Distribution of glacial ice masses could have been a cause of the Han IQ being higher than that of the Germanic nations. At the last glacial maximum, northern Europe was ice-bound, and the European peri-glacial tundra was at much lower latitudes than was the most northerly tundra in largely ice-free eastern Siberia, i.e., in the Upper Paleolithic Han populations probably had to function in colder climates than did Western Hunter Gatherer populations.
The Templer p-values seem elevated to the extent that similar populations (for example, Baltic bordering and West African) are sampled via small, highly-divided political units that raise N, rather than by a biologically meaningful scheme that can be applied to all temperature regimes equally. Easy data is sloppy data.
So there seems to be a Goldilocks zone for evolution of intelligence in humans? (pun intended).
Emil you are correct in surmising that there are countervailing factors. One fairly obvious one might be a sharp reduction in selection pressure within established agricultural communities - we know that adequate food produces a sharp reduction in mortality.
Then cultural or societal factors must be invoked. For example, the Greek city-states were notoriously combative and only became unified in the face of a greater threat.
And we know that culturally they valued intelligence - I refer to Odysseus.
"But historically, it seems the most clever people lived in warmer climate, as judged by their ability to invent agriculture (Mesopotamia, India etc.) and, well, Western civilization (in Greece and Rome, not in Scandinavia!)."
Crop production means grain-based food, which makes larger populations possible. This in itself increases the occurrence of mutations that affect the intellect. However, mycotoxins in cereals, in particular aflatoxin (the most potent naturally occurring genotoxin), increase this effect by orders of magnitude due to extra mutations. It would be worthwhile to address this effect...
In addition, aflatoxin-producing aspergilli can produce three times more toxins on rice starch than on maize or wheat starch. This is an interesting coincidence with the higher average IQ in East Asia.
I don't think the logic that suggests not migrating in winter should select for bigger brains is sound. Bigger rains aren't strictly better, they have an energy cost, to say cold climates favour big brains more than warm ones it needs to be the case that cold climates offer enough payoff for higher intelligence to offset the extra energy cost. Which isn't obviously true, maybe there's not actually anything you can use extra intelligence for and it's just a waste of energy. There's no reason to assume the point where the gains from extra intelligence balance the costs is higher in cold environments just because they're harsher.
Anyway, we'll be able to deduce IQ directly from the genome fairly soon, so we can just test archaeological remains and know for certain when intelligence increased for different populations. My hunch is we'll find it was within the last few centuries in most places, as is the case for the Ashkenazim.
Yes, defitinitely. The main cause why it cold winter theory works in humans is because of clothes; we don't have fur and we are at threshold where more or less intelligence means no or winter clothes. Much less intelligence = nobody has clothes, no selection. Much more intelligence = everyone is smart enough to do, no selection.
Possibly, although Neanderthals survived very cold temperatures with a relative primitive material culture. It seems like clothes that are good enough are fairly low on the tech tree.
Neanderthals actually tended to inhabit the more temperate regions at the time as far as I know, you see some of the biggest sites in places like Spain which were essentially African Savannah at the time
There were Neanderthals in places like Spain and the Middle East, which would have been pretty warm during glacial minimums.
But there were also Neanderthals in the Siberian tundra during glacial maximums. We find Neanderthal sites where the animal remains (from hunting) are 90%+ reindeer.
Surviving in the tundra during Ice Age takes more intelligence than surviving in the tropics. Keeping warm, finding food (no fruit or easy prey, just large animals in thick snow), storing food over the winter, taking care of babies and children, sexual selection for mates based on these abilities, etc. The environment in the cold is more predictable and harsh, while the tropics are unpredictable but favorable.
Won't intelligence be less useful in predictable environments, since you'll always know what to do? Seems like unpredictability would more favour foresight.
If resources are abundant typically that leads to overpopulation and war. Maybe war favours intelligence more than keeping warm or storing food does.
I really don't think it's obvious which environments favour intelligence more a priori. You can't just assume it's the harsh ones.
Predictable and harsh selects for intelligence more than unpredictable/random and pleasant since it allows intelligent people to predict and ameliorate their conditions. Unpredictability in the tropics cannot be selected for since intelligence in hunter-gatherers and agriculturalists cannot do anything about sudden, random infectious disease/parasite/STD outbreaks, floods, droughts, animal migrations, extinctions, etc. Also, the article showed you that there is evidence for cold winters theory from bird studies, among others. I do find it obviously plausible that living in Ice Age Europe is more difficult than living in the tropics. That's why tropics have more biodiversity. It can support more organisms. It's why people want to vacation in the tropics or subtropics instead of Europe or Siberia during the winter. It's why we have commonly used terms like "tropical paradise". I don't think there is an equivalent like "arctic paradise". Even humans adapted and evolved for the cold are virtually always more comfortable in warmer climates even today with all the technology. They don't need as much food since the temperature is higher (metabolic rate might be an an additional factor here since cold environments require animals to have a higher resting metabolic rate which can be used to synthesize more brain matter).Winter in Northern Europe is unpleasant psychologically and physically even today with central heating. i can't imagine how horrible it was for my heroic ancestors for tens of thousands of years to survive in the wilderness of Ice Age Europe.
