Together, the 11 experiments showed that individuals who scored high on the old evaluation were very likely to respond in the affirmative.
"It's pretty cool actually, because narcissists aren't afraid to tell you they're narcissistic," said Brad Bushman, co-author of the study and a professor of communication and psychology at The Ohio State University.
If you ask people whether they have casual sex or take drugs, they're not likely to be honest with you. But narcissists just aren't ashamed of their narcissism... And they'll tell you so.
The results do seem like common sense: By definition, narcissists are egotistical, self-focused, and vain. It would follow that a true narcissist wouldn't see self-absorption as something negative. And because narcissists tend to lack empathy, they'd probably have trouble understanding why a desire to put themselves first should be seen as a negative trait.
It's great that a single question can identify people with the trait, Bushman said, because that makes it easier to research. "There are single item scales for other traits, like self-esteem for example," Bushman said, "But the existing measure for narcissism is 40 items long."
With such a cumbersome test, researchers may have difficulty getting participants to finish surveys. While answering the single question might take about 20 seconds, working at the same speed would make the traditional test take over 13 minutes.
"But it's an important personality dimension to measure," Bushman said.
It's bad for the individual, because if you already think you're great you're not going to make any efforts to improve yourself. And it's bad for society as well, because if you're selfish you're less likely to be a cooperative and helpful member of your community.
Bushman's previous research has indicated that narcissism is becoming a more common trait, so he hopes that having such a short testing metric will encourage more study.
"In today's digital age, when anyone can broadcast themselves to the world, narcissism is becoming more of a problem," Bushman said. "Social media is absolutely related to narcissistic behaviour." And as narcissism increases, empathy will continue to fall.
I've been studying aggression for about 30 years, and I've seen that the most harmful belief that a person can have is that they're superior to others... Men are better than women, my race is better than your race, my religion is superior to your religion. When people believe they're better than other people, they act accordingly.
He hopes that more research can help us understand where narcissism comes from, and perhaps help us to stem the tide.
If people could believe that everyone on the planet is part of the same human family, and deserves the same respect, so many problems would be solved.