Bullying seems to be present in all cultures, particularly among children..
It is so common, it may very well be that it performs some useful social function, even though it may be at the cost of destroying a few good and decent kids, and worse, of convincing some natural leaders that hurting and humiliating others is the best way to lead them.
I hope not, but it may not be a good idea to prevent children from bullying each other. It may be a form of instruction for the young, something to prepare them for future conflict and competition. Either way,, I think that our society's recognition of bullying as evil (not just a boys-will-be-boys thing) is to its credit. I hope that view tends to prevail.