YOU LIVE WITH A PSYCHOPATH?!

Sadism, narcissism, Machiavellianism, psychopathy, dark personality traits. What are the numbers? How common is it? >> This is a complicated question because all these traits exist on a continuum. The proportion of people that we say are high on these traits depends on where you put that cut point. If we're talking about psychopathy and clinical levels, that means a score of 30 out of 40 on the psychopathy checklist revised or higher, that's about 1% of the population. Narcissistic personality disorder, so again, very extreme levels, that would be 2 to 5%. We don't have clinical cutoffs for um sadism and Machiavellianism. What we do have is a

ton of data of people who have completed self-report questionnaires. One way that you can get a sense of how many people are high on these traits is by looking at the proportion of people who on average agree with the items. I am a born leader. To what extent do you agree with that? That's narcissism. To what extent do you say you like to see other people get hurt? Sadism trait. Yeah, I agree with that. If you just look at the people who on average agree with the items that we use to self-report assess these traits, it's about 10% of the population.