There is a white matter tract that connects the amygdala and [orbitofrontal cortex] OFC, which is called the uncinate fasciculus (UF).
They found a significant reduction in the integrity of the small particles that make up the structure of the UF of people with psychopathic personality disorder, compared to control groups of people with the same age and IQ. Also, the degree of abnormality was significantly related to the degree of psychopathy.
No word here on what might be the cause of this deficit, such as genetics or damage in the womb, or on potential treatments.
The same article also notes
Also some investigators stress mainly social reasons to explain antisocial behaviours.
Consider, for example, the following by Emily Yoffe
Narcissistic personality disorder is not simply about taking normal egoism to extremes. NPD is one of fewer than a dozen personality disorders described by the American Psychiatric Association. These differ from the major mental illnesses, such as schizophrenia and manic-depression, which are believed to have a biological origin. Personality disorders are seen as a failure of character development. Others include anti-social personality disorder (these people are also commonly called “sociopaths” or “Bernie Madoff”) and borderline personality disorder (think of Livia Soprano).
I predict that most personality disorders, especially sociopathy, will be shown to “have a biological origin”. That doesn’t mean that the cause of the damage must necessarily be genetic in all cases. Environmental toxins and severe child abuse can do significant and permanent biological damage, too.