Children with conduct disorder usually lack appropriate feelings of guilt or remorse and usually feel that their aggressive behavior is justified. They will often blame others for their misdeeds. The developmental stage of the child must also be taken into account. For example, it is part of normal development for two-year-olds to have tantrums. This behavior is not normal when seen in a nine-year-old.

The child with conduct disorder is usually described by parents as having been a difficult child from infancy or the toddler years. Such a child may have been more irritable, fussy, and oppositional than other children. The parents often feel that the child did not seem much attached to family members. The child often has had a hard time making or keeping friends and may be described as a loner. Unfortunately, a negative cycle may begin between child and parent. Because of the child's difficult behavior, parents may tend to decrease their interactions with the child, thus worsening the behavior. Parents may tend to stay home more as they are afraid of what problem behaviors the child may exhibit in public or around other family or friends. The early behavior problems of conduct disorder will tend to worsen with time if not treated.

Although the cause of conduct disorder is unknown, most researchers agree that a complex interplay between genetics, environment and biology results in these extreme behavior problems. Conduct disorder seems to run in families and is also more common if either parent has depression or another mental illness. Research has identified three primary risk factors of conduct disorder: harsh, inconsistent parenting, poor academic performance and exposure to parental discord. Any of these, but particularly the combination, is thought to contribute to the development of conduct disorder.

With its usual onset in middle childhood, the diagnosis has no lower age limit and is being seen increasingly at younger ages. If conduct disorder has its onset in childhood, it is less likely to be correlated with lower socio economic status and more likely to be associated with other conditions, such as ADHD or learning disorders. Childhood-onset conduct disorder occurs much more often in boys than in girls. Also, the childhood-onset type of conduct disorder has a poorer prognosis than the adolescent-onset type. Therefore, these children are more likely to grow up to become criminals. The good news is that specific treatments have been identified to treat conduct disorder. It seems that the earlier the interventions are started, the better chance the child has to grow to his or her full potential, and the more likely society will be saved the emotional and economic costs associated with juvenile crime.