I have been thinking of one thing: If IQ evolved a lot during the last thousand years, how can it then be so similar in the whole of Western Europe? Different Western European societies had limited population exchange. Some places were crowded, like England and Germany. Others had a lot of marginal land to explore got those brave, strong and lucky enough to succeed, like Scandinavia. And still, Germans and Scandinavians have more or less identical IQ levels, as far as I know. Even in Spain, so far away and with such a different history (exporting an important share of their population to the colonies in the 16th century when others didn't), have that typical around 100 IQ according to Lynn and Vanhanen's data.
If today's IQ levels evolved so recently, how can they be so similar? Or are there indications that they are not similar after all?
Yes, there is regional variation in mean IQ within Western Europe. Higher-IQ regions seem to coincide with those areas that were inhabited mainly by semi-rural artisans, i.e., Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont, and Lombardy.
We see this in France. Mean IQ is highest in Brittany and the eastern departments, and those regions also show the highest economic performance (the Paris region should be excluded because it performs well due to high government investment and its ability to attract the most talented individuals).
Do you know of any studies that compares markers of IQ in ancient DNA from like two thousand years ago and recent humans? I mean, studies on 23andme and such places have linked some genes to educational attainment. Do you know if someone has looked for those genes in DNA from graves?
Woodley, M.A., Younuskunju, S., Balan, B., Piffer, D. (2017). Holocene selection for variants associated with general cognitive ability: comparing ancient and modern genomes. Twin Res Hum Genet 20, 271-280. https://doi.org/10.1017/thg.2017.37
I would also recommend reading the following paper on cognitive evolution in Ancient Rome. It's still under review.
Ancient textual sources are necessarily scarce, scattershot, copies of copies of copies, and third-hand, fourth-hand, fifth-hand, and Xth hand. So, if the few ancient sources tell us things about Black Africans that match what we observe among Black Africans today, then we may have no choice but to believe them. If you claim an edit by copyists, then you need a good reason why. Neither Galen nor Ibn Khaldun would be religious sources, the passages are not religious in nature, and copyists in monasteries would be apparently interested merely in preserving ancient knowledge.
Nubians are a respectable example of an ancient advanced Black African civilization. But, they are a people intermediate between caucasoid and negroid. They still exist today: see pictures of Nubians, and you will see what I mean. Go further south, among the true sub-Saharan Africans, and the persisting ancient architecture is scarce, the ancient art is simple, and the ancient written language or ancient domesticated animals are nonexistent.
I don't doubt that the writings of Ibn Khaldun are authentic. As for the quote from Galen, it may or may not be. In Antiquity, people would often lend credibility to their opinions by saying that a Great Person of the Past held the same opinion.
Intermediate? Only if you're talking about the Nubians of today. They have been considerably Arabicized both culturally and genetically. We actually have ancient DNA from Nubians of the Meroitic period (2100 to 2300 years ago), and its shows that they had more sub-Saharan than Egyptian ancestry.
In this kind of debate, it may be best to go straight to the subtext. You seem to believe that human populations are slowly evolving and that their mental and behavioral characteristics were essentially acquired back in the Pleistocene. I repeatedly run into this view on both sides of the fence, yet it is clearly false.
Human genetic evolution accelerated more than a 100-fold some 10,000 years ago. At that time, humans had already spread over the earth from the equator to the Arctic. So that acceleration wasn't caused by adaptation to new natural environments. It was caused by adaptation to new cultural environments. There has been more genetic evolution over the past 10,000 years than over the previous 100,000, and much of that recent evolution has been necessarily mental and behavioral.
Also: in other comments you referenced the the Fox (1997) study, and I should have paid attention. That study examines the frequency of only one variant, but it shows a frequency among ancient Nubians (27%) closer to Europeans (0%) than to sub-Saharan Africans (69%). See Figure 2.
The strongly latitudinal gradient and skin color gradient of IQ variation tells me that racial IQ differences have their roots in paleolithic climate differences. I would be happy if I were to learn that IQ differences had more recent roots, as I expect that the Flynn effect is a matter of real intelligence gains, which means 100 years is all it took to trend the difference between Black Africans (IQ of 70) and White Europeans. The 10,000 year explosion theory of IQ does not predict the latitudinal gradient.
I did not know about the genetic analyses of ancient Nubians. But, I found a PhD dissertation on the matter, and ancient Nubian genomes seem to be just as intermediate between negroids and caucasoids as modern Nubian genomes (though the author does not seem to numerically quantify the differences). See Figure 4.16 on page 118.
Neither skin color nor IQ shows a strong correlation with latitude. Among the Indigenous inhabitants of the Americas, there is very little variation in skin color, even though they have been present there for 12,000 to 15,000 years. In East Asia, we likewise see little variation in skin color, although part of the reason is the southward expansion of Han Chinese during historic times.
In Europe, we do see very light skin, but this seems to be a comparatively recent development. Modern humans were dark-skinned for at least the first 20,000 years of their presence in Europe, and dark skin seems to have persisted in western Europe until 7,000 years ago. I covered this last point in another post:
IQ likewise shows only a weak correlation with latitude. Mean IQs of Siberian peoples are lower than that of the Chinese. Trading peoples (e.g., Ashkenazi Jews, Igbo, Parsis) show evidence of high cognitive ability, regardless of latitude. I've dealt with this question in my 2019 paper:
Frost, P. (2019). The Original Industrial Revolution. Did Cold Winters Select for Cognitive Ability? Psych 1(1): 166-181. https://doi.org/10.3390/psych1010012
In my opinion, the Flynn effect is not a real gain in cognitive ability. It probably reflects increasing familiarity with test-taking. Do you believe that Millennials are 6 to 8 points more intelligent than the Baby Boomers and 11 to 15 points more intelligent than the Silent Generation?
