I've long been skeptical of common explanations for East Asian personality traits, mainly because populations that have had only limited sedentary agricultural history and little Confucianism influence etc. still seem to share these traits.
I did my anthropology MA studying minorities in West China and thought about this a lot.
Tibetans, the Yi, the Hmong/Miao etc. have shared very few of the ethnoreligious, cultural or agricultural traditions, or evolutionary pressures of Han Chinese over the last few millenia, but many of the traits you mention in the article are common to all of these groups, especially when compared to other global major population groups. So I definitely agree that there's some preagriculture explanation
As for the Arcticist explanation, I'm not 100% convinced yet- I feel I'd need to understand why other early stages of East Asian evolutionary history were unlikely to produce these traits, but it seems very plausible and I love the way you've done it.
That’s quite interesting, there is very little psych data on Tibetans, Yi, Hmong, that I know of, I appreciate your perspective on them.
If you read the paper, I mention in my TEE model framework that ancestral environments like LGM Ice Age Siberia which deviates markedly from the “normal” temperate/subtropical environments that preOoA humans lived in (which was also what most of the pre-LGM east Eurasians lived in), leave substantial differentiating biological, genetic, and I propose Arcticist psychological traits on their descendants.
I’d love to hear more in detail of your experiences with them. How closely or differently did they resemble other East Asians in personality and other characteristics?
I spent the best part of a year with Hmong/Miao people in China and Southeast Asia, but I didn't do any careful personality analysis.
The Hmong/Miao are often seen by the Han as a bit savage and "simple" - in their traditions, the "Chinese man" is usually a trickster. They're more "genuine" than the Han and have very strong honesty norms (perhaps the biggest difference). They practice shamanism (which is very Arctic/Siberian, of course), and are generally a bit more spiritual. They are incredibly good at hunting and war (visio-spatial skills, perhaps).
Like Han Chinese, they're relatively insular and intraverted - eye contact is not common. They might dance and sing a bit more, but don't have a strong culture of spontenaiety. They have strong in-group harmony (significantly stronger than Han Chinese), with complex clan identities. They care a lot about their own and their clan's reputation. They're famous for incredible endurance and perserverance, as their 20th century war history shows. Despite being more honest, they are not generally direct, and avoid social confrontation.
Tibetans and Yi people are more clearly different from the Han- the men are a bit more confident-more of a swagger and a warrior vibe (I've been directly threatened by Yi and Tibetan men in only a few weeks in the regions, but never by Hmong men). They are more artistic and individualistic than Han or Hmong people. But I think you have a similar cluster of overall pyschological and social traits that you don't get in Southeast Asians or Turkic people, for example.
This is amazing. I am 50%~ Northern Peruvian, 10%~ Chinese, 35%~ Southern European and 5%~ West African.
I can say this: I do not know anger. I do not even try to restrain myself. Anger is not known to me. I was raised among Western Europeans (think French descendants) in the province of Quebec in Canada.
I was asked to talk more, I was told I do not talk enough. Yet, I was happy. This is interesting. Please, may the Peruvian lady inspire you to write more about Peruvians :)
Ah yes, my father is one with Chinese ancestry and more Peruvian and my mom is the one with African and more European. (They both have European and Peruvian).
My father never gets angry or rather expresses it. I saw him make an angry face only once in my life. My mother is more bubbly, she is known for that.
Is Asian behavior shaped by Confucianism or is Confucianism shaped by Asian behavior? Maybe a bit of both! Good article btw.
For an interesting alternative (and non-scholarly) read on Confucianism and its impact on Asian people's psyche and behavior, you should check out "The Confucian Mind" by Daniel Wang. I thought this to be the most unvarnished and honest look at the family dynamic created by Confucian ideology. But maybe it's genetic? I definitely see recurring patterns of behavior of Asian parenting across all generations, whether raise in the West or the East, in Confucian or non-Confucian households.
There's also an interesting study of racial differences in reactivity of infants. The experiment was to put a napkin on the infant's faces and see how quickly they reacted. Black infants showed the most reactivity, white intermediate, and Asian infants showed the least. That says a lot about inherent tendencies
btw, I extremely doubt Asians and Europeans came "out of Africa" (as in all races descending from a recent common African ancestor), and so the actual origins of the races is an even greater mystery, which is an offshoot of the question of behavior differences rooted in their genetics
Excellent article! I really enjoyed it. Your insights are spot on, and the way you’ve presented everything is engaging and thoughtful. It’s clear you put a lot of work into it, and it shows.
