Barchia and Bussey (2011) conducted a follow-up study in which
they collected data at the beginning and the end of a school year among
1,167 Australian adolescents. When using Time 2 (T2) aggression as the outcome
variable, the researchers found that Time 1 (T1) moral disengagement
as well as T1 aggression efficacy (that is, self-efficacy to enact physical,
relational, and verbal aggression) predicted higher T2 peer aggression, suggesting
that an increase of aggressive acts occur among children prone to
morally disengage. However, the researchers found no significant effect of
T1 aggression on change in moral disengagement across time.