Psychopathy, Sadism, Narcissism: These Personality Traits Reveal Your Underlying 'Dark Core'

Researchers mapping the darkest corners of the human psyche—psychopathy, sadism, egoism—have discovered a common denominator behind these traits: a "dark core" underlying our murkiest tendencies.

In practise, this means if you're prone to one dark tendency, you're more likely to engage in the others. Although narcissism, spitefulness and Machiavellianism may manifest in different ways, scientists reported in Psychological Review, they're all cut from the same, selfish cloth.

Researchers asked more than 2,500 people how strongly they agreed or disagreed with statements like, "It is hard to get ahead without cutting corners here and there," and "I know that I am special because everyone keeps telling me so."

Using the answers, and self-reported tendencies including selfishness and aggression, the team mapped nine commonly-described "dark" personality traits: egoism, Machiavellianism, psychopathy, narcissism, moral disengagement, psychological entitlement, sadism, self-interest and spitefulness.

Their findings suggest all of these traits can be traced back to one element. "The underlying principle of dark personality traits is the D-factor, and, in turn, the D-factor represents the dark core of personality," study author and University of Copenhagen researcher Ingo Zettler told Newsweek.

The results, the researchers reported, echo the findings of Charles Spearman who, a century ago, discovered people that succeed in one kind of intelligence test often score highly in others. "In the same way, the dark aspects of human personality also have a common denominator, which means that—similar to intelligence—one can say that they are all an expression of the same dispositional tendency," Zettler explained in a statement.

Most of our darker traits, the researchers reported, reflect an underlying tendency to put your own interests ahead of—and perhaps even at the expense of—those of other peoples. In fact, you might even take pleasure in the harm your actions cause. "Individual utility is sought despite running contrary to the interests of others—or even for the sake of other's disutility," Zettler told Newsweek.

These dark tendencies will likely be intertwined with beliefs that help you justify your harmful deeds and prevent you feeling guilty. "Narcissism, for example, is a strong justification for malevolent behavior, because such individuals feel entitled to deserve more and to be simply better than others," he added.

For one person, the "D-factor" may be heavily weighted towards one trait like psychopathy. In others, it might be manifested as a combination of a number of dark traits. By mapping the D-factor itself, researchers can get a hold on, "how likely a person is to engage in behaviour associated with one or more of these dark traits," Zettler explained in the statement.

Knowing these tendencies are deepy linked, Zettler said, may be useful for therapists and researchers probing the shadowier crevices of the human mind. "In cases of extreme violence, or rule-breaking, lying, and deception in the corporate or public sectors...knowledge about a person's D-factor may be a useful tool, for example to assess the likelihood that the person will reoffend or engage in more harmful behaviour," he said.

But don't worry if you think you might be harboring a dark side. Research into the D-factor is in its early stages, Zettler told Newsweek. Now, his team are investigating the development of the D-factor over time, as well as how it may impact your work and personal life.

Personality traits have hit the headlines recently, with researchers suggesting there are four major personality types and that one specific character trait could be key to financial success.

This article has been updated to include comment from Ingo Zettler.