How many friends do you have on Facebook? If the answer is a lot, a new study says you might be a narcissist.

Researchers at Western Illinois University found that the number of friends you have on Facebook directly correlates to how much of a socially disruptive narcissist you are.

Using the Narcissistic Personality Inventory, the study measured 'self-promoting' and 'anti-social' behaviors of 292 participants, aged 18 to 65. Self-promoting Facebook behavior involved posting status updates and photos and anti-social behaviors included getting angry when friends didn't 'like' a status.

The higher the score on the Inventory the more narcissistic you were.

People who had high scores had more friends on Facebook and updated their newsfeed frequently, concluding that young people are becoming more narcissistic and are obsessed with self-image and shallow friendships.

Facebook offers a gateway for hundreds of shallow relationships and emotionally detached communication, said Professor Christopher Carpenter who conducted the study.

The study, published this month in Personality and Individual Differences, outlined the behavior of narcissist, which included responding aggressively to negative comments and changing one's profile picture frequently.

Facebook provides a platform for people to self-promote by changing profile pictures and showing how many hundreds of friends you have. I know of some who have more than 1,000, said Carpenter to the Guardian.

Carpenter confirmed suspicions that social media sites like Facebook and Twitter lead to shallow relationships and more bullying among young people.

In general, the 'dark side' of Facebook requires more research in order to better understand Facebook's socially beneficial and harmful aspects in order to enhance the former and curtail the latter, said Carpenter to the Guardian.

If Facebook is to be a place where people go to repair their damaged ego and seek social support, it is vitally important to discover the potentially negative communication one might find on Facebook and the kinds of people likely to engage in them, he said. Ideally, people will engage in pro-social Facebooking rather than anti-social me-booking.