Have you read https://traditionsofconflict.substack.com/p/the-intelligence-of-african-hunters (the title "The Intelligence of African Hunters, and the Ignorance of Popular Hereditarians" states the thesis. On Twitter the author has even qquoted Galton on how clever the Bushmen are! You're also familiar with the conundrum of GSCEs in Britain (minimal black-white gap) https://georgefrancis.substack.com/p/solving-the-gcse-mystery . If the GSCEs were an accurate measure of IQ gaps in Britain, wouldn't African immigrants have to be mathematically impossibly unrepresentative of their home populations if African mean IQ was really 70? Even if we throw the GSCEs out, the black white gap in Britain seems noticeably smaller than in the US. And of course African and Caribbean immigrants regularly outperform native blacks in the States. Have you written about any of this?
To answer your last question, my guess is that the citizens from Africa and the Caribbean who are immigrants in the first place are probably more intelligent on average. Can't speak for the UK, but the US culturally incentivizes the 'high achieving' immigrant quite a bit. Think doctors, engineers, etc.
The list is pretty comprehensive. And as you might guess, there are no important contributions from Sub-Saharan Africa. There are important contributions from Ancient Egypt. But the people in North Africa are more closely related to Europeans than to Southern Africans.
Richard Lynn mentioned in his book about dysgenics that the American black population is more dysgenic than the American white population. Does anyone know its cause? Lynn hypothesized that it's due to (1) race differences in IQ distributions by sex with black women potentially lacking the IQ mean and SD disadvantage that white women have as adults with respect to men of their own race as well as (2) the prevalence of American black men in jail. Can intranational studies on race differences in dysgenics help us understand the international differences in dysgenic trends?
I would think that (2) would result in eugenic selection over time. Incarceration tends to select for some combination of low intelligence and aggression.. and prisoners don't have the same "reproductive opportunities" as those on the outside. I would think the internecine gang warfare in would have similar selection effects as well.
To put it in a slogan, it is the difference between being born without legs and being born short. SSAs are not born without legs at a greater rate than others, but they are shorter on average.
(1) Figure 2, the Jensen one, is misdrawn. The lower hump should be part of the unshaded distribution, rather than a separate distribution-- a single line, rather than two lines. What he is saying is that the density is bimodal.
(2) A helpful diagram would show the black adn white densities, but both of them bimodal. This could be real data, or just a theoretical density representing the idea you're explaining. Then shade the ordinary left tails differently from the "autism, etc." left tails to show that a bigger proportion of the white low scores are "autism, etc.".
(3) Another diagram could do this with the height of the bell curves proportional to size of the white and the black populations, so the white one is much taller. This could show the absolute numbers of white-black and ordinary-autism-etc. IQs below 70.
(3)My guess is that blacks have as many or more "truly retarded" people as whites, but that the "truly retarded" causes don't push them down any further, so the black and white truly retarded mean IQs would be the same. E.g., my hypothesis is that chromosome abnormality pushes you down to 60 whether you would have been 80 or 120 without it.
"You can think of it as throwing 6 standard dice. The expected sum is 21, but it is possible to get only 6, or get as much as 36."
Emil, I have long wondered what if the intellect is not an additive but a combinative resultant of the intellect-related genes. In other words, what if we are not rolling dice, but playing a game of poker. Just as an example, because I'm Hungarian, we Ashkenazi Jews are full of figure decks, we Hungarians are the normal deck of cards, and our Gypsies hardly have any figure cards... So the task is to discover the rules of our beautiful game of "Intellect"...
After a second read of your comment I am not sure I understand what you are referring to. If a gene is additive it usually means that a heterozygotic speciment will have a measurable trait at the midpoint between the two homozygotic cases. Or maybe that there are no significant gene-gene interactions. Your game of poker analogy refers to what variants at what frequency are available in a population. To me the two issues seem orthogonal.
Or did you refer to the probability of positive gene-gene interaction in certain populations? If that happened we would see outbreeding depression. Is there any credible observation of that?
The GWAS studies (and polygenic risk scores) on intelligence tend to find basically no non-additive common variants. There seems to be some evolutionary reasons for it. There certainly are a few non-additive variants - otherwise there would be no inbreeding depression, but they tend to be rare and have large effects (usually something is just messed up - like a faulty protein encoding that causes a recessive disorder) and go extinct (usually) or get fixated if it is advantageous (rarely).
