Estimating the Size and Practical Relevance of the Ability Differentiation Effect

• In Event: Cognition and Assessment

Abstract

Measuring intelligence accurately in all populations is crucial because of its importance in many areas of life. To do so, we need to know whether the structural organization of cognitive abilities is invariant. The ability differentiation hypothesis describes changes in this structural organization depending on intelligence level. However, the practical relevance of the effect is disputed, as it is assumed to only have a small size. We identified available studies that investigated ability differentiation using nonlinear factor analysis and determined the median effect size and the consequences for measurement precision of general intelligence. The effect size indicated a decrease in model-implied reliability from over .80 for below average intelligence (IQ<100) to less than .40 for very high intelligence (IQ=130).

Authors

• Moritz Lion Breit, University of Trier
  Presenting Author

• Martin Brunner, University of Potsdam
  Non-Presenting Author

• Dylan Molenaar, University of Amsterdam
  Non-Presenting Author

• Franzis Preckel, University of Trier
  Non-Presenting Author