Excellent content and compelling arguments; Ty. I bet the 1 SD advantage on average IQ of black Americans over black Africans is attributed to tiny but impactful greater amount of Neanderthal DNA in the former due to greater interbreeding with non-Africans because there is a high positive correlation between a race’s average IQ and the amount of their DNA traced to Neanderthals. I also agree with you that environments play an important role in outcomes.
As Richard suggests, the clearly superior of performance of African immigrants relative to Black Americans may very well be primarily a self-selection thing. There are ~40 million Black Americans while Africa as a whole has a population of ~1.4 billion.
But, if we assume an average IQ of 85 for Black Americans and 70 for Africans, that would mean that on a per capita basis there should be roughly 43 times as many Black Americans as Africans among those with IQs of at least 130. +3 SD above the mean is roughly 1 in 740 while +4 SD above the mean is roughly 1 in 32,000. It's also not clear that African immigrants are being drawn from the entire continent as a whole as opposed to disproportionately from certain countries like Nigeria.
Whenever you hear about some Black kid who scored a 1500 plus out of 1600 on the SAT and got accepted to every Ivy League school, that individual invariably turns out to be an African immigrant, often an Igbo Nigerian. Based on the numbers above, I'd lean towards there being more than just a self-selection effect in terms of explaining the superior performance of African immigrants relative to Black Americans.
If we take the psychometric literature at face value, we should in fact expect slightly higher absolute numbers of Black Americans with IQs above 130 than across the entire continent of Africa. Yet there's little indication that this is the case. There are ~35x as many Africans as Black Americans, but the latter in theory outnumber the former on a per capita basis by ~43x above an IQ threshold of 130.
“Our conclusion, that the Black–White IQ difference is partly heritable, ac- cords with previous analytic reviews of this literature. Loehlin et al. (1975) concluded that Black–White IQ differences “probably” reflected “genetic differ- ences among the groups” (p. 238).” https://www1.udel.edu/educ/gottfredson/30years/Rushton-Jensen30years.pdf
THIRTY YEARS OF RESEARCH ON RACE DIFFERENCES IN COGNITIVE ABILITY
J. Philippe Rushton Arthur R. Jensen
The University of Western Ontario University of California, Berkeley
I'm not necessarily dismissing the psychometric literature on race and intelligence. In any case I don’t have the mathematical or technical background to rigorously evaluate it, so like many I mostly take my cues from the likes of Charles Murray on these matters.
My point was more that if the strong hereditarian thesis is going to be presented as gospel, there are some empirical oddities in need of clarification. In particular, the superior performance of African immigrants relative to that of Black Americans deserves an explanation given that psychometrics suggests that the former possess an average IQ 1 SD lower relative to that of the latter.
Most people will reflexively explain this as the result of self-selection from Africa’s much larger population, but as I argued above, when you actually crunch the numbers the picture isn’t nearly as clear. Based on accepted group IQ data, we would actually expect slightly more Black Americans in absolute terms above an IQ of 130 relative to number of people with IQs 130+ across the entire continent of Africa. To anyone who's lamented the lagging performance of native born Blacks relative to their African immigrant counterparts, the prior conclusion would probably be surprising.
Based on SAT data, I'd say that IQ 130 is roughly the threshold for the average student at an elite high school like Stuyvesant or a lower tier Ivy League university, hence why I picked it for this discussion.
Thanks; btw don’t trust entrance criteria at schools because a lot let legacies in no matter how stupid they are and many don’t use SAT’s anymore because they could hit their Affirmative Action quotas (because their were not enough minorities testing high enough).
More likely explained by average white admixture of approx. 20% in (slave-descended) African Americans as well as 1st world/3rd world resources and upbringing when comparing AAs to black West Africans (whence American slave populations were drawn).
Excellent content and compelling arguments; Ty. I bet the 1 SD advantage on average IQ of black Americans over black Africans is attributed to tiny but impactful greater amount of Neanderthal DNA in the former due to greater interbreeding with non-Africans because there is a high positive correlation between a race’s average IQ and the amount of their DNA traced to Neanderthals. I also agree with you that environments play an important role in outcomes.
As Richard suggests, the clearly superior of performance of African immigrants relative to Black Americans may very well be primarily a self-selection thing. There are ~40 million Black Americans while Africa as a whole has a population of ~1.4 billion.
But, if we assume an average IQ of 85 for Black Americans and 70 for Africans, that would mean that on a per capita basis there should be roughly 43 times as many Black Americans as Africans among those with IQs of at least 130. +3 SD above the mean is roughly 1 in 740 while +4 SD above the mean is roughly 1 in 32,000. It's also not clear that African immigrants are being drawn from the entire continent as a whole as opposed to disproportionately from certain countries like Nigeria.
Whenever you hear about some Black kid who scored a 1500 plus out of 1600 on the SAT and got accepted to every Ivy League school, that individual invariably turns out to be an African immigrant, often an Igbo Nigerian. Based on the numbers above, I'd lean towards there being more than just a self-selection effect in terms of explaining the superior performance of African immigrants relative to Black Americans.
If we take the psychometric literature at face value, we should in fact expect slightly higher absolute numbers of Black Americans with IQs above 130 than across the entire continent of Africa. Yet there's little indication that this is the case. There are ~35x as many Africans as Black Americans, but the latter in theory outnumber the former on a per capita basis by ~43x above an IQ threshold of 130.
“Our conclusion, that the Black–White IQ difference is partly heritable, ac- cords with previous analytic reviews of this literature. Loehlin et al. (1975) concluded that Black–White IQ differences “probably” reflected “genetic differ- ences among the groups” (p. 238).” https://www1.udel.edu/educ/gottfredson/30years/Rushton-Jensen30years.pdf
THIRTY YEARS OF RESEARCH ON RACE DIFFERENCES IN COGNITIVE ABILITY
J. Philippe Rushton Arthur R. Jensen
The University of Western Ontario University of California, Berkeley
I'm not necessarily dismissing the psychometric literature on race and intelligence. In any case I don’t have the mathematical or technical background to rigorously evaluate it, so like many I mostly take my cues from the likes of Charles Murray on these matters.
My point was more that if the strong hereditarian thesis is going to be presented as gospel, there are some empirical oddities in need of clarification. In particular, the superior performance of African immigrants relative to that of Black Americans deserves an explanation given that psychometrics suggests that the former possess an average IQ 1 SD lower relative to that of the latter.
Most people will reflexively explain this as the result of self-selection from Africa’s much larger population, but as I argued above, when you actually crunch the numbers the picture isn’t nearly as clear. Based on accepted group IQ data, we would actually expect slightly more Black Americans in absolute terms above an IQ of 130 relative to number of people with IQs 130+ across the entire continent of Africa. To anyone who's lamented the lagging performance of native born Blacks relative to their African immigrant counterparts, the prior conclusion would probably be surprising.
Based on SAT data, I'd say that IQ 130 is roughly the threshold for the average student at an elite high school like Stuyvesant or a lower tier Ivy League university, hence why I picked it for this discussion.
Thanks; btw don’t trust entrance criteria at schools because a lot let legacies in no matter how stupid they are and many don’t use SAT’s anymore because they could hit their Affirmative Action quotas (because their were not enough minorities testing high enough).
More likely explained by average white admixture of approx. 20% in (slave-descended) African Americans as well as 1st world/3rd world resources and upbringing when comparing AAs to black West Africans (whence American slave populations were drawn).