You asked me about the Flynn effect. That is the topic I enjoy the most, and the less-interesting topic of the causes of racial IQ differences (in which you may be correct) can be put to the side. You can see below that I have a lot to write, but it all climaxes with an important proposition for you.
I suspect that the Flynn effect is a real increase in intelligence, because it is not just a matter of increasing scores but also a matter of many covariates of intelligence changing in a direction as though intelligence has been increasing since the industrial revolution, including such biological traits as child mortality, fertility, adult height, adult longevity, myopia, intracranial volume and brain volume, and cultural traits as educational attainment, GDP per capita, and literacy prevalence. Increasing IQ is therefore less a puzzle that must be solved--it would be more of a puzzle if IQ got left behind among so many of its covariates.
That means, yes, younger generations have become smarter than the older generations, though maybe some White populations by now have reached the Flynn-effect ceiling and are now trending dysgenically downward.
The primary argument (though not the only argument) in favor of the position that the Flynn effect is not a real increase of intelligence is the method of correlated vectors: on a scatterplot of g-loadings of subtests versus cohort score gaps ("d"), the correlation is negative, not positive, ergo no "g" gain of the Flynn effect. But, I claim that the argument is a non-sequitur, as a better conclusion would be that the non-g gain exceed the g gain. If we extend the regression line to where g-loading is 1.0, emulating a test that is perfectly g-loaded, then the d value may positive, negative or zero. In the case of Rushton & Jensen's 2010 data, the d value is (non-significantly) positive, indicating a g gain of the Flynn effect, more likely than not.
The implicit reason we may resist the idea that the Flynn effect is real is because it otherwise seems a paradox that IQ can be so strongly heritable but change two standard deviations in such a short time. But, the "paradox" depends on an understanding of biology that is a century out of date, before we knew that the heritable components of traits can and do change drastically across generations. We discovered 100 years ago that grasshoppers and the respective locusts were the same species, even the same race. For humans, adult height is 80 to 90% heritable, and yet some peoples have become taller by more than two standard deviations. That would be possible only if heritable gene expressions change across generations independently of any DNA change much like grasshoppers shifting to locusts.
It is not just intelligence and height, but many other partly-heritable traits have changed across the 20th century, including fertility, low birth weight prevalence, longevity, juvenile mortality, age at menopause, age at menarche, and body-mass index. The directions of change across time match the cross-sectional directions from less-advantaged countries to more-advantaged countries.
I think I figured out why: lesser juvenile mortality is driving these changes. When "juvenile mortality" is defined as deaths aged 0-24 divided by total deaths in a given year (better matching the biological life-history definition), then it correlates best on a country-level with the other traits. It is an offspring quantity-quality trade-off rooted in life-history evolution.
And, I found that a structural equation model with excellent fit indices effectively proves it. My model contains an indirect feedback loop that I call "the biological engine of the industrial revolution": decreasing juvenile mortality causes increasing intelligence, which causes increasing GDP per capita, which causes juvenile mortality to decrease further.
I am writing a paper on the matter. To get it published in an appropriate interdisciplinary high-impact journal (i.e. Nature or Science), I need experienced collaborators. I am outside of academia, and I am not experienced in scientific publishing. After I complete my draft (it may be a few months or more), maybe I can send it to you, and, if you find it convincing enough, then maybe you can be a co-author with me so you can help me edit it, do further necessary research, and/or recruit more heterodox collaborators. Please let me know, and I will send you an email.
The dramatic decline in child mortality happened during the early 20th century. So the credit for that should go to people who were born before the Flynn Effect. The same goes for many technological advances. Television was invented in the 1920s. A lot of progress in science and technology was held up by the Great Depression (and by WWII for consumer goods). To a great degree, we are living off the intellectual capital that was created during that period.
The Flynn Effect came to a halt some time after the year 2000. If the Flynn Effect was real, milllennials should, on average, be 10 points smarter than Baby Boomers.
Does that claim seem believable? A 10-point increase should be discernable in popular culture, but I don't see it. When I compare magazines of the 1960s with those of today, I see a startling difference, but not in that direction. The font is larger now, and the sentences are shorter and simpler. When I pick up a copy of Reader's Digest, I have the impression of reading something written for children.
If you're convinced only by hard data, what do you make of the lengthening of reaction time among people born since the mid-1970s? What about the reduction in vocabulary over the same period? See my post on the Great Decline: https://peterfrost.substack.com/p/the-great-decline
I am sorry, I was too quick to interpret what you were saying about the relationship between child mortality and the Flynn effect.
The beginning of the child mortality trend seems to be variable, and I can not find good data on the start of the trend for the USA (though I expect it exists somewhere). I could find info for Sweden, and it seems to go back to around 1750. See page 23 here:
We can precisely track the trend of child mortality, but we have only a maximum value for the beginning of the Flynn effect, because it is limited by the administration of the first IQ tests (1910 or so, if I remember correctly). The beginning of the trend of increasing intelligence could have happened any time before that, and it likely happened some time in the 19th century when GDP per capita among industrializing nations started to take a steep upward climb.
The Flynn effect may have recently reached a ceiling in may European nations. But, that does not undercut the reality of the Flynn effect, that scores have been increasing globally all across the 20th century.
