In his review of the African IQ literature, Heiner Rindermann concluded that the mean IQ of Sub-Saharan Africa was somewhere between 68 and 78, adding that "given the quality of the data, it is not possible to come to a really precise result." His criticisms of that literature are worth quoting:

"The usual phrase ‘‘further research is needed’’ is very appropriate here: We need representative samples of the ages 10–70; samples representative of the full range of school education, including the share without or with only little education; the use of fluid (school-distant) and crystallized (school-near) cognitive ability tests; and up-to-date norms from Great Britain. Furthermore, as African samples have less cognitive task experience, the estimates could be increased by a short test training or a more general cognitive training."

I think you're missing the point when you write: "We don't disregard African data for any other variable just because it is of low quality." The problem here isn't simply the low quality of the data. If that were the case, there would just be more variability around a mean that is nonetheless more or less right. There is also the problem of low cognitive task experience.

In European and Asian cultures, you can easily spend a third of your life at school. So almost everyone is familiar with testing, and most people have learned what to do and what not to do on a test (like spending too much time on the hard questions). People are also familiar with the idea of answering questions in rapid-fire succession. That's less the case in Africa and elsewhere in the world. Even in traditional European cultures, that was less the case. It used to be considered rude to ask direct questions, especially in a rapid-fire manner. When I was doing fieldwork, I was warned against "pumping" older interviewees by asking one question after another.

I agree that there is global variation in mean cognitive ability, but I disagree with the sometimes naïve acceptance of IQ data from Africa and other places.


Rindermann, H. (2013). African cognitive ability: Research, results, divergences and recommendations. Personality and Individual Differences 55: 229-233. https://doi.org/10.1016/j.paid.2012.06.022

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> So there are 8 different studies with sample sizes totaling about 10,000 people. […]The IQs from these studies ranged from 67 to 85. It's these studies:

An observation: Using SD(IQ) =15 and N=1250, for illustration, we get SE=0.42, which means these numbers are —Bayes forgive me— significantly different. They are contradictory, as they make conflicting predictions for the population. For example, using 67 as the mean, only 11.5% of the population are above 85, contradicting the prediction of 50% given by the 85 mean.

If physicists estimating the gravity of Z'ha'dum got different numbers (beyond the precision of their instruments), they would consider _all_ numbers invalid until they could explain the difference and determine which number (possibly a new number) makes accurate predictions for a ballistic trajectory in Z'ha'dum.

Just a thought on what measurement means. I have no cat in the fight that's the topic of the post.

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I have a hard time squaring the low African IQ estimates with the US-African immigrant overperformance on scholastic measures compared to native African-Americans.

Do you think that 67 is really the *genotypic* average IQ of Nigeria?

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I think the one fair point made by Carr is it seems to me unlikely that mean Nigerian is severely cognitively impaired

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So what is the typical African nations’ IQ? We don’t know, too much noise in the “data” we are told. However, perhaps we have a better handle on Africans not native to Africa? For example, the USA. Blacks, who are descendant from African slaves brought over primarily from Africa’s West coast. I’ve heard many excuses for American Blacks low IQ score vis a vis other races native to the USA, but all of these have been shown lacking in merit.

Seems to me that the best measure we have is that the USA Black race is at an average IQ of 85–one SD below the mean IQ for the nation. Is this to be explained away as well with the African trope? My suspicion is that this mean score observation is probably a good guess for the very maximum average IQ of African (Subsaharan) nations. (Note I do not deny that there are probably sub populations within Africa that are quite high (relatively) wrt their IQ).

I believe it was Lynn that noted there were no functional nations with average IQ’s less than 90. Seems about right when observing African national dysfunction today. So are we arguing about minor differences here? A distinction without a difference?

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My take-away from this is that malnourishment seems to cause low IQs.

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Thanks for this. Do know about a go-to rebuttal for race realism specifically? It's annoying when people believe racial constructivism (or "it's just skin colour/phenotype") but I don't know of any resources that only details the measurable differences in genetic distance and distinctiveness between ethnoracial groups without also conflating it with racial differences in traits e.g. IQ, height, disease proclivity etc.

Of course, these are related arguments and I believe race denialists axiomatically deny the former in order to cynically discredit the latter. Nonetheless, I think it would be useful to have a resource to show to intellectually curious people that proves genetic nature of race without addressing racial differences in traits that would scare them off

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Second picture:

> And that is just the average! Half of the distribution would be expected to have an IQ lower than that.

Kareem Carr is a “statistician” that doesn’t know the distinction between mean and median. That alone should be enough to discount anything he has to say.

Great article in any case!

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