"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 published in PLoS ONE.
Earlier studies by Konrath and others have shown that the level of narcissism is rising in American culture, and that narcissism tends to be more prevalent among males. The personality trait is characterized by an inflated sense of self-importance, overestimations of uniqueness, and a sense of grandiosity.
For the new study, Konrath and colleagues David Reinhard of the University of Virginia, and William Lopez and Heather Cameron of the University of Michigan examined the role of narcissism and sex on cortisol levels in a sample of 106 undergraduate students. Cortisol, which can be measured through saliva samples, is a widely used marker of physiological stress.
The researchers measured cortisol levels at two points in time in order to assess baseline levels of the hormone, which signals the level of activation of the body's key stress response system, the hypothalamic-pituitary-adrenal (HPA) axis. Participants were not asked to complete any tasks that would elevate their stress. Elevated levels of cortisol in a relatively stress-free situation would indicate chronic HPA activation, which has significant health implications, increasing the risk of cardiovascular problems.
To assess participants' narcissism, the researchers administered a 40-item narcissism questionnaire that measures five different components of the personality trait. Two of these components are more maladaptive, or unhealthy – exploitativeness and entitlement; and the other three are more adaptive, or healthy – leadership/authority, superiority/arrogance, and self-absorption/self-admiration.
"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 said. "These kinds of coping strategies are linked with increased cardiovascular reactivity to stress and higher blood pressure, so it makes sense that higher levels of maladaptive narcissism would contribute to highly reactive stress response systems and chronically elevated levels of stress."
Reinhard, Konrath 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.
They also found that there was no relationship between healthy narcissism and cortisol in either males or females.
"These findings extend previous research by showing that narcissism may not only influence how people respond to stressful events, but may also affect how they respond to their regular day-to-day routines and interactions," Konrath said. "Our findings suggest that the HPA axis may be chronically activated in males high in unhealthy narcissism, even without an explicit stressor."
Why should narcissism affect males differently? "Given societal definitions of masculinity that overlap with narcissism – for example, the belief that men should be arrogant and dominant – men who endorse stereotypically male sex roles and who are also high in narcissism may feel especially stressed," Konrath said.
In future research, she hopes to examine why narcissism is not as physiologically taxing for women as it is for men, and also to examine the potential links between maladaptive narcissism and other physiological responses related to stress and poor coping, including inflammatory markers such as C-Reactive Protein.
Konrath is an assistant research professor at the U-M Institute for Social Research (ISR) and is also affiliated with the University of Rochester Medical Center.