*I* know how you came across this book -- I recommended it to you (about 2 years ago I think). I still recommend it. Robert Hare's first book, which has been revised a few times, is a don't-miss one: Without Conscience: The Disturbing World of the Psychopaths Among Us.True story.
We tend to think of psychopaths as serial killers like Ted Bundy, but in fact the defining characteristic of psychopaths is a total lack of conscience. They are all about me, me, me and have no empathy for others, nor any scruples about exploiting or cheating others. Since they are totally focused on their own needs and goals, they usually are not criminals; however, they are often cunning manipulators, narcissistic power-trippers, and they wreak emotional havoc wherever they go. Snakes in Suits deals with such charmers in the workplace.
Robert Hare is a world-reknowned authority on the topic, and a lucid writer who gives insight into how to deal with such individuals. A rather high percentage of the population (something like 5% IIRC) has psychopathic tendencies, so we are all bound to encounter them.
They are less attracted to the "helping professions" than to other venues for their talents, but I have known more than one in public education, and these individuals taught very briefly before rising through the management ranks where they could do ever more damage on a wider scale.
Hare does share some useful strategies, as well as cautions against courses of action that are known to backfire badly. Counter-intuitively, therapy and counselling makes these individuals worse and more dangerous, since it enables them to con people even more effectively. They often fool mental health professionals.
A long ways back, I was trying to decide whether to sign with a particular agent.
I had some concerns, so after lunch with my possible new agent, I stopped in a bookstore and skimmed Without Conscience to see if he/she fit the profile for psychopathy.
I must have spent at least an hour with the book, finally reaching the conclusion that, no, my potential agent was not a psychopath.
The significance of the fact that I had just spent an hour of my life researching the question escaped me at the time.
Suffering Souls: The Search for the Roots of Psychopathy
by John Seabrook
The New Yorker | November 10, 2008