The secular rise in IQs in the Netherlands: Is the Flynn effect on g? Jan te Nijenhuis a, * , Henk van der Flier b a Work and Organizational Psychology, University of Amsterdam, Amsterdam, The Netherlands b Work and Organizational Psychology, Free University, Amsterdam, The Netherlands Received 27 October 2006; received in revised form 22 February 2007; accepted 22 March 2007 Available online 8 June 2007 Abstract IQ scores have been increasing over the last half century, a phenomenon known as the Flynn effect. In this study, we focused on the question to what extent these secular gains are on the g factor. Two IQ bat- teries: the Interest-School achievement-Intelligence Test (ISI) and the Groningen Final Examination Pri- mary Education (GALO) yielded small and modest negative correlations between standardized gains and g loadings. As these studies employ large samples this suggests that the combined literature now shows a modest negative relationship between d (the secular change in test score) and g. Ó 2007 Elsevier Ltd. All rights reserved. Keywords: Flynn effect; Secular score gains; g; g score; g loadings; IQ tests; Intelligence; Method of correlated vectors 1. Introduction Many studies have shown that IQ scores have been increasing over the last half century. These increases have been reported in countries on all continents (Flynn, 2006). The most essential re- search question is to what extent these empirical gains are on the g factor and therefore reflect a functional increase of real-life problem solving ability rather than simply an increase in familiarity 0191-8869/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.paid.2007.03.016 * Corresponding author. Tel.: +31 20 6002067. E-mail address: JanteNijenhuis@planet.nl (J. te Nijenhuis). www.elsevier.com/locate/paid Personality and Individual Differences 43 (2007) 1259–1265