Older generations tend to have a pessimistic perspective of the intelligence of younger generations, but the hard data tends to indicate the opposite. It is not just IQ but almost every covariate of intelligence, both cultural and biological (including brain size!), have trended in the direction of increasing intelligence.
There are exceptions to such covariates, and the increasing reaction time is one of them. Color acuity is another. Inspection time is another. Those three covariates have been trending at odds with the Flynn effect. Those three abilities are not uniquely human, and they depend on the lower cortices. That tells me that the adaptive reaction norm for intelligence is not a whole-brain function, but it is focused on the uniquely-human upper cortices.
That is a somewhat ad hoc explanation, but the dysgenic trends of such traits as reaction time is not something that would be predicted by those who claim the Flynn effect is really a Brand effect, because reaction time is also affected by practice--kids today play more video games than ever, and reaction time is a huge advantage.
One way or the other, are you willing to review my draft after I complete it? Thanks.
You don't seem to show much data for Europeans beyond the Italian polygenic score gradient and a mention of Finns. Is there hard data supporting the idea that in general medieval European polygenic scores suggest low 90s IQ? Have we extensively tested medieval European DNA (preferably thousands of samples)? The narrative of craftsmen being more reproductively successful is interesting but the conclusion is speculative without good data.
The data seems to show the Nubians were very close, genetically, to Egyptians and also had significant west Eurasian admixture.
I believe most American blacks are of equatorial west African origin.
There's also the Pittsburgh study (see above). Hopefully, we will soon get Edu PGS studies of ancient DNA, but no such studies have yet been done on medieval Europeans.
Ancient Nubians (Meroitic period) were genetically closer to sub-Saharan Africans than to Egyptians and west Eurasians, although there clearly was Egyptian admixture.
Fox CL. mtDNA analysis in ancient Nubians supports the existence of gene flow between sub-Sahara and North Africa in the Nile Valley. Ann Hum Biol. 1997 May-Jun;24(3):217-27.
Even within West Africa, we see differences in Edu PGS between different populations (see my earlier post on West Africa). Admixture can provide interesting alleles for selection to act upon, but mental and behavioral traits are ultimately determined by selection.
You're a PhD anthropologist and I'm an internet reader so I'll defer to your expertise but a quick search indicates that Nubians are a roughly equal admixture of Nilotic northeast Africans ("black" Africans I suppose but not Bantus) and Eurasian migrants. If so, this example of an advanced sub-Saharan African civilization is "colored" or "mulatto" as traditionally described in the Americas.
I actually read your posts of West Africans and polygenic scores, I believe at your website. As I recall, we have Yoruba data but not Igbo (which would be very interesting). I wouldn't be surprised if the gap in the genetically-influenced component of g is much smaller between the Igbo and Europeans.
It's important to distinguish between the Nubians who existed 2,100-2,300 years ago (Meroitic period) and those who exist today. During the Meroitic period, the Nubians were still genetically closer to other Nilo-Saharan groups, like the Dinka of South Sudan. During the 14th century, Nubia came under Arab control, which led to an influx of Arabs into the region thereafter (as well as some Turks and Albanians in the 19th century).
The study you referenced is based on the Nubians as they exist today. The study I referenced is based on ancient DNA from the Meroitic period.
Ah - good point! I didn't remember any ancient DNA evidence from Nubians but your comment indicates there must be some. I wonder how much we can infer about the IQ of people who took over (for a time) another, established culture.
Actually, you were right. For the Fox study, I was looking at the figure of 39%, which is the admixture estimate and not the population frequency of the genetic variant. The Meroitic Nubians thus had a Sub-Saharan admixture of 39%.
Are there papers on IQ needed in order to successfully farm and domesticate plants and animals? That's what happened in the middle east and spread outward. North American Indians didn't farm that much. Central and south American Indians did domesticate corn and could farm. Neither group invented the wheel though. Australian aborigines couldn't farm and couldn't domesticate animals.
If the IQ needed to form a peaceful farming society is 90, going from average of 90 to an average of 100 today take only a few centuries. But going from Australian or Subsaharan IQ of 60 to 100 will take a lot longer.
Not a lot of people have written about farming (or any mode of production) from the perspective of cognitive evolution. Henry Harpending had thoughts on that subject but (to the best of my knowledge) he never published them. The same goes for Pierre van den Berghe and L.L. Cavalli-Sforza. When ideas don't get written down and openly debated, they tend to be a dog's breakfast of this and that.
Another problem is that "farming" is a heterogeneous concept. Take, for example, the serf who produces food for his family, plus a portion for his lord. His cognitive tasks are not at all like those of a yeoman farmer who has to produce for an ever-changing market. When I was preparing my paper on Tay-Sachs in Quebec, I discovered that many "farmers" on census returns also operated other businesses, and sometimes those other businesses made more money than farming. But they described themselves as "farmers" because it was more prestigious to be a land-owning farmer than a "trader."
Even the serfs that farm on a king's land needs a minimum IQ. Knowing about planting seasons and taking care of animals is not trivial.
Agree with you on the "free enterprise" part of farming. Ron Unz wrote a lot about this in the context of Chinese rice farmers. Those that produce more, get to eat/keep more and become richer. But in modern times, calling yourself a farmer has a lot of tax advantages because almost every country subsidizes farming in some way.
Anyone who has taken courses in paleoanthropology knows that, for example, the survival of Neanderthals in Europe for at least 200,000 years is contradictory to the cold winter theory.
Research on the cognitive abilities of Neanderthals is progressing, it is admitted that they were less intelligent than sapiens, they did not have the same mutation for neuronal proliferation for example ....
