The Dark Side of Human Psychology: What Is the Dark Triad?

For much of history, science knew little about the most dangerous personality disorders: psychopathy, narcissism, and Machiavellianism. Over the past century, our understanding has grown. We now know, for example, that some people with these disorders lack empathy but can convincingly fake it, and that a predisposition to psychopathy can be innate. What does modern science know about the so-called “dark triad” of personality disorders, and why are they grouped together?

What Is the Dark Triad and How Did It Emerge?

The dark triad is a psychological model describing three personality traits: narcissism, psychopathy, and machiavellianism.

• Narcissism is marked by a sense of one’s own uniqueness, a desire to be the center of attention, and a dismissive attitude toward others. Narcissists genuinely believe they are superior and that their interests should come first.
• Psychopathy is characterized by low emotional sensitivity, poor self-control, a craving for thrills, fearlessness, and a sense of superiority. Psychopaths are, in some ways, rebels.
• Machiavellianism involves low empathy, a tendency to manipulate, and amorality. People high in Machiavellianism believe the ends justify the means and see others as tools to achieve their goals.

Humanity first learned about narcissism, then psychopathy, and later Machiavellianism. Narcissism was initially described by psychoanalysts in the 19th century as an exaggerated sense of self-importance. This didn’t make narcissists happy; they often suffered from self-criticism and loneliness, struggling to form and maintain relationships. Being close to someone who truly believes the world revolves around them is difficult—they don’t recognize others’ needs, refuse to compromise, and react harshly to criticism.

By the late 20th century, psychologists began discussing non-clinical narcissism. In 1979, one of the first questionnaires to identify narcissistic traits within the normal range was developed. Today, there are several such questionnaires, but no universal test—researchers see narcissism as a collection of traits rather than a single core characteristic.

Psychopathy was identified through studies of prisoners. In the late 19th century, psychologists studying criminals wondered what caused antisocial behavior. They described traits common among offenders: fearlessness, low anxiety, antisocial tendencies, egocentrism, lack of empathy, impulsivity, and poor self-control. These traits formed the basis for diagnosing a specific sociopathic personality disorder.

For example, psychology professor Robert Hare, in his book Without Conscience: The Disturbing World of the Psychopaths Among Us, showed that American rehabilitation programs for inmates don’t work for those with high levels of psychopathy. Instead of truly changing, psychopaths would fake remorse and obedience, get released, and then reoffend more often than non-psychopaths.

Today, we know that psychopathic traits can exist in people who have never committed crimes. Scientists debate the existence of primary and secondary psychopathy. Primary psychopathy is likely linked to genetic factors, such as differences in the development of mirror neurons, which are crucial for empathy. Secondary psychopathy develops due to adverse life circumstances, leading to poor self-control, impulsivity, and antisocial behavior. For treatment, the origin of psychopathy is less important than the severity of its traits and their impact on life.

Machiavellianism began to be tested in the 1970s with the “Mach Scale,” developed by Richard Christie and Florence Geis. This test measures a person’s tendency to manipulate others in relationships and reflects a general distrust of others. While researchers now study subdomains within Machiavellianism, these distinctions are not yet central to correcting manipulative behavior.

Until the turn of the 21st century, narcissism, psychopathy, and Machiavellianism were studied separately. Recently, they have been grouped as traits of the dark, negative side of personality. Since the 2000s, scientists have debated whether these are independent traits or different expressions of a single “dark core” of personality.

Modern researchers believe these traits share a common core but also have unique features. The dark triad is now seen as a supplement to the classic “Big Five” personality model, which includes extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience. While the Big Five are socially acceptable traits, the dark triad includes characteristics that lead to maladaptation.

What Do Narcissists, Psychopaths, and Machiavellians Have in Common?

All three share a disregard for others and a tendency to devalue those around them, though this manifests differently:

• Narcissists devalue others because they see themselves as grand and central to the universe.
• Machiavellians see others as mere tools for achieving personal goals.
• Psychopaths devalue others due to a lack of empathy—people are, in a sense, soulless puppets to them.

Other traits—such as hostility, deceitfulness, and emotional coldness—overlap among the three, but it’s not yet clear which are causes and which are effects.

The combined traits of the dark triad pose a danger to society because their devaluation of others contradicts principles like equality and the value of human life. Beyond isolating those with extreme levels of these traits, there is currently no clear solution.

Narcissism, psychopathy, and Machiavellianism are also conceptually linked. Academic psychologists are working to create a universal model of personality traits. The Big Five describes positive traits, while the dark triad now serves as a model for negative traits.

Where Is the Line Between Pathology and Normalcy?

Dark triad traits can exist in non-clinical forms and still affect a person’s quality of life and interactions with others. When these traits are within the normal range, they are not considered personality disorders. Such cases still require attention, but isolation is unnecessary—the person likely poses no danger to others. One way to draw the line is to assess how well the person adapts to society. If they don’t commit crimes or endanger others, they are within the norm, even if they have some dark triad traits.

To measure the extent of narcissism, Machiavellianism, and psychopathy within the normal range, psychologists use the Dirty Dozen questionnaire. This 12-item survey helps build individual profiles of these traits and explore their links to decision-making and conflict behavior.

Personality profiles are not perfect reflections of a person’s traits—questionnaires have inherent inaccuracies, as do all measurement tools. Still, the Dirty Dozen allows researchers to assess individual differences in these characteristics and study how narcissism, Machiavellianism, and psychopathy influence various aspects of life.