Just to add a tidbit; how many people adapted to living in a cold climate live out their retirement in the north versus the south? Thailand is more popular than Scandinavia even today. If you proposed to my ancestors a deal where their families and villages/towns would be transported to an uninhabited and protected settlement in Thailand, I think they would be persuaded. It is an interesting thought experiment. If you asked the Finns whether they'd be willing to move en masse their whole populations to an alternative universe where Finland is an uninhabited tropical island, would they consider it a good idea. Would they envy the Finns in an alternative universe with the same genetics living on a Mediterranean island? It's an interesting experiment. It would be interesting to ask of people what their ideal climate and biogeography would look like. What would their heaven on Earth, so to speak, look like? What would their ideal location look like? Would it be a tropical or subtropical paradise? If they couldn't choose central heating, they might. On the other hand, with no air conditioning, some Northern people might prefer the cold to which they have habituated. I think I prefer a Mediterranean/Southern European climate; not too cold, not too hot, just right. Would people's instincts with respect to which environment is most optimal for survival without modern technology align with the cold winters theory? We could survey people across different latitudes. Would they prefer themselves/their children/their parents to have been born in a warmer climate, all else being equal? What country/area is ideal for human survival and flourishing sans modern technology? I would imagine something like coastal South-East Asia.
Is it possible to to test correlatoin IQ vs (summer temp minus winter temp)? or IQ vs. T1-T2*K and see which K gets best correlation.
The Australian Abos and Kalahari people are only recently live in deserts after their kin was displaced from more comfy environments, like you point what happened with Amerindians.
The fig 1 is probably more about nearly identical plant/insect species than only handful of specialists in entire world can tell apart of. For large mammals than humans domesticate, the picture would look somewhat different.
Nice read! Glad someone had looked into this.
Distribution of glacial ice masses could have been a cause of the Han IQ being higher than that of the Germanic nations. At the last glacial maximum, northern Europe was ice-bound, and the European peri-glacial tundra was at much lower latitudes than was the most northerly tundra in largely ice-free eastern Siberia, i.e., in the Upper Paleolithic Han populations probably had to function in colder climates than did Western Hunter Gatherer populations.
https://www.nature.com/articles/s41467-019-11601-2/figures/1
The Templer p-values seem elevated to the extent that similar populations (for example, Baltic bordering and West African) are sampled via small, highly-divided political units that raise N, rather than by a biologically meaningful scheme that can be applied to all temperature regimes equally. Easy data is sloppy data.
Would be easy to rerun with spatial autocorrelation/geography controls, which should be done.
So there seems to be a Goldilocks zone for evolution of intelligence in humans? (pun intended).
Emil you are correct in surmising that there are countervailing factors. One fairly obvious one might be a sharp reduction in selection pressure within established agricultural communities - we know that adequate food produces a sharp reduction in mortality.
Then cultural or societal factors must be invoked. For example, the Greek city-states were notoriously combative and only became unified in the face of a greater threat.
And we know that culturally they valued intelligence - I refer to Odysseus.
After becoming more intelligent wouldn't the groups start moving more south for an easier life?
"But historically, it seems the most clever people lived in warmer climate, as judged by their ability to invent agriculture (Mesopotamia, India etc.) and, well, Western civilization (in Greece and Rome, not in Scandinavia!)."
Crop production means grain-based food, which makes larger populations possible. This in itself increases the occurrence of mutations that affect the intellect. However, mycotoxins in cereals, in particular aflatoxin (the most potent naturally occurring genotoxin), increase this effect by orders of magnitude due to extra mutations. It would be worthwhile to address this effect...
In addition, aflatoxin-producing aspergilli can produce three times more toxins on rice starch than on maize or wheat starch. This is an interesting coincidence with the higher average IQ in East Asia.
I don't think the logic that suggests not migrating in winter should select for bigger brains is sound. Bigger rains aren't strictly better, they have an energy cost, to say cold climates favour big brains more than warm ones it needs to be the case that cold climates offer enough payoff for higher intelligence to offset the extra energy cost. Which isn't obviously true, maybe there's not actually anything you can use extra intelligence for and it's just a waste of energy. There's no reason to assume the point where the gains from extra intelligence balance the costs is higher in cold environments just because they're harsher.
Anyway, we'll be able to deduce IQ directly from the genome fairly soon, so we can just test archaeological remains and know for certain when intelligence increased for different populations. My hunch is we'll find it was within the last few centuries in most places, as is the case for the Ashkenazim.
