women play chess. Look at the playing hall at an open tournament and the usual severe under-representation of women becomes apparent. In January 2012, only about 8.51% of FIDE-rated players were female. The “participation rate hypothesis” proposed by some researchers holds that the sex difference at the top in chess arises simply because so many more males play and statistically there are likely to be fewer females at the top due to their under-representation.

For instance, a study by a team led by Merim Bilalic, then of Oxford University, looked at the April 2007 German Chess Federation rating list, on which only 5.82% of the players were female. The team argued that the percentage of top-rated females on this list was about what would be expected statistically from this tiny percentage of 5.82.

Why are (the best) women so good at chess?
Participation rates and gender differences in intellectual domains

By Merim Bilalic, Kieran Smallbone, Peter McLeod and Fernand Gobet

A popular explanation for the small number of women at the top level of intellectually demanding activities from chess to science appeals to biological differences in the intellectual abilities of men and women. An alternative explanation is that the extreme values in a large sample are likely to be greater than those in a small one. Although the performance of the 100 best German male chess players is better than that of the 100 best German women, we show that 96 per cent of the observed difference would be expected given the much greater number of men who play chess. There is little left for biological or cultural explanations to account for. In science, where there are many more male than female participants, this statistical sampling explanation, rather than differences in intellectual ability, may also be the main reason why women are under-represented at the top end.

Problem solved? The study featured on the German ChessBase website in 2009 and in newspaper reports around the world, with grave tones of finality. This study settles the issue for good. There are no differences in chess talent between the sexes. The male predominance is due just to the differing participation rates.

But the study can been criticized on several grounds. First, it is difficult to determine cause and effect. We tend to like and persist at activities we are good at and avoid those that we are poor at. If I wanted to be a champion boxer and kept getting knocked out in the first round despite extensive training, soon I would abandon boxing. If women do have less talent for chess on average, their under-representation may simply reflect this tendency to drop out due to early lack of success. Second, Michael Knapp of the University of Bonn argued that their statistical approach was inappropriate and only accounted for about two thirds of the claimed extent of female under-representation at the top.

Third, there was no evident control for number of rated games and the women in the German rating list may have played many fewer games, as in the international domain. Also, the assumption is that males and females are randomly drawn from or at least are drawn from the same parts of their respective talent distributions. But the few women who play chess may come from a different part of the female talent distribution. Perhaps these 5.82% were the cream of the female talent distribution while the males came from the whole spread of male talent.

Finally, the study used just one data point and it is risky to generalize from only one data point. Let us assume that the sexes played the same number of games on average and that statistically the proportion of females at the top on the list is exactly what would be expected from the differing participation rates. This may mean everything or absolutely nothing. It could be a fluke and the only way to be certain is to use more data points. It would be more convincing if they found another chess federation in which the percentage of females was say 15% and the proportion of top-rated females was much higher and was exactly what was expected from that percentage and then found another federation in which the percentage was say 25% and the number of top-rated females was even higher and was exactly what would be expected from that percentage. One data point is unimpressive. Three data points would be better.

We can do something much like this with nations in the FIDE list. Some nations have no female FIDE-rated players, some have very few, and in some such as Vietnam and the Caucasus nation of Georgia, over 30% of players are female. I looked at all FIDE-rated players who had played over 350 games and took their ratings at about 350 games. I then took categories of nations with at least one female player and in which the percentage of female players was 5% or less, between 10 and 15%, or 25% or greater. If the participation rate hypothesis is correct, the rating sex difference should decline as the percentage of females in a group of nations increases. But numerically we find just the opposite trend, as the figure shows. As the percentage of female players rises, the rating gap rises too. Why might this be so? Let us assume that in the 5% nations, the top 5% of female talent is mobilized. If we widen this percentage to 15%, the additional females will be less talented, and the gap would widen.

I also tackled the participation rate hypothesis by replicating a variety of studies with players from Georgia, where women are strongly encouraged to play chess and the female FIDE participation rate is high at over 30%. The overall results were much the same as with the entire FIDE list, but sometimes not quite as pronounced.

