Early in my career as the University of North Dakota’s director of public relations, I mentioned to the late School of Medicine Professor Helge Ederstrom that I was looking for more insight into what it was that motivated human attitudes and behavior.

I was especially interested in those individual PR people — then rather naively described as “opinion leaders” — who possessed more than their share of power and influence. How could one better reach and nudge them in ways (other than, say, buying them off) that would benefit the organization he or she was representing?

Helge recommended I go to the Med School library and check out a book called “The Diagnostic and Statistical Manual of Mental Disorders,” published by the American Psychiatric Association.

I did so, and found it to be helpful in thinking about persuasion, influence and power.

On Thursday, I happened upon a used copy of an 886-page, newer version of the manual than the one I had previously read and purchased it for $2.99.

Lately, the “DSM,” as it’s called, has sometimes been quoted in the news and social media, particularly with respect to at least one of the candidates for president of the United States.

Here are the DSM’s diagnostic criteria for “Histrionic Personality Disorder.”

The individual generally exhibits a pattern of five (or more) of the following:

• Is uncomfortable in situations in which he or she is not the center of attention.
• Interaction with others is often characterized by inappropriate sexually seductive or provocative behavior.
• Displays rapidly shifting and shallow expression of emotion.
• Consistently uses physical appearance to draw attention to self.
• Has a style of speech that is excessively impressionistic and lacking in detail.
• Shows self-dramatization, theatricality, and exaggerated expression of emotion.
• Is suggestible, i.e., easily influenced by others or circumstances.
• Considers relationships to be more intimate than they actually are.

Enough said?