characteristics of antisocial

Can you tell me what characteristics of antisocial persons are? I am interested in this for I think my cousin might be suffering of what is called antisocial personality disorder. He is now 17 years old and doesn't care for any social rule and I am worried that one day he might ended up in jail. I have also noticed he doesn't care at all what other persons feels or needs and he turned into pretty much aggressive boy. Do you think I exaggerate or this is just the part of growing up?

Well it all depends on how long this condition persist but no matter this whenever someone as violent or aggressive and without any interesting in other people's feelings and needs than those are usually marked as major characteristic of antisocial persons. Anyway if you are positive still that this is not regular behavior than your cousin needs to have some psychotherapy which is in severe cases usually combined with taking meds or drugs. The treatment is usually focused on making affected person being aware of his behavior –though more the patient is aggressive the less are the chances that he would cooperate but according to the researches the characteristics of antisocial behavior reduces by years and by the time of 40 the problem is pretty much solved expect in case of some mental illness involved.