That said, we shouldn’t forget that for modern White Europeans, especially Northern Europeans, the largest portion of their ancestry comes from the prehistoric Proto-Indo-Europeans. These people themselves descended from Mesolithic Eastern European hunter-gatherers, who were in turn descended from Ancient North Eurasians who lived in Ice Age Siberia. Scandinavians and other northern Europeans likely have additional EHG and ANE ancestry from the Scandinavian Hunter-Gatherers (SHG), a group that was a mix of both Western and Eastern European hunter-gatherers.
Genetic studies show that the Ancient North Eurasians were more closely related to modern Europeans than to modern East Asians. It’s even believed that the gene for classic European blond hair likely comes from them.
When we look at White European culture, so many timeless elements can be traced back to the Proto-Indo-Europeans. From our languages to our classic literature - from the Iliad and Beowulf to Shakespeare and Racine, from Goethe’s Faust to the legends of King Arthur - Indo-European roots are everywhere. We can even see it in the tripartite social structures that lasted until the French Revolution.
Some scholars, like Ricardo Duchesne in his excellent book The Uniqueness of Western Civilisation, even argue that the Faustian creative and dynamic spirit of Western civilisation can be traced back to the Proto-Indo-Europeans.
Given all of this, I’m curious. Where do the Proto-Indo-Europeans (and white Europeans in general) who have significant ancestry from the Ancient North Eurasians of Paleolithic Siberia, fit into your theory on Arcticism?
Ancient North Eurasian admixture in modern Europeans is about 20% max, and although they indeed inhabited Siberia as well, it's not clear if they were as cold selected to the same degree as Ancient Northern East Asians (East Asian Siberian ancestors).
Certain parts of the Ice Age were more or less intense for different populations, likely due to geographical boundaries. In my paper I wrote "Population geneticists note that despite ancestral East Asians and Europeans experiencing the same genetic bottleneck event, timed and proposed to be associated with the LGM, it was significantly more intense for East Asians, leading to greater differentiating genetic drift for East Asians than Europeans since OoA (Keinan et al., 2007). "
Also, other components of modern europeans, such as Caucasus Hunter Gatherers, were living in the refugium of the Caucasus mts during the Last Glacial Maximum, and Western European Hunter Gatherers were in warmer Iberia refugium. Eastern European Hunter Gatherers however, probably were cold selected in Siberia.
So Indo-Europeans, and white Europeans have some but less cold selected admixture compared to East Asians. Future studies that meticulously plot out the various paleoclimate and ecologies of the groups that formed Indo-europeans can clarify this in detail.
It's important to note that relatively recent migration into Northern Europe and Scandinavia also adds recent cold adaptation (it would predict modern N.Euros have more intense "Arcticist" traits compared to central and especially southern Euros).
This is excellent research, David. Really impressive. You clearly work hard and have a lot of talent as a researcher. I highly recommend you check out Dr. Edward Dutton’s work, especially on Finland, the personality of the Finnish people, and evolutionary psychology. You should consider getting in touch with him too. He also runs a popular YouTube channel. Just a heads-up, he’s not politically correct or woke at all, which makes his work refreshingly honest.
One (peripheral) remark, regarding "South American indigenous peoples": you know that there was a population, notably in the Amazonian basin, living there before the arrival of Amerindians? They were very distantly related to today's Andaman Islanders, but did not leave any genetic trace in modern populations of the region (as if something, er, happened to them after the Amerindians arrived). Anyway.
If your theory is true, there is one mystery: why the two populations (Amerindian and East Asian) didn't diverge more in the period after they were separated (14ky), given that they inhabited very different environments? Human evolution is known to produce significant changes in much shorter time periods...
Yes there were many waves of migration into Americas, the australasian ones may be from pre-LGM along the coast or via boat.
Great question, according to my TEE model, climates or events that severely deviate from our "normal" ancestral temperate/subtropical savannah environment, such as the Last Glacial Maximum which was a severe bottleneck event for Ancient Northern East Asians (who contributed ancestry to Amerindians), leave a stronger "mark" or retained adaptive psychological traits in their descendant populations, that persist even when controlling for modern environment (EA rice farmers don't generally psychologically resemble SEA or Indian rice farmers, and strongly resemble Inuit)
Wow. Reading this article was like an alternate history of myself.
