IQ and the Wealth of Nations is a controversial 2002 book by Dr. Richard Lynn, Professor Emeritus of Psychology at the University of Ulster, Northern Ireland, and Dr. Tatu Vanhanen, Professor Emeritus of Political Science at the University of Tampere, Tampere, Finland. Lynn, R. and Vanhanen, T. (2002). IQ and the wealth of nations. Westport, CT: Praeger. ISBN 0-275-97510-X The book argues that differences in national income (in the form of per capita gross domestic product) correlate with differences in the average national intelligence quotient (IQ). The authors interpret this correlation as showing that IQ is one important factor contributing to differences in national wealth and rates of economic growth, but that it is not the only determinant of these differences. The data, methodology, and conclusions have been criticized. The 2006 book IQ and Global Inequality is a follow-up to IQ and the Wealth of Nations.