So when polygenic scores are powerful enough to assess an individual's IQ thereby rendering IQ tests redundant, surely there can no longer be any debate about the role played by heritability in IQ? Will IQ tests then remain only in order to measure the cultural aspect of IQ?
There shouldn't be any debate now. For that matter, there is no debate; there are just lots of people who try to shut down debate.
IQ tests will become less common (and they've already become less common). But they will still be useful to measure what people do with their genetic endowment.
I see. Sorry to ask this but if we all lived in the same environment then all differences in intelligence must be due to genes, right? And the more equal a society's environment, the more differences must be due to genes. Conversely, in very unequal societies even identical twins could have quite different IQ scores if their environments differed wildly. So where does the figure of 80% of the difference in adult intelligence in a population being due to genes come from? Surely in a perfectly equal society the figure should be close to 100% genetic while in a very unequal society the figure could be extremely low. Does this figure of 80% assume a certain level of environmental equality?
The estimates range from 60% to 80%, probably because the degree of environmental inequality varies by that amount. As far as I know, most twin studies have been done in the U.S.
This question tends to obscure debate, since we always have to judge the importance of something in relation to its context. Is a winter coat important when its hot outside? No, but it will be in a few months. The immediate context is not always the best frame of reference. The same with IQ. It's silly to argue that genetic differences don't matter because we also have environmental differences. In fact, by focusing solely on environmental differences, we end up making genetic differences more important.
Thanks for taking the time to answer my question. How and why intelligence is important is for me an unrelated question. I'm only interested in understanding how researchers arrived at the 60% to 80% estimate - which I'm sure is correct - for genetic differences.
Another insightful post Peter in which I also gained new learnings about European people's cognitive evolution. A question that comes to my mind about the limitation of polygenic scores today in not being able to estimate the IQ of an individual -- when do you think the metric will be able to accurately forecast at that individual fidelity? How much data is needed and what type of data would that be?
At present, edu polygenic scores explain 12 to 16% of the variance among individuals. This score is based on alleles identified from 3 million individuals. For a population, the mean edu polygenic score has a 98% correlation with mean population IQ. This high correlation is probably due to the fact that natural selection for cognitive ability has a similar effect on all alleles associated with cognitive ability. A small sample is therefore sufficient to provide the big picture.
It looks like cognitive ability has risen in humans through very small, incremental changes at a very large number of gene loci. We've probably already picked the low-hanging fruit of alleles that have relatively big effects. It will take a lot more time, and AI, to get the above figure up to 50%. I hope we will get there in 10 to 20 years, but I may be wrong.
I wonder about some populations in Europe: did they fully undergo the transition to operational thinking? Some speculations (I don't invoke Piaget) on consequences for social trust of a missing middle class here:
I believe this cognitive evolution began in certain parts of Western Europe, i.e., Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont and Lombardy. It began wherever there were large numbers of "ma and pa" cottage industries operating in a dynamic market. This evolution then spread to most of Europe, with the exception of the Ottoman territories.
The Russians have a word for this class of people who exhibit middle-class qualities of mind and behavior: intelligentsiya. (It doesn't mean what most non-Russians think it means).
'Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont and Lombardy.'
This is a very specific list. I'm not disputing it, but why do you cite these places in particular?
'The Russians have a word for this class of people who exhibit middle-class qualities of mind and behavior: intelligentsiya. (It doesn't mean what most non-Russians think it means).'
This is true. There has been semantic some broadening--maybe adaptation is the more accurate word--with its borrowing into English. I think in Russia, as in other parts of E Europe, this class was largely foreign in origin or at least cultural orientation (ie towards the Enlightenment and succeeding intellectual currents).
The above-mentioned regions were those that had a high concentration of "ma and pa" cottage industries during the period of proto-industrialization (16th - 19th centuries). These were family workshops that produced for a competitive market. The key feature was that they had to create their workforce with their loins, i.e., successful workshop owners had more children and encouraged them to marry earlier. The labour market was much less developed at that time and consisted largely of unreliable riff-raff. As a result, economic success was efficiently translated into reproductive success.
