books.google.fr - Lynn and Vanhanen test the hypothesis on the causal relationship between the average national intelligence (IQ) and the gap between rich and poor countries by empirical evidence. Based on an extensive survey of national IQ tests, the results of their work challenge the previous theories of economic development...https://books.google.fr/books/about/IQ_and_the_Wealth_of_Nations.html?hl=fr&id=KQ4rLiAbHQQC&utm_source=gb-gplus-shareIQ and the Wealth of Nations
