Testing for psycopaths is a good idea!
There is one cop I know
about who I am 100% sure is a psycopath. He thrives in ghettos all over Nairobi where crime is a serious problem. People there all think of him as a hero. The man has killed---it is widely told--hundreds of youth, point blank. They are all criminals, so people believe him to be some kind of saint. But there is no way he is normal. If all the legends that have grown around his name are true. I am sure he is a psycopath. A clever one who knows exactly
who to kill to keep people supporting his addiction.
On a different note, I think psycopaths are the explanation for legends of vampires, witches and the like in primitive human society. There was no way to understand serial killers and other doers of shocking acts back in the day, so these supernatural explanations were provided. The reason I say this is that psycopathy exists in all human populations (in differing percentages) yet you dont find it in the folklore or common beliefs of the people. So how did they explain the inevitable psycopathic acts when they did happen? Just a curiosity of mine. Off topic, I know.