“Trolls will lie, exaggerate, and offend to get a response. What kind of person would do this? Some Canadian researchers decided to find out. They conducted two online studies with over 1,200 people, giving personality tests to each subject along with a survey about their Internet commenting behavior. They were looking for evidence that linked trolling with the 'Dark Tetrad' of personality traits: narcissism, Machiavellianism, psychopathy, and sadism. They found that Dark Tetrad scores were highest among people who said trolling was their favorite Internet activity.”