Testing the personality differentiation by intelligence hypothesis in a representative sample of Swedish hexagenerians

The Personality Differentiation by Intelligence Hypothesis (PDIH) predicts larger trait-variances, and smaller across-trait covariances for individuals with higher intelligence. We tested these predictions using multiple-group confirmatory factor analyses (MG-CFA), while controlling for the potential confound of systematic method variance related to reversed items using a correlated trait, correlated method (CTCM) approach. Participants between the ages of 62 and 68 completed measures of personality (Mini-IPIP: Donnellan et al., 2006) and intelligence (Raven APM-12: Arthur & Day, 1994). After establishing strict measurement invariance (MI), we found no support for larger variances, and only minor support for lower trait covariances as related to higher intelligence. Overall, the findings provide scant support for the PDIH when controlling for systematic method variance.