Well - women are the "means" men are the "extremes" as exemplified by the latter’s overrepresentation in both tails of the distributions on seemingly any variety of traits. The way I phrased the general point holds well for the personality traits, but I see the confusion when it comes to IQ.
A preponderance of males in the most cognitively-demanding fields, despite only a small difference in standard deviation between the sexes is of course a result of this larger distribution. Physicists from the top research universities are not people that re two standard deviations above the mean, but more towards three-four standard deviations above the mean. Which is drawing from a very small pool of the population, the vast majority of which will be men.
The point being is that even small differences in the standard deviation will translate into very large differences in the available pool substantially out on the tail of the distribution, even if this small pool isn’t quite enough to significantly offset the standard deviation in the IQ distribution between the sexes. There is an article/paper that quantifies this somewhere, but I remember from it a figure of about one female for every five males at the high end.
To reference a few older posts, it is also poignant to note just how substantial the impact of IQ is within already gifted subpopulations, particularly for those majors which have actual cognitive thresholds.
Whatever samples are used, male IQ shows more variability at the tail ends, even if mentally deficient individuals (more likely to be males, as that study posited) are ousted. Maybe the four-point standard deviation between males and females is the high-end estimate. The mean could be statistically zero, but you’d still find males overrepresented at the tail ends.
I probably won’t be rewriting the original post to reflect all of this. The paper that measured the variability in personality traits becomes more relevant when you consider the effects personality traits have on life outcomes, which, similar to IQ, is rewarded in the labour market, independent of education. That is, measures of personality traits (again, more variable in men) alone will slightly impact life’s outcomes just as your interests and IQ will.
- To make this into a lengthier reply, you can perhaps apply this variation argument in explaining Western innovation in science and engineering (all of which really have no peer) relative to that in the East, despite a difference in standard deviation favouring East Asians:
The problem is any sort of credible data for "racial IQ variation" is extremely lacking. This study used data from two nationally representative cohort studies and compared students of various of ethnicities who attend the same schools, and found that the the academic achievement gap among Asians (East, South, Filipino & Southeast) and whites (one big pool, as always) is attributed to academic hard work, motivation from cultural teachings, and general parental pressures, rather than advantages in tested cognitive abilities or socio-demographics, despite the E. Asian subgroup displaying a cognitive advantage.
This is all well and good, but with a relatively useless measure like high school GPA the study isn’t doing much here. Although when controlled for GPA, and particularly PISA assessments, are quite a nice measure of IQ, but both high school GPA and PISA definitely show some variation which can only be explained by differences in national educational system. Whereas "coaching" can not really improve performance on IQ tests.
Moreover, most studies of national IQ are quite crude, and subject to numerous methodological uncertainties, even if the overall results tend to correlate with PISA results. So it looks like we won’t be testing this racial IQ variation argument any time soon.
From prehistory Europe traded cultural and scientific innovations with the East, arguably developing parallel, with some deviations here and there. This of course was followed by the innovations of classical antiquity, then by a drop off after the fall of Rome, then complete Western dominance leading into the industrial revolution:
There has to be something going on here beyond cultural explanations, it’ll be mostly genetic, as it often is. It’ll be something that developed rather recently too. Consider work such as Gregory Clark’s Farewell to Arms comes. (See this post) Which with empirical studies finds that substantial evidence of the descendants of the rich replacing the poor in Britain leading right up to the industrial revolution, in what may well be population dynamics where positive traits (for commerce, long term planning, wealth accumulation, market organization, etc) replaced negative traits during what is really an accelerated period of human evolution. This phenomena (rich replacing poor) was also observed in other parts of Europe and East Asia.
Considering that intelligence is polygenic (many genes involved, each with a very small effect) and that high intelligence is largely a consequence of possessing fewer rare deleterious mutations, perhaps natural selection (not just on cognitive ability) impacted East Asians and Europeans differently, resulting in the posited variation we see today - why not?
The cliché explanation that East Asians are well attuned for academic rigour and comprehending the great progress of mankind, but are less intuitive and creative (Satoshi Kanazawa posited (perhaps excessively) exactly this) may well just be enough. Going back to the influence of personality, apply this to explain underrepresentation of East Asians in leadership positions in the West, despite their high academic achievements, perhaps…
To go one step further, Northwestern Europe, had – unique in the world – a long history of avoiding inbreeding. Cousin marriages and tribal warfare now only exist elsewhere in the world. This was the work of Christianity as the Church instituted several restrictions on marriage and family systems (banning cousin marriage) that discouraged the large kinships that typify tribal societies - as we know the German barbarians that invaded Rome were close-knit and tribal extended families, and the breakdown of clan loyalties was fundamental for Christian universalism. As a result, the regions of Europe took a unique direction in its evolution which manifests today - altruism in Europe shifted from close kinship and spread around the whole society. Everyone in a country became related to everyone else, to some degree, and it goes toward explaining the low genetic differentiation among Europeans. The consequence of this is perhaps increased outgroup altruism - largely a product of NW Europeans.
There is data on this out there, and it (distinct evolutionary history) is absolutely the case. The distribution of genes influencing psychological traits in both Greece and Rome were different than they are today. Similarly, Europe, particularly Europe within the Hajnal line (as seen in the image below and which is also known to roughly tracks areas where there were low rates of inbreeding) underwent a different genetic pathway.
This is clearly a more lengthier reply than intended, but it’s relevant enough to publish.