Conduct Disorder has the highest measure of aggressive behavior among childhood disorders. Why? Well, the definition itself is explanatory. Conduct disorder is a mental illness in which children specifically present themselves in an aggressive manner, meaning they have tendencies to commit theft, lie, bully, and intimidate. Children with conduct disorder are not very attentive; they disregard general rules and lack empathy and social acceptable behavior. This is most of the time a result of how they were treated or if anything happened to them traumatically such as brain damage.