Reciprocal relationships between adolescent aggression and close friendship quality in middle and high school

This study assessed the overarching hypotheses that aggression will predict future peer functioning and similarly that peer functioning will predict future levels of aggression across the transition from middle to high school (age 13 to age 15). Multimethod, longitudinal data, obtained on a diverse community sample of 182 adolescents, their best friends, other friends, and acquaintances addressed these hypotheses using multiple approaches to assessing aggression and peer functioning. Three aspects of aggression were assessed: aggressive problem behavior, relational aggression, and violent aggression. Several different domains of peer functioning were considered as well: popularity and peer rejection, observed positive aspects of dyadic friendships (overall levels of support and engagement), and negative aspects of dyadic friendships (levels of conflict in relationships and use of rude and hostile communication styles). Hypotheses were tested using both regression and structural equation modeling methods.;Lower levels of aggressive problem behavior and of violent aggression at age 13 were found to be predictive of higher levels of peer functioning at age 15. Conversely, aggressive problem behavior and violent aggression at age 15 were predicted by popularity and engagement with a best friend at age 13. When both effects were considered simultaneously in models that also accounted for baseline levels of predicted outcomes, only popularity and engagement with peers at age 13 were found predictive of the severity of violent aggression at age 15. Overall, these results provide little evidence of a causal relationship between peer functioning and aggression over time, but suggest that both constructs are likely manifestations of an unmeasured underlying vulnerability. The relationships revealed between these constructs in the current study are nevertheless potentially useful to parents, teachers, and therapists who often only have access to information in only one domain (e.g. aggression or peer functioning), which can now be used to improve knowledge of potential risks in other domains.