Extraversion and intelligence: A meta-analytic investigation.
Aspects of the Ackerman and Heggestad (1997) meta-analysis were updated and expanded to address the complex, contradictory findings of the extraversion–intelligence relation. Although the estimated effect sizes in the current study remained slightly positive, there was a decrease in the magnitude of the effect across extraversion–intelligence pairs in comparison to the 1997 meta-analytic results. Correlations between the date of publication of the study and the observed extraversion–intelligence correlations were generally negative, which suggested a change in the magnitude of the extraversion–intelligence relation over time. Furthermore, the estimated effect size between extraversion and intelligence for studies conducted in the year 2000 and later was (p < .05), indicating that not only has the magnitude of the correlation decreased, but also that the direction of the correlation has changed from positive to slightly negative. Trends associated with two potential moderator variables are also discussed: the use of different measures and the average age of the samples.