Jan te Nijenhuis


E-mail: nijen631@planet.nl
Room: 1C-25

I am currently involved in a number of projects. A selection includes

  • Bias in IQ testing of immigrants/minorities
  • Meta-analysis
  • Publication bias
  • Intelligence decline (reverse Flynn effect)
  • Intelligence decline due to Alzheimer’s disease (Chosun University, South Korea)
I collaborate with researchers from US, UK, Ireland, Norway, Sweden, Denmark, Finland, Estonia, Germany, Russia, Ukraine, Portugal, Croatia, Cyprus, Saudi Arabia, Libya, Israel, Palestine, Egypt, Yemen, Somalia, Brazil, South Africa, South Korea, Japan, China, and the Netherlands.



I studied at Groningen University and worked at my PhD at the Free University in Amsterdam and at the Dutch Railways. I worked at various universities, including recently Chosun University in Gwangju, Korea. I worked as a consultant on mainly personnel selection issues for companies and for the Armed Forces, resulting in 26 reports. I also work as a science writer, resulting in 47 professional publications. I received a scientific prize for my master thesis and for my PhD thesis. Three of my undergraduate students won the Van Lennep Award for the best master thesis in applied psychology and one won the prize for the best master thesis  in psychology at the University of Amsterdam. My research on declining genetic intelligence with Michael Woodley and Raegan Murphy in 2013 received an enormous amount of attention in the popular press all over the world and led to TV interviews in France, Germany, the Netherlands, the US, and on Al Jazeera. I review for two dozen journals and am a member of the editorial board of the multidisciplinary journal Intelligence (2006-present).


Research interests

  • personnel selection/assessment/Human Resource Management
  • individual differences in intelligence and personality
  • test training
  • discrimination
  • bias in IQ testing and assessment of immigrants
  • group differences in intelligence and personality
  • evolutionary psychology
  • publication bias
  • meta-analysis
  • intelligence increase (Flynn effect) and intelligence decrease (reverse Flynn effect)


  • Advanced Organizational Research Skills (master course)
  • Supervising bachelor and master theses

Recent publications

J te Nijenhuis, KY Choi, YY Choi, JJ Lee, EH Seo, H Kim & KH Lee (2018) Differences Between APOE Carriers and Non-APOE Carriers on Neurocognitive Tests: Jensen Effects?. American Journal of Alzheimer's Disease & Other Dementias®, 1533317518765895
J te Nijenhuis, M van den Hoek, D Metzen & H David (2017) Spearman's hypothesis not supported? Three meta-analyses of Black and White prisoners, Northeast Asians, and Arabs and Jews. Personality and Individual Differences 117, 52-59
J Te NijenhuiS, AA Batterjee, M Van Den Hoek, J Allik & V Sukhanovskiy (2017) Spearman’s hypothesis tested comparing Saudi Arabian children and adolescents with various other groups of children and adolescents on the items of the Standar.... Journal of biosocial science 49 (5), 634-647
J te Nijenhuis, M van den Hoek & D Willigers (2017) Testing Spearman’s Hypothesis with Alternative Intelligence Tests: A Meta-Analysis. Mankind Quarterly 57 (4)
YM Hur, J te Nijenhuis & HUK Jeong (2017) Testing Lynn’s Theory of Sex Differences in Intelligence in a Large Sample of Nigerian School-Aged Children and Adolescents (N> 11,000) using Raven’s Standard.... Mankind Quarterly 57 (3), 428-437
HBF Fernandes, J te Nijenhuis, M Peñaherrera-Aguirre & AJ Figueredo (2017) General intelligence is a source of individual differences between species: Solving an anomaly. Behavioral and Brain Sciences 40
AA Al-Shahomee, J te Nijenhuis, M van den Hoek, G Spanoudis & ... (2017) Spearman’s Hypothesis Tested Comparing Young Libyan with European Children on the Items of the Standard Progressive Matrices. Mankind quarterly 57 (3), 456-466
J te Nijenhuis, AA Al-Shahomee, M van den Hoek, J Allik, A Grigoriev & ... (2017) Corrigendum to “Spearman's hypothesis tested comparing Libyan secondary school children with various other groups of secondary school children on the items of t.... Intelligence, 180-181
I Voronin, J Te Nijenhuis & SB Malykh (2016) The correlation between g loadings and heritability in Russia. Journal of biosocial science 48 (6), 833-843
J te Nijenhuis, HBF Fernandes & D Metzen (2016) Small to medium magnitude Jensen effects on brain volume: A meta-analytic test of the processing volume theory of general intelligence. Learning and Individual Differences 51, 215-219
EL Armstrong, J te Nijenhuis, HBF Fernandes, O Must & A Must (2016) A NIT-picking analysis: Abstractness dependence of subtests correlated to their Flynn effect magnitudes. Intelligence 57, 1-6
J te Nijenhuis & M van den Hoek (2016) Spearman’s Hypothesis Tested on Black Adults: A Meta-Analysis. Journal of Intelligence 4 (2), 6
J te Nijenhuis, SF Bakhiet, M van den Hoek, J Repko, J Allik, MS Žebec & ... (2016) Spearman's hypothesis tested comparing Sudanese children and adolescents with various other groups of children and adolescents on the items of the Standard Pr.... Intelligence 56, 46-57
J te Nijenhuis, A Grigoriev & M van den Hoek (2016) Spearman's hypothesis tested in Kazakhstan on the items of the Standard Progressive Matrices Plus. Personality and Individual Differences 92, 191-193
B Marcus, J te Nijenhuis, M Cremers & K Heijden‐Lek (2016) Tests of integrity, HEXACO personality, and general mental ability, as predictors of integrity ratings in the Royal Dutch Military Police. International Journal of Selection and Assessment 24 (1), 63-70
J te Nijenhuis, D Willigers, J Dragt & H van der Flier (2016) The effects of language bias and cultural bias estimated using the method of correlated vectors on a large database of IQ comparisons between native Dutch and eth.... Intelligence 54, 117-135
E Dutton, J Kukkola & J te Nijenhuis (2015) Stress, Political Instability, and Differences between British and Franco-German Twentieth Century Philosophy. Mankind Quarterly 56 (2), 173
J te Nijenhuis & R Murphy (2015) The Victorians were still faster than us. Commentary: Factors influencing the latency of simple reaction time. Frontiers in human neuroscience 9, 452
J te Nijenhuis, AA Al-Shahomee, M van den Hoek, J Allik, A Grigoriev & ... (2015) Spearman's hypothesis tested comparing Libyan secondary school children with various other groups of secondary school children on the items of the Standard Pro.... Intelligence 50, 118-124
J te Nijenhuis, M van den Hoek & EL Armstrong (2015) Spearman's hypothesis and Amerindians: A meta-analysis. Intelligence 50, 87-92

View full list of publications on Google Scholar