# A Closer Look at the Sleep/Wake Habits and Dark Triad Traits
## 4 Discussion  
DT traits are socially aversive characteristics which are normally associated with negative psychological outcomes. It was earlier evidenced that those who grade higher on DT traits suffer more frequently from sleep disturbances. In this study, we sought to recruit a more generous set of sleep variables to further understand individuals' overall sleep conditions and their sleep/wake habits and to estimate to what extent the DT could predict sleep timing and quality. To the best of our knowledge, this is the first study to examine the DT and its association with sleep behavior on the basis of such a granular dataset in more than 600 individuals. In that matter, bivariate correlations revealed that psychopathy acted as the most related DT trait and proved to be associated with both later sleep/wake timing and poorer sleep quality. However, none of the DT traits were associated with subjective sleep quality, as studied by a single-item subscale of the PSQI asking subjects to rate their overall sleep quality during the past month. Due to the relationships between DT traits and sleep problems, this seems surprising. It could well be that those individuals might not be able to judge their own sleep quality adequately or they are intentionally simulating in order to create a better look. It may also be due to the inadequacy of single-item measurements to function accurately among these individuals. A study [27] demonstrated a positive relationship between Machiavellianism and secondary psychopathy and a negative relationship between narcissism and subjective sleep quality. Therefore, research on this issue should be continued. Psychopathy emerged as the one DT trait with greater correlation coefficients with sleep variables. In general, psychopaths are assumed to be more evening-oriented [24; 27; 36], even when adjusting for age, sex, anxiety, and depression [37]. Although being a night person is beneficial for the psychopaths' \"cheater strategy\" [24], it also has some strong connections with negative mood, personality, and sleep disorders (see [38] for a review). Our data did not demonstrate that narcissism is a relevant trait with regard to sleeping behavior. This result was in line with the wider body of literature indicating no consistent proof for a relevant link between narcissism and chronotype [24; 36], insomnia [27], sleep disturbances [13], and sleep quality [28]. In contrast, a positive association between narcissism and poor sleep quality was reported in two different studies [25; 27]. Since overall conflicting data has been published concerning narcissism and sleeping behavior, dedicated research is warranted and should focus on including detailed questionnaires to assess the link between the facets of narcissism and sleep variables separately instead of considering it as an overall trait. The regression analyses performed revealed that both psychopathy and Machiavellianism anticipate the largest amount of the shared variance of bedtime prior to free days compared to the other sleep variables examined. This finding has two important implications. First, individuals with a strong DT trait--more specifically, those with an inclination toward psychopathy and Machiavellianism--tend to show an increased proclivity toward staying up late in the night when they are free the next day. Interestingly, narcissism is not associated with this specific behavior. Second, this might equip them with better cognitive functioning at night, accelerating a protean social style [39].