Males on average may have some innate advantages in developing chess skill due to previous differing evolutionary pressures on the sexes. Females may have greater talent on average in other domains, however. If the male predominance in chess was due just to social factors it should have greatly lessened or disappeared by now. Indeed, some researchers now recognize that many psychological sex differences are due to complex interactions between nature and nurture.

This conclusion is unpalatable to many but it is best to acknowledge how the world actually is.


  • Bilalic, M., Smallbone, K., McLeod, P. & Gobet, F. (2009). Why are (the best) women so good at chess? Participation rates and gender differences in intellectual domains. Proceedings of the Royal Society B, 276, 1161-1165.
  • Chabris, C.F. & Glickman, M.E. (1996). Sex differences in intellectual performance. Psychological Science, 17, 1040-1046.
  • Howard, R.W. (2005). Are gender differences in high achievement disappearing? A test in one intellectual domain. Journal of Biosocial Science, 37, 371-380.
  • Howard, R. W. (2014). Explaining male predominance at the apex of intellectual achievement. Personality and Individual Differences.
  • Howard, R. W. (2014). Gender differences in intellectual achievement persist at the limits of individual capabilities. Journal of Biosocial Science, 46, 386-404.
  • Knapp, M. (2010). Are participation rates sufficient to explain gender differences in chess performance? Proceedings of the Royal Society B, 277, 2269-2270.
  • Maass, A., D’Ettole, C., & Cadinu, M. (2008). Checkmate? The role of gender stereotypes in the ultimate intellectual sport. European Journal of Social Psychology, 38, 231-245.

Full study by Robert Howard


One view attributes male predominance at the apex of intellectual achievement partly to some innate ability differences. Another view attributes it only to such social factors as socialisation practices, lack of female role models, glass ceilings and male gatekeepers downplaying female achievement. The present study examined sex differences in performance at the top in international chess. This domain allows controls over the latter two social factors because chess has an objective performance measure based on game results and little of a glass ceiling as most tournaments are open to all and talent can rise quickly. The sex difference in performance in the top 10 and 50 of all international players is large at about one standard deviation and stayed roughly constant from 1975 to 2014. A large difference remained when examined over number of rated games played and also occurred, but not as strongly, with Georgian players, who have a high female participation rate. Male predominance in chess and related domains may be due partly to sex differences in innate abilities.


