A new study from the University of Buffalo School of Management says that men are, on average, more narcissistic than women. The study relies on data from more than 475,000 participants collected over 30 years.

The study, forthcoming in the journal Psychological Bulletin, drew from 31 years of research on narcissism. It found that men, regardless of generation of age, consistently scored higher in two of three major areas. However, that didn’t always work out too badly, for the men at least.

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

Grijalva is assistant professor of organization and human resources in the UB School of Management.

The team examined more than 355 journal articles, manuscripts, technical manuals and dissertations as well as data from college students collected between 1990 and 2013.

They specifically looked at three aspects of narcissism: leadership/authority, grandiose/exhibitionism and entitlement.

Entitlement showed the widest gap and suggested that men were far more likely to feel entitled to privileges and to exploit others.

There was also a marked difference in the leadership and authority category.

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

Additionally, based on the data collected over 23 years starting in 1990 neither group showed any difference in narcissistic tendencies over time.

According to the authors, research has shown that some of the personality differences associated with narcissism can arise based on gender stereotypes and expectations. The researchers speculate that the lack of women in leadership roles may partially sim from the “disparity between stereotypes of femininity and leadership”.

“Individuals tend to observe and learn gender roles from a young age, and may face backlash for deviating from society’s expectations. In particular, women often receive harsh criticism for being aggressive or authoritative, which creates pressure for women, more so than for men, to suppress displays of narcissistic behavior,” says Grijalva.

The finding is in keeping with a 2011 study by Anne M. Koenig, Alice H. Eagly and others. Although the researchers note that the view of leadership is changing they report that the stereotypes associated with strong leadership remain masculine.

“An extensive body of research demonstrates that our beliefs about gender affect the way we perceive men and women in leadership roles. In a meta-analysis of 69 previous studies, my colleagues and I found that the characteristics people typically associate with leadership are often stereotypically masculine. In particular, people associate leadership with agentic traits – conventionally masculine descriptors such as “assertive,” “forceful,” “dominant,” and “competitive,”” they write.

An August, 2014 survey from Pew Research also says that attitudes are changing but that men are still perceived as superior leaders, even by women.

“Women are the most likely to say they prefer a male boss, according to Gallup. Though half of men (51%) say they have no preference for the gender of their boss, only 32% of women agree. Fully 40% of women say they prefer a male boss compared with 27% who say they prefer a female boss, while 29% of men say they would prefer a male boss, compared with 18% who prefer a female boss,” says the report.

Grijalva says that future research could investigate the cultural, biological and social factors that contribute to gender differences.