Yes, defitinitely. The main cause why it cold winter theory works in humans is because of clothes; we don't have fur and we are at threshold where more or less intelligence means no or winter clothes. Much less intelligence = nobody has clothes, no selection. Much more intelligence = everyone is smart enough to do, no selection.
Possibly, although Neanderthals survived very cold temperatures with a relative primitive material culture. It seems like clothes that are good enough are fairly low on the tech tree.
Neanderthals actually tended to inhabit the more temperate regions at the time as far as I know, you see some of the biggest sites in places like Spain which were essentially African Savannah at the time
There were Neanderthals in places like Spain and the Middle East, which would have been pretty warm during glacial minimums.
But there were also Neanderthals in the Siberian tundra during glacial maximums. We find Neanderthal sites where the animal remains (from hunting) are 90%+ reindeer.
Surviving in the tundra during Ice Age takes more intelligence than surviving in the tropics. Keeping warm, finding food (no fruit or easy prey, just large animals in thick snow), storing food over the winter, taking care of babies and children, sexual selection for mates based on these abilities, etc. The environment in the cold is more predictable and harsh, while the tropics are unpredictable but favorable.
Won't intelligence be less useful in predictable environments, since you'll always know what to do? Seems like unpredictability would more favour foresight.
If resources are abundant typically that leads to overpopulation and war. Maybe war favours intelligence more than keeping warm or storing food does.
I really don't think it's obvious which environments favour intelligence more a priori. You can't just assume it's the harsh ones.
Predictable and harsh selects for intelligence more than unpredictable/random and pleasant since it allows intelligent people to predict and ameliorate their conditions. Unpredictability in the tropics cannot be selected for since intelligence in hunter-gatherers and agriculturalists cannot do anything about sudden, random infectious disease/parasite/STD outbreaks, floods, droughts, animal migrations, extinctions, etc. Also, the article showed you that there is evidence for cold winters theory from bird studies, among others. I do find it obviously plausible that living in Ice Age Europe is more difficult than living in the tropics. That's why tropics have more biodiversity. It can support more organisms. It's why people want to vacation in the tropics or subtropics instead of Europe or Siberia during the winter. It's why we have commonly used terms like "tropical paradise". I don't think there is an equivalent like "arctic paradise". Even humans adapted and evolved for the cold are virtually always more comfortable in warmer climates even today with all the technology. They don't need as much food since the temperature is higher (metabolic rate might be an an additional factor here since cold environments require animals to have a higher resting metabolic rate which can be used to synthesize more brain matter).Winter in Northern Europe is unpleasant psychologically and physically even today with central heating. i can't imagine how horrible it was for my heroic ancestors for tens of thousands of years to survive in the wilderness of Ice Age Europe.
Just to add a tidbit; how many people adapted to living in a cold climate live out their retirement in the north versus the south? Thailand is more popular than Scandinavia even today. If you proposed to my ancestors a deal where their families and villages/towns would be transported to an uninhabited and protected settlement in Thailand, I think they would be persuaded. It is an interesting thought experiment. If you asked the Finns whether they'd be willing to move en masse their whole populations to an alternative universe where Finland is an uninhabited tropical island, would they consider it a good idea. Would they envy the Finns in an alternative universe with the same genetics living on a Mediterranean island? It's an interesting experiment. It would be interesting to ask of people what their ideal climate and biogeography would look like. What would their heaven on Earth, so to speak, look like? What would their ideal location look like? Would it be a tropical or subtropical paradise? If they couldn't choose central heating, they might. On the other hand, with no air conditioning, some Northern people might prefer the cold to which they have habituated. I think I prefer a Mediterranean/Southern European climate; not too cold, not too hot, just right. Would people's instincts with respect to which environment is most optimal for survival without modern technology align with the cold winters theory? We could survey people across different latitudes. Would they prefer themselves/their children/their parents to have been born in a warmer climate, all else being equal? What country/area is ideal for human survival and flourishing sans modern technology? I would imagine something like coastal South-East Asia.
Critique this? https://emilkirkegaard.dk/en/wp-content/uploads/Only-in-America-Cold-Winters-Theory-race-IQ-and-well-being-Pesta-2014.pdf
You can simulate changing temperature in hangar just with automatons which give more or less food/water.
Is it possible to to test correlatoin IQ vs (summer temp minus winter temp)? or IQ vs. T1-T2*K and see which K gets best correlation.
The Australian Abos and Kalahari people are only recently live in deserts after their kin was displaced from more comfy environments, like you point what happened with Amerindians.
The fig 1 is probably more about nearly identical plant/insect species than only handful of specialists in entire world can tell apart of. For large mammals than humans domesticate, the picture would look somewhat different.
Ashkenazi Jews were extremely small population in the middle ages, and still they developed high IQ.
They could borrow good mutations from nearby populations