It's false in the sense that it doesn't explain the entire picture, but it does explain part of the picture, i.e., cognitive evolution before the rise of complex societies.
Neanderthals adapted to cold climates mainly through biological adaptations. Modern humans adapted much more through cultural adaptations: tailored clothing, shelter construction, hearths and even kilns, which in turn led to pottery manufacture and eventually metal working.
I discussed this point in my 2019 article:
Frost, P. (2019). The Original Industrial Revolution. Did Cold Winters Select for Cognitive Ability? Psych 1(1): 166-181. https://doi.org/10.3390/psych1010012
Here is the abstract:
Rushton and Jensen argued that cognitive ability differs between human populations. But why are such differences expectable? Their answer: as modern humans spread out of Africa and into northern Eurasia, they entered colder and more seasonal climates that selected for the ability to plan ahead, in order to store food, make clothes, and build shelters for winter. This cold winter theory is supported by research on Paleolithic humans and recent hunter-gatherers. Tools become more diverse and complex as effective temperature decreases, apparently because food has to be obtained during limited periods and over large areas. There is also more storage of food and fuel and greater use of untended traps and snares. Finally, shelters have to be sturdier, and clothing more cold-resistant. The resulting cognitive demands are met primarily by women because the lack of opportunities for food gathering pushes them into more cognitively demanding tasks, like garment making, needlework, weaving, leatherworking, pottery, and kiln operation.
The northern tier of Paleolithic Eurasia thus produced the “Original Industrial Revolution”—an explosion of creativity that preadapted its inhabitants for later developments, i.e., farming, more complex technology and social organization, and an increasingly future-oriented culture. Over time, these humans would spread south, replacing earlier populations that could less easily exploit the possibilities of the new cultural environment. As this environment developed further, it selected for further increases in cognitive ability.
Indeed, mean intelligence seems to have risen during recorded history at temperate latitudes in Europe and East Asia. There is thus no unified theory for the evolution of human intelligence. A key stage was adaptation to cold winters during the Paleolithic, but much happened later.
It's impossible to give a percentage because that factor interacts with the time factor. It's like asking how much of area is due to width and how much to length.
Adaptation to seasonality gave northern hunters an edge in being able to exploit later developments, particularly the need for seasonal planting, harvesting, and food storage. Those developments happened not only later but also farther south, in temperate and tropical environments. There was thus a southward expansion of these northern peoples that would eventually cover almost all of Eurasia, North Africa, Oceania, and the Americas. Most of the world's surface is now inhabited by people whose ancestors lived in the northern tier of Eurasia 10,000 years ago.
The temperate and tropical zones offered more possibilities for building larger and more complex societies, and those possibilities were exploited more effectively by northern hunting peoples. This can be seen in variation at COMT, a gene linked to executive function, working memory, and intelligence. At this gene, the Met allele is positively correlated with population IQ (r = 0.57) and is more frequent in farming societies than in hunter-gatherers, who have very low frequencies of the Met allele and a disproportionate predominance of the Val allele. This correlation has one exception: “hunter-gatherers living at high latitudes (Inuit) show high frequencies of the Met allele, possibly due to the higher pressure on technological skills and planning abilities posed by the adverse climatic conditions near the North Pole.”
The fact that despite these all these hundreds of thousand of years, they have been unable to go to Beringia and to Americas, and only later sapiens did it, should tell you something?
Earlier hominids were restricted even closer to equator.
Thanks for an interesting article, I didnt know our IQ had only recently peaked. Two questions:
1. Was the IQ of the ancient Greeks higher than medieval Europe's? If so, why? If I remember right their polygenic scores were slightly over 100 but not sure how reliable that is.
2. Did the high rate of execution of criminals from 1000AD onwards (as you wrote in 2015) increase the IQ of Western Europe? I assume it would domesticate us, narrow the facial width average and increase average IQ slightly.
1. A team led by Woodley of Menie studied ancient DNA from Greece (released by the Reich Lab). It looks like there was a progressive increase in the polygenic score from Neolithic to Mycenaean times, followed by a decrease. They were never able to publish their findings, however. See:
Woodley of Menie, M.A., J. Delhez, M. Peñaherrera-Aguirre, and E.O.W. Kirkegaard. (2019). Cognitive archeogenetics of ancient and modern Greeks. London Conference on Intelligence
I suspect that ancient Greece went through a process similar to that of late medieval/post-medieval Europe, i.e., pacification of social relations → expansion of the market economy → selection for trade-related skills (negotiation, budgeting, numeracy, literacy, etc.).
Eventually, a cognitive decline set in: increase in social inequality → polygyny in the upper class + female hypergamy in the lower class, influx of slaves and containment of demographic expansion of the productive middle class → decreasing fertility initially because socially appropriate niches are in scarce supply and because descent to lower-class niches is impossible (deemed suitable only for slaves).
2. That would be a secondary factor. In fact, the two share a common cause: a determined effort by Church and State to pacify social relations.
I have been thinking of one thing: If IQ evolved a lot during the last thousand years, how can it then be so similar in the whole of Western Europe? Different Western European societies had limited population exchange. Some places were crowded, like England and Germany. Others had a lot of marginal land to explore got those brave, strong and lucky enough to succeed, like Scandinavia. And still, Germans and Scandinavians have more or less identical IQ levels, as far as I know. Even in Spain, so far away and with such a different history (exporting an important share of their population to the colonies in the 16th century when others didn't), have that typical around 100 IQ according to Lynn and Vanhanen's data.
If today's IQ levels evolved so recently, how can they be so similar? Or are there indications that they are not similar after all?
