Defiant behavior is a normal part of being a kid. But for some kids, defiance goes beyond the realm of normal behavior. They become so uncooperative and combative that the defiant behavior interferes with their ability to learn, thrive and get along with people. This is called oppositional defiant disorder (ODD) and it occurs in about 10% of children in the U.S. From the Discovery Health Channel.
emotional disturbance, oppositional defiant disorder