Aggression is childhood is the emotional trait that is the strongest predictor of later maladjustment. If not shown other ways than anger and violence to get what they are seeking, they are prone to have difficulties later in life, ranging from trouble with the law to depression and neuroses.
Shared traits of aggressive children are the inability to imagine ways to react in the heat of anger other than to strike out. Such children also tend to perceive slights where none are intended. Boys are twice as likely as girls to suffer from this problem.