Spot these characteristics in someone and you can be sure that whatever good is left in them, they will use it against you. These results can be compared to a study from 100 years ago by Charles Spearman, which showed that 'people who score highly in one type of intelligence test typically also score highly in other types of intelligence tests, because there is something like a general factor of intelligence.'Īnd while a person's 'dark core' includes traits that make up the dark triad - psychopathy, narcissism, and Machiavellianism - other traits include sadism, spitefulness, egoism, and self-interest. The study found that these dark traits originate with placing one's own interests over others, taking pleasure in hurting others in the process, and not feeling guilt or shame. The study defines the D-factor as 'the general tendency to maximize one's individual utility - disregarding, accepting, or malevolently provoking disutility for others - accompanied by beliefs that serve as justifications.' The common factor of these dark traits is known as the D-factor.

In a study from the University of Copenhagen, researchers found that certain traits - such as sadism, narcissism, psychopathy, and others - are common in people with a dark personality.