The concept of the Dark Triad (DT) consists of the dimensions of Machiavellianism, narcissism, and psychopathy, and has gained increased interest within the last 15 years for its predictive power to explain success in the fields of economy, politics, and professional sport. However, recent research suggests that the associations between DT and behavior are not as uniform as expected.

Investigating the associations between DT traits and vulnerable narcissism, mental toughness, sleep quality, and stress perception.

A total of 720 participants between 18 and 28 years took part in the study. The sample consisted of military cadres in the US (n=238), Switzerland (n=220), and of students from the university of Basel (n=262). Participants completed self-rating questionnaires covering DT traits, mental toughness, vulnerable narcissism, sleep quality, and perceived stress.

Irrespective of the sample, participants scoring high on vulnerable narcissism also reported higher DT traits, lower mental toughness, poor sleep quality, and higher scores on perceived stress.

The present pattern of results suggests a more fine-grained association between DT traits and further behavior, calling into question to what extent DT traits might be a predictor for greater success in the fields of economy, politics or elite sports. Specifically, vulnerable narcissism seems to be key for more unfavourable behavior.