Men with an inflated view of their importance, who are incapable of putting themselves in other people's shoes and who see themselves as "special" and superior to others, some of the traits of a narcissistic personality, may pay for this with their health. This is because a new study suggests even when such men are not under stress, they have high levels of cortisol in their bloodstream, increasing their risk for developing cardiovascular problems. The study was published online on 23 January in PLoS ONE.

Narcissism appears to be on the rise in America, and it is more prevalent in men, according to previous investigations by study co-author Sara Konrath and others.

Konrath is a psychologist at the University of Michigan in Ann Arbor in the US. She told the press:

"Narcissistic men may be paying a high price in terms of their physical health, in addition to the psychological cost to their relationships."

She said their study extends other previous findings 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".

However, the personality trait is not all negative; it also has its positive points.

In this study, Konrath and colleagues assessed five different components of narcissism: two unhealthy (exploitativeness and entitlement) and three healthy (leadership/authority, superiority/arrogance, and self-absorption/self-admiration). These components are measured on a 40-item questionnaire called the Narcissistic Personality Inventory.

Cortisol is a commonly used measure of psychological stress. Levels of the hormone rise sharply during the body's "fight or flight" response and help to activate key resources to deal with the immediate perceived challenge.

The hormone signals the level of activation of the hypothalamic-pituitary-adrenal (HPA) axis. High levels of cortisol when there are no stress challenges around would suggest that the HPA axis is active all the time, which has significant implications for long term health and increases the risk of cardiovascular problems.

For the study, the researchers recruited 106 volunteer students who were attending one Midwestern and one Southwestern American university. They were 79 females and 27 males and their average age was 20.

The researchers measured the participants' baseline cortisol levels from two saliva samples from each person. At this stage, the researchers deliberately did not ask them to complete any tasks that would raise their stress levels.

The participants also completed the 40-item Narcissistic Personality Inventory questionnaire.

Using regression analysis, the researchers looked at the statistical effect of narcissism and gender on the levels of cortisol they measured.

They found that the most unhealthy components of narcissism were linked to higher levels of cortisol in the males, but not in the females. In fact, the unhealthy components were more than twice as likely to predict high cortisol in males than in females.

They found no link between healthy narcissism and cortisol in either males or females.

Konrath said:

"Our findings suggest that the HPA axis may be chronically activated in males high in unhealthy narcissism, even without an explicit stressor."

Speculating on why this might be, first author David A. Reinhard, from the Department of Psychology at the University of Virginia in Charlottesville, said:

"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."

He said that aggressive coping strategies are linked to higher blood pressure and higher reactivity of the cardiovascular system to stress. So to him, it seems to make sense that higher levels of the unhealthy components of narcissism would "contribute to highly reactive stress response systems and chronically elevated levels of stress".

But, why should there be such a stark contrast between men and women, why does narcissism predominantly affect males in this way?

Konrath offered a suggestion:

"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 is planning further studies along these lines. She wants to explore why narcissism does not impose such a high health cost on women like it seems to on men, and also to study links to other biological responses of stress and poor coping. Also, Konrath wants to use more inflammatory markers, such as C-Reactive Protein.

Written by Catharine Paddock PhD