I think they can change the way children behave because that way they are thaught that if you do good things, you earn good things, and the opposite. I think it is important for a kids education to be punished from time to time. Of course, they should also be explained what they did wrong. Usually, if children do good things and are not rewarded, they will get bored and do something less good. Children should also be given verbal rewards, not just material ones like candy or money. Also, as they grow up, there should be less and less rewards and punishmants so they get to make the differance themselves between good and bad and learn from their mistakes
