Survey of expert opinion on intelligence: The FLynn effect and the future of intelligence Heiner Rindermann a, ⁎, David Becker a , Thomas R. Coyle b a Department of Psychology, Chemnitz University of Technology, Wilhelm-Raabe-Str. 43, D-09107 Chemnitz, Germany b University of Texas at San Antonio, Department of Psychology, One UTSA Circle, San Antonio, TX 78249, USA abstract article info Article history: Received 24 August 2016 Received in revised form 28 October 2016 Accepted 31 October 2016 Available online xxxx Experts on intelligence, cognitive ability and student achievement were surveyed for their opinions on the causes of the 20th century rise in intelligence test results called the “FLynn effect”, on the causes of a possible end of the FLynn effect and on the future development of IQ in different world regions. Ratings from N = 75 experts attrib- uted the secular IQ rise to better health and nutrition, more and better education and rising standards of living. Genetic changes were seen as not important. A possible stagnation or retrograde of the FLynn effect was attrib- uted to asymmetric fertility (genetic and socialization effects), migration, declines in education and the influence of media. Experts expected 21st century IQ increases in currently on average low-ability regions (+6 to +7 IQ points, in Latin America, Africa, India) and in East Asia (+7 IQ), but not in the West (a stagnation, below +1 IQ), with a small decline in the US (-0.45 IQ). Similar results were obtained for all experts and experts on the FLynn effect itself (mean r = 0.90 to 0.97; N = 17). The results correlated strongly with and confirmed a recent meta-analysis on the causes of the FLynn effect (r = 0.65 to 0.71; Pietschnig & Voracek, 2015). © 2016 Elsevier Ltd. All rights reserved. Keywords: Intelligence Survey Experts FLynn effect Secular rise in IQ National cognitive ability development 1. Introduction Among the most discussed topics in intelligence research is the rise of average IQ test results across generations in the 20th century. The trend was first reported by Rundquist (1936). The American-New- Zealand political scientist Flynn (1984) systematically reviewed evi- dence of the trend in his seminal paper, “The mean IQ of Americans: Massive gains 1932 to 1978”. The effect was later labeled the “Flynn effect”. Lynn (1982) described the same phenomenon for Japan. Because both Lynn and Flynn rediscovered the trend, we label it the “FLynn effect”. In Western countries, the increase in IQ in the 20th century has been about 3 IQ points per 10 years, or 2.83 IQ points per decade, according to a meta-analysis by Pietschnig and Voracek (2015). There is evidence of a decline or inversion of the FLynn effect in developed countries and of recent gains in IQ in developing countries. In particular, the FLynn effect has declined, stopped or inverted in Norway (stopped; Sundet, Barlaug, & Torjussen, 2004), Denmark (in- version; Teasdale & Owen, 2008), England (inversion measured by Pia- get tests; Shayer & Ginsburg, 2009), Australia (stopped; Cotton et al., 2005), Finland (inversion; Dutton & Lynn, 2013; Heller-Sahlgren, 2015b), Austria (inversion; Pietschnig & Gittler, 2015), and the US (decline; Rindermann & Thompson, 2013). The FLynn effect has also inverted in Western countries for mental speed (inversion; Woodley, te Nijenhuis, & Murphy, 2013), which has been linked to intelligence, and for world achievements and school grades (Jensen, 2006; Rindermann & Neubauer, 2000). Positive trends of the FLynn effect can co-occur with negative trends across scales, subgroups and coun- tries (co-occurrence model; Woodley of Menie & Fernandes, 2015). There seems to be a certain historical timeframe for the FLynn effect. The decline of the FLynn effect in developed countries, and its increase in developing regions with currently lower than average ability levels (e.g., Africa), may lead to a narrowing of international gaps (Meisenberg & Woodley, 2013; Rindermann, 2013). Future IQ changes are linked to past cognitive development and ex- pected demographic changes, which permit predictions of future devel- opment at the country level (e.g., + 0.45 to + 0.76 IQ points per decade in the US; Rindermann & Pichelmann, 2015). Demographic changes may be linked to genetic effects, which are influenced by asymmetric birth rates in modern populations (e.g., Lynn, 2011; Nyborg, 2012). Neg- ative genetic effects on intergenerational changes in ability are plausibly linked to: (a) parent-children correlations in intelligence (for individ- uals about r = 0.40 to 0.50; Plomin, DeFries, Knopik, & Neiderhiser, 2013, p. 76), (b) the well established theory that intelligence is not only transmitted via family environment but also via genes (backed by twin research; Plomin et al., 2013) and (c) better educated and more intelligent adults having fewer children (e.g., Loehlin, 1997). If these three statements are correct, negative genetic effects on inter- generational intelligence development are a logically compelling conse- quence. Such negative effects may be aggravated, if migration produces brain drain in developing countries, which occurs when high ability people in developing countries immigrate to developed countries Personality and Individual Differences xxx (2016) xxx–xxx ⁎ Corresponding author. E-mail addresses: heiner.rindermann@psychologie.tu-chemnitz.de (H. Rindermann), david.becker@s2009.tu-chemnitz.de (D. Becker), thomas.coyle@utsa.edu (T.R. Coyle). PAID-07942; No of Pages 6 http://dx.doi.org/10.1016/j.paid.2016.10.061 0191-8869/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Personality and Individual Differences journal homepage: www.elsevier.com/locate/paid Please cite this article as: Rindermann, H., et al., Survey of expert opinion on intelligence: The FLynn effect and the future of intelligence, Person- ality and Individual Differences (2016), http://dx.doi.org/10.1016/j.paid.2016.10.061