My son who is 2 years old tends to get aggressive at times. Starts hitting people, banging his head against people and biting. His behaviour was not like this earlier. Last month we (me, wife and son) took a holiday along with both sets of grandparents. He was pampered and was getting his way with his grandparents. Since that holiday my son has been showing signs of aggressive behaviour everytime he doesn't get what he wants. My wife and I have never encouraged this kind of behaviour and are worried about his aggressive behaviour. At times he does this to other kids at his play group.