My Grandson is 4 years old. He is constantly yelling and screaming. You can't ask him a simple question with out an answer of yelling and screaming and sometimes going into a tantrum. He has been around children his age when he played tee-ball from April-June 2007. He didn't do that around them. My parents babysit him daily .They also pick up my niece and nephew from school. He is with them a few hours after school. He is always trying to boss them and gets very angry if they argue back. Have any idea what the problem may be? He doesn't want to fight . Just yell and scream.