Yes, there is regional variation in mean IQ within Western Europe. Higher-IQ regions seem to coincide with those areas that were inhabited mainly by semi-rural artisans, i.e., Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont, and Lombardy.
We see this in France. Mean IQ is highest in Brittany and the eastern departments, and those regions also show the highest economic performance (the Paris region should be excluded because it performs well due to high government investment and its ability to attract the most talented individuals).
https://www.challenges.fr/classement/quelles-sont-les-regions-les-plus-performantes-de-france_7001
Do you know of any studies that compares markers of IQ in ancient DNA from like two thousand years ago and recent humans? I mean, studies on 23andme and such places have linked some genes to educational attainment. Do you know if someone has looked for those genes in DNA from graves?
Woodley, M.A., Younuskunju, S., Balan, B., Piffer, D. (2017). Holocene selection for variants associated with general cognitive ability: comparing ancient and modern genomes. Twin Res Hum Genet 20, 271-280. https://doi.org/10.1017/thg.2017.37
I would also recommend reading the following paper on cognitive evolution in Ancient Rome. It's still under review.
https://openpsych.net/files/submissions/4_Intelligence_Trends_in_Ancient_Rome_The_Rise_and_Fall_of_Roman_Polygenic_Scores.pdf
Ancient textual sources are necessarily scarce, scattershot, copies of copies of copies, and third-hand, fourth-hand, fifth-hand, and Xth hand. So, if the few ancient sources tell us things about Black Africans that match what we observe among Black Africans today, then we may have no choice but to believe them. If you claim an edit by copyists, then you need a good reason why. Neither Galen nor Ibn Khaldun would be religious sources, the passages are not religious in nature, and copyists in monasteries would be apparently interested merely in preserving ancient knowledge.
Nubians are a respectable example of an ancient advanced Black African civilization. But, they are a people intermediate between caucasoid and negroid. They still exist today: see pictures of Nubians, and you will see what I mean. Go further south, among the true sub-Saharan Africans, and the persisting ancient architecture is scarce, the ancient art is simple, and the ancient written language or ancient domesticated animals are nonexistent.
I don't doubt that the writings of Ibn Khaldun are authentic. As for the quote from Galen, it may or may not be. In Antiquity, people would often lend credibility to their opinions by saying that a Great Person of the Past held the same opinion.
Intermediate? Only if you're talking about the Nubians of today. They have been considerably Arabicized both culturally and genetically. We actually have ancient DNA from Nubians of the Meroitic period (2100 to 2300 years ago), and its shows that they had more sub-Saharan than Egyptian ancestry.
In this kind of debate, it may be best to go straight to the subtext. You seem to believe that human populations are slowly evolving and that their mental and behavioral characteristics were essentially acquired back in the Pleistocene. I repeatedly run into this view on both sides of the fence, yet it is clearly false.
Human genetic evolution accelerated more than a 100-fold some 10,000 years ago. At that time, humans had already spread over the earth from the equator to the Arctic. So that acceleration wasn't caused by adaptation to new natural environments. It was caused by adaptation to new cultural environments. There has been more genetic evolution over the past 10,000 years than over the previous 100,000, and much of that recent evolution has been necessarily mental and behavioral.
Also: in other comments you referenced the the Fox (1997) study, and I should have paid attention. That study examines the frequency of only one variant, but it shows a frequency among ancient Nubians (27%) closer to Europeans (0%) than to sub-Saharan Africans (69%). See Figure 2.
You're right, I'm wrong. I was looking at the figure of 39% (which is actually the admixture estimate). I'll add that correction to the other thread.
The strongly latitudinal gradient and skin color gradient of IQ variation tells me that racial IQ differences have their roots in paleolithic climate differences. I would be happy if I were to learn that IQ differences had more recent roots, as I expect that the Flynn effect is a matter of real intelligence gains, which means 100 years is all it took to trend the difference between Black Africans (IQ of 70) and White Europeans. The 10,000 year explosion theory of IQ does not predict the latitudinal gradient.
I did not know about the genetic analyses of ancient Nubians. But, I found a PhD dissertation on the matter, and ancient Nubian genomes seem to be just as intermediate between negroids and caucasoids as modern Nubian genomes (though the author does not seem to numerically quantify the differences). See Figure 4.16 on page 118.
https://deepblue.lib.umich.edu/bitstream/handle/2027.42/153487/abstein_1.pdf?sequence=1
Neither skin color nor IQ shows a strong correlation with latitude. Among the Indigenous inhabitants of the Americas, there is very little variation in skin color, even though they have been present there for 12,000 to 15,000 years. In East Asia, we likewise see little variation in skin color, although part of the reason is the southward expansion of Han Chinese during historic times.
In Europe, we do see very light skin, but this seems to be a comparatively recent development. Modern humans were dark-skinned for at least the first 20,000 years of their presence in Europe, and dark skin seems to have persisted in western Europe until 7,000 years ago. I covered this last point in another post:
https://peterfrost.substack.com/p/a-people-of-many-colors
IQ likewise shows only a weak correlation with latitude. Mean IQs of Siberian peoples are lower than that of the Chinese. Trading peoples (e.g., Ashkenazi Jews, Igbo, Parsis) show evidence of high cognitive ability, regardless of latitude. I've dealt with this question in my 2019 paper:
Frost, P. (2019). The Original Industrial Revolution. Did Cold Winters Select for Cognitive Ability? Psych 1(1): 166-181. https://doi.org/10.3390/psych1010012
In my opinion, the Flynn effect is not a real gain in cognitive ability. It probably reflects increasing familiarity with test-taking. Do you believe that Millennials are 6 to 8 points more intelligent than the Baby Boomers and 11 to 15 points more intelligent than the Silent Generation?