I was in a history PhD program in the early 2010s and I came with a quixotic idea: discovering a new spirituality through computer technology. My idea was to look at shifts in information technology (pre-literate to literate, scroll to codex) and how they affected our souls, which was...received by the academic establishment with a measure of bemusement. I remember at one point proposing a computer filesystem based on the teachings of Thomas Aquinas.
I ended up dropping out because I found the politics stultifying, and it seemed like people only got to be truly creative at the end of their careers once they had established enough clout.
When I quit, I told myself that I would enter tech and become wealthy enough to pursue my own independent scholarship. I dreamed of doing exactly what you were doing; it sent chills down my spine when I read about how you grinded through 100 papers per month.
12 years later in my tech career and I've done alright, but I'm nowhere near wealthy enough to pursue that dream. Also, the dream itself faded. I'm not so sure if it was ever what it was meant to be. I was never brave enough to put my savings toward something like this (although I was brave enough to do that in creating my own startup).
Still, I'm happy for you that you went through with it. I have no particular opinion on your hypothesis, but I highly enjoyed reading about your process.
Are you glad that you followed through? What are you feeling these days?
You can just read and write papers and publish online these days, I think it’s actually more productive than formal academia in some ways. Tech x spirituality is a cool thesis, you could definitely pursue it as a free time scholarship. Something along the lines of does a permanent online record and constant online connection to others affect how we behave morally, or in atheists? Idk lol.
I’m glad I followed through but it feels more like I was forced by fate.
As a person with n.Am ancestry, I relate to this and find it well argued that these psychological characteristics were adaptive in the arctic. But why does your conjecture about heat stress impute only maladaptive psychological characteristics to people in hot places? It comes off as biased at best. Surely if there is an **adaptation** to heat stress it would be something like less neuroticism or a propensity to resolve conflict, perhaps mediated by a facet of extroversion. The things you posit are not just negative, but actually maladaptive.
The heat stress paper is not out yet, but there are some positives. Lower rates of depression, low anxiety, high emotional expressiveness (which could be charismatic), some evidence of higher self esteem etc. in the posts context it was briefly discussing longstanding sociocultural issues.
Your argument for Arcticism is about psychological adaptations to arctic conditions. But your conjecture about people from hot places leaned into the psychological impacts of heat stress itself, NOT adaptations to it. If impulsivity is a response to stress itself, then an adaptation to mitigate that would be something like mindfulness, tolerance, positive-affect, preparedness, or perceptivity. All of which are historically observed in S.Asian, African, and tropical descendants.
Instead of citing adaptations to cope with heat stress, you claimed that rather than adapt their personalities had "fit" the "effects" of heat-stress. This is the opposite of what you did with Arcticism.
I'm glad you've identified a few positive adaptations, but you fail to examine the inconsistency of your logic and approach.
Many people adapted to heat stress appear to have personalities well-adapted to deescalate conflicts (not just suppress them).
I can list many personalities traits more adaptive to heat stress.
You may not see them if you only look at "longstanding sociocultural issues" in societies deeply wounded by guns, germs, and poverty.
Have you sought evidence as you did with E. Asians from before agriculture and colonialism? Have you looked at successful people (descended from very hot places) living in comfortable communities with comfortable climates or climate control?
Your ideas are worth exploring, but your post betrays a lack of engagement with how to eliminate bias and look for evidence to falsify your hypothesis.
That's not wokeness. That is scientific methodology.
We all start from our limited experience, but consider what would falsify your hypothesis, apply the same logic consistently, and adjust your confidence to the quality of your evidence.
I did not claim their personalities had fit the effects of heat stress. If you reread it says the effects of heat stress appears to be a parsimonious fit for sociocultural problems in tropical regions- meaning that one single theoretical model (heat stress) was the most matched to their social issues. “Parsimonious fit” is about simplicity of a theory, and not that it “fits” personalities. There’s formal ways to test which is an adaptation vs byproduct of heat stress using long term personnel studies etc. You are inferring way too much from a brief paragraph of an unpublished paper.
It is also not merely about positives and negatives. Surely, every personality has both? And a trait can be positive in some aspects/contexts and negative in others. Rather, it is about unbiased examination of what is a psychological adaptation.
This is very cool.
I've long been skeptical of common explanations for East Asian personality traits, mainly because populations that have had only limited sedentary agricultural history and little Confucianism influence etc. still seem to share these traits.
