The old saying goes that you shouldn't judge a book by its cover, but according to a new study, you can pick out a narcissist just by looking at their eyebrows.
Egotistical and self-centred people are more likely to have distinct 'brows, particularly those that are thick and dense, scientists claim.
Arrogant people love attention and admiration and so are more likely to 'tweeze, tattoo or colour their eyebrows so they are noticed', researchers said.
Their controversial study suggests we learn to subconsciously identify narcissists by their bushy features.
Scientists claim we develop this skill to avoid people who initially seem nice but later turn out to be selfish or unhelpful.iPhone transfer software
The researchers, led by University of Toronto psychologist Miranda Giacomin, wrote in their paper: 'Though initially charming and inviting, narcissists often engage in negative interpersonal behaviours.
'Identifying and avoiding narcissists therefore carries adaptive value.'
The team tested a group of men and women to find out how far along the narcissism scale they were.
They asked them how much they agreed with statements such as 'if I ruled the world it would be a better place' and then took pictures of them posing with neutral expressions.
When they then showed these images to another group, they found that they could correctly identify the self-centred individuals from their more humble counterparts.
When the researchers removed the eyebrows from the pictures, however, the participants could no longer differentiate between them.
Arrogant people love attention and admiration and so are more likely to 'tweeze, tattoo or colour their eyebrows so they are noticed, researchers said. Musicians Madonna and Noel Gallagher have a reputation as narcissists, as well distinct eyebrows
Then, in a follow-up study in which only pictures of the eyebrows were shown to the group, they were again able to correctly identify the narcissists.
Dr Giacomin said: 'Narcissists seem to have more distinct eyebrows - thicker and denser.'