Men, on average, are more narcissistic than women, according to a recent study.

In a study that compiled 31 years of narcissism research, investigators at the University of Buffalo School of Management found that men consistently scored higher in narcissism across multiple generations and regardless of age.

"Narcissism is associated with various interpersonal dysfunctions, including an inability to maintain healthy long-term relationships, unethical behavior and aggression," Emily Grijalva, lead author of the study, said in a statement. "At the same time, narcissism is shown to boost self-esteem, emotional stability and the tendency to emerge as a leader. By examining gender differences in narcissism, we may be able to explain gender disparities in these important outcomes."

For the study, researchers examined more than 355 journal articles, dissertations, manuscripts and technical manuals, and studied gender differences in the three aspects of narcissism: leadership/authority, grandiose/exhibitionism and entitlement. They found the widest gap in entitlement.

The second largest difference was in leadership/authority.

"Compared with women, men exhibit more assertiveness and desire for power," Grijalva says. "But there was no difference in the exhibitionism aspect, meaning both genders are equally likely to display vanity or self-absorption."

Research has shown that personality differences, like narcissism, can arise from gender stereotypes and expectations that have been ingrained over time. Researchers speculate that the persistent lack of women in senior leadership roles may partially stem from the disparity between stereotypes of femininity and leadership.

The findings are detailed in the journal Psychological Bulletin.