What are the observable differences between "pure" antisocial personality disorder and psychopathy? How to decide whether one has antisocial personality disorder, psychopathy, or both?
What are the traits which non-psychopaths with APD have but psychopaths don't have, or vice versa?
Antisocial personality disorder (APD) and psychopathy are not distinct entities, but highly overlapping constructs. APD is the diagnosis currently supported by the latest iterations of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and psychopathy is rarely used in clinical contexts today, though the terms are often used interchangeably.
The criteria of APD are centered around antisocial behaviors such as norm violating behavior, impulsivity, aggressiveness, and a lack of remorse. Psychopathy lacks a specific set of criteria, but for instance the often used Hare Psychopathy Checklist (PCL-R)include aspects such as impulsivity, aggressivity, and a greater focus than APD on the lack of empathy and Machiavellianism, that is manipulativeness and callousness.