Some dark personality traits may help the body handle stress more easily, finds new study

Better immunity to stress is a superpower most of us would like to possess. Surprisingly, people with certain dark personality traits do have better protection against stress than most people.

A recent study has found that people with the Dark Triad of personality traits—narcissism, psychopathy and Machiavellianism—respond to stress differently.

To explore how personality shapes the body's response to stress, researchers recruited 139 undergraduate students from a large research university in the Southwestern United States. Participants first completed the Short Dark Triad questionnaire, which measured their personality traits. They were then asked to tackle a task designed to induce stress.

The findings revealed a clear pattern. Students who scored higher in narcissism reported feeling less anxious under pressure and showed smaller increases in blood pressure, suggesting that their bodies were less reactive to stress. Those with higher levels of psychopathy also reported lower stress levels and experienced smaller increases in heart rate. Machiavellianism, on the other hand, showed no meaningful relationship with how people experienced or reacted to pressure.

The findings were published in the International Journal of Psychophysiology.

Socially harmful yet physiologically useful

Over the past two decades, the Dark Triad of personality and its real-world consequences have drawn growing interest from psychologists.

The first trait, narcissism, centers on an exaggerated sense of self-importance. People high in narcissism often feel entitled to special treatment and have a strong desire for dominance and superiority over others. The second trait, psychopathy, combines emotional coldness with impulsivity.

People high in psychopathy are more likely to break rules, manipulate others for personal gain and engage in criminal behavior. The third trait, Machiavellianism, is all about calculated manipulation. People high in Machiavellianism use cunning social strategies to get what they want, even if it comes at the expense of others.

While these traits are considered to have negative social consequences, some research suggests they might also act as protective factors, helping people cope with and respond to stress in adaptive ways.

This idea comes from the reactivity hypothesis, which suggests that people who experience sharp increases in heart rate or blood pressure during stressful moments may be more likely to develop heart problems later in life.

Some studies have found that people with these personality traits show smaller physical reactions when stressed, which could point to greater resilience or even better heart health. However, the results have been inconsistent, with some studies showing these traits led to lower stress reactions and others showing higher ones.

Instead of studying the Dark Triad as a single entity, the researchers decided to examine each trait and its stress outcomes individually. They recruited college students ages 18–26 without heart conditions to ensure the heart rate and blood pressure readings during the stress test were accurate. The students were also asked to avoid coffee and exercise before the test.

The study team first created a relaxing environment for the students as they completed the Short Dark Triad survey. They then spent 10 quiet minutes while a blood pressure cuff measured their baseline heart rate and blood pressure five times.

Next, they were given a mental math test, performing arithmetic under pressure while a researcher corrected them and asked them to start over every time they made a mistake. Throughout the task, their heart rate and blood pressure were continuously measured. After the math task, students reported how much stress and anxiety they actually felt.

The data indicated that people with psychopathy and narcissism stayed calmer both mentally and physically when they were under pressure.

People with high psychopathy scores found the task much less stressful to complete, and those with narcissism reported feeling significantly less anxious than others. Initially, Machiavellianism didn't seem to change how people reacted to the stress at all, but when all three traits were analyzed together in the same model, it revealed that people with this trait felt more anxious during the stress test.

These findings suggest narcissism and psychopathy might actually be linked to better heart health through a biological pathway in the body, which needs further exploration. The researchers suggest future studies should include a wider range of participants across different ages and health conditions to see if the protective shield effect still holds true.