You asked me about the Flynn effect. That is the topic I enjoy the most, and the less-interesting topic of the causes of racial IQ differences (in which you may be correct) can be put to the side. You can see below that I have a lot to write, but it all climaxes with an important proposition for you.
I suspect that the Flynn effect is a real increase in intelligence, because it is not just a matter of increasing scores but also a matter of many covariates of intelligence changing in a direction as though intelligence has been increasing since the industrial revolution, including such biological traits as child mortality, fertility, adult height, adult longevity, myopia, intracranial volume and brain volume, and cultural traits as educational attainment, GDP per capita, and literacy prevalence. Increasing IQ is therefore less a puzzle that must be solved--it would be more of a puzzle if IQ got left behind among so many of its covariates.
That means, yes, younger generations have become smarter than the older generations, though maybe some White populations by now have reached the Flynn-effect ceiling and are now trending dysgenically downward.
The primary argument (though not the only argument) in favor of the position that the Flynn effect is not a real increase of intelligence is the method of correlated vectors: on a scatterplot of g-loadings of subtests versus cohort score gaps ("d"), the correlation is negative, not positive, ergo no "g" gain of the Flynn effect. But, I claim that the argument is a non-sequitur, as a better conclusion would be that the non-g gain exceed the g gain. If we extend the regression line to where g-loading is 1.0, emulating a test that is perfectly g-loaded, then the d value may positive, negative or zero. In the case of Rushton & Jensen's 2010 data, the d value is (non-significantly) positive, indicating a g gain of the Flynn effect, more likely than not.
The implicit reason we may resist the idea that the Flynn effect is real is because it otherwise seems a paradox that IQ can be so strongly heritable but change two standard deviations in such a short time. But, the "paradox" depends on an understanding of biology that is a century out of date, before we knew that the heritable components of traits can and do change drastically across generations. We discovered 100 years ago that grasshoppers and the respective locusts were the same species, even the same race. For humans, adult height is 80 to 90% heritable, and yet some peoples have become taller by more than two standard deviations. That would be possible only if heritable gene expressions change across generations independently of any DNA change much like grasshoppers shifting to locusts.
It is not just intelligence and height, but many other partly-heritable traits have changed across the 20th century, including fertility, low birth weight prevalence, longevity, juvenile mortality, age at menopause, age at menarche, and body-mass index. The directions of change across time match the cross-sectional directions from less-advantaged countries to more-advantaged countries.
I think I figured out why: lesser juvenile mortality is driving these changes. When "juvenile mortality" is defined as deaths aged 0-24 divided by total deaths in a given year (better matching the biological life-history definition), then it correlates best on a country-level with the other traits. It is an offspring quantity-quality trade-off rooted in life-history evolution.
And, I found that a structural equation model with excellent fit indices effectively proves it. My model contains an indirect feedback loop that I call "the biological engine of the industrial revolution": decreasing juvenile mortality causes increasing intelligence, which causes increasing GDP per capita, which causes juvenile mortality to decrease further.
I am writing a paper on the matter. To get it published in an appropriate interdisciplinary high-impact journal (i.e. Nature or Science), I need experienced collaborators. I am outside of academia, and I am not experienced in scientific publishing. After I complete my draft (it may be a few months or more), maybe I can send it to you, and, if you find it convincing enough, then maybe you can be a co-author with me so you can help me edit it, do further necessary research, and/or recruit more heterodox collaborators. Please let me know, and I will send you an email.
The dramatic decline in child mortality happened during the early 20th century. So the credit for that should go to people who were born before the Flynn Effect. The same goes for many technological advances. Television was invented in the 1920s. A lot of progress in science and technology was held up by the Great Depression (and by WWII for consumer goods). To a great degree, we are living off the intellectual capital that was created during that period.
The Flynn Effect came to a halt some time after the year 2000. If the Flynn Effect was real, milllennials should, on average, be 10 points smarter than Baby Boomers.
Does that claim seem believable? A 10-point increase should be discernable in popular culture, but I don't see it. When I compare magazines of the 1960s with those of today, I see a startling difference, but not in that direction. The font is larger now, and the sentences are shorter and simpler. When I pick up a copy of Reader's Digest, I have the impression of reading something written for children.
If you're convinced only by hard data, what do you make of the lengthening of reaction time among people born since the mid-1970s? What about the reduction in vocabulary over the same period? See my post on the Great Decline: https://peterfrost.substack.com/p/the-great-decline
I am sorry, I was too quick to interpret what you were saying about the relationship between child mortality and the Flynn effect.
The beginning of the child mortality trend seems to be variable, and I can not find good data on the start of the trend for the USA (though I expect it exists somewhere). I could find info for Sweden, and it seems to go back to around 1750. See page 23 here:
https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/936/WP90-07_Childhood_Mortality.pdf
We can precisely track the trend of child mortality, but we have only a maximum value for the beginning of the Flynn effect, because it is limited by the administration of the first IQ tests (1910 or so, if I remember correctly). The beginning of the trend of increasing intelligence could have happened any time before that, and it likely happened some time in the 19th century when GDP per capita among industrializing nations started to take a steep upward climb.
The Flynn effect may have recently reached a ceiling in may European nations. But, that does not undercut the reality of the Flynn effect, that scores have been increasing globally all across the 20th century.
