The current study provided some support for the theoretical assumption
(Bandura, 1999, 2002) that people involved in aggressive behavior for
a longer period will increase their moral disengagement in order for their
moral view of themselves to be congruous with their aggression (the escalation
hypothesis). Stable bullies showed a significant increase in moral
disengagement compared to desisting bullies and nonbullies. However,
when comparing the stable bullies T1 and T2 levels of moral disengagement
only a (nonsignificant) trend occurred. Thus, the findings of the current
study did not find conclusive support for the escalation hypothesis. Future
research should aim at further investigating the causal and temporal aspects
of moral disengagement and bullying in order to determine whether moral
disengagement predicts bullying or vice versa, and whether the development
of moral disengagement evolves in a reciprocal interplay between
legitimizing thoughts and aggressive behavior.