Nations can vary greatly in their wealth, democratic rights, and the well-being of their citizens. These gaps are often obvious, and by studying the flow of immigration, one can easily predict people's wants and needs. But why are there also large differences in the level of education and disparities in a population's cognitive ability? How are cognitive ability and a country's economic development related? In this book, Heiner Rindermann establishes a new model to find an answer for these hotly-debated issues. This new model is based on studies of cross-country differences in cognitive capital, exploring how levels of education are linked to a nation's economic development. This is an important text for graduate students and researchers in a wide range of fields, including economics, psychology, sociology and political science, and those working on economic growth, human capital formation and cognitive development.