A 2007 study by Rindermann found a high correlation between the results of international student assessment studies including TIMSS, PIRLS, and PISA, and national average IQ scores.[12][13] The results were broadly similar to those in Richard Lynn and Tatu Vanhanen's book IQ and the Wealth of Nations. According to Earl B. Hunt, due to there being far more data available, Rindermann's analysis was more reliable than those by Lynn and Vanhanen. By measuring the relationship between educational data and social well-being over time, Rindermann also performed a causal analysis, finding that nations investing in education leads to increased well-being later on.[14]
Some of Rindermann's work has concentrated on the "smart fraction" theory, which states that the prosperity and performance of a society depends on the proportion of the population that is above a particular threshold of intelligence, with the threshold point being well above the general median intelligence level in most societies.[15][16][17]
Rindermann's book Cognitive capitalism: Human capital and the wellbeing of nations was released by Cambridge University Press in 2018.[18]
^Rindermann, Heiner (August 8, 2007). "The g-factor of international cognitive ability comparisons: the homogeneity of results in PISA, TIMSS, PIRLS and IQ-tests across nations". European Journal of Personality. 21 (5): 667–706. doi:10.1002/per.634. S2CID8662680.
^Flores-Mendoza, Carmen; Ardila, Rubén; Rosas, Ricardo; Lucio, María Emilia; Gallegos, Miguel; Reátegui Colareta, Norma (2018), Flores-Mendoza, Carmen; Ardila, Rubén; Rosas, Ricardo; Lucio, María Emilia (eds.), "Intelligence, Latin America, and Human Capital", Intelligence Measurement and School Performance in Latin America: A Report of the Study of Latin American Intelligence Project, Springer International Publishing, pp. 79–112, doi:10.1007/978-3-319-89975-6_6, ISBN9783319899756
^Hunt, Earl. Human Intelligence. Cambridge University Press, 2011. Page 440-443.