In plain language
Decades of research show that children with higher IQs tend to live longer and healthier adult lives, but very little research has asked when intelligence begins to shape health behavior. Does it already matter during high school? This study, part of the longitudinal Wollongong Youth Study in Australia, tracked whether intelligence measured at the start of high school predicted health behaviors five years later.
Students completed standardized verbal and numerical ability tests and a measure of the personality trait conscientiousness in Grade 7 (average age 12.3), and then reported their health-related behaviors in Grade 11 (average age 16.2). The matched sample included 420 adolescents (188 males, 232 females). Health measures covered substance use, eating habits, physical exercise, TV viewing, and consumption of stimulant drinks such as Red Bull.
Brighter students showed several healthier patterns: they started smoking cigarettes later, watched less television, and drank fewer stimulant drinks — and these effects held even after accounting for conscientiousness, socio-economic status, and gender. One surprise ran against the adult literature: more intelligent teens actually exercised less, possibly reflecting school social cultures where sport belongs to the “jocks” rather than the “brains.” The findings suggest that intelligence starts shaping health trajectories well before adulthood, making adolescence a key window for health interventions.
Key findings
- Higher verbal ability in Grade 7 predicted a later age of first smoking a cigarette (r = .18), a protective delay in smoking onset.
- Higher intelligence significantly predicted less TV viewing and lower consumption of stimulant drinks (e.g., Red Bull, V) in Grade 11, with medium effect sizes.
- Unexpectedly, higher intelligence predicted lower participation in physical exercise — the opposite of findings in adult samples.
- Intelligence remained a significant predictor of these health behaviors after controlling for conscientiousness, socio-economic status, and gender.
- Conscientiousness in Grade 7 was associated with less drug use and stimulant-drink intake and with more healthy eating and physical exercise.
- Boys started smoking cigarettes and marijuana significantly earlier than girls, exercised more, ate more junk food, and consumed more stimulant drinks; girls ate more healthy food.
How to cite
APA
Ciarrochi, J., Heaven, P. C. L., & Skinner, T. (2012). Cognitive ability and health-related behaviors during adolescence: A prospective study across five years. Intelligence, 40, 317–324. https://doi.org/10.1016/j.intell.2012.03.003
BibTeX
@article{ciarrochi2012cognitive,
author = {Ciarrochi, Joseph and Heaven, Patrick C. L. and Skinner, Timothy},
title = {Cognitive ability and health-related behaviors during adolescence: A prospective study across five years},
journal = {Intelligence},
year = {2012},
volume = {40},
pages = {317--324},
doi = {10.1016/j.intell.2012.03.003}
}
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- All publications by Joseph Ciarrochi (searchable, with free PDFs)
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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.