  • Male predominance at the apex of intellectual achievement has several explanations.
  • The notion that only social factors are responsible was tested.
  • Male predominance in international chess remained roughly constant in 1975 - 2014.
  • Game count and participation rate differences evidently are not responsible.
Robert Howard holds a PhD in psychology from the University of Queensland in Australia and has research interests in human intelligence, learning and memory, and in the development of expertise. He has carried out many research studies examining expertise in general, using chess data. Until recently, he taught at the University of New South Wales in Sydney. He has authored five books, the latest being Islands in the Orient Sea: Travels in the Edgy 21st-Century Philippines, published in 2012.
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kurumban kurumban 6/19/2014 12:59
One has to be cautious regarding innate superiority arguments based on evolutionary psychology. Under-representation in top chess is seen not only in the case of women, but also in the case of various ethnic groups. But in their case, the evolutionary argument surely doesn't apply, and arguments based on social and cultural factors are more correct. So, in the case of women too, socio-cultural factors may be a better explanation. As to men displaying superior killer instinct, the author obviously is not married!
Marigje Arriens Marigje Arriens 6/19/2014 01:16
"Males on average may have some innate advantages in developing chess skill due to previous differing evolutionary pressures on the sexes". Thanks for the use of "may". The only innate advantage I can see it's related to slavery and a man-made world, where women, among other chaps like African-Americans for instance, didn't have any chance to compete in male endeavors - or to compete at all - for centuries. I think we're just keeping them behind and I personally don't see how "If the male predominance in chess was due just to social factors it should have greatly lessened or disappeared by now.", I think this is the point that deserved more sustainable arguments and data to be showed about as the whole hypothesis land on this concept to be reasonable.
On the contrary I find it outrageous how, especially in chess, the establishment is still bureaucratically divided into sexes at its core. It does make little sense and it's very unfair. It still seems to me that to women in chess aren't been given the same equal chances. Judith Polgar missed the shot by a mile, but who has the guts to blame her? She was the only woman competing with the best at the time. I'm waiting for the day when, even against the constrictions and subjugation, people like Hou Yifan will kick some and show men are simply no better. I also think Magnus Carlsen is a fair-minded block and won't obstruct the natural course of human events - which is to get rid of the sex category mentality in chess, if it isn't clear enough yet -, but I'm not sure about Kasparov who's probably going to take the podium, once again. If he starts teaching young talented females consistently, like he has done with Carlsen (but for free, sorry Kaspa), I may change my mind, but since then, I'm sure that the Male Chess Establishment, or better known by all as simply the chess establishment or FIDE, will persistently give women the black pieces.
littleboots littleboots 6/19/2014 02:14
Typical pseudo-science using statistics to hide lack of objectivity.
By using the same specious analysis as the article, it is patently obvious that white jewish males are far superior in chess than any other race or creed, which must be based upon some past evolutionary pressures and inherent biological inferiority in all others .. 6/19/2014 03:22
It is totally irresponsible for chessbase to claim that this article has some "profound meaning". The article completely fails to factor the long known, and obvious factor that extreme skill "grandmaster" ability is generally rare, and that the total number of female players is small in comparison to the total number of male players, which makes the number of rare outliers less likely to appear, let alone extreme outliers such as Judit polgar 2700. Further the article doesn't consider factors such as due to the extremely small pool of female players vs the larger pool of male players how the average early age and exposure to "quality" chess environments will be less common amongst female players as female players are less common in the population. This whole article is seeking a conclusion and using data points to try to demonstrate variable skill as being caused by some innate factors which has in no way been demonstrated by anything that the article has said. I think this guy needs to have his educational credentials reviewed.
hasan kurusogan hasan kurusogan 6/19/2014 04:48
Replace in the above article "women" with "japanese". Why are there so few japanese with GM titles? There must be evolutionary pressures that must have given rise to the discrepancy, right?? Not right.... It is entirely possible for a large group of humanity to be not so successful at chess because of cultural/social reasons.
Petrosianic Petrosianic 6/19/2014 04:54
Evolutionay psychology theories are pseudo-scientific at best, and based on the unscientific idea that evolution is a conscious entity with wants and purposes. Acquired traits are not genetically passed on, in any case. A man may develop biceps of steel by working as a smith his whole life, but that trait doesn't pass on to his son unless his son does that same work.
Anthony Migchels Anthony Migchels 6/19/2014 06:02
It is ghastly, how feminist political correctness makes the simple truth unthinkable, even for scientists.

The reason why males dominate at chess is eminently simple: men have an 11% larger brain and are thus markedly more intelligent than women.

That's why men are better at chess and every other intellectual pursuit and that's why men continue to create all the great art, science, inventions etc for the betterment of us all.

