Scientists have developed and validated a new method to identify which people are narcissistic（自恋的）: just ask them. In a series of 11 experiments involving more than 2,200 people of all ages, the researchers found they could reliably identify narcissistic people by asking them this exact question (including the note):

To what extent do you agree with this statement: "I am a narcissist." (Note: The word "narcissist" means egotistical自我本位的, self-focused, and vain.)

Participants rated themselves on a scale of 1 (not very true of me) to 7 (very true of me).

Results showed that people's answer to this question lined up very closely with several other validated measures of narcissism, including the widely used Narcissistic Personality Inventory.

The difference is that this new survey -- which the researchers call the Single Item Narcissism Scale (SINS) -- has one question, while the NPI has 40 questions to answer.

"People who are willing to admit they are more narcissistic than others probably actually are more narcissistic," said Brad Bushman, co-author of the study and a professor of communication and psychology at The Ohio State University.

"People who are narcissists are almost proud of the fact. You can ask them directly because they don't see narcissism as a negative quality -- they believe they are superior to other people and are fine with saying that publicly."

Bushman conducted the study with Sara Konrath of the Indiana University Lilly Family School of Philanthropy (formerly of the University of Michigan) and Brian Meier of Gettysburg College. Their results appear in the journal PLOS ONE.