All of that changed with the rise of factory capitalism. It became easier and cheaper to hire workers, with the result that middle-class fertility fell into decline.
What I was driving at was why eg the cities of Tuscany, Umbria and the Veneto from about the 13th century and/or the 'German model' cities of the Hanseatic League/Transylvania/Bavaria/Silesia etc from around the same time were excluded. Not 'ma and pa' enough? Too guild-centred?
*For 'semantic some broadening' obv read 'some semantic broadening'...
Cottage industries tended to be located in semi-rural areas near cities. They produced on contract for urban merchants and had to keep costs down. Otherwise, the merchant would outsource work to a workshop with lower overhead.
These areas were "demographic hothouses" with very high fertility. In contrast, cities tended to be demographic sinks.
It is increasingly evident that the European rise to prominence and the general growth in IQ scores are intertwined. This however gives room to all those no-no conversations that make liberals queasy and make you liable to be called racist or other rubbish.
Hi again Peter, on a slightly different topic what's your opinion on the Caucasus' "Georgian model" of increasing their population's fertility rate, with a combination of homogeneity (over 90% being Orthodox Christian), statr family incentives and the change in 2007 when the Patriarch Ilia II, of the Georgian Orthodox Church, announced to the nation that he would personally baptize and become godfather to any third or above child born to a married couple in Georgia. Subsequently, the third-order birthrate doubled between 2007 and 2010, then continued to rise. Do you think there is any learning here for the West?
So when polygenic scores are powerful enough to assess an individual's IQ thereby rendering IQ tests redundant, surely there can no longer be any debate about the role played by heritability in IQ? Will IQ tests then remain only in order to measure the cultural aspect of IQ?
There shouldn't be any debate now. For that matter, there is no debate; there are just lots of people who try to shut down debate.
IQ tests will become less common (and they've already become less common). But they will still be useful to measure what people do with their genetic endowment.
I see. Sorry to ask this but if we all lived in the same environment then all differences in intelligence must be due to genes, right? And the more equal a society's environment, the more differences must be due to genes. Conversely, in very unequal societies even identical twins could have quite different IQ scores if their environments differed wildly. So where does the figure of 80% of the difference in adult intelligence in a population being due to genes come from? Surely in a perfectly equal society the figure should be close to 100% genetic while in a very unequal society the figure could be extremely low. Does this figure of 80% assume a certain level of environmental equality?
The estimates range from 60% to 80%, probably because the degree of environmental inequality varies by that amount. As far as I know, most twin studies have been done in the U.S.
This question tends to obscure debate, since we always have to judge the importance of something in relation to its context. Is a winter coat important when its hot outside? No, but it will be in a few months. The immediate context is not always the best frame of reference. The same with IQ. It's silly to argue that genetic differences don't matter because we also have environmental differences. In fact, by focusing solely on environmental differences, we end up making genetic differences more important.
Thanks for taking the time to answer my question. How and why intelligence is important is for me an unrelated question. I'm only interested in understanding how researchers arrived at the 60% to 80% estimate - which I'm sure is correct - for genetic differences.
Another insightful post Peter in which I also gained new learnings about European people's cognitive evolution. A question that comes to my mind about the limitation of polygenic scores today in not being able to estimate the IQ of an individual -- when do you think the metric will be able to accurately forecast at that individual fidelity? How much data is needed and what type of data would that be?
At present, edu polygenic scores explain 12 to 16% of the variance among individuals. This score is based on alleles identified from 3 million individuals. For a population, the mean edu polygenic score has a 98% correlation with mean population IQ. This high correlation is probably due to the fact that natural selection for cognitive ability has a similar effect on all alleles associated with cognitive ability. A small sample is therefore sufficient to provide the big picture.
It looks like cognitive ability has risen in humans through very small, incremental changes at a very large number of gene loci. We've probably already picked the low-hanging fruit of alleles that have relatively big effects. It will take a lot more time, and AI, to get the above figure up to 50%. I hope we will get there in 10 to 20 years, but I may be wrong.