Older generations tend to have a pessimistic perspective of the intelligence of younger generations, but the hard data tends to indicate the opposite. It is not just IQ but almost every covariate of intelligence, both cultural and biological (including brain size!), have trended in the direction of increasing intelligence.
There are exceptions to such covariates, and the increasing reaction time is one of them. Color acuity is another. Inspection time is another. Those three covariates have been trending at odds with the Flynn effect. Those three abilities are not uniquely human, and they depend on the lower cortices. That tells me that the adaptive reaction norm for intelligence is not a whole-brain function, but it is focused on the uniquely-human upper cortices.
That is a somewhat ad hoc explanation, but the dysgenic trends of such traits as reaction time is not something that would be predicted by those who claim the Flynn effect is really a Brand effect, because reaction time is also affected by practice--kids today play more video games than ever, and reaction time is a huge advantage.
One way or the other, are you willing to review my draft after I complete it? Thanks.
You don't seem to show much data for Europeans beyond the Italian polygenic score gradient and a mention of Finns. Is there hard data supporting the idea that in general medieval European polygenic scores suggest low 90s IQ? Have we extensively tested medieval European DNA (preferably thousands of samples)? The narrative of craftsmen being more reproductively successful is interesting but the conclusion is speculative without good data.
The data seems to show the Nubians were very close, genetically, to Egyptians and also had significant west Eurasian admixture.
I believe most American blacks are of equatorial west African origin.
There's also the Pittsburgh study (see above). Hopefully, we will soon get Edu PGS studies of ancient DNA, but no such studies have yet been done on medieval Europeans.
Ancient Nubians (Meroitic period) were genetically closer to sub-Saharan Africans than to Egyptians and west Eurasians, although there clearly was Egyptian admixture.
Fox CL. mtDNA analysis in ancient Nubians supports the existence of gene flow between sub-Sahara and North Africa in the Nile Valley. Ann Hum Biol. 1997 May-Jun;24(3):217-27.
Even within West Africa, we see differences in Edu PGS between different populations (see my earlier post on West Africa). Admixture can provide interesting alleles for selection to act upon, but mental and behavioral traits are ultimately determined by selection.
You're a PhD anthropologist and I'm an internet reader so I'll defer to your expertise but a quick search indicates that Nubians are a roughly equal admixture of Nilotic northeast Africans ("black" Africans I suppose but not Bantus) and Eurasian migrants. If so, this example of an advanced sub-Saharan African civilization is "colored" or "mulatto" as traditionally described in the Americas.
https://www.annualreviews.org/doi/10.1146/annurev-genom-083117-021759
I actually read your posts of West Africans and polygenic scores, I believe at your website. As I recall, we have Yoruba data but not Igbo (which would be very interesting). I wouldn't be surprised if the gap in the genetically-influenced component of g is much smaller between the Igbo and Europeans.
It's important to distinguish between the Nubians who existed 2,100-2,300 years ago (Meroitic period) and those who exist today. During the Meroitic period, the Nubians were still genetically closer to other Nilo-Saharan groups, like the Dinka of South Sudan. During the 14th century, Nubia came under Arab control, which led to an influx of Arabs into the region thereafter (as well as some Turks and Albanians in the 19th century).
The study you referenced is based on the Nubians as they exist today. The study I referenced is based on ancient DNA from the Meroitic period.
My wish list includes Edu PGS data from the Igbo.
Ah - good point! I didn't remember any ancient DNA evidence from Nubians but your comment indicates there must be some. I wonder how much we can infer about the IQ of people who took over (for a time) another, established culture.
Actually, you were right. For the Fox study, I was looking at the figure of 39%, which is the admixture estimate and not the population frequency of the genetic variant. The Meroitic Nubians thus had a Sub-Saharan admixture of 39%.
Are there papers on IQ needed in order to successfully farm and domesticate plants and animals? That's what happened in the middle east and spread outward. North American Indians didn't farm that much. Central and south American Indians did domesticate corn and could farm. Neither group invented the wheel though. Australian aborigines couldn't farm and couldn't domesticate animals.
If the IQ needed to form a peaceful farming society is 90, going from average of 90 to an average of 100 today take only a few centuries. But going from Australian or Subsaharan IQ of 60 to 100 will take a lot longer.
Not a lot of people have written about farming (or any mode of production) from the perspective of cognitive evolution. Henry Harpending had thoughts on that subject but (to the best of my knowledge) he never published them. The same goes for Pierre van den Berghe and L.L. Cavalli-Sforza. When ideas don't get written down and openly debated, they tend to be a dog's breakfast of this and that.
Another problem is that "farming" is a heterogeneous concept. Take, for example, the serf who produces food for his family, plus a portion for his lord. His cognitive tasks are not at all like those of a yeoman farmer who has to produce for an ever-changing market. When I was preparing my paper on Tay-Sachs in Quebec, I discovered that many "farmers" on census returns also operated other businesses, and sometimes those other businesses made more money than farming. But they described themselves as "farmers" because it was more prestigious to be a land-owning farmer than a "trader."
Even the serfs that farm on a king's land needs a minimum IQ. Knowing about planting seasons and taking care of animals is not trivial.
Agree with you on the "free enterprise" part of farming. Ron Unz wrote a lot about this in the context of Chinese rice farmers. Those that produce more, get to eat/keep more and become richer. But in modern times, calling yourself a farmer has a lot of tax advantages because almost every country subsidizes farming in some way.
Cold winters theory is false.
Anyone who has taken courses in paleoanthropology knows that, for example, the survival of Neanderthals in Europe for at least 200,000 years is contradictory to the cold winter theory.
