I use weasel words like "seem" because I've had to change my mind on certain things in the past and will probably do so in the future.
I'm pretty sure that Western cognitive evolution slowed down during the late 19th century and peaked around the First World War. That's the pattern we're seeing in genetic data from Iceland, the UK, and the US. It's also a pattern that others have noticed in soft cultural data, although they usually blame it on the carnage of WW1.
The First World War gets blamed for a lot of changes that would have happened anyway or were already under way when it broke out. Undoubtedly, this war removed many obstacles to change, thus speeding up social, demographic, and even genetic evolution in many areas of life.
I estimate that Western cognitive ability peaked in the late 1800s and had been declining thereafter. As new contraception technologies were developed and commercially distributed in the 1800s, the upper social classes were more able to afford them than the lower classes. The end result is that the lower classes had comparatively higher fertility rates than the upper classes. https://zerocontradictions.net/faqs/overpopulation#contraception-1800s
Most historical evidence points to behavioral methods—especially withdrawal (coitus interruptus) and delayed or reduced sexual frequency—being the primary drivers of the fertility decline in the late 19th and early 20th centuries, with modern contraceptive technologies playing only a minor role until much later. See: https://www.jstor.org/stable/j.ctvxrpxqd.8
Contraception was, in fact, criminalized in many Western countries during the late 19th century. In Canada, it was not decriminalized until 1969. In the US, it was decriminalized through Supreme Court rulings between 1965 and 1972.
In the UK, it was never criminalized but access was restricted by social norms and medical gatekeeping. This was also true for Canada and the US during the 1970s. It really wasn't until the 1980s that you could buy a condom at any drugstore.
Just because something is illegal, that doesn't mean that people don't do it.
As a great example, consider how the Catholic Church has a strong and longstanding opposition to contraception. Even though the Church doesn't sanction birth control, a majority of Catholics use birth control these days: https://en.wikipedia.org/wiki/Christian_views_on_birth_control#Dissent.
The same thing goes for birth control during the 1800s. Contraception might've technically been illegal in Western countries. However, by the end of the century, about half of the population still used it (in privacy and secrecy, obviously).
This is an interesting view, but if it’s about capitalism or the Black Death or the Church or what have you, then wouldn’t it be reasonable to expect the countries on the European periphery to be less inclined towards reason…?
But if you take Portugal, Ireland, Scotland, Norway, Finland, Estonia, and look at their PISA results they seem to be doing OK.
In your discussion of the modern (post-1850) era, I think there's a particularly important comment: "Reproductive success was thus severed from socioeconomic success." This theme has been explored before, of course, but looking at it through the lens of cognitive evolution, and in particular, the drift of the genes of the elites downwards through the class system, is highly informative, I find.
As you pointed out, we have yet another way in which modern times resemble the Roman Empire (arguably in decline since its inception), but perhaps the modern phenomenon is even more severe. From what I understand, reproductive (fertility) rates are very low among all classes of all native populations of Europe, but they are particularly low among the upper classes – for various socioeconomic reasons, perhaps, though I would propose above all cultural ones. Thus percolation of genes downwards from the elites can be presumed to have almost entirely ceased in this age. Which may even be a good thing in certain ways, though evidently not in terms of IQ! I do wonder if the breakdown of firm cultural obstacles to cross-class partnerships, combined with the rampant female hypergamy that now obtains, has only assisted this collapse and accelerated the reverse effect – of the genes of the lower classes diffusing upwards. Not that status is as heritable between generations as it used to be (from what I can surmise).
Re the historical argument, I feel the need to make a surprising claim, based on my knowledge of European history and above all my genealogical studies in several European nations. To wit, that aristocratic surnames are by no means overrepresented in the general population of England compared to other western or central European countries. In fact, I would argue the very opposite appears to be case. This would on the surface suggest less downward class mobility in England since the Middle Ages, though it is of course merely based on a rough impression from my experience. (I was not able to find any formal studies on this subject that permit serious international comparisons, although there is some good work by Gregory Clark in the English context.) It's probably worth noting however that England's population has grown by a larger factor than any other major Western European nation since 1350, and it would be surprising if a large proportion of that came from the aristocracy.
One of the explanations in the Discussion section of this essay doesn't make sense.
We agree that the Black Death made it easier for middle-class men and women to have more children. When labor became more scarce, the middle-class people thus got higher wages. The elimination of a large fraction of the population also would've created new niches to fill with people. So it makes sense that the black death improved life for the middle class that survived.
However, it doesn't make sense that having more children would provide a family business with cheaper labor. If anything, labor would've been cheaper before the Black Death when the population (and labor pool) was larger. Even if the parents of family businesses couldn't have as many children, there was still a large pool of cheap labor. They easily could've hired many different people for cheap rates.
