In plain language
Intelligence is one of the best-known predictors of school success, and personality traits like conscientiousness also matter. But do intelligence and personality work together? This longitudinal study asked whether being high in "openness/intellect" — the personality trait of enjoying ideas, imagination, and abstract thinking — pays off more for students who also have high cognitive ability.
The researchers followed 786 Australian high school students from the Wollongong Youth Study. Students completed standardised verbal and numerical ability tests in Grade 7, then reported their personality (the Big Five traits) in Grade 10, when their end-of-year marks in Religious Studies, English, Mathematics, Science, History, and Geography were also collected.
Intelligence measured three years earlier was the strongest predictor of Grade 10 performance, and conscientiousness also helped. But the most interesting finding was the interaction: openness/intellect was associated with better grades only among students with higher intelligence. In other words, being interested in ideas and thinking is not enough on its own to earn better grades — the benefit of an intellectually curious personality emerges when it is paired with the cognitive ability to act on that curiosity. This pattern held across every school subject and survived multiple statistical checks, suggesting that efforts to improve achievement should consider how ability and personality combine, not just each one alone.
Key findings
- Grade 7 intelligence was the strongest predictor of Grade 10 academic performance three years later (beta = .50 for total grade), across 786 high school students.
- Openness/intellect predicted higher grades only among students with higher intelligence; among lower-ability students it made little difference (significant IQ x Intellect interaction, beta = .13, p < .01).
- The interaction between intelligence and openness/intellect was significant for every individual subject: Religious Studies, English, Mathematics, Science, History, and Geography.
- The effect held in nonparametric bootstrapping analyses (interaction beta = .19, 95% CI .075 to .297) and was not eliminated when the other Big Five personality traits were controlled.
- Conscientiousness was a significant independent predictor of total grade and of most individual subjects, including Mathematics and Science.
- Intelligence predicted Religious Studies more weakly than any other subject, suggesting subject areas differ in how strongly they draw on cognitive ability.
How to cite
APA
Heaven, P. C. L., & Ciarrochi, J. (2012). When IQ is not everything: Intelligence, personality and academic performance at school. Personality and Individual Differences. https://doi.org/10.1016/j.paid.2012.04.024
BibTeX
@article{heaven2012when,
author = {Heaven, Patrick C. L. and Ciarrochi, Joseph},
title = {When IQ is not everything: Intelligence, personality and academic performance at school},
journal = {Personality and Individual Differences},
year = {2012},
doi = {10.1016/j.paid.2012.04.024}
}
Related work
- All publications by Joseph Ciarrochi (searchable, with free PDFs)
- Process-Based Therapy & Idionomic Analysis
Author: Joseph Ciarrochi (ORCID 0000-0003-0471-8100). Free copy hosted with permission for scholarly use. Please cite the published version via the DOI above.