Research on the cognitive abilities of Neanderthals is progressing, it is admitted that they were less intelligent than sapiens, they did not have the same mutation for neuronal proliferation for example ....
This is a theory that is false...
It's false in the sense that it doesn't explain the entire picture, but it does explain part of the picture, i.e., cognitive evolution before the rise of complex societies.
Neanderthals adapted to cold climates mainly through biological adaptations. Modern humans adapted much more through cultural adaptations: tailored clothing, shelter construction, hearths and even kilns, which in turn led to pottery manufacture and eventually metal working.
I discussed this point in my 2019 article:
Frost, P. (2019). The Original Industrial Revolution. Did Cold Winters Select for Cognitive Ability? Psych 1(1): 166-181. https://doi.org/10.3390/psych1010012
Here is the abstract:
Rushton and Jensen argued that cognitive ability differs between human populations. But why are such differences expectable? Their answer: as modern humans spread out of Africa and into northern Eurasia, they entered colder and more seasonal climates that selected for the ability to plan ahead, in order to store food, make clothes, and build shelters for winter. This cold winter theory is supported by research on Paleolithic humans and recent hunter-gatherers. Tools become more diverse and complex as effective temperature decreases, apparently because food has to be obtained during limited periods and over large areas. There is also more storage of food and fuel and greater use of untended traps and snares. Finally, shelters have to be sturdier, and clothing more cold-resistant. The resulting cognitive demands are met primarily by women because the lack of opportunities for food gathering pushes them into more cognitively demanding tasks, like garment making, needlework, weaving, leatherworking, pottery, and kiln operation.
The northern tier of Paleolithic Eurasia thus produced the “Original Industrial Revolution”—an explosion of creativity that preadapted its inhabitants for later developments, i.e., farming, more complex technology and social organization, and an increasingly future-oriented culture. Over time, these humans would spread south, replacing earlier populations that could less easily exploit the possibilities of the new cultural environment. As this environment developed further, it selected for further increases in cognitive ability.
Indeed, mean intelligence seems to have risen during recorded history at temperate latitudes in Europe and East Asia. There is thus no unified theory for the evolution of human intelligence. A key stage was adaptation to cold winters during the Paleolithic, but much happened later.
To what extent does the cold winter theory explain the Variance in intelligence between races ?
As a percentage...?
It's impossible to give a percentage because that factor interacts with the time factor. It's like asking how much of area is due to width and how much to length.
Adaptation to seasonality gave northern hunters an edge in being able to exploit later developments, particularly the need for seasonal planting, harvesting, and food storage. Those developments happened not only later but also farther south, in temperate and tropical environments. There was thus a southward expansion of these northern peoples that would eventually cover almost all of Eurasia, North Africa, Oceania, and the Americas. Most of the world's surface is now inhabited by people whose ancestors lived in the northern tier of Eurasia 10,000 years ago.
The temperate and tropical zones offered more possibilities for building larger and more complex societies, and those possibilities were exploited more effectively by northern hunting peoples. This can be seen in variation at COMT, a gene linked to executive function, working memory, and intelligence. At this gene, the Met allele is positively correlated with population IQ (r = 0.57) and is more frequent in farming societies than in hunter-gatherers, who have very low frequencies of the Met allele and a disproportionate predominance of the Val allele. This correlation has one exception: “hunter-gatherers living at high latitudes (Inuit) show high frequencies of the Met allele, possibly due to the higher pressure on technological skills and planning abilities posed by the adverse climatic conditions near the North Pole.”
Extremely arrogant comment: "Cold winters theory is false."
There's evidence for it as well as reasonable arguments against it. It remains plausible as an explanation for some of the picture as Peter suggests.
Kirkegaard makes a case for it:
https://kirkegaard.substack.com/p/cold-winters-theory-a-summary-of
The fact that despite these all these hundreds of thousand of years, they have been unable to go to Beringia and to Americas, and only later sapiens did it, should tell you something?
Earlier hominids were restricted even closer to equator.
Thanks for an interesting article, I didnt know our IQ had only recently peaked. Two questions:
1. Was the IQ of the ancient Greeks higher than medieval Europe's? If so, why? If I remember right their polygenic scores were slightly over 100 but not sure how reliable that is.
2. Did the high rate of execution of criminals from 1000AD onwards (as you wrote in 2015) increase the IQ of Western Europe? I assume it would domesticate us, narrow the facial width average and increase average IQ slightly.
1. A team led by Woodley of Menie studied ancient DNA from Greece (released by the Reich Lab). It looks like there was a progressive increase in the polygenic score from Neolithic to Mycenaean times, followed by a decrease. They were never able to publish their findings, however. See:
Woodley of Menie, M.A., J. Delhez, M. Peñaherrera-Aguirre, and E.O.W. Kirkegaard. (2019). Cognitive archeogenetics of ancient and modern Greeks. London Conference on Intelligence
https://www.youtube.com/watch?v=UES_tpDxz9A
I suspect that ancient Greece went through a process similar to that of late medieval/post-medieval Europe, i.e., pacification of social relations → expansion of the market economy → selection for trade-related skills (negotiation, budgeting, numeracy, literacy, etc.).
Eventually, a cognitive decline set in: increase in social inequality → polygyny in the upper class + female hypergamy in the lower class, influx of slaves and containment of demographic expansion of the productive middle class → decreasing fertility initially because socially appropriate niches are in scarce supply and because descent to lower-class niches is impossible (deemed suitable only for slaves).
2. That would be a secondary factor. In fact, the two share a common cause: a determined effort by Church and State to pacify social relations.
Thanks for the detailed reply