Another problem with that hypothesis (i.e. more children implies cheaper labor for family businesses) is that it costs money and energy to raise children. Parents couldn't raise children for free in those days, as welfare didn't exist. Even if the children did some labor for the parents, it wouldn't be enough to cover the labor and costs that the parents spent on raising the children to adulthood. The children also probably wouldn't be working for their parents forever. Once they get old enough to get married and have children, they would be working for themselves instead.
As to how the Black Death enabled cognitive ability to rise in Europe, it's better to stick with emphasizing the transition from feudalism to a market economy, as well as the replacement of the lower class by the middle class.
Aside from that one disagreement, I otherwise enjoyed reading the article.
During feudal times, there were relatively few workers available for hire. Most of the labor force was locked up in feudal estates. They were "bound" to the land and, in fact, referred to as "bondsmen." This was true to a lesser extent in the towns and cities, where a large part of the population was bound as servants to the nobility.
Yes, free labor did exist, but they were relatively small in number and often stigmatized as vagrants of little worth. This is why merchants preferred to employ family members — they were trustworthy and loyal as fellow family members. They were also good human capital because they inherited the aptitudes of their parents.
The rise of a true labor market came later in time, essentially the 1700s and 1800s with the mass movement of people off the land and into the new industrial towns.
You talk about the high costs of raising children at a time when welfare didn't exist. That's a very modern perspective. I put this question to my AI assistant and got this reply:
* For most of history, childhood was not viewed as a protected, non‑working stage of life. Families expected children to contribute through farm work, domestic labor, craft production, or wage labor. Their work helped support not only themselves but also younger siblings and sometimes widowed or single parents.
* Did children “pay for themselves”? In many cases, yes, but with important caveats:
- Direct economic contribution: Children’s labor often produced immediate income or reduced household expenses (e.g., tending animals, gathering fuel, caring for siblings).
- Low opportunity cost of schooling: Because formal education was limited or costly, families often saw greater value in children working.
- But not fully cost‑neutral. Young children consumed more than they produced. Net positive contribution typically came in later childhood or adolescence.
Yes, being bound to the land was definitely a major barrier to modernizing civilization, economy, and cognitive ability.
We agree that those are all good reasons to employ family members as human capital. What we don't agree on is that family businesses hiring their children is a source of cheap labor. I think the more appropriate term to use here would be "high-quality" labor. All the reasons that you listed suggest that merchants hired family members because they had good qualities, not because they were cheap to hire.
To be clear, I'm not suggesting that children didn't work during childhood for most of human history. What I'm saying is that it doesn't make economic sense for parents to have children just to make their children work for them. Children are not slaves.
Unfortunately, I can't read your entire comment for some reason, no matter what I do or how the page loads, so I have nothing more to say.
The nascent middle class (merchants, self-employed artisans, independent farmers) preferred family labor to hired labor for three reasons:
- their children were more reliable and trustworthy than hired labor
- they were better human capital (being inculcated with middle-class values and possessing the aptitudes of their parents)
- they were cheaper.
We disagree on the last point. Hired labor was expensive and unreliable. This was when the labor market was much smaller, with most of the working population being locked up in feudal or semi-feudal relationships.
Many economists and historians emphasize the labor value of children during this period, particularly with the rise of proto-industrial production (i.e., cottage industry, Verlagssystem):
"Proto-industrialization raised the potential value of children to their parents' households. It was therefore a rational strategy (if not necessarily a conscious one) to get on with childbearing, entering the most draining phase of the family cycle while the couple were still in their prime. The eldest children would then be in a position to begin making a substantial contribution to the family economy as the productivity of their elders went into decline. Except in times of economic depression, adults endeavoured to keep their offspring at home, working from an early age as members of the family labour team."
It is cheaper for parents to hire their children, but that's only if they already have children to hire. What I'm saying is that if you weigh out all the costs that parents had to put into raising children vs what they gain from having their children work for them, having children would still be a net cost to their living expenses.
Overall, it would cheaper to have no children at all and to hire other adults to do the labor instead. However, that would also be maladaptive, and the labor would be of lower quality.
What’s interest about this is that the timeline is unsatisfying.
When people say “Europe was a backwater” you can say “yes, their genetic superiority is recent”.
Then when people say “well if genes can change it’s all environment”. Then you say “sure, I need 1000 years of dead starving poor children and executed criminals and we’ll fix black peoples genes.”
People assume that evolution ended back in the Pleistocene, even people who are open to the idea that genes are responsible for differences in mind and behavior. So they focus on differences between men and women. Or between children and adults.