Not 1000 years of feminism will ever change this.
Slowman Slowman 6/19/2014 06:07
Congratulations to Mr. Howard for his excellent paper and for having the guts to prove what everyone living on planet Earth already knows! It's hilarious to see the politically correct horde denying logic, science, statistics, experience and common sense just because it doesn't fit their agenda.
Yes, sexes are not identical. There are major statistical differences which allow men to perform better in certain activities while women are superior in others. Our brains are different, not just the size, but also the grey/white matter ratio and the size, number of synapses and activity of various parts of the brain. That's why women outperform men in some areas and men outperform women in others (on average). Anyone who has worked as a chess coach with boys and girls knows just how different they are.
The idea that the difference is simply the result of fewer women playing chess is a case of not understanding cause and effect. Obviously people tend to do mostly what they're good at. By using the same egalitarian logic we could say that very short people are just as good at basketball as tall players, they just don't get to the very top in the NBA because their pool is smaller. Not to mention that the author clearly shows that in countries with a higher percentage of female chess players the rating gap is even bigger.
@Petrosianic, you are criticizing lamarckism, not our understanding of evolution. It's not about acquired traits, it's about genes coding for certain traits becoming prevalent. The hunter who had genes allowing him to find his way back home survived and passed on his genes, the one whose genes didn't allow for such spacial abilities got lost and died. Some of these genes are located on the Y chromosome (present only in men). There's also a well known effect of testosterone on the brain - not the place to get into details.
skata skata 6/19/2014 08:47
Great article! To all your disagreements there is an answer in the article, you just don't want to admit that you can't be as good as men at chess... Sorry!
Raymond Labelle Raymond Labelle 6/20/2014 03:14
On the other hand, we have the Polgar experience. Mr. Polgar was (he may be retired now) a psychologist and he did not have a particular talent in chess, at least not at GM and not even master level. He happened to have three daughters. He wanted to know if, by education and environmental conditions from an early age, he could make the girls excellent at chess. And it worked. The probability that all the three daughters be exceptionally favoured genetically for chess is quite low, even if we admitted that the concept makes sense, which is discussable. This is a true psycho-educational experiment rather than an inference from statistical interpretation.
Raymond Labelle Raymond Labelle 6/20/2014 03:28
To Hasan Kurusogan. One possible explanation for which there is not a great proportion of Japanese amongst the chess grandmasters could be that chess is not practiced as much in Japan as in the Occident and Russia, which in turn can be explained by the fact that Shogi takes the place that chess takes in Occident. Shogi is a cousin of chess, descending also from the common Indian ancestor of chess, but it has also important differences. Shogi is the hot chess-like game in Japan, not chess itself. It is reasonable to envisage that, in the statistical great numbers, the Japanese would crush the Occidentals and Russians who would try Shogi, at least for the time the game would be understood as well by the non-Japanese.
Peter B Peter B 6/20/2014 05:36
The connection to Math/Physics/Engineering is misguided. Many women are world leaders in these fields, and women have won Nobel Prizes.

I think chess is different because it needs a certain single-mindedness to excel, something which comes more naturally to men. Men are not more intelligent, it just that chess suits us better. Women raised in an atmosphere where this single-mindedness was encouraged - i.e. the Polgar sisters - have excelled too.
PerfectConscience PerfectConscience 6/20/2014 05:54
Male predominance in chess and other sports, and in all quarters as a matter of fact, is best explained by their physical and mental superiority. Men excel in analytical and calculative fields thanks to their much better cerebral activity, especially their LEFT brain dominance, not to mention physical and mental stamina and will power.
jefferson jefferson 6/20/2014 06:29
A good analysis of the problems with the participation rate hypothesis, but there's a big, gaping hole in the "men are superior" argument too. Before I get to it, we need to talk about chess talent/ability—we don’t really know what it is. Mr. Howard never really goes into the meat of what constitutes chess talent. Is it IQ or a subset of g like spatial intelligence? What about working memory? Does mathematical ability mean anything? Contrary to Mr. Howard's tortured sea-lion example, it's not at all clear yet how great a role intelligence plays in chess talent (maybe motivation is more important). These questions haven't been fully answered. Still, I'll go ahead and agree that intelligence, or IQ, is probably pretty important.

A 1992 study published in the British Journal of Psychology (1) found that the overall IQ's of gifted young Belgian chess players were 121, with a performance IQ of 129. So chess talent might depend upon an above average IQ, and in particular high spatial intelligence. Critically, as was documented in Der Spiegel 52 from 1987, Kasparov, perhaps the greatest chess genius who has ever lived, took two IQ tests, scoring 135 on the first and 123 on the second. OK. But when talking about women in chess this creates a huge problem for the "men are superior" hypothesis.

