their own bullying involvement and how they judge the bullying involvement
of others. Regarding themselves, children are more likely to judge that they
are involved in bullying as well as in victimizations whereas children tend
to have a more dichotomized categorization of their peers. In addition, the
social reputation seems to be more stable than the self-evaluation of being a
bully or a victim. Gender differences were found for peer-nominated bullying
showing that at T2 boys were more likely to be considered bullies by their
peers than were girls, whereas no significant gender differences occurred
for changes in self-reported bullying. The differences found in the current
study supported previous findings of differences between self-reported and
peer-nominated bullying and victimization (Graham et al., 2007; Juvonen
et al., 2001; Obermann, 2011b), pointing to the importance of including
both measures in research on peer aggression. In the current study, only
changes in self-reported bullying showed a significant influence on changes
in moral disengagement whereas changes in peer-nominated bullying were
unrelated to changes in moral disengagement. This finding suggests that
temporal aspects of moral disengagement are related to the personal experience
of being a bully, whereas changes in the peer opinions of whether
one is a bully or not, do not affect changes in moral disengagement. In that
respect, the findings of this study are contrary to the findings of a previous
cross-sectional study finding that moral disengagement relates to both selfreported
and peer-nominated bullying (Obermann, 2011b). Future research
might aim at further investigating whether changes in moral disengagement
are primarily related to the personal experience of being a bully and at locating
the causes for peer-nominated bullying not being related to changes in
moral disengagement