New study reveals varied links between dark personality traits and mental health

A recent study published in the Journal of Personality explores the dynamic relationship between certain dark personality traits and mental health symptoms over time. Researchers found that traits like narcissism, Machiavellianism, and psychopathy interact with depression, anxiety, and stress in unique ways. For instance, increases in narcissism appeared to coincide with a decrease in mental health symptoms, while elevated levels of psychopathy and Machiavellianism were associated with concurrent increases in symptoms.

The Dark Triad refers to three personality traits—narcissism, Machiavellianism, and psychopathy—often associated with manipulative, self-serving, and, at times, socially antagonistic behaviors. Narcissism involves a strong sense of self-importance, entitlement, and a need for admiration, while Machiavellianism is characterized by a cynical view of others, strategic manipulation, and a focus on self-advantage. Psychopathy, in this context, reflects a lack of empathy, impulsiveness, and a tendency toward antisocial behavior.

While earlier studies had shown connections between these traits and mental health symptoms, the nature of this relationship—whether one precedes and possibly influences the other—was still unclear. Most prior research only captured a snapshot at one point in time, making it challenging to determine whether these personality traits contribute to worsening mental health or whether individuals with certain mental health challenges might develop more narcissistic, Machiavellian, or psychopathic tendencies.

“Recently, many studies have demonstrated a link between the Dark Triad and poor mental health,” said study author Yu L. L. Luo, an associate professor at the Institute of Psychology at the Chinese Academy of Sciences. “However, most of the studies were cross-sectional, and cannot inform which is the cause and which is the consequence. We wondered whether the Dark Triad would make people distressful in a long term, or whether emotional distress would turn people malevolent. So, we conducted this study.”

The study’s methodology involved tracking over 1,800 Chinese university students over three years, collecting data annually on their levels of narcissism, Machiavellianism, psychopathy, and mental health symptoms. The participants, ranging in age from 15 to 24, completed a series of self-reported questionnaires.

To assess the Dark Triad traits, researchers used the Short Dark Triad (SD3) measure, a validated questionnaire designed to capture tendencies toward manipulative, self-centered, and impulsive behavior. For mental health symptoms, they used the Depression, Anxiety, Stress Scale (DASS-21), which gauges various forms of emotional distress commonly associated with mental health challenges.

By repeating these assessments over three time points, the researchers could analyze both individual and group changes in personality traits and mental health symptoms over time, allowing them to explore not only if but also how these constructs influenced one another.

One of the study’s key findings was a reciprocal relationship between narcissism and mental health symptoms. Individuals with higher-than-average levels of narcissism in one year often saw a reduction in depression, anxiety, or stress symptoms in the following year, while those with elevated mental health symptoms showed a tendency for reduced narcissism later on.

This finding suggests a complex interaction, where narcissistic traits may act as a buffer against psychological distress by boosting self-esteem and mental resilience. However, worsening mental health symptoms might decrease narcissistic tendencies over time, possibly by diminishing self-confidence and resilience.

This effect was not observed for Machiavellianism or psychopathy, suggesting that narcissism might uniquely influence, and be influenced by, mental health in a way that is less applicable to the other two traits.

“Narcissism and symptoms of psychological distress seem to influence each other in interesting ways,” Luo told PsyPost. “When someone’s narcissism increases, their depressive and/or anxious symptoms often decrease later, but when those symptoms get worse, their narcissism tends to go down at a later time point. In contrast, Machiavellianism and psychopathy do not show such a reciprocal connection with emotional distress over time. Instead, higher levels of psychopathy and Machiavellianism are linked to a rise in emotional distress at the same time.”

Higher levels of psychopathy and Machiavellianism correlated with greater distress, not only across different individuals but also within each person at specific points in time. For instance, students who reported higher levels of Machiavellianism or psychopathy tended to experience heightened depression, anxiety, and stress. However, these associations were concurrent rather than predictive over time.

“Interestingly, the study found that neither Machiavellianism nor psychopathy predicts future emotional distress,” Luo explained. “Likewise, experiencing distress didn’t lead to an increase in these traits over time. This suggests that, unlike narcissism, Machiavellianism and psychopathy might not influence—or be influenced by—emotional distress in the long term.”

Although this study offers new insights into the Dark Triad’s effects on mental health, it is not without limitations. One issue is that the study relied solely on self-reported questionnaires, which can introduce biases like social desirability.

“The major limitation concerns the measurement of the Dark Triad,” Luo explained. “We used a concise measure, the Short Dark Triad (SD3), which is easy and quick to administer in a large-scale, multi-wave study like ours. However, such a concise measure may not capture every nuance of the Dark Triad, as each dark trait is constituted of multiple facets or dimensions.”

Additionally, while the sample size was large, the participants were all university students, limiting the findings’ generalizability to broader populations or different age groups. Future research could expand on these findings by incorporating more diverse methods, such as physiological measurements or reports from people close to the participants, to further explore these relationships.

“We aim to understand how socially aversive personality, like the Dark Triad, interact with mental health,” Luo said. “We hope to search for the mechanisms that can account for their connection, as well as ways to reduce the link.”

The study, “Will the Dark Triad Engender Psychopathological Symptoms or Vice Versa? A Three-Wave Random Intercept Cross-Lagged Panel Analysis,” was authored by Mengpei Wei, Jingguang Li, Xingbo Wang, Zhenglian Su, and Yu L. L. Luo.