Adjustment problems and school bullying in grade school: Differentiating between- and within-person associations

This study examined the longitudinal relations between adjustment problems and school bullying in middle childhood by differentiating between- and within-person effects and putting the co-occurrence into consideration. Participants were 1091 U.S. children (51.2 % boys, 80.5 % White) and their teachers. When children were in the third, fifth, and sixth grades, bullying perpetration and victimization were self-reported and adjustment problems were rated by teachers. Using the random intercept cross-lagged panel models, the results demonstrated that adjustment problems, particularly externalizing problems, were independently predicative of bullying and victimization at the between-person level, adjusting for within-person fluctuations and the co-occurrence of adjustment problems. Moreover, at the between-person level, bullying perpetration and victimization were positively related, as were internalizing and externalizing problems. The findings contribute evidence that adjustment problems and school bullying were stably related over time and highlight the importance of adjustment problems in better understanding involvement in school bullying among school-aged children.