Understanding Antisocial Personality Disorder

From Drugs.com:

A person with [Antisocial Personality] disorder usually does not take responsibility for any of his or her own suffering.

But then...

Antisocial personality disorder is probably caused by a combination of factors. Having any of these characteristics does not necessarily mean that a person has antisocial personality disorder.

• Influences from the environment. A chaotic family life contributes to the development of this personality disorder, especially where there has been little supervision from parents or other adult role models. The disorder also may be more common where the community is not supportive or provides little reward for positive behavior. In some situations, there may even be reinforcement for sociopathic behavior.
• Genetic (inherited) or biological factors. Researchers have found certain physiological responses that may occur more frequently in people with antisocial personality disorder. For example, they have a comparatively flat response to stress. They seem to get less anxious than the average person. They seem to have a harder time maintaining daytime arousal. They also have a weak "startle reflex," the involuntary response to loud noises. This relative insensitivity may affect their ability to learn from reward and punishment.
• The frontal lobe, the area of the brain that governs judgment and planning, also appears to be different in people with antisocial personality disorder. Some researchers have found changes in the volume of brain structures that mediate violent behavior. People with this kind of brain function may thus have more difficulty restraining their impulses, which may account for the tendency toward more aggressive behavior. Neurobiologists cannot say with certainty that these variations in brain structure are a cause of antisocial personality. The variations could easily be the result of life experiences that are more common in people with this personality disorder rather than a cause.