The diagnostic process to arrive at a reliable and valid rating of the President on the Checklist was rigorous. Robert Hare, the developer of the Checklist, wrote a book length manual in which he provided extensive definitions and behavioral examples for each item on the Checklist in order to facilitate consistency and reliability in ratings. He also spelled out the fundamental tasks of the evaluator, to wit:
- Collect as much relevant information (life history data points) on Trump as you can.
- Cull all the informational data that supports each item on the checklist.
- Provide a rating for each item on the checklist and then determine the level of psychopathy in the President.
Collecting relevant information on Trump, although overwhelming at times, was not difficult. There is extensive informant data because of the many biographies and investigative reporting on the man. There is also a wealth of archival data, in large part due to the televised nature of celebrity and the Presidency. There are thousands of hours of videotape available for behavioral observation of relevant diagnostic markers.
The next step is to catalogue the mass of information available on Trump. Robert Hare laid down guidelines to prioritize certain batches of information over others:
- Information from his childhood, adolescence and young adulthood. The condition of psychopathy expresses itself early in life. Data is needed from these earlier stages of development to make an assessment.
- Information in which the trait is expressed in overt behavior (e.g., an instance of his lying is privileged over an accusation of his lying).
- Information that reflects his typical functioning and lifelong patterns vs. descriptions of more flamboyant, occasional behavior.
- Information that is well-resourced, substantiated and has some type of external validation.
- Behavior that lends itself to coding and thus quantification (e.g., number of documented lies, lawsuits, or grandiose statements).
The next step is to go through each item of the checklist and cull all the informational data that supports that particular item on the checklists. This enables us to generate a data-rich rating for each item on the Checklist, and then an overall score.