How is narcissism connected to the dark triad of personality traits?

In psychology, the dark triad is a cluster of three distinct but overlapping negative personality traits: narcissism, Machiavellianism, and psychopathy. While each trait has unique characteristics—narcissism is defined by grandiosity and excessive self-importance, whereas Machiavellianism involves manipulation and psychopathy involves callousness—they are grouped together because they share several core features.12

These traits are connected through their common association with emotional coldness, duplicity, aggressiveness, and a tendency toward self-promotion. When analyzed using the interpersonal circumplex, all three traits fall into the same quadrant, representing personalities that are both dominant and hostile. Furthermore, research indicates that all three traits are disagreeable according to the five-factor model of personality.1

Within the context of the dark triad, narcissism is typically considered at a subclinical level, meaning individuals may possess these traits without meeting the criteria for a clinical disorder, yet they still often exhibit aversive behaviors in personal and professional settings.12