David Reich in an interview with Ali Akbari talked about the acceleration of evolution during the Neolithic-Bronze Age transition. I interpreted this (my framing, not his) as farming having created the conditions for later evolutionary acceleration, but not necessarily the acceleration itself immediately. There were also severe genetic bottlenecks around this time in Europe—presumably tied to the Yanmaya expansion-massive demographic turnover-possible plague decimating Neolithic populations. This would have accelerated genetic drift.
But I am curious about the cognitive changes that might have happened at this time. Perhaps the higher population densities that came with the larger Bronze Age settlements (already becoming civilizations) represented a more decisive shift in terms of environment. I am curious whether the shift from localized mythologies to universal philosophies around this time (the Axial Age) is associated with some kind of cognitive shift in response to this new environment.
Farming was the trigger for many other changes. Because it created a much higher ratio of people to land, populations became larger, more complex, and more specialized. These changes in turn facilitated other changes, and so on and so forth.
So it's difficult, if not impossible, to attribute the rise in cognitive ability to a single cultural change. There was too much going on at the same time.
As for the Axial Age (800 to 200 BCE), it was associated with the great Greek philosophers, Confucius, Lao Tzu, Buddha, and the Hebrew prophets. In my opinion, these thinkers were a consequence, and not a cause, of the rise in cognitive ability. In fact, this rise leveled off and began to reverse not long after.
This is not to say that these thinkers caused the cognitive stagnation and decline of Imperial Rome and post-Sui China. Rather, there may have been a common cause. When the elites, including the intellectual class, reach a certain level of social and material development, they begin to forego family life and increasingly engage in non-procreative lifestyles.
"But the initial rise was unusually sharp. We see nothing like it in the cognitive evolution of East Asia after the advent of farming. There is just a gradual increase until 1,500 years ago.
Does Europe show an initial surge simply because early farmers were adapting to the demands of farming? Or were they intermixing with a population of higher cognitive ability as they moved farther north into Europe?"
But does this not suggest a possible cart-before-the-horse scenario? In other words, an increase in intelligence prompted the change from hunting to farming.
"After the turn of the millennium, it lost further ground as evidence mounted for recent cognitive evolution at temperate or even subtropical latitudes, among such groups as Ashkenazi Jews,4 the Chinese,5 and the English from the late Middle Ages onward."
This does not negate the possibility that there are a number of reasons humans gain intelligence.
Bottom line, as you seem to suggest, the pressure for selection of intelligence is rather nuanced and not so well understood.
Yes, this is what I suggest. Cognitive ability is not a product of a single selection pressure. It has been shaped by a different mix of selection pressures at different times and in different places.
"But does this not suggest a possible cart-before-the-horse scenario? In other words, an increase in intelligence prompted the change from hunting to farming."
I don't see how. Between 9,000 and 7,000 years ago (and thereafter as well), the ancient DNA is overwhelmingly from Neolithic farming sites.
"I don't see how. Between 9,000 and 7,000 years ago (and thereafter as well), the ancient DNA is overwhelmingly from Neolithic farming sites."
Maybe I didn't word it right. What I meant was that perhaps an increase in intelligence among some hunters led to a shift toward farming, which in turn continued the increase in intelligence. Since hunting is a rather nomadic endeavor, maybe the reason for ancient DNA being overwhelmingly from Neolithic farming sites is that.
Piffer and Kirkegaard looked at cognitive evolution in Europe before 9,000 years ago in their 2024 paper: "Evolutionary Trends of Polygenic Scores in European Populations From the Paleolithic to Modern Times."
It's difficult to say anything definitive because the sample sizes are small. Two findings relate to your question:
- Cognitive ability began to increase around 20,000 years ago. This was well before the time of farming.
- Hunter-gatherer ancestry, especially ancestry from Western Hunter Gatherers, was negatively associated with cognitive ability (EA3, EA4, and IQ).
These two findings seem to be contradictory. One problem is that this study provides no information on Scandinavian Hunter Gatherers (Most studies divide European hunter-gatherers into three groups: Western, Eastern, and Scandinavian). I suspect there was a positive association between cognitive ability and Scandinavian hunter-gatherer ancestry, but this group was either excluded from analysis or included in the Eastern Hunter-Gatherers (who may have shown a weak positive association with cognitive ability).
I would have to dig deeper into their paper to find out.
