Testing the reciprocal longitudinal association between pro-aggressive bystander behavior and diffusion of responsibility in Swedish upper elementary school students

The overall objective of this study was to investigate the longitudinal association between diffusion of responsibility and pro-aggressive bystander behavior across three time points in upper elementary education. This three-wave longitudinal study included 1905 Swedish students who completed a questionnaire in at least one of the three waves: the fourth (M-age = 10.56), fifth (M-age = 11.55), and/or sixth grades (M-age = 12.58). Both traditional and random intercept cross-lagged panel models revealed a reciprocal relationship between pro-aggressive bystanding and diffusion of responsibility from the fourth to fifth grades, whereas the only significant cross-lagged path from the fifth to sixth grades was from pro-aggression to diffusion of responsibility in the traditional cross-lagged panel model. Thus, this study provides evidence for bidirectional longitudinal associations between diffusion of responsibility and pro-aggressive bystander behavior but did not support a full cross-lagged bidirectional model.