Do you think that much of the bullying in school stems from a past experience of being bullied? For example, a 5th grade boy bullies a 2nd grade boy because the former was bullied at that age?
I am not sure that the reason for bullying gets so precise that a person bullies another based on the year in which he first was bullied. Yet, it is our hypothesis that many of those who bully have experienced such unfair treatment by someone (or more than one person) that they are very angry. Their anger, from past hurts against them, now is displaced onto unsuspecting others in their lives. A son who is treated cruelly by his father, for example, may bring his pent-up anger to school and start to exhibit bullying behavior. He needs to forgive his father if his bullying is to stop.