Briefly stated, recent cognitive evolution in Ashkenazi Jews is indicated by four lines of evidence:
1. A study using polygenic scores with a small sample size (n=53)
Dunkel, C.S, M.A. Woodley of Menie, J. Pallesen, & E.O.W. Kirkegaard. (2019). Polygenic scores mediate the Jewish phenotypic advantage in educational attainment and cognitive ability compared with Catholics and Lutherans. Evolutionary Behavioral Sciences, 13(4), 366-375. https://psycnet.apa.org/doi/10.1037/ebs0000158
2. A study using polygenic scores and a larger sample size (n=145)
Piffer, D. (2019). Evidence for recent polygenic selection on educational attainment and intelligence inferred from Gwas hits: A replication of previous findings using recent data. Psych, 1, 55–75. https://doi.org/10.3390/psych1010005
4. High incidences in Ashkenazi Jews of nine neurological disorders of genetic origin: Tay-Sachs (two unrelated alleles), Gaucher's (five unrelated alleles), Niemann-Pick, and Mucolipidosis Type IV. These disorders affect the capacity of neural tissue to store sphingolipids, which are vital to the growth of neurons.
All nine mutations arose independently in the same metabolic pathway and have become unusually frequent in the same population over the same short time. They are thus markers of intense selection for cognitive ability.
Cochran, G., J. Hardy, & H. Harpending. (2006). Natural history of Ashkenazi intelligence. Journal of Biosocial Science, 38(5), 659-693. https://doi.org/10.1017/S0021932005027069
Thoughts on whether intelligence is mainly maternal vs both parents? Seems surprising given the X chromosome is ~5% of the genome and XX individuals have a more unimodal or centered IQ distribution than XY
Intelligence is due to small effects at many gene loci — literally thousands of loci. The vast majority are not on the X-chromosome. In fact, the X-chromosome seems to be underrepresented:
"Even adjusting for sample-size differences, the number of lead SNPs on the X-chromosomal
analysis is about one third as large as the number of SNPs on autosomes of similar
length: we identify 12 lead SNPs on the X chromosome, whereas on chromosomes 6
through 10, the average number of lead SNPs is 33" (p. 66)
There seems to be some sex-linkage, but it's not strong. Men have a broader distribution of IQs, being over-represented among the most intelligent and the least intelligent. There is also evidence that men are superior in spatial navigation and that women are superior in identifying small items from a landscape (as would be predicted from male specialization in hunting and female specialization in gathering).
Thoughts on whether intelligence is mainly maternal vs both parents? Seems surprising given the X chromosome is ~5% of the genome and XX individuals have a more unimodal or centered IQ distribution than XY
Very interesting. There was a Tom Rowsell YouTube video suggesting blue eyes are better adapted at seeing in the dark. He suggested it was an adaptation to hunting by moonlight, but my thinking is that crafting and mending things indoors (with only small windows and firelight) may be the better explanation.
The evidence that blue eyes provide better night vision is weak. Most research finds no meaningful advantage, and some studies even suggest slightly worse low‑light performance in blue‑eyed individuals due to increased internal light scatter.
A small study hints at a possible advantage, but it has not been replicated and is considered preliminary. This is a New Scientist report from 2024. The researchers themselves caution that the finding needs confirmation in larger studies.
European eye color diversified about the same time as European hair color, i.e., between 10,000 and 20,000 years ago. The genes are different in each case, so the cause may be a selection pressure for new colors, particularly bright colors that catch attention.
I've written about this subject in the past. Two articles can be found here:
Quote: "Women had few opportunities for food gathering most of the year, so they specialized in tasks like weaving, pottery, needlework, garment making, leatherworking, shelter building, and ornamentation. For these tasks, they invented new tools, like hand-powered rotary drills to make ornamental objects and perhaps fire. They also built kilns heated to between 500 and 800 degrees C. and made a wide range of woven goods: ropes for rafts and nets, knotted netting, plaited wicker-style basketry, and textiles."
Interesting. When you add cooking and the development of agriculture to that list, it would appear that women were responsible for most if not all ot the major technological developments prior to the rise of civilization. Were they also smarter and better looking?
It’s hard to say which sex is smarter. Men are better at navigating in all four dimensions of space and time. Women are better at identifying small items against a complex background.
These differences originate in the different cognitive demands of hunting versus gathering, and they have helped both sexes develop abilities for other tasks.
This is excellent work. Thank you!
David Reich in an interview with Ali Akbari talked about the acceleration of evolution during the Neolithic-Bronze Age transition. I interpreted this (my framing, not his) as farming having created the conditions for later evolutionary acceleration, but not necessarily the acceleration itself immediately. There were also severe genetic bottlenecks around this time in Europe—presumably tied to the Yanmaya expansion-massive demographic turnover-possible plague decimating Neolithic populations. This would have accelerated genetic drift.
But I am curious about the cognitive changes that might have happened at this time. Perhaps the higher population densities that came with the larger Bronze Age settlements (already becoming civilizations) represented a more decisive shift in terms of environment. I am curious whether the shift from localized mythologies to universal philosophies around this time (the Axial Age) is associated with some kind of cognitive shift in response to this new environment.
