Aggression and academic performance

Introduction: A negative relationship between aggression and academic performance has been reported. Here, we assess the effects of age, of different measures of aggression, and of different raters on the association and then... [ view full abstract ]

Introduction: A negative relationship between aggression and academic performance has been reported. Here, we assess the effects of age, of different measures of aggression, and of different raters on the association and then ask whether the association between aggression and academic performance can be confirmed in within-family comparisons.

Methods: We studied three twin cohorts participating in the ACTION consortium (Aggression in Children: Unraveling gene-environment interplay to inform Treatment and InterventiON strategies; http://www.action-euproject.eu/): FinnTwin12 (from Finland, N = 3122), CATSS (from Sweden, N = 5387) and NTR (from Netherlands, N = 10430). Grade point average (GPA) at ages 12 (FinnTwin12 & NTR), 14 (FinnTwin12) and 15 (CATSS) was used as a measure of academic performance. Aggression at ages 7 (NTR), 10 (NTR), 12 (NTR & FinnTwin12), 14 (FinnTwin12), and 15 (CATTS) was measured with three different instruments: Child Behavior Checklist in NTR, Multidimensional Peer Nomination Inventory in FinnTwin12, and Strengths and Difficulties questionnaire in CATSS. We investigated the association between aggression and GPA by conducting between-family and within-family analyses in each cohort separately for different aggression raters (parent, teacher, self) at different ages.

Results: Between-family analyses indicated consistently significant negative associations between aggression and GPA across different ages, instruments and raters. In within-family analyses of all twins, the negative association between aggression and GPA was statistically significant in 13 out of 15 analyses. In separate analyses limited to MZ twins, most of the associations were non-significant. However, within-family analyses of DZ twins indicated more significant associations between aggression and GPA.

Conclusions: There is a robust negative association between aggression and academic performance as measured with GPA. The lack of association in within-family analyses of MZ twins indicate that this relationship is due to shared genetic influences between childhood aggression and academic performance.