Trajectories and predictors of indirect aggression: results from a nationally representative longitudinal study of Canadian children aged 2-10.

The purposes of this study were to model the development of indirect aggression among a nationally representative sample of 1,401 Canadian children aged 4 at T2, 6 at T3, 8 at T4 and 10 at T5, and to examine predictors of trajectory group membership from T1 (age 2) child, familial, and parenting variables. Using a semi-parametric group-based modeling approach, two distinct trajectories were identified: "increasing users" comprising of 35% of the sample and "stable low users" comprising of 65% of the sample. Using logistic regression analyses to distinguish these two groups, we found that for girls, more frequent, increasing use of indirect aggression was associated with prior prosocial and physically aggressive behavior, low SES and low parental social support at age 2.