This is the case with evolutionary psychologists. "Behavioral evolution must be slow because it takes many, many generations to create an entirely new behavior with a substantial genetic component."
Well, Ok. But who said the behavior has to be new? Why can't an old behavior be adjusted or altered?
The same with cognitive ability. The genetic variability is already there. Just increase the prevalence of certain alleles and decrease the prevalence of others. And if a population lacks certain alleles, it can "poach" them from another population through gene flow. None of this takes eons of evolutionary time.
Feudalism in England took a knock after The Great Fire of London, 1666, when London sucked in craftsmen from across the country, accompanied by increased pay. Before that date, craft qualifications were awarded and recognised on a city/town basis, which kept the population tied to where they were born.
The Chinese have been consciously creating a middle class for at least 2,000 years–and it shows. Indeed, the current dynasty wants everyone to be middle class with a Gini coefficient like Finland and Norway, by 2049.
I wouldn't say the Chinese "consciously" created a middle class. A merchant was always considered to be inferior to a landowner (as in Europe). Perhaps you could provide a source for your comment.
"At the height of the Middle Ages, most Western Europeans were still trapped in ways of thinking that discouraged the use of reason."
Are you going to argue that things have changed much? LOL. In light of the current actions of 'elected' European 'leaders', that may be a hard sell.
It appears that the West is undergoing another pause, or worse, a decline in capacity for reason.
Thanks for an interesting article.
Things did change a lot, but only until the late 19th century. We now seem to be in a period of cognitive decline.
"We now seem to be in a period of cognitive decline."
I would say 'seem to be' is understated—I would say demonstrable.
I use weasel words like "seem" because I've had to change my mind on certain things in the past and will probably do so in the future.
I'm pretty sure that Western cognitive evolution slowed down during the late 19th century and peaked around the First World War. That's the pattern we're seeing in genetic data from Iceland, the UK, and the US. It's also a pattern that others have noticed in soft cultural data, although they usually blame it on the carnage of WW1.
The First World War gets blamed for a lot of changes that would have happened anyway or were already under way when it broke out. Undoubtedly, this war removed many obstacles to change, thus speeding up social, demographic, and even genetic evolution in many areas of life.
I estimate that Western cognitive ability peaked in the late 1800s and had been declining thereafter. As new contraception technologies were developed and commercially distributed in the 1800s, the upper social classes were more able to afford them than the lower classes. The end result is that the lower classes had comparatively higher fertility rates than the upper classes. https://zerocontradictions.net/faqs/overpopulation#contraception-1800s
Most historical evidence points to behavioral methods—especially withdrawal (coitus interruptus) and delayed or reduced sexual frequency—being the primary drivers of the fertility decline in the late 19th and early 20th centuries, with modern contraceptive technologies playing only a minor role until much later. See: https://www.jstor.org/stable/j.ctvxrpxqd.8
Contraception was, in fact, criminalized in many Western countries during the late 19th century. In Canada, it was not decriminalized until 1969. In the US, it was decriminalized through Supreme Court rulings between 1965 and 1972.
In the UK, it was never criminalized but access was restricted by social norms and medical gatekeeping. This was also true for Canada and the US during the 1970s. It really wasn't until the 1980s that you could buy a condom at any drugstore.
Contraception was criminalized during the late 1800s, but that didn't stop people from using it. To the contrary, behavioral methods were not the primary method of contraception in the late 1800s and early 1900s, nor were they the cause of fertility decline. https://en.wikipedia.org/wiki/Birth_control_in_the_United_States#Birth_control_before_20th_century
As an aside, I recommend to stop counting centuries: https://dynomight.substack.com/p/centuries.
Just because something is illegal, that doesn't mean that people don't do it.
As a great example, consider how the Catholic Church has a strong and longstanding opposition to contraception. Even though the Church doesn't sanction birth control, a majority of Catholics use birth control these days: https://en.wikipedia.org/wiki/Christian_views_on_birth_control#Dissent.
The same thing goes for birth control during the 1800s. Contraception might've technically been illegal in Western countries. However, by the end of the century, about half of the population still used it (in privacy and secrecy, obviously).
"I'm pretty sure that Western cognitive evolution slowed down during the late 19th century and peaked around the First World War."
That is certainly reflected in science, especially in theoretical physics. Little progress has been made since the mid-1930s.
See my comment above. I agree, and the scientific progress that has occurred has been more dependent on shared group knowledge.
Powerful article
China's civilization has been rational/skeptical for 2000-3000 years. Their scientific legacy in that time is unparalleled.
Not over the past 500 years.