I did my anthropology MA studying minorities in West China and thought about this a lot.
Tibetans, the Yi, the Hmong/Miao etc. have shared very few of the ethnoreligious, cultural or agricultural traditions, or evolutionary pressures of Han Chinese over the last few millenia, but many of the traits you mention in the article are common to all of these groups, especially when compared to other global major population groups. So I definitely agree that there's some preagriculture explanation
As for the Arcticist explanation, I'm not 100% convinced yet- I feel I'd need to understand why other early stages of East Asian evolutionary history were unlikely to produce these traits, but it seems very plausible and I love the way you've done it.
That’s quite interesting, there is very little psych data on Tibetans, Yi, Hmong, that I know of, I appreciate your perspective on them.
If you read the paper, I mention in my TEE model framework that ancestral environments like LGM Ice Age Siberia which deviates markedly from the “normal” temperate/subtropical environments that preOoA humans lived in (which was also what most of the pre-LGM east Eurasians lived in), leave substantial differentiating biological, genetic, and I propose Arcticist psychological traits on their descendants.
I’d love to hear more in detail of your experiences with them. How closely or differently did they resemble other East Asians in personality and other characteristics?
I spent the best part of a year with Hmong/Miao people in China and Southeast Asia, but I didn't do any careful personality analysis.
The Hmong/Miao are often seen by the Han as a bit savage and "simple" - in their traditions, the "Chinese man" is usually a trickster. They're more "genuine" than the Han and have very strong honesty norms (perhaps the biggest difference). They practice shamanism (which is very Arctic/Siberian, of course), and are generally a bit more spiritual. They are incredibly good at hunting and war (visio-spatial skills, perhaps).
Like Han Chinese, they're relatively insular and intraverted - eye contact is not common. They might dance and sing a bit more, but don't have a strong culture of spontenaiety. They have strong in-group harmony (significantly stronger than Han Chinese), with complex clan identities. They care a lot about their own and their clan's reputation. They're famous for incredible endurance and perserverance, as their 20th century war history shows. Despite being more honest, they are not generally direct, and avoid social confrontation.
Tibetans and Yi people are more clearly different from the Han- the men are a bit more confident-more of a swagger and a warrior vibe (I've been directly threatened by Yi and Tibetan men in only a few weeks in the regions, but never by Hmong men). They are more artistic and individualistic than Han or Hmong people. But I think you have a similar cluster of overall pyschological and social traits that you don't get in Southeast Asians or Turkic people, for example.
This is amazing. I am 50%~ Northern Peruvian, 10%~ Chinese, 35%~ Southern European and 5%~ West African.
I can say this: I do not know anger. I do not even try to restrain myself. Anger is not known to me. I was raised among Western Europeans (think French descendants) in the province of Quebec in Canada.
I was asked to talk more, I was told I do not talk enough. Yet, I was happy. This is interesting. Please, may the Peruvian lady inspire you to write more about Peruvians :)
Very cool! Do you feel like there is a difference between the personalities of your Peruvian parent and your other parent?
Ah yes, my father is one with Chinese ancestry and more Peruvian and my mom is the one with African and more European. (They both have European and Peruvian).
My father never gets angry or rather expresses it. I saw him make an angry face only once in my life. My mother is more bubbly, she is known for that.
Is Asian behavior shaped by Confucianism or is Confucianism shaped by Asian behavior? Maybe a bit of both! Good article btw.
For an interesting alternative (and non-scholarly) read on Confucianism and its impact on Asian people's psyche and behavior, you should check out "The Confucian Mind" by Daniel Wang. I thought this to be the most unvarnished and honest look at the family dynamic created by Confucian ideology. But maybe it's genetic? I definitely see recurring patterns of behavior of Asian parenting across all generations, whether raise in the West or the East, in Confucian or non-Confucian households.
There's also an interesting study of racial differences in reactivity of infants. The experiment was to put a napkin on the infant's faces and see how quickly they reacted. Black infants showed the most reactivity, white intermediate, and Asian infants showed the least. That says a lot about inherent tendencies
btw, I extremely doubt Asians and Europeans came "out of Africa" (as in all races descending from a recent common African ancestor), and so the actual origins of the races is an even greater mystery, which is an offshoot of the question of behavior differences rooted in their genetics
Looking forward to more from you!
