As far as average IQ scores go, this is what the world looks like. But there are two relevant tests: the Stanford-Binet, and life itself. If a country scored low on IQ but at the same time led the world in Cavorite production, or cured cancer, or built spindizzies, we would say “screw Stanford-Binet”, and we would be right to do so.
Does that happen? Are there countries with low average scores that tear up the technological track? Mostly not – generally, fairly high average IQ seems to be a prerequisite for creativity in science and mathematics. Necessary, although not sufficient: bad choices (Communism), having the world kick you in the crotch (Mongols), or toxic intellectual fads can all make smart peoples unproductive.
The exceptions, such as they are, seem to be a result of strong population substructure. India has a low average IQ, but there are distinct subpopulations (castes) that apparently have much higher IQ – although I’d love to see some decent studies on this. With numbers.
A population with a low average has drastically fewer people that exceed a high threshold – should, anyhow, if the distribution is much like a gaussian. This means that most of the world with average scores well below 100 produces very few sharp cookies, and thus I wouldn’t expect them to do much in the way of scientific and technical innovation. Nor do they.
So when you hear about even a few people with impressive intellectual accomplishments from a country whose average IQ is not very high, you suspect population substructure. Which is why I suspect that there is significant population substructure in Iran. But maybe there’s something else going on?
Of course classes are an example of substructure: higher socioeconomic groups usually have higher average scores, and most of that difference is probably genetic. If recruiting and retaining people into the upper classes goes up with IQ, then the upper classes will be smarter – some, anyhow. It’s not inevitable – certainly isn’t true in the UAE.
So as a population evolves from egalitarian tribesmen to a more hierarchical society, you may see a higher fraction of people with IQ above high threshold X, X being what you need to make progress on Diophantine equations, or write the Popol Vuh, or whatever. Even if the average IQ of the population as a whole does not change. In the same way, if someone comes in and chases off your upper classes to France, or simply kills everyone living in a city, that fraction is going to go down. Decapitation. Moreover, those fewer smart cookies left are probably less likely to meet and cooperate.
You could improve the situation, raise the average, by selection for IQ. But that takes a long time, and I know of no case where it was done on purpose. You could decrease inbreeding, for example by banning cousin marriage. That only takes one generation. You could make environmental improvements, iodine supplementation being the best understood. People assume that there are a lot of other important environmental variables, but I sure don’t know what they are. In practice the rank ordering of populations seem to be the same everywhere, which is not what you would expect if there were strong, malleable environmental influences.
Let me expand a little on that. Diasporas track. The populations that scored low at home score low in new lands: those that scored high continue to score high. Chinese that entered Malaysia as illiterate tin miners end up doing well in a few generations: Japanese that moved to Brazil to pick coffee are high achievers now.
Is it easy to notice such differences? Well, for ordinary people, it’s real easy. Herero would ask Henry why Europeans were so smart – he said he didn’t know. But with the right education, it apparently becomes impossible to see. Few anthropologists know that such differences exist and even fewer admit it. I’m sure that most have never even read any psychometrics – more importantly, they ignore their lying eyes. Economists generally reject such explanations, which is one reason that they find most of the Third World impossible to understand. I must give credit to Garret Jones, who is actually aware of this general pattern. Sure, he stepped on the dick of his own argument there at the end of his book, but he was probably lying, because he had to. Sociologists? It is to laugh.
Generally, you could say that the major job of social science is making sure that people do not know this map. Not knowing has its attractions: practically every headline is a surprise. The world must seem ever fresh and new to the dis-illuminati – something like being Henry Molaison, who had his hippocampus removed by a playful neurosurgeon and afterwards could not create new explicit memories.
So when we tried a new intervention aimed at eliminating the GAP, and it failed, Molaison was surprised, even if 47 similar programs had already failed. Neurologically, he was much like a professor of education.