Inconsistent Flynn effect patterns may be due to a decreasing positive manifold: Cohort-based measurement-invariant IQ test score changes from 2005 to 2024

Autor(en)
Sandra Oberleiter, Jonathan Fries, Florence Dejardin, Johanna Heller, Christian Schaible, Marco Vetter, Martin Voracek, Jakob Pietschnig
Abstrakt

Generational IQ test score changes in the general population (i.e., the Flynn effect, typically reported as increases of 2–4 IQ points per decade) have recently been observed to behave inconsistently. It has been speculated that these inconsistencies may be attributable to the well-established negative relation of test score gains with psychometric g. Here, we provide the first direct empirical investigation of cross-temporal changes in the positive manifold of intelligence. In this cohort-comparison study, we examined performance changes in two population-representative Germanophone samples (N = 1267) across six measurement-invariant intelligence subscales from 2005 to 2024. Our analyses revealed substantial declines in single-factor analysis-based g assessments (ΔR

2 range: ‐.037 to -.066) from 2005 to 2024. Despite this decrease in the positive manifold strength, we observed meaningful test score increases in all domains (d range: 0.18 to 1.24), with the largest gains in the lower tail of the intelligence distribution (i.e., conforming to Rodgers', 1998, idea of narrowing ability distributions). Our findings provide direct evidence for a decreasing strength of the positive manifold of intelligence as a noticeable driver of the accumulating evidence for negative Flynn effects, which may be a consequence of increasing ability differentiation in the general population.

Organisation(en)
Institut für Psychologie der Entwicklung und Bildung, Institut für Psychologie der Kognition, Emotion und Methoden
Externe Organisation(en)
Universität Wien, Paris-Lodron Universität Salzburg
Journal
Intelligence: a multidisciplinary journal
Band
107
ISSN
0160-2896
DOI
https://doi.org/10.1016/j.intell.2024.101867
Publikationsdatum
11-2024
Peer-reviewed
Ja
ÖFOS 2012
501018 Psychologische Diagnostik, 501004 Differentielle Psychologie
Schlagwörter
ASJC Scopus Sachgebiete
Experimental and Cognitive Psychology, Developmental and Educational Psychology, Arts and Humanities (miscellaneous)
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/9fe59a68-5d98-4c68-8f3e-7f34fb8514f8