How to Address Dark Personalities in the Workplace

With Dr. Cynthia Mathieu: psychologist, professor, and researcher.

Photo by Tony Rojas on Unsplash | Written with the contribution of Leah Brown
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Another Monday morning in the office and you’re standing by the coffee machine. Your colleague approaches you and mentions that your manager’s new idea is revolutionary! They explain it, only for you to realize that it’s your idea and your boss has claimed it as their own. You confront your boss, but they deny it. What do you do? Though maybe that’s not the question we should be asking. How did your boss get to that position of power in the first place? Dark personalities in the workplace can have dire consequences. For this article, we’ve interviewed Dr. Cynthia Mathieu to find out more.

Dr. Mathieu and I first met when I was at university. Although she was never my professor, we briefly crossed paths when I took part in academic competitions. Back then, she already had ambitious research projects in mind. With the recent release of her book Dark Personalities in the Workplace, Dr. Mathieu gained praise from Emeritus Professor of Psychology, Robert D. Hare. In the preface of her book, Hare writes: “Dark Personalities in the Workplace is a remarkable book by a leader in the bourgeoning field of organizational behaviour.”

By her own admission, Dr. Cynthia Mathieu has an atypical background. She has a Ph.D. in clinical psychology, a postdoctoral degree in criminal psychology, experience in organizational psychology, and works as a professor at a business department. Her unique academic journey has culminated in years of research on dark personalities and their impact on organizations.

The term “dark personalities” refers to 3 personality types: narcissism, Machiavellianism, and psychopathy. Research suggests that genetic predispositions exist. But that’s only part of the story. Environmental variables such as our upbringing, access to opportunities, education, wealth, and more, are also at play.

Narcissistic, Machiavellian, and psychopathic individuals share some commonalities. For instance, they all have an exaggerated sense of their own importance. All 3 personality types exhibit little to no empathy towards others and repeatedly disregard opinions contrary to theirs. Their impact in the workplace range in scope but often results in negative outcomes for their colleagues and their work environment. By and large, dark personalities are problematic for organizations.

But there is good news! As research progresses, awareness is slowly making its way into business communities across the country. According to Dr. Mathieu, understanding dark personalities is the first step to solving the problem. So, we might as well dig deeper…


Narcissistic individuals think highly of themselves. They are vain, egotistic, and characterized by their desire to be admired, powerful, and famous. This clip from the 1993 movie Malice, starring Alec Baldwin and Nicole Kidman shows a perfect portrayal of narcissism. When Baldwin’s character is asked if he has a God complex, he responds: “I am God”.

In the workplace, narcissistic individuals may be regarded as good candidates at first. Their show of confidence in their own skills and abilities can help them get hired swiftly. In fact, newly hired narcissistic people are often perceived as performant employees. But that won’t last long! Narcissism and performance at work are incompatible. As they settle in the job, a new reality will emerge.

Narcissistic employees are impulsive and often spend more time managing their own image than working. Their tendency to manipulate others and to steal ideas can result in disruptive relations with their colleagues. Moreover, criticism, questions, and feedback aimed at narcissistic individuals can easily escalate into aggressive behaviours.


Machiavellianism takes its name from the Italian diplomat, philosopher, and writer Niccolò Machiavelli (1469–1527). In his work The Prince, Machiavelli suggests that the use of immoral means is acceptable to achieve glory and survival. In other words, the end justifies the means.

Machiavellian individuals are characteristically less impulsive, outgoing, and charismatic than the 2 other dark personalities. They are calculated and patient individuals who have the ability to orchestrate undercover schemes and sustain them for a while. They are good at controlling perceptions which helps them to manipulate individuals and avoid suspicions.

In the workplace, Machiavellian individuals seek to earn the trust of key players to secure their reputation. But don’t be fooled! Their only concern is to achieve their own personal goals. Machiavellian people disregard the well-being of others. This can lead to stealing ideas, falsifying documents, or fabricating narratives to get ahead of their colleagues.


Psychopathy is characterized by an ineptitude to feel emotions, express empathy, and show remorse. Thus, psychopaths are known to commit the worst crimes in society. By far, this is the most dangerous dark personality type.

Psychopaths prey on individuals, use charisma to build followership, and manipulate their way into positions of power. They are pathological liars, opportunistic individuals, and have no consideration for ethics or others. They often act impulsively and are prone to psychological and physical violence.

Psychopaths are particularly worrying in the workplace. They can harass, threaten, or hurt coworkers and coerce them into silence. When caught, psychopaths brush it off, manipulate public perceptions, lie about their own involvement and move on. This helps them evade punishment for their behaviour. As a direct consequence, organizations often struggle to identify psychopaths within their ranks.

Keeping Dark Personalities Away

For the reasons mentioned above, preventing dark personalities from joining organizations is crucial. That’s why Dr. Mathieu stresses the importance of the hiring process. Job descriptions should list the organization’s values and ethics requirements to work there. In addition to technical skills, organizations should also list interpersonal skill must-haves. This can help prevent dark personalities from applying in the first place.

Work Culture Matters

Work culture is another area to consider. Dark personalities should not have room to grow in any workplace. One way to achieve this is through performance reviews. These evaluations should review interpersonal skills as well as technical skills. When interpersonal skills are valued in the workplace, organizations will be rewarded with lower turnover rates and improved employee satisfaction, which can in turn result in harder working employees. Organizations invested in building and upholding a healthy work culture are less likely to enable dark personalities to flourish.

Leadership Matters

Individuals with dark personalities won’t qualify for management positions if interpersonal skills such as conflict management, empathy, and leadership are required to be promoted. Furthermore, Dr. Mathieu suggests that individuals in leadership positions should also be subjected to performance reviews by their team. Incentives such as end-of-year bonuses can be considered for leaders who show positive interpersonal skills. In other words, leaders should be accountable for their behaviour and rewarded when their leadership style is in line with the culture of the organization.

While it would seem that your boss made it to a management position despite the boundaries that should be put in place, not all hope is lost! There are ways to prevent dark personalities from entering and growing in the workplace. Businesses should rethink their hiring process and improve their work culture. When organizations value well-being, they also reduce their exposure to disruptive dark personalities. In turn, this can lead to lower turnover rates and reduce costs for recruitment and training. After all, profit, performance and well-being can coexist in the workplace!

Finally, I would like to thank Dr. Mathieu for sharing her research and extensive knowledge with us. Her generous time contribution brought this piece to life! To stay up to date with Cynthia Mathieu and her research, please visit her website!

Small business owner in Toronto, Canada!

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