I've been looking at Richard Lynn's studies on average African IQ, and he seems to estimate really low IQs in the 60s range (e.g. http://www.sciencedirect.com/science/article/pii/S0160289609001275?via%3Dihub).

However, is this inherently wrong, as somebody who would score that low in a Western country would no doubt be mentally retarded (and this isn't the case for most African people)?

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    $\begingroup$ The study has been heavily criticized e.g. Wicherts and his colleagues examined over 100 published studies, concluding that there is no evidence to back up Lynn's claims. Amongst other flaws, Lynn used selective data by systematically ignoring Africans with high IQ scores (Controversial study of African IQ levels is 'deeply flawed') Lynn replied to the criticism but not at all convincingly. No one seems to have taken him very seriously outside of racist hacks looking to support their bigotry $\endgroup$
    – iayork
    Sep 22, 2017 at 14:02
  • $\begingroup$ I am not sure this really is a biology question. Sounds more like a question of social demography. $\endgroup$
    – Remi.b
    Sep 23, 2017 at 4:55

2 Answers 2


IQ is just a measure of how good you are at taking IQ tests, that's it. Those tests are usually culturally biased towards middle income first world citizens (among other things). Think of it this way, questions about mortgages, supermarkets, airplanes, or such thing presuppose the person being questions knows a reasonable amount about those things, this is not a reasonable assumption in many places around the world.

The classic "a train leave chicago at 10:00..." is a perfect example since the reader needs to know what a trains is, that chicago is a place, and what 10:00 means additionally they need to be familiar with reading exact measures of time and velocity, that they have already been taught basic math, are familiar with abstract questions, and that they are experienced readers, these are all fine assumptions for the New York suburbs but pretty bad ones for sub saharan subsistence farmers.

People who try to write the questions for said cultures often run into the reverse problem, we think of travels as a steady rate but to people who travel by boat know allowances need to be given for things like the speed the stream is moving, or the paddler taking breaks for lunch, information the writer may wrongfully assume or not understand. I recall a question about two people traveling along the same road that was consistently wrong because people in that culture thought is was proper for the faster person to slow down to match the slower for the safety of both (the norm in said society) so they constantly calculated their speed as the same, something the writers never anticipated.

There are millions of these differences across cultures and these cultural differences quickly snowball in to large differences when taking identical tests. So you are not seeing a real difference in intelligence just an artifact of culturally biased testing.

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    $\begingroup$ +1 That and when the metric becomes the goal, it's no longer a good metric. $\endgroup$
    – CKM
    Sep 22, 2017 at 16:55
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    $\begingroup$ Yeah, it's like trying to judge my intelligence by asking questions about TV shows or popular music - to which my answers would be a universal "Duh?" :-) $\endgroup$
    – jamesqf
    Sep 22, 2017 at 18:52

How do you define being "mentally retarded"? In order to minimize the difference in measured IQ that might be due to people growing up under different circumstances in different cultures you could try to measure how people with different ethnic backgrounds achieve in a multicultural society. Citation from a paper regarding school results in Florida, USA:

The number of ill-prepared students in Florida remains troubling, as do the differences by race and ethnicity: 38 percent of black students currently read at grade level. That compares with 53 percent of Hispanics, 69 percent of whites and 76 percent of Asians.


Obviously being able to read at some level does not have to correlate with IQ in a simple fashion and people in Florida who are reported to be "white" or "black" might have a mixed ethic background. I do not know if any large scale investigations trying to link IQ with ethnic background in countries such as the USA are done, as the subject might be deemed as controversial. If there are differences in school results, SAT-scores etc. that might at least give you a hint of how large the differences between different ethnic groups might be.


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