In the book The Sociopath Next Door, the author states that 1 out of 4 people in the United States are sociopaths - ranging from the petty bureaucrat at the DMV to the Ted Bundy types.
“Sociopath: a person with a personality disorder manifesting itself in extreme antisocial attitudes and behavior and a lack of conscience.”
Interesting. Does answer those questions during the day when you wonder “How can people just do stuff like that?”