Excellent article! I really enjoyed it. Your insights are spot on, and the way you’ve presented everything is engaging and thoughtful. It’s clear you put a lot of work into it, and it shows.
That said, we shouldn’t forget that for modern White Europeans, especially Northern Europeans, the largest portion of their ancestry comes from the prehistoric Proto-Indo-Europeans. These people themselves descended from Mesolithic Eastern European hunter-gatherers, who were in turn descended from Ancient North Eurasians who lived in Ice Age Siberia. Scandinavians and other northern Europeans likely have additional EHG and ANE ancestry from the Scandinavian Hunter-Gatherers (SHG), a group that was a mix of both Western and Eastern European hunter-gatherers.
Genetic studies show that the Ancient North Eurasians were more closely related to modern Europeans than to modern East Asians. It’s even believed that the gene for classic European blond hair likely comes from them.
When we look at White European culture, so many timeless elements can be traced back to the Proto-Indo-Europeans. From our languages to our classic literature - from the Iliad and Beowulf to Shakespeare and Racine, from Goethe’s Faust to the legends of King Arthur - Indo-European roots are everywhere. We can even see it in the tripartite social structures that lasted until the French Revolution.
Some scholars, like Ricardo Duchesne in his excellent book The Uniqueness of Western Civilisation, even argue that the Faustian creative and dynamic spirit of Western civilisation can be traced back to the Proto-Indo-Europeans.
Given all of this, I’m curious. Where do the Proto-Indo-Europeans (and white Europeans in general) who have significant ancestry from the Ancient North Eurasians of Paleolithic Siberia, fit into your theory on Arcticism?
Ancient North Eurasian admixture in modern Europeans is about 20% max, and although they indeed inhabited Siberia as well, it's not clear if they were as cold selected to the same degree as Ancient Northern East Asians (East Asian Siberian ancestors).
Certain parts of the Ice Age were more or less intense for different populations, likely due to geographical boundaries. In my paper I wrote "Population geneticists note that despite ancestral East Asians and Europeans experiencing the same genetic bottleneck event, timed and proposed to be associated with the LGM, it was significantly more intense for East Asians, leading to greater differentiating genetic drift for East Asians than Europeans since OoA (Keinan et al., 2007). "
Also, other components of modern europeans, such as Caucasus Hunter Gatherers, were living in the refugium of the Caucasus mts during the Last Glacial Maximum, and Western European Hunter Gatherers were in warmer Iberia refugium. Eastern European Hunter Gatherers however, probably were cold selected in Siberia.
So Indo-Europeans, and white Europeans have some but less cold selected admixture compared to East Asians. Future studies that meticulously plot out the various paleoclimate and ecologies of the groups that formed Indo-europeans can clarify this in detail.
It's important to note that relatively recent migration into Northern Europe and Scandinavia also adds recent cold adaptation (it would predict modern N.Euros have more intense "Arcticist" traits compared to central and especially southern Euros).
This is excellent research, David. Really impressive. You clearly work hard and have a lot of talent as a researcher. I highly recommend you check out Dr. Edward Dutton’s work, especially on Finland, the personality of the Finnish people, and evolutionary psychology. You should consider getting in touch with him too. He also runs a popular YouTube channel. Just a heads-up, he’s not politically correct or woke at all, which makes his work refreshingly honest.
Thank you, and I appreciate the recommendation, I'll check out his work.
More power to you, I say!
One (peripheral) remark, regarding "South American indigenous peoples": you know that there was a population, notably in the Amazonian basin, living there before the arrival of Amerindians? They were very distantly related to today's Andaman Islanders, but did not leave any genetic trace in modern populations of the region (as if something, er, happened to them after the Amerindians arrived). Anyway.
If your theory is true, there is one mystery: why the two populations (Amerindian and East Asian) didn't diverge more in the period after they were separated (14ky), given that they inhabited very different environments? Human evolution is known to produce significant changes in much shorter time periods...
All the best in your future endeavors.
Yes there were many waves of migration into Americas, the australasian ones may be from pre-LGM along the coast or via boat.
Great question, according to my TEE model, climates or events that severely deviate from our "normal" ancestral temperate/subtropical savannah environment, such as the Last Glacial Maximum which was a severe bottleneck event for Ancient Northern East Asians (who contributed ancestry to Amerindians), leave a stronger "mark" or retained adaptive psychological traits in their descendant populations, that persist even when controlling for modern environment (EA rice farmers don't generally psychologically resemble SEA or Indian rice farmers, and strongly resemble Inuit)
Wow. Reading this article was like an alternate history of myself.
