Higher IQ in adolescence was related to higher openness, lower neuroticism, lower extraversion, lower agreeableness and lower conscientiousness 50 years later

IQ in adolescence and cognition over 50 years later: The mediating role of adult personality. Yannick Stephan et al. Intelligence, Volume 94, September–October 2022, 101682. https://doi.org/10.1016/j.intell.2022.101682

Highlights

• Higher IQ in adolescence was related to better cognition 50 years later.

• Higher IQ was related to higher openness to experience in adulthood.

• Higher openness mediated the link between adolescent IQ and late life cognition.

Abstract: There is substantial evidence for the association between higher early life IQ and better cognition in late life. To advance knowledge on potential pathways, the present study tested whether Five-Factor Model personality traits in adulthood mediate the association between adolescent IQ and later-life cognition. Participants were from the Graduate sample of the Wisconsin Longitudinal Study on Aging (WLS; N = 3585). IQ was assessed in 1957 (about age 17), personality was assessed in 2003–2005 (age = 64), and cognition was assessed in 2011 (age = 71). Controlling for demographic factors, higher IQ in adolescence was related to higher openness, lower neuroticism, lower extraversion, lower agreeableness and lower conscientiousness in adulthood. Higher openness partially mediated the association between higher IQ and better cognition. Additional analyses indicated that the pattern of associations between IQ, personality and cognition was similar when the polygenic score for cognition was included as an additional covariate. Although effect size were small, this study provides new evidence that openness in adulthood is on the pathway between early life IQ and later-life cognition.

Keywords: IQPersonality traitsCognitionMediationLongitudinal study