Some of that "data" is hard to take seriously when you come across quotes such as the following:

Upon reading the original reference, we found that the “data point” that Lynn and Vanhanen used for the lowest IQ estimate, Equatorial Guinea, was actually the mean IQ of a group of Spanish children in a home for the developmentally disabled in Spain.

There's a similar issue with the next lowest IQ on the list, and when you learn that the greater portion of the "country IQ" figures were obtained by averaging IQ data from nearby countries, you see how this kind of data quality issue could have contaminated the entire data set. But say I am inclined to take the data seriously and dismiss a few mistakes. This is from Wikipedia's page on "IQ and the Wealth of Nations" by Lynn and Vanhanen:

The authors believe that average IQ differences between nations are due to both genetic and economic factors. They also believe that low GDP can cause low IQ, just as low IQ can cause low GDP. [...] The authors write that it is the ethical responsibility of rich, high-IQ nations to financially assist poor, low-IQ nations, as it is the responsibility of rich citizens to assist the poor.

IOW, the authors whose work justifies your conclusions arrive at more or less opposite conclusions from yours. You're seeing a correlation, and assuming a causation in one direction, without (so far as I can see) a proper argument for that direction. Since this is one of the classic mistakes people are warned against in the sciences, I'll maintain my skeptical attitude until you adress my actual arguments.

When you do, please take into account how cognitive abilities actually develop (i.e. if you're fed, healthy and go to school you'll end up smarter than if you're starving, sick and nobody ever talks to you, and the former is more likely in a rich country).