This is an interesting view, but if it’s about capitalism or the Black Death or the Church or what have you, then wouldn’t it be reasonable to expect the countries on the European periphery to be less inclined towards reason…?
But if you take Portugal, Ireland, Scotland, Norway, Finland, Estonia, and look at their PISA results they seem to be doing OK.
Hopefully, we will soon have polygenic data from those countries.
If we look at mean IQ, we see that the highest scores are in western and northern Europe, particularly Protestant Europe. These were the countries that went the furthest in internalizing the capitalist ethic. See Max Weber https://en.wikipedia.org/wiki/The_Protestant_Ethic_and_the_Spirit_of_Capitalism
I did a quick search for a map of mean IQ by country. This is what I found:
https://www.reddit.com/r/MapPorn/comments/ijh2ho/iq_map_of_europe/
Very interesting piece.
In your discussion of the modern (post-1850) era, I think there's a particularly important comment: "Reproductive success was thus severed from socioeconomic success." This theme has been explored before, of course, but looking at it through the lens of cognitive evolution, and in particular, the drift of the genes of the elites downwards through the class system, is highly informative, I find.
As you pointed out, we have yet another way in which modern times resemble the Roman Empire (arguably in decline since its inception), but perhaps the modern phenomenon is even more severe. From what I understand, reproductive (fertility) rates are very low among all classes of all native populations of Europe, but they are particularly low among the upper classes – for various socioeconomic reasons, perhaps, though I would propose above all cultural ones. Thus percolation of genes downwards from the elites can be presumed to have almost entirely ceased in this age. Which may even be a good thing in certain ways, though evidently not in terms of IQ! I do wonder if the breakdown of firm cultural obstacles to cross-class partnerships, combined with the rampant female hypergamy that now obtains, has only assisted this collapse and accelerated the reverse effect – of the genes of the lower classes diffusing upwards. Not that status is as heritable between generations as it used to be (from what I can surmise).
Re the historical argument, I feel the need to make a surprising claim, based on my knowledge of European history and above all my genealogical studies in several European nations. To wit, that aristocratic surnames are by no means overrepresented in the general population of England compared to other western or central European countries. In fact, I would argue the very opposite appears to be case. This would on the surface suggest less downward class mobility in England since the Middle Ages, though it is of course merely based on a rough impression from my experience. (I was not able to find any formal studies on this subject that permit serious international comparisons, although there is some good work by Gregory Clark in the English context.) It's probably worth noting however that England's population has grown by a larger factor than any other major Western European nation since 1350, and it would be surprising if a large proportion of that came from the aristocracy.
One of the explanations in the Discussion section of this essay doesn't make sense.
We agree that the Black Death made it easier for middle-class men and women to have more children. When labor became more scarce, the middle-class people thus got higher wages. The elimination of a large fraction of the population also would've created new niches to fill with people. So it makes sense that the black death improved life for the middle class that survived.
However, it doesn't make sense that having more children would provide a family business with cheaper labor. If anything, labor would've been cheaper before the Black Death when the population (and labor pool) was larger. Even if the parents of family businesses couldn't have as many children, there was still a large pool of cheap labor. They easily could've hired many different people for cheap rates.
Another problem with that hypothesis (i.e. more children implies cheaper labor for family businesses) is that it costs money and energy to raise children. Parents couldn't raise children for free in those days, as welfare didn't exist. Even if the children did some labor for the parents, it wouldn't be enough to cover the labor and costs that the parents spent on raising the children to adulthood. The children also probably wouldn't be working for their parents forever. Once they get old enough to get married and have children, they would be working for themselves instead.
As to how the Black Death enabled cognitive ability to rise in Europe, it's better to stick with emphasizing the transition from feudalism to a market economy, as well as the replacement of the lower class by the middle class.
Aside from that one disagreement, I otherwise enjoyed reading the article.
During feudal times, there were relatively few workers available for hire. Most of the labor force was locked up in feudal estates. They were "bound" to the land and, in fact, referred to as "bondsmen." This was true to a lesser extent in the towns and cities, where a large part of the population was bound as servants to the nobility.
Yes, free labor did exist, but they were relatively small in number and often stigmatized as vagrants of little worth. This is why merchants preferred to employ family members — they were trustworthy and loyal as fellow family members. They were also good human capital because they inherited the aptitudes of their parents.
The rise of a true labor market came later in time, essentially the 1700s and 1800s with the mass movement of people off the land and into the new industrial towns.
You talk about the high costs of raising children at a time when welfare didn't exist. That's a very modern perspective. I put this question to my AI assistant and got this reply:
* For most of history, childhood was not viewed as a protected, non‑working stage of life. Families expected children to contribute through farm work, domestic labor, craft production, or wage labor. Their work helped support not only themselves but also younger siblings and sometimes widowed or single parents.
