Lynn and Vanhanen even argue that IQ was correlated with incomes as far back as 1820 -- a neat trick given that the IQ test wasn't invented until a century later.
As that surprising finding might suggest, most of Lynn and Vanhanen's data is, in fact, made up. Of the 185 countries in their study, actual IQ estimates are available for only 81. The rest are "estimated" from neighboring countries. But even where there is data, it would be a stretch to call it high quality. A test of only 50 children ages 13 to 16 in Colombia and another of only 48 children ages 10 to 14 in Equatorial Guinea, for example, make it into their "nationally representative" dataset.
Psychologist Jelte Wicherts at the University of Amsterdam and colleagues trawled through Lynn and Vanhanen's data on Africa. They found once again that few of the recorded tests even attempted to be nationally representative (looking at "Zulus in primary schools near Durban" for example), that the data set excluded a number of studies that pointed to higher average IQs, and that some studies included dated as far back as 1948 and involved as few as 17 people.
There is a great deal more on the second page of the article, which suggest further problems with the data. Naturally I find this information to be a relief, but I know that Joe in particular has looked closely at the information and tends to support the conclusions; so, I thought I would post the link here and ask what he (and the rest of you) may think of it.
There's a more interesting genetics-related suggestion (than IQ) in the article as well:
Enrico Spolaore and Romain Wacziarg have gone even further back, arguing that "genetic distance" -- or the time since populations shared a common ancestor -- has a considerable role to play in the inequality of incomes worldwide. They estimate that variation in genetic distance may account for about 20 percent of the variation in income across countries.
Spolaore and Wacziarg take pains to avoid suggesting that one line of genetic inheritance is superior to another, preferring instead an interpretation that argues genetic distance is related to cultural differences -- and thus a more complex diffusion of ideas: "the results are consistent with the view that the diffusion of technology, institutions and norms of behavior conducive to higher incomes, is affected by differences in vertically transmitted characteristics associated with genealogical relatedness.… these differences may stem in substantial part from cultural (rather than purely genetic) transmission of characteristics across generations," they write.
Now that argument seems intuitively plausible. Economic success is largely the result of trade, and trade is most successful where communication is most easy. That means that barriers to communication and common understanding would tend to complicate trade, and thus lower economic success. These could be linguistic or cultural barriers, but a genuinely distinct genetic heritage might also affect sense perception and brain activity in interesting ways. That could cause a long-separate population to have a different way of seeing the world, literally in some cases, which would be a kind of barrier to communication. Thus, "genetic distance" might indeed raise barriers to economic success.
However, there's a very obvious counter-example: the Japanese. Few societies have been as successful historically at isolating themselves, culturally and genetically. Even today they have a quite distinct culture and genetic heritage; but especially in the 19th century, when American gun boats finally forced their doors, they were as distinct as you could want a population to be.
Japan nevertheless rapidly industrialized and in only a few years was defeating Russia at war; a few years later it was challenging the United States as a naval power. This was done by addressing cultural distance only: the Japanese sent people abroad to study (as for example to Paris, where they studied the police department carefully, and then replicated it carefully in Tokyo). There was no effort to intermarry with gaijin.
That would appear to recommend against a racial/genetic model even here. Again, though, I'd like to hear your thoughts on the subject.