Are Extraverts Less Intelligent?

Although extraversion had a slight negative correlation with intelligence (predicting lower intelligence), the effect size was extremely small and near zero.

Source: 0fjd125gk87 / pixabay

Are extraverts less intelligent than introverts, or is the opposite true? According to researchers, introversion-extraversion may affect performance on intelligence tests. Eysenck’s arousal theory (1994) proposes that introverts arouse more easily and therefore are less risk-taking than extraverts, which in turn affects test-taking behaviors. Whereas introverts work more slowly for accuracy, extraverts work more quickly and make more mistakes on intelligence tests. Indeed, researchers found that introverts did better on intelligence tests when it was quiet, whereas extraverts performed worse when it was quiet.

However, the research in this area is far from conclusive. Some studies do not support the arousal theory. In addition, some studies find that extraversion is related to greater intelligence, whereas others (especially more recent studies) find the opposite.

To resolve these mixed findings, Wolf and Ackerman (2005) conducted a meta-analysis of 100 studies for correlations between extraversion and IQ among English speakers. Altogether, there were 166 samples, 1018 correlations, and over 50K participants.

Results indicated that although extraversion had a slight negative correlation with intelligence (predicting lower intelligence), the effect size was extremely small and near zero, indicating a practically unimportant effect. Interestingly, over time, not only did the effect size become smaller, but the correlation became negative instead of positive.

Furthermore, some moderators, such as age, were found to be important. At younger ages (10-13), there was a positive relationship between extraversion and intelligence, whereas at older ages (15-19), a negative relationship appeared. The same trend was found when comparing 10-29-year-olds versus 30-49-year-olds.

The researchers also examined two different dimensions of extraversion: social potency, or wanting to make an impact on others, and social closeness, or wanting to be close to others. They expected social closeness to be negatively related to intelligence as people high in this dimension may prefer to spend time with others versus developing their intelligence. Social potency was expected to be unrelated. Results indicated that social closeness mattered less than social potency for intelligence. Social potency had a very small positive association with intelligence, whereas social closeness had a near-zero correlation with intelligence.

Overall, these findings confirm that the relationship between extraversion and intelligence is complex; there is no clear answer. Over time, extraversion might be becoming more negatively associated with intelligence. However, newer studies tended to use older participants, which could explain this trend. Therefore, the researchers advise to account for three moderators to explain inconsistencies in results: the time of the study, the measures used for extraversion and intelligence, and the age of participants.