The Intelligence of Nations. National IQs and Correlates

Intelligence is by far the most important human trait. This holds true at the level of individuals as well as at the level of nations. The average cognitive performance of their inhabitants is the most important determinant of the social, cultural, and economic development of nations. The article considers cognitive ability of nations from the perspective of psychometric intelligence research, international student assessment studies, and Piaget’s developmental psychology. Based on up-to-date data, the national IQ of 205 countries is estimated. Then it is shown that national IQs are closely related to a wide range of variables from different domains of life. Overall, it is demonstrated that the central findings of psychometric intelligence research hold unchanged. A special feature is the consideration of non-linear relationships. Using a specific threshold model derived from Piagetian developmental psychology, it is shown that the importance of national IQs is greater than previously known.