The items used in the original version of the PPI were based on a number of conceptual constructs theorized (by previous researchers such as Hervey Cleckley and Robert D. Hare) to be related to psychopathy. It consists of a series of statements to which subjects respond on how accurately the statement describes them using a 4-point Likert scale (“False, “Mostly False”, “Mostly True”, “True”).
- Machiavellian Egocentricity (ME): A lack of empathy and sense of detachment from others for the sake of achieving one’s own goals
- Social Potency (SOP): The ability to charm and influence others
- Coldheartedness (C): A distinct lack of emotion, guilt, or regard for others’ feelings
- Carefree Nonplanfulness (CN): Difficulty in planning ahead and considering the consequences of one’s actions
- Fearlessness (F): An eagerness for risk-seeking behaviors, as well as a lack of the fear that normally goes with them
- Blame Externalization (BE): Inability to take responsibility for one’s actions, instead blaming others or rationalizing one’s behavior
- Impulsive Nonconformity (IN): A disregard for social norms and culturally acceptable behaviors
- Stress Immunity (STI): A lack of typical marked reactions to traumatic or otherwise stress-inducing events
Additionally, the PPI also included two special validity scales designed to detect participants who were giving random, inconsistent, or insincere answers. This was to avoid attempts at malingering, and to eliminate subjects who seemed to have difficulty understanding multiple items.