* Did children “pay for themselves”? In many cases, yes, but with important caveats:
- Direct economic contribution: Children’s labor often produced immediate income or reduced household expenses (e.g., tending animals, gathering fuel, caring for siblings).
- Low opportunity cost of schooling: Because formal education was limited or costly, families often saw greater value in children working.
- But not fully cost‑neutral. Young children consumed more than they produced. Net positive contribution typically came in later childhood or adolescence.
Yes, being bound to the land was definitely a major barrier to modernizing civilization, economy, and cognitive ability.
We agree that those are all good reasons to employ family members as human capital. What we don't agree on is that family businesses hiring their children is a source of cheap labor. I think the more appropriate term to use here would be "high-quality" labor. All the reasons that you listed suggest that merchants hired family members because they had good qualities, not because they were cheap to hire.
To be clear, I'm not suggesting that children didn't work during childhood for most of human history. What I'm saying is that it doesn't make economic sense for parents to have children just to make their children work for them. Children are not slaves.
Unfortunately, I can't read your entire comment for some reason, no matter what I do or how the page loads, so I have nothing more to say.
The nascent middle class (merchants, self-employed artisans, independent farmers) preferred family labor to hired labor for three reasons:
- their children were more reliable and trustworthy than hired labor
- they were better human capital (being inculcated with middle-class values and possessing the aptitudes of their parents)
- they were cheaper.
We disagree on the last point. Hired labor was expensive and unreliable. This was when the labor market was much smaller, with most of the working population being locked up in feudal or semi-feudal relationships.
Many economists and historians emphasize the labor value of children during this period, particularly with the rise of proto-industrial production (i.e., cottage industry, Verlagssystem):
"Proto-industrialization raised the potential value of children to their parents' households. It was therefore a rational strategy (if not necessarily a conscious one) to get on with childbearing, entering the most draining phase of the family cycle while the couple were still in their prime. The eldest children would then be in a position to begin making a substantial contribution to the family economy as the productivity of their elders went into decline. Except in times of economic depression, adults endeavoured to keep their offspring at home, working from an early age as members of the family labour team."
Seccombe, W. (1992). A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe. London: Verso. https://archive.org/details/millenniumoffami0000secc/page/n3/mode/2up
It is cheaper for parents to hire their children, but that's only if they already have children to hire. What I'm saying is that if you weigh out all the costs that parents had to put into raising children vs what they gain from having their children work for them, having children would still be a net cost to their living expenses.
Overall, it would cheaper to have no children at all and to hire other adults to do the labor instead. However, that would also be maladaptive, and the labor would be of lower quality.
What’s interest about this is that the timeline is unsatisfying.
When people say “Europe was a backwater” you can say “yes, their genetic superiority is recent”.
Then when people say “well if genes can change it’s all environment”. Then you say “sure, I need 1000 years of dead starving poor children and executed criminals and we’ll fix black peoples genes.”
People assume that evolution ended back in the Pleistocene, even people who are open to the idea that genes are responsible for differences in mind and behavior. So they focus on differences between men and women. Or between children and adults.
This is the case with evolutionary psychologists. "Behavioral evolution must be slow because it takes many, many generations to create an entirely new behavior with a substantial genetic component."
Well, Ok. But who said the behavior has to be new? Why can't an old behavior be adjusted or altered?
The same with cognitive ability. The genetic variability is already there. Just increase the prevalence of certain alleles and decrease the prevalence of others. And if a population lacks certain alleles, it can "poach" them from another population through gene flow. None of this takes eons of evolutionary time.
Period of rise and IQ clearly tracks with the lifespan of the holy Roman empire from 800 to 1800
The Holy Roman Empire was in decline during its last few centuries.
Feudalism in England took a knock after The Great Fire of London, 1666, when London sucked in craftsmen from across the country, accompanied by increased pay. Before that date, craft qualifications were awarded and recognised on a city/town basis, which kept the population tied to where they were born.
The Chinese have been consciously creating a middle class for at least 2,000 years–and it shows. Indeed, the current dynasty wants everyone to be middle class with a Gini coefficient like Finland and Norway, by 2049.
East Asia has followed a similar trajectory of cognitive evolution. See my review of Davide Piffer's study.
https://www.aporiamagazine.com/p/cognitive-evolution-in-eastern-eurasia
I wouldn't say the Chinese "consciously" created a middle class. A merchant was always considered to be inferior to a landowner (as in Europe). Perhaps you could provide a source for your comment.