Disentangling Between- and Within-Person Effects of Nonphysical Aggression and Nonphysical Victimization Over Time in Adolescence.

Nonphysical aggression and victimization are common in adolescence, yet their long-term associations remain poorly understood, particularly with regard to within-person processes. To disentangle stable between-person differences from dynamic within-person associations, this study employed a random-intercept cross-lagged panel model with four waves of data collected every 6 months over 2 years from 856 Taiwanese adolescents aged 13-16. At the between-person level, adolescents with higher average levels of nonphysical aggression tended to report higher average levels of nonphysical victimization. At the within-person level, positive deviations from an individual's mean level of nonphysical aggression were associated with subsequent negative deviations from their mean level of nonphysical victimization, whereas deviations in victimization did not predict later deviations in aggression. Multigroup analyses indicated no gender differences in within-person associations; however, boys had higher average levels of nonphysical aggression than girls at the between-person level. These findings suggest that adolescents' within-person changes in nonphysical aggression may reflect short-term functional processes that differ from the stable risk patterns observed at the between-person level. Intervention strategies are discussed.