The dark tendencies humans may have, such as psychopathy (lack of empathy), narcissism (excessive self-absorption), egoism and sadism are based on the same single underlying source: a drive to maximize one's individual interests, and to disregard or malevolently cause harm to others' interests. These tendencies often underlie the most serious violent crime in any society, usually dealt with by imprisonment. Psychiatrists say that people with these characteristics are notoriously difficult to change. This suggests that these personality traits are likely to be inherited genetic dispositions over which people have no control. It is wrong, therefore, to punish people for the actions that have resulted from such tendencies. The justice system should not imprison someone for actions over which they had no control.