As only two data collections were conducted, it was impossible to say
whether bigger or minor changes in bullying and moral disengagement may
have occurred between T1 and T2. Due to the design of the study, it was not
possible to estimate exactly when within the 12-month period between the
T1 and the T2 data collection the desisted bullies had stopped bullying—this
point in time might have occurred anywhere between 12 and 3 months prior
to the T2 data collection. Hence, future research should further investigate
the crystallization and the escalation hypotheses using studies with multiple
and frequent measures of bullying and disengagement. Another future
research aspect may be the tendency for desisted bullies to start bullying
again. Darley (1992) put forward the assumption that ordinary, morally concerned
people once involved in severely violent and immoral behavior will
become likely to commit evil acts on a permanent basis. Future longitudinal
research might clarify whether desisted bullies would be more likely to
start bullying again compared to children holding other positions in school