Hervey Cleckley, who first observed and defined the psychopath, came up with this 16 point checklist of symptoms:

1. Considerable superficial charm and average or above average intelligence.

2. Absence of delusions and other signs of irrational thinking

3. Absence of anxiety or other "neurotic" symptoms considerable poise, calmness, and verbal facility.

4. Unreliability, disregard for obligations no sense of responsibility, in matters of little and great import.

5.Untruthfulness and insincerity

7. Antisocial behavior which is inadequately motivated and poorly planned, seeming to stem from an inexplicable impulsiveness.

7.Inadequately motivated antisocial behavior

8.Poor judgment and failure to learn from experience

9. Pathological egocentricity. Total self-centeredness incapacity for real love and attachment.

10. General poverty ot deep and lasting emotions.

11. Lack of any true insight, inability to see oneself as others do.

12. Ingratitude for any special considerations, kindness, and trust.

13. Fantastic and objectionable behavior, after drinking and sometimes even when not drinking--vulgarity, rudeness, quick mood shifts, pranks.

14. No history of genuine suicide attempts.

15. An impersonal, trivial, and poorly integrated seX life.

16. Failure to have a life plan and to live in any ordered way, unless it be one promoting self-defeat.