Farming was the trigger for many other changes. Because it created a much higher ratio of people to land, populations became larger, more complex, and more specialized. These changes in turn facilitated other changes, and so on and so forth.
So it's difficult, if not impossible, to attribute the rise in cognitive ability to a single cultural change. There was too much going on at the same time.
As for the Axial Age (800 to 200 BCE), it was associated with the great Greek philosophers, Confucius, Lao Tzu, Buddha, and the Hebrew prophets. In my opinion, these thinkers were a consequence, and not a cause, of the rise in cognitive ability. In fact, this rise leveled off and began to reverse not long after.
This is not to say that these thinkers caused the cognitive stagnation and decline of Imperial Rome and post-Sui China. Rather, there may have been a common cause. When the elites, including the intellectual class, reach a certain level of social and material development, they begin to forego family life and increasingly engage in non-procreative lifestyles.
"But the initial rise was unusually sharp. We see nothing like it in the cognitive evolution of East Asia after the advent of farming. There is just a gradual increase until 1,500 years ago.
Does Europe show an initial surge simply because early farmers were adapting to the demands of farming? Or were they intermixing with a population of higher cognitive ability as they moved farther north into Europe?"
But does this not suggest a possible cart-before-the-horse scenario? In other words, an increase in intelligence prompted the change from hunting to farming.
"After the turn of the millennium, it lost further ground as evidence mounted for recent cognitive evolution at temperate or even subtropical latitudes, among such groups as Ashkenazi Jews,4 the Chinese,5 and the English from the late Middle Ages onward."
This does not negate the possibility that there are a number of reasons humans gain intelligence.
Bottom line, as you seem to suggest, the pressure for selection of intelligence is rather nuanced and not so well understood.
Yes, this is what I suggest. Cognitive ability is not a product of a single selection pressure. It has been shaped by a different mix of selection pressures at different times and in different places.
"But does this not suggest a possible cart-before-the-horse scenario? In other words, an increase in intelligence prompted the change from hunting to farming."
I don't see how. Between 9,000 and 7,000 years ago (and thereafter as well), the ancient DNA is overwhelmingly from Neolithic farming sites.
"I don't see how. Between 9,000 and 7,000 years ago (and thereafter as well), the ancient DNA is overwhelmingly from Neolithic farming sites."
Maybe I didn't word it right. What I meant was that perhaps an increase in intelligence among some hunters led to a shift toward farming, which in turn continued the increase in intelligence. Since hunting is a rather nomadic endeavor, maybe the reason for ancient DNA being overwhelmingly from Neolithic farming sites is that.
Piffer and Kirkegaard looked at cognitive evolution in Europe before 9,000 years ago in their 2024 paper: "Evolutionary Trends of Polygenic Scores in European Populations From the Paleolithic to Modern Times."
It's difficult to say anything definitive because the sample sizes are small. Two findings relate to your question:
- Cognitive ability began to increase around 20,000 years ago. This was well before the time of farming.
- Hunter-gatherer ancestry, especially ancestry from Western Hunter Gatherers, was negatively associated with cognitive ability (EA3, EA4, and IQ).
These two findings seem to be contradictory. One problem is that this study provides no information on Scandinavian Hunter Gatherers (Most studies divide European hunter-gatherers into three groups: Western, Eastern, and Scandinavian). I suspect there was a positive association between cognitive ability and Scandinavian hunter-gatherer ancestry, but this group was either excluded from analysis or included in the Eastern Hunter-Gatherers (who may have shown a weak positive association with cognitive ability).
I would have to dig deeper into their paper to find out.
Thanks, that is informative.
I am not convinced by the Ashkenazi jew high IQ story. How about an article on that.
I wrote an article on this subject four years ago:
https://www.anthro1.net/p/ashkenazi-jews-and-recent-cognitive
Since then, Emil Kirkegaard has written a good review article:
Kirkegaard, E. (2026). Genetic evidence of Ashkenazi intelligence, Just Emil Kirkegaard Things, April 28. https://www.emilkirkegaard.com/p/genetic-evidence-of-ashkenazi-intelligence
Briefly stated, recent cognitive evolution in Ashkenazi Jews is indicated by four lines of evidence:
1. A study using polygenic scores with a small sample size (n=53)
Dunkel, C.S, M.A. Woodley of Menie, J. Pallesen, & E.O.W. Kirkegaard. (2019). Polygenic scores mediate the Jewish phenotypic advantage in educational attainment and cognitive ability compared with Catholics and Lutherans. Evolutionary Behavioral Sciences, 13(4), 366-375. https://psycnet.apa.org/doi/10.1037/ebs0000158
2. A study using polygenic scores and a larger sample size (n=145)
Piffer, D. (2019). Evidence for recent polygenic selection on educational attainment and intelligence inferred from Gwas hits: A replication of previous findings using recent data. Psych, 1, 55–75. https://doi.org/10.3390/psych1010005
3. Two genetic admixture studies (n=~300 and 477)
Kirkegaard, E. (2026). Genetic evidence of Ashkenazi intelligence, Just Emil Kirkegaard Things, April 28. https://www.emilkirkegaard.com/p/genetic-evidence-of-ashkenazi-intelligence
4. High incidences in Ashkenazi Jews of nine neurological disorders of genetic origin: Tay-Sachs (two unrelated alleles), Gaucher's (five unrelated alleles), Niemann-Pick, and Mucolipidosis Type IV. These disorders affect the capacity of neural tissue to store sphingolipids, which are vital to the growth of neurons.
