COPENHAGEN, Denmark — Psychologists studying the roots of nefarious behavior have identified a group of personality traits linked to one another through what they dub a common “dark core.” This connection, they believe, leads researchers to believe that if an individual demonstrates one of these negative traits, they’re likely to display others.
The team of Danish and German psychologists say this so-called dark core of personality is the common denominator linking nine traits: psychopathy, sadism, egoism, narcissism, Machiavellianism, spitefulness, psychological entitlement, self-interest, and moral disengagement. They say these behaviors are all exhibited when a person puts his or her own needs and goals above those of their peers, to the point that hurting others can bring about feelings of pleasure.
The researchers, headed by Ingo Zettler, a professor of psychology at the University of Copenhagen, surveyed more than 2,500 people, asking how strongly they agreed or disagreed with statements such as, “It is hard to get ahead without cutting corners here and there,” and, “It is sometimes worth a little suffering on my part to see others receive the punishment they deserve.”  They also recorded other self-reported negative and immoral behaviors by participants.
Their results showed that certain personality traits have an inherent bond to similar traits and behaviors. In this case, that bond, the dark core — or D-factor — is likened to results of a century-old study by renowned psychologist Charles Spearman, who showed that people who present high levels of intelligence in one area are likely to score highly in other areas.
“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,” explains Zettler in a university release.
While this self-preservation tendency can manifest itself as narcissism in one person, it can come out as psychopathy or sadism in another, the authors argue. In other words, possessing a strong D-factor raises the odds that a person who enjoys seeing others suffer are also more likely to cheat or lie, for example. The finding could be useful for therapists who work with patients who exhibit one or more of the nine traits.
“We see it, for example, in cases of extreme violence, or rule-breaking, lying, and deception in the corporate or public sectors. Here, 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 behavior,” says Zettler.
The full study was published on July 12, 2018 in the journal Psychological Review.