Razib had an interesting interview with James Lee on this topic, you might be interested in that:
Have you read https://traditionsofconflict.substack.com/p/the-intelligence-of-african-hunters (the title "The Intelligence of African Hunters, and the Ignorance of Popular Hereditarians" states the thesis. On Twitter the author has even qquoted Galton on how clever the Bushmen are! You're also familiar with the conundrum of GSCEs in Britain (minimal black-white gap) https://georgefrancis.substack.com/p/solving-the-gcse-mystery . If the GSCEs were an accurate measure of IQ gaps in Britain, wouldn't African immigrants have to be mathematically impossibly unrepresentative of their home populations if African mean IQ was really 70? Even if we throw the GSCEs out, the black white gap in Britain seems noticeably smaller than in the US. And of course African and Caribbean immigrants regularly outperform native blacks in the States. Have you written about any of this?
To answer your last question, my guess is that the citizens from Africa and the Caribbean who are immigrants in the first place are probably more intelligent on average. Can't speak for the UK, but the US culturally incentivizes the 'high achieving' immigrant quite a bit. Think doctors, engineers, etc.
Charles Murray posted the data for his "Human Accomplishments" book. Here is the post with a link to the Excel spreadsheet that one can download.
https://www.aei.org/research-products/working-paper/data-tools-3-the-full-inventory-of-scientific-events-from-human-accomplishment/
The list is pretty comprehensive. And as you might guess, there are no important contributions from Sub-Saharan Africa. There are important contributions from Ancient Egypt. But the people in North Africa are more closely related to Europeans than to Southern Africans.
Richard Lynn mentioned in his book about dysgenics that the American black population is more dysgenic than the American white population. Does anyone know its cause? Lynn hypothesized that it's due to (1) race differences in IQ distributions by sex with black women potentially lacking the IQ mean and SD disadvantage that white women have as adults with respect to men of their own race as well as (2) the prevalence of American black men in jail. Can intranational studies on race differences in dysgenics help us understand the international differences in dysgenic trends?
I would think that (2) would result in eugenic selection over time. Incarceration tends to select for some combination of low intelligence and aggression.. and prisoners don't have the same "reproductive opportunities" as those on the outside. I would think the internecine gang warfare in would have similar selection effects as well.
https://www.amren.com/blog/2021/06/what-could-be-driving-dysgenics-in-the-black-population/
Black college-educated women have extremely low fertility rates for one.
Maybe they're as dumb so using birth control is difficult for them.
To put it in a slogan, it is the difference between being born without legs and being born short. SSAs are not born without legs at a greater rate than others, but they are shorter on average.
We do know that dysgenics is much worse in African countries...
Not really. Almost no studies from there.
Very good article.
(1) Figure 2, the Jensen one, is misdrawn. The lower hump should be part of the unshaded distribution, rather than a separate distribution-- a single line, rather than two lines. What he is saying is that the density is bimodal.
(2) A helpful diagram would show the black adn white densities, but both of them bimodal. This could be real data, or just a theoretical density representing the idea you're explaining. Then shade the ordinary left tails differently from the "autism, etc." left tails to show that a bigger proportion of the white low scores are "autism, etc.".
(3) Another diagram could do this with the height of the bell curves proportional to size of the white and the black populations, so the white one is much taller. This could show the absolute numbers of white-black and ordinary-autism-etc. IQs below 70.
(3)My guess is that blacks have as many or more "truly retarded" people as whites, but that the "truly retarded" causes don't push them down any further, so the black and white truly retarded mean IQs would be the same. E.g., my hypothesis is that chromosome abnormality pushes you down to 60 whether you would have been 80 or 120 without it.
"You can think of it as throwing 6 standard dice. The expected sum is 21, but it is possible to get only 6, or get as much as 36."
Emil, I have long wondered what if the intellect is not an additive but a combinative resultant of the intellect-related genes. In other words, what if we are not rolling dice, but playing a game of poker. Just as an example, because I'm Hungarian, we Ashkenazi Jews are full of figure decks, we Hungarians are the normal deck of cards, and our Gypsies hardly have any figure cards... So the task is to discover the rules of our beautiful game of "Intellect"...
After a second read of your comment I am not sure I understand what you are referring to. If a gene is additive it usually means that a heterozygotic speciment will have a measurable trait at the midpoint between the two homozygotic cases. Or maybe that there are no significant gene-gene interactions. Your game of poker analogy refers to what variants at what frequency are available in a population. To me the two issues seem orthogonal.
Or did you refer to the probability of positive gene-gene interaction in certain populations? If that happened we would see outbreeding depression. Is there any credible observation of that?
The GWAS studies (and polygenic risk scores) on intelligence tend to find basically no non-additive common variants. There seems to be some evolutionary reasons for it. There certainly are a few non-additive variants - otherwise there would be no inbreeding depression, but they tend to be rare and have large effects (usually something is just messed up - like a faulty protein encoding that causes a recessive disorder) and go extinct (usually) or get fixated if it is advantageous (rarely).
Razib had an interesting interview with James Lee on this topic, you might be interested in that:
https://unsupervisedlearning.libsyn.com/james-lee-genes-and-educational-attainment
This is correct, but linear approximation is good at first.