All nine mutations arose independently in the same metabolic pathway and have become unusually frequent in the same population over the same short time. They are thus markers of intense selection for cognitive ability.
Cochran, G., J. Hardy, & H. Harpending. (2006). Natural history of Ashkenazi intelligence. Journal of Biosocial Science, 38(5), 659-693. https://doi.org/10.1017/S0021932005027069
Diamond, J.M. (1994). Jewish Lysosomes. Nature, 368, 291-292. https://doi.org/10.1038/368291a0
Thoughts on whether intelligence is mainly maternal vs both parents? Seems surprising given the X chromosome is ~5% of the genome and XX individuals have a more unimodal or centered IQ distribution than XY
Eg.
https://pmc.ncbi.nlm.nih.gov/articles/PMC3114203/
Intelligence is due to small effects at many gene loci — literally thousands of loci. The vast majority are not on the X-chromosome. In fact, the X-chromosome seems to be underrepresented:
"Even adjusting for sample-size differences, the number of lead SNPs on the X-chromosomal
analysis is about one third as large as the number of SNPs on autosomes of similar
length: we identify 12 lead SNPs on the X chromosome, whereas on chromosomes 6
through 10, the average number of lead SNPs is 33" (p. 66)
https://static-content.springer.com/esm/art%3A10.1038%2Fs41588-018-0147-3/MediaObjects/41588_2018_147_MOESM1_ESM.pdf
There seems to be some sex-linkage, but it's not strong. Men have a broader distribution of IQs, being over-represented among the most intelligent and the least intelligent. There is also evidence that men are superior in spatial navigation and that women are superior in identifying small items from a landscape (as would be predicted from male specialization in hunting and female specialization in gathering).
Thoughts on whether intelligence is mainly maternal vs both parents? Seems surprising given the X chromosome is ~5% of the genome and XX individuals have a more unimodal or centered IQ distribution than XY
Eg.
https://pmc.ncbi.nlm.nih.gov/articles/PMC3114203/
Very interesting. There was a Tom Rowsell YouTube video suggesting blue eyes are better adapted at seeing in the dark. He suggested it was an adaptation to hunting by moonlight, but my thinking is that crafting and mending things indoors (with only small windows and firelight) may be the better explanation.
The evidence that blue eyes provide better night vision is weak. Most research finds no meaningful advantage, and some studies even suggest slightly worse low‑light performance in blue‑eyed individuals due to increased internal light scatter.
https://biologyinsights.com/do-blue-eyes-see-better-at-night-the-science
A small study hints at a possible advantage, but it has not been replicated and is considered preliminary. This is a New Scientist report from 2024. The researchers themselves caution that the finding needs confirmation in larger studies.
https://www.newscientist.com/article/2415329-blue-eyes-may-be-better-for-reading-in-dim-light-than-brown-eyes/
European eye color diversified about the same time as European hair color, i.e., between 10,000 and 20,000 years ago. The genes are different in each case, so the cause may be a selection pressure for new colors, particularly bright colors that catch attention.
I've written about this subject in the past. Two articles can be found here:
https://www.anthro1.net/p/3-why-does-estrogen-make-my-brown
https://www.anthro1.net/p/a-people-of-many-colors
Quote: "Women had few opportunities for food gathering most of the year, so they specialized in tasks like weaving, pottery, needlework, garment making, leatherworking, shelter building, and ornamentation. For these tasks, they invented new tools, like hand-powered rotary drills to make ornamental objects and perhaps fire. They also built kilns heated to between 500 and 800 degrees C. and made a wide range of woven goods: ropes for rafts and nets, knotted netting, plaited wicker-style basketry, and textiles."
Interesting. When you add cooking and the development of agriculture to that list, it would appear that women were responsible for most if not all ot the major technological developments prior to the rise of civilization. Were they also smarter and better looking?
It’s hard to say which sex is smarter. Men are better at navigating in all four dimensions of space and time. Women are better at identifying small items against a complex background.
These differences originate in the different cognitive demands of hunting versus gathering, and they have helped both sexes develop abilities for other tasks.