punishment is needed but...
Telling right and wrong is one of important things that children must have to know on the early age. On the way in teaching difference, one useful mean is punishing them.
I believe that punishment works on forbidding little boys and girls from doing wrong. After decision they made, people could realize that is a false if punishment follow with it. From that on, painful experience become a reminder to themselves, and stop them to do it again.
Violence is one kind of familiar and widespread choice in penalization. Even it comes with a significant effect, a reflection will company with that children will copy violent behaviour. For example, person who born in family which has domestic violence problem has high possibilities becoming aggressive in school, like hurting other classmates.
Consequence from actions they made is a good lesson to kids. How to penalize would influence person's personality in future. Therefore, teens need to understand the consequence if someone behave same thing to them on their own. Like criticizing on somebody only by his or her outlook, parent or teacher can force children to be on a side which reluctantly receiving criticization they said before. First, they might feel uncomfortable about the words, then be sad that no one wants to know they really are and turn to be unconfident. After all, adult should tell them the reason why they been punished and why they did is unacceptable.
In other words, punishment is needed for teach distinction, although, we need to choose better methods to execute penalization.