At the Core of Dark Personalities

What do selfie-obsessed teens, sadistic bosses and inside-traders have in common? The common denominator, say researchers, is called the Dark Factor of Personality or, simply, D.

The Dark Factor is the tendency to ruthlessly pursue one's own interests, even when it means harm to others — and sometimes just for the sake of harming or intimidating others and the set of beliefs, for example, that one is more worthy than others, that justify these actions.

Your Machiavellian boss and your spiteful mother-in-law probably have more in common than you might think.

Like all personality traits, this darker side of personality exists on a continuum and is related to a person's stage of development. Spending an excessive amount of time in front of a mirror is not particularly sinister or harmful to others. But the self-absorption of someone who spends inordinate amounts of time fixated on themselves seems to spring from the same well that allows others to backstab a colleague at work.

History and everyday life offer many examples of people acting ruthlessly, maliciously or selfishly. According to the University of Copenhagen researchers, the Dark Factor is the unifying thread tying them together.

People who display one of the nine dark behaviors described below are more likely than other people to display other behaviors on the list. That's because, at their core, these dark traits actually have more in common than sets them apart — your Machiavellian boss and your spiteful mother-in-law probably have more in common than you might think.

The nine traits examined were:

Egoism: an excessive preoccupation with one's own advantage at the expense of others and the community;

Machiavellianism: a manipulative, callous attitude and a belief that the ends justify the means;

Moral disengagement: cognitive processing style that allows behaving unethically without feeling distress;

Narcissism: excessive self-absorption, a sense of superiority and an extreme need for attention from others;

Psychological entitlement: a recurring belief that one is better than others and deserves better treatment;

Psychopathy: lack of empathy and self-control combined with impulsive behavior;

Sadism: a desire to inflict mental or physical harm on others for one's own pleasure or to benefit oneself;

Self-interest: a desire to further and highlight one's own social and financial status;

Spitefulness: destructiveness and willingness to cause harm to others, even if one harms oneself in the process.

High D individuals may know that they are behaving selfishly and that their actions harm others, but they rely on certain beliefs — such as their own or their group's superiority — to justify dark behavior.

The researchers conducted three online surveys of over 2,500 people. These tested for the nine personality traits listed above, asking how well people agreed with statements such as “I know that I am special because everyone keeps telling me so” and “I’ll say anything to get what I want.” The surveys also tested for several ethically, morally and socially questionable behaviors, such as participants' tendency to cheat, lie or steal.

People who score highly on one of the traits, such as narcissism, will typically also score highly on others, such as psychopathy, self-interest or moral disengagement, or any other dark personality trait.

Though individuals relying on these traits may see that they are acting selfishly and harming others, there are many beliefs that are used to justify dark behavior. For example, high-D individuals generally consider themselves (or their group) superior, see others as inferior, have a cynical world view or consider the world a competitive jungle in which there can be only winners and losers.

The study appears in Psychological Review.