If all it takes is an IQ in the 120's to be considered gifted, and maybe 135 or so to become world champion... where are all the women? Kasparov's IQ is well above average, but it is not "genius" level. It certainly is nowhere near that sky high score at which point women would become seriously underrepresented by orders of magnitude. Why? Because at an IQ of 130, men outnumber women "just" 2 or 3 to 1. Therefore, even if IQ is wholly to blame for the gender gap, we are still missing some 20-30 women in the top 100. Instead they are almost absent. Thus if Kasparov's IQ of about 130 is super GM status, something else is happening to all the women about that IQ to make them not play chess, or not reach their potential, because I assure you they do exist! This is the main problem with the argument. Apparently, you don't need an IQ of 200 to be world champion or be considered "one of the greats". Something 1-2.5 standard deviations above average will suffice, and this includes hundreds of millions of women.

I won't press this point, but there's also some nagging doubt about the extent to which women really are underrepresented on the uppermost percentiles of IQ in all domains. Mensa volunteering their data is not a very random sample of people. You'd have to test millions of people from a random sample to really find the truth, as those high IQ's are that rare.

For final consideration, let me point out that IQ, including spatial IQ, is usually unchangeable after a certain age, but there may be specific exceptions. For example, in a 2007 study, 10 hours of action videogames almost eliminated the spatial differences between men and women, including scores on a mental rotation test. Women benefited more than men. (2) Nature is important but don't underestimate the environment either. I'll only comment on Slowman and Anthony's naked misogyny enough to say I hope they never teach the next Judit Polgar. If attitudes like those are common, it's no wonder more women don't play chess.

The participation rate hypothesis has problems, but the "men are superior" argument, clearly has problems too. The whole question is not resolved by any means and needs further high quality studies to elucidate what chess talent or ability is before we can begin to seriously answer the question of why women are underrepresented in chess. Honestly, this is a loaded topic, and it would be best if everyone just suspends judgment until all the facts are in before we all rush to judgment.

PerfectConscience PerfectConscience 6/20/2014 07:49
Slowman's TALL vs SHORT basketball players is a perfect analogy for male dominance. Men are specifically good at analytical activities bcoz they are LEFT brain dominant. Polgar seems to be the best example for authorities maintaining a relatively weaker player at the top in order to attract more people from the weaker sex.
RooksCanKill RooksCanKill 6/20/2014 04:59
"...can strain the processing limits of our monkey brains, which evolved to carry out much simpler tasks." -

speak for yourself, sir....
GMCarlsenSJAKSkak GMCarlsenSJAKSkak 6/21/2014 02:50
Curiously, Padre Polgar allegedly refused a sponsorship offer of some millionaire to repeat his coaching experiment on an African boy.
JGranny JGranny 6/21/2014 03:14
Take it from a Jewish nanny, Judit is truly exceptional! 6/28/2014 02:48
The statistical analysis in this article contains a serious flaw. Howard argues that women require more rated games to reach the same rating, hence have less aptitude for chess. But this reasoning only holds if men and women face similar opposition in rated games. If there is a systematic difference in the standard of opposition, we can conclude nothing. And, in fact, an obvious difference of this kind exists: men only play in open tournaments, women in both open tournaments and women's tournaments.

I wrote to Howard to ask if had controlled for this problem. His response was that it was not necessary, since women play most of their games in open tournaments. But a quick glance at some online databases shows that his claim is factually incorrect. Most of the top woman players appear to play a large proportion of their rated games in women's tournaments. Some of them play nearly all their rated games there.

There are very few women who refuse on principle to play in women's tournaments, so it is hard to say with any degree of certainty what might happen if this became more common. But considering that one of the women who has done so is Judith Polgar, you can't help wondering.

Maybe someone on Chessbase would like to compile a table showing, for the top woman players, what proportion of their games they play against other women? It would probably take no more than a few hours to do, and would make this debate a little more quantitative.