How sociodemographic factors shape the link between personality and cognitive ability

This study systematically investigated how links between personality traits and cognitive ability vary across key sociodemographic strata. Numerous studies have supported a robust but modest association between cognitive ability and certain personality traits, notably Big Five Openness and Neuroticism. Recent meta-analyses have also indicated that the personality–cognitive ability link is moderated by sociodemographic factors. However, previous research has often been limited by selective samples and has thus lacked systematic consideration of sociodemographic moderators. Drawing on a large, population-representative sample ( N = 137,395) from 27 countries in the OECD's PIAAC 2023 data set, our analyses filled this research gap by examining associations between the Big Five personality domains and facets and cognitive ability (as a composite of numeracy, literacy, and problem solving) by gender, age, and educational attainment. Results indicate remarkable cross-gender stability of the personality–cognitive ability link. By contrast, substantial differences emerged for age and especially for educational attainment. Personality–cognitive ability correlations were stronger among older and less-educated respondents. Effect sizes for Openness and Neuroticism/Negative Emotionality were up to three times larger in respondents without compared with those with higher education. Furthermore, Conscientiousness was–for respondents with higher education–negatively related to cognitive ability. Robustness checks confirmed the consistency of these patterns across different cognitive domains, Big Five measures, and response tendencies. These findings thus highlight the importance of considering age and particularly educational attainment when interpreting personality–cognitive ability associations, and they support theories proposing personality-driven investment in intellectual growth, particularly among individuals with fewer formal educational opportunities.