Jun 14, 2025 09:00:00

Lack of sleep may bring out darker traits such as narcissism and psychopathy in the workplace

The Dark Triad , a collective term for traits such as narcissism , Machiavellianism, and psychopathy , is said to be an element that forms an antisocial personality and is associated with unproductive behavior and harmful power relationships in the workplace. A new study has shown that 'sleep-deprived employees have a higher level of the Dark Triad in the workplace.'

Rise of the Dark Side: How Sleep Perception Triggers Dark Triad States at Work - Kuijpers - Journal of Organizational Behavior - Wiley Online Library
https://onlinelibrary.wiley.com/doi/10.1002/job.2885

Poor sleep can bring out the 'dark side' of personality at work, study finds
https://www.psypost.org/poor-sleep-can-bring-out-the-dark-side-of-personality-at-work-study-finds/

The dark triad, which includes narcissism, characterized by grandiosity, low self-esteem, and lack of empathy; Machiavellianism, characterized by self-centered thinking and a tendency to manipulate and exploit others; and psychopathy, characterized by antisocial behavior, selfishness, and lack of self-reflection, are known to have harmful effects in many aspects of everyday life.

Most research on the Dark Triad has treated these traits as stable and permanent, but a team of researchers from the Free University of Brussels (Vrije Universiteit Brussel ) wondered whether sleep duration might be related to the manifestation of the Dark Triad in the workplace, as people's ability to control themselves is affected by periods of rest and recovery.

'Our interest in this issue arose from the realization that everyone has dark personality traits to some degree, and that people in positions of power, especially within organizations, tend to score particularly high on these traits,' lead author Evi Cuypers , a postdoctoral researcher at the Free University of Brussels, told PsyPost.

The researchers surveyed 103 workers in Belgium and Argentina over a 10-day period using

experience sampling , a research technique in which participants are asked to report on their thoughts, feelings and behaviours across a range of situations and time periods.

In this study, participants were asked to fill out questionnaires in the morning and evening each day. The morning questionnaire assessed the quality and duration of their sleep the previous day, while the evening questionnaire assessed their levels of narcissism, Machiavellianism, and psychopathy, as well as their stress tolerance, for that day.

After analyzing a total of 786 days of data collected from the subjects, it was found that both 'quantity and quality of sleep' were negatively correlated with the expression of the Dark Triad. In other words, people who reported lack of sleep or sleeping less than usual were more likely to show tendencies such as narcissism, Machiavellianism, and psychopathy at work that day. The association between lack of sleep and the Dark Triad remained significant even after individual differences were taken into account.

'We were somewhat surprised that sleep perceptions, and in particular sleep quality, were able to consistently predict dark triad changes across individuals,' Cueypers said. 'It's also noteworthy that even small changes in day-to-day sleep can have a significant impact on behavior.'

The research team also examined whether the association between sleep and the Dark Triad was influenced by distress tolerance, or the ability to tolerate unpleasant sensations. They found that sleep deprivation reduced participants' distress tolerance, which in turn increased Dark Triad tendencies.

For example, subjects who had a sleep-deprived night reported feeling less able to cope with stress and frustration the next day, and as a result were more likely to exhibit the dark triad during the day. This effect was significant for both sleep quality and duration, but the effect of quality was slightly stronger, suggesting that 'how restful the sleep' may be more important.

The research team also investigated whether the relationship between sleep and the Dark Triad works in the opposite direction, that is, whether 'exhibiting the Dark Triad during the day affects sleep the following night.' As a result, they found evidence that the Dark Triad is indeed related to the next night's sleep, and it was reported that the influence of Machiavellianism was particularly large. However, the influence on sleep explained by the expression of the Dark Triad was extremely small, and the influence of sleep on the Dark Triad was higher.

'We found that people who suffer from inadequate both quality and quantity of sleep are more likely to engage in dark triad behaviours, in part because they have a harder time coping with stress,' said Cueypers. 'These findings highlight the importance of good quality sleep for employees to manage their emotions and avoid harmful behaviours in the workplace.'

Psychology media PsyPost points out that the dark triad can damage workplace relationships, reduce work performance, and lead to a toxic environment. Because sleep is an adjustable factor, companies should consider fostering a more positive work culture by promoting healthy sleep habits, such as by limiting long working hours, and introducing sleep break spaces and nap policies in the workplace.