Seems an interesting book
The Jewish expulsion hypothesis to explain backwardness in the mezzogiorno is obviously mistaken.
Ricardo Duchesne also used Piaget's developmental stages to examine variation in adult human populations (he acknowledges Oesterdiekhoff):
https://counter-currents.com/2018/10/jean-piaget-the-superior-psychogenetic-cognition-of-europeans-1/
https://counter-currents.com/2018/10/jean-piaget-the-superior-psychogenetic-cognition-of-europeans-part-ii/
I wonder about some populations in Europe: did they fully undergo the transition to operational thinking? Some speculations (I don't invoke Piaget) on consequences for social trust of a missing middle class here:
https://shadeofachilles.substack.com/p/long-since-come-apart-romanias-trust?r=3jr7ai
I believe this cognitive evolution began in certain parts of Western Europe, i.e., Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont and Lombardy. It began wherever there were large numbers of "ma and pa" cottage industries operating in a dynamic market. This evolution then spread to most of Europe, with the exception of the Ottoman territories.
The Russians have a word for this class of people who exhibit middle-class qualities of mind and behavior: intelligentsiya. (It doesn't mean what most non-Russians think it means).
'Ulster, Lancashire, Yorkshire, Brittany, Flanders, Alsace, Westphalia, Saxony, the Zurich uplands, the Piedmont and Lombardy.'
This is a very specific list. I'm not disputing it, but why do you cite these places in particular?
'The Russians have a word for this class of people who exhibit middle-class qualities of mind and behavior: intelligentsiya. (It doesn't mean what most non-Russians think it means).'
This is true. There has been semantic some broadening--maybe adaptation is the more accurate word--with its borrowing into English. I think in Russia, as in other parts of E Europe, this class was largely foreign in origin or at least cultural orientation (ie towards the Enlightenment and succeeding intellectual currents).
The above-mentioned regions were those that had a high concentration of "ma and pa" cottage industries during the period of proto-industrialization (16th - 19th centuries). These were family workshops that produced for a competitive market. The key feature was that they had to create their workforce with their loins, i.e., successful workshop owners had more children and encouraged them to marry earlier. The labour market was much less developed at that time and consisted largely of unreliable riff-raff. As a result, economic success was efficiently translated into reproductive success.
All of that changed with the rise of factory capitalism. It became easier and cheaper to hire workers, with the result that middle-class fertility fell into decline.
See: Seccombe, W. 1992. A Millennium of Family Change. Feudalism to Capitalism in Northwestern Europe, London: Verso. https://www.amazon.ca/Millennium-Family-Change-Capitalism-Northwestern/dp/1859840523
I see.
What I was driving at was why eg the cities of Tuscany, Umbria and the Veneto from about the 13th century and/or the 'German model' cities of the Hanseatic League/Transylvania/Bavaria/Silesia etc from around the same time were excluded. Not 'ma and pa' enough? Too guild-centred?
*For 'semantic some broadening' obv read 'some semantic broadening'...
- too guild-dominated and too expensive
Cottage industries tended to be located in semi-rural areas near cities. They produced on contract for urban merchants and had to keep costs down. Otherwise, the merchant would outsource work to a workshop with lower overhead.
These areas were "demographic hothouses" with very high fertility. In contrast, cities tended to be demographic sinks.
Gotcha
It is increasingly evident that the European rise to prominence and the general growth in IQ scores are intertwined. This however gives room to all those no-no conversations that make liberals queasy and make you liable to be called racist or other rubbish.
Hi again Peter, on a slightly different topic what's your opinion on the Caucasus' "Georgian model" of increasing their population's fertility rate, with a combination of homogeneity (over 90% being Orthodox Christian), statr family incentives and the change in 2007 when the Patriarch Ilia II, of the Georgian Orthodox Church, announced to the nation that he would personally baptize and become godfather to any third or above child born to a married couple in Georgia. Subsequently, the third-order birthrate doubled between 2007 and 2010, then continued to rise. Do you think there is any learning here for the West?
The increase in the birth rate is not just due to the Patriarch. Georgia has fully legal, low-cost surrogacy for infertile couples.