Central to understanding individuals diagnosed with antisocial personality disorder is that they appear to experience a limited range of human emotions. This can explain the lack of empathy for the suffering of others, since they cannot experience emotion associated with either empathy or suffering. Risk-seeking behavior and substance abuse may be attempts to escape feeling empty or emotionally void. The rage exhibited by psychopaths and the anxiety associated with certain types of antisocial personality disorder may represent the limit of emotion experienced, or there may be physiological responses without analogy to emotion experienced by others.
According to the older theory of Freudian psychoanalysis, a sociopath has a strong id and ego that overpowers the superego. The theory proposes that internalized morals of our unconscious mind are restricted from surfacing to the ego and consciousness. However, this explanation provides no insight into the cause or treatment of the problem.
Research has shown that individuals with antisocial personality disorder are indifferent to the possibility of physical pain or many punishments, and show no indications that they experience fear when so threatened. This may explain their apparent disregard for the consequences of their actions, and their lack of empathy with the suffering of others. Although it is agreed upon by most psychiatrists that antisocial personality disorder is extremely difficult to treat, there is some evidence that shows that they respond to impersonalized loss.