I was in a history PhD program in the early 2010s and I came with a quixotic idea: discovering a new spirituality through computer technology. My idea was to look at shifts in information technology (pre-literate to literate, scroll to codex) and how they affected our souls, which was...received by the academic establishment with a measure of bemusement. I remember at one point proposing a computer filesystem based on the teachings of Thomas Aquinas.
I ended up dropping out because I found the politics stultifying, and it seemed like people only got to be truly creative at the end of their careers once they had established enough clout.
When I quit, I told myself that I would enter tech and become wealthy enough to pursue my own independent scholarship. I dreamed of doing exactly what you were doing; it sent chills down my spine when I read about how you grinded through 100 papers per month.
12 years later in my tech career and I've done alright, but I'm nowhere near wealthy enough to pursue that dream. Also, the dream itself faded. I'm not so sure if it was ever what it was meant to be. I was never brave enough to put my savings toward something like this (although I was brave enough to do that in creating my own startup).
Still, I'm happy for you that you went through with it. I have no particular opinion on your hypothesis, but I highly enjoyed reading about your process.
Are you glad that you followed through? What are you feeling these days?
You can just read and write papers and publish online these days, I think it’s actually more productive than formal academia in some ways. Tech x spirituality is a cool thesis, you could definitely pursue it as a free time scholarship. Something along the lines of does a permanent online record and constant online connection to others affect how we behave morally, or in atheists? Idk lol.
I’m glad I followed through but it feels more like I was forced by fate.
As a person with n.Am ancestry, I relate to this and find it well argued that these psychological characteristics were adaptive in the arctic. But why does your conjecture about heat stress impute only maladaptive psychological characteristics to people in hot places? It comes off as biased at best. Surely if there is an **adaptation** to heat stress it would be something like less neuroticism or a propensity to resolve conflict, perhaps mediated by a facet of extroversion. The things you posit are not just negative, but actually maladaptive.
The heat stress paper is not out yet, but there are some positives. Lower rates of depression, low anxiety, high emotional expressiveness (which could be charismatic), some evidence of higher self esteem etc. in the posts context it was briefly discussing longstanding sociocultural issues.
Your argument for Arcticism is about psychological adaptations to arctic conditions. But your conjecture about people from hot places leaned into the psychological impacts of heat stress itself, NOT adaptations to it. If impulsivity is a response to stress itself, then an adaptation to mitigate that would be something like mindfulness, tolerance, positive-affect, preparedness, or perceptivity. All of which are historically observed in S.Asian, African, and tropical descendants.
Instead of citing adaptations to cope with heat stress, you claimed that rather than adapt their personalities had "fit" the "effects" of heat-stress. This is the opposite of what you did with Arcticism.
I'm glad you've identified a few positive adaptations, but you fail to examine the inconsistency of your logic and approach.
Many people adapted to heat stress appear to have personalities well-adapted to deescalate conflicts (not just suppress them).
I can list many personalities traits more adaptive to heat stress.
You may not see them if you only look at "longstanding sociocultural issues" in societies deeply wounded by guns, germs, and poverty.
Have you sought evidence as you did with E. Asians from before agriculture and colonialism? Have you looked at successful people (descended from very hot places) living in comfortable communities with comfortable climates or climate control?
Your ideas are worth exploring, but your post betrays a lack of engagement with how to eliminate bias and look for evidence to falsify your hypothesis.
That's not wokeness. That is scientific methodology.
We all start from our limited experience, but consider what would falsify your hypothesis, apply the same logic consistently, and adjust your confidence to the quality of your evidence.
I did not claim their personalities had fit the effects of heat stress. If you reread it says the effects of heat stress appears to be a parsimonious fit for sociocultural problems in tropical regions- meaning that one single theoretical model (heat stress) was the most matched to their social issues. “Parsimonious fit” is about simplicity of a theory, and not that it “fits” personalities. There’s formal ways to test which is an adaptation vs byproduct of heat stress using long term personnel studies etc. You are inferring way too much from a brief paragraph of an unpublished paper.
It is also not merely about positives and negatives. Surely, every personality has both? And a trait can be positive in some aspects/contexts and negative in others. Rather, it is about unbiased examination of what is a psychological adaptation.