The more narcissistic a person is, the more likely they are to have health problems like heart disease or hypertension.
Surprisingly, the personality trait – defined by researchers as being characterised by inflated self-importance, overestimations of uniqueness, and a sense of grandiosity - may have an especially negative effect on men’s health, according to a study published in PLoS One. "Narcissistic men may be paying a high price in terms of their physical health, in addition to the psychological cost to their relationships," said Sara Konrath, a University of Michigan psychologist who co-authored the study.
For the study, Konrath and colleagues examined the effect of narcissism and sex on cortisol levels in a sample of 106 people. Cortisol, which can be measured through saliva samples, is a widely used marker of physiological stress. To assess participants' narcissism, the researchers administered a questionnaire that measures different components of the personality trait.
"Even though narcissists have grandiose self-perceptions, they also have fragile views of themselves, and often resort to defensive strategies like aggression when their sense of superiority is threatened," Reinhard explained. "These coping strategies are linked with increased cardiovascular reactivity to stress and higher blood pressure, so it makes sense that higher levels of narcissism would contribute to highly reactive stress response systems and chronically elevated levels of stress."
Reinhard and colleagues found that the most toxic aspects of narcissism were indeed associated with higher cortisol in male participants - but not in females. In fact, unhealthy narcissism was more than twice as large a predictor of cortisol in males as in females. "These findings show that narcissism not only influences how people respond to stressful events, but also affect how they respond to their regular day-to-day interactions. Our findings suggest that men who endorse stereotypically male sex roles and who are also high in narcissism may feel especially stressed," Konrath said.