Do you find yourself glancing in passing reflections, actively reverting the conversation back to you with routine name drops, or taking things too personally? You may have a narcissistic personality disorder and can find out the extent of it by just answering one question.

Researchers from Indiana University and Gettysburg College published their study in the journal PLOS ONE, which revealed the power of answering one question in finding out if you’re narcissistic, with surprisingly accurate results. "People who are willing to admit they are more narcissistic than others probably actually are more narcissistic," the study’s co-author Brad Bushman, and a professor of communication and psychology at The Ohio State University, said in a press release.

After putting 2,200 people with varying ages through 11 different experiments, scientists were able to confirm how narcissistic a person was on the Single Item Narcissism Scale (SINS). Participants rated how much they agreed with the statement "I am a narcissist." (Note: The word "narcissist" means egotistical, self-focused, and vain.) on a scale of one (not very true of me) to seven (very true of me).

Results showed the single question from the SINS test was almost as accurate as other tests to validate narcissism, such as the widely used Narcissistic Personality Inventory, which has 40 questions. While researchers note that SINS shouldn’t be a replacement for the longer and more thorough narcissism questionnaires, it can be used as a screening tool for experts to use.

"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 said. "For example, narcissistic people have low empathy, and empathy is one key motivator of philanthropic behavior such as donating money or time to organizations."

Narcissistic personality disorder is considered a mental disorder with symptoms that vary from expecting praise and admiration to fantasizing about power, success, and attractiveness. With an inflated sense of their own importance and a deep-seeded need for admiration coupled with fragile self-esteem, narcissists rarely enter treatment, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM), which published by the American Psychiatric Association to diagnose mental disorders.

"Overall, narcissism is problematic for both individuals and society. Those who think they are already great don't try to improve themselves," Bushman said. "And narcissism is bad for society because people who are only thinking of themselves and their own interests are less helpful to others."

The word narcissism comes from the Greek mythological character Narcissus, who was known for his beauty and punished for breaking a nymph’s heart. Nemesis, the Goddess of Revenge heard the story and condemned him to fall in love with his own reflection in the water. Once he realized his love could not be reciprocated, he killed himself.

Even centuries ago, the Greeks realized the power and fault in loving oneself with such fervency it destroys not only the people around you but also yourself. People who tested higher on the narcissism scale reported more positive feelings, more extravert behaviors, and were less depressed. However, the more narcissistic they were rate, the more likely they were less agreeable, angrier, more shameful, guilty, and experienced fear more frequently.

Source: Bushman BJ, Konrath S, and Meier BP. Development and validation of the Single item Narcissism Scale (SINS). PLOS ONE. 2014.