Sex Differences and Similarities in Risk Factors of Physical Aggression in Adolescence

Considerable research has documented risk factors of physical aggression in adolescence. However, less is known of sex differences in these associations. The current study addressed this important area by examining sex differences in concurrent associations of physical aggression with mental health concerns, trauma exposure, and substance use. The study sample consisted of 3686 boys (mean age 15.9 years) and 3881 girls (mean age 16.0 years) from Young-HUNT3, a population-based study of adolescents in Norway. Logistic regression was used to analyze the association of physical aggression, measured as involvement in physical fighting, with possible risk factors: attention problems, anxiety and depression, loneliness, self-esteem problems, trauma exposure, PTSD symptoms, and substance use. Twenty-one percent ( n = 773) of boys and three percent ( n = 133) of girls reported participating in physical fights. The results indicated that all risk factors were associated with physical aggression in the total sample as well as in boys and girls separately. Interaction effects with sex emerged for attention problems, anxiety and depression, loneliness, traumatic events, alcohol intoxication, and narcotics use, with larger odds ratios for girls than for boys. Attention problems, traumatic events, and alcohol intoxication showed unique associations with physical aggression for both boys and girls, in addition to PTSD symptoms for boys. In sum, boys’ and girls’ engagement in physical aggression was associated mainly with the same risk factors, but several of the factors increased the relative risk more for girls than for boys. The findings can inform interventions targeting physical aggression in adolescence.