woman in makeup
Simon Cowell has them, so does Madonna. Audrey Hepburn's and Marilyn Monroe's have been emulated by millions of women.

But what do having thick and distinctive eyebrows reveal about our personality?

Psychologists have been combing through the evidence - and conclude that eye-catching eyebrows mean... you're probably a narcissist.

Researchers discovered that those with 'thicker and denser' brows are more likely to be self-centred than others.

A group of men and women who took part in a study were asked how much they agreed with statements such as 'If I ruled the world it would be a better place'.

Photos were then taken of them posing with neutral expressions. When the images were shown to another group, it was 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.

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.

Lead author Dr Miranda Giacomin, from the University of Toronto, said: 'Narcissists seem to have more distinct eyebrows - thicker and denser.'

It may be that they naturally have more distinctive brows, or they might groom them in such a way so that they are more easily recognised by other people, she explained in a paper published in the Journal of Personality.

Previous research has found how brows can be a bigger aid to facial recognition than eyes.

Studies have found, for example, that people struggle to recognise celebrities without their eyebrows.

Dr Giacomin said: 'Narcissists love attention and admiration and may maintain distinct eyebrows so that they are noticed, recognized, and remembered. This increases their likeability and maintains their overly positive self-views.'

She added that thicker brows may boost masculinity or femininity, which in the past may have helped us attract more partners.

It may explain why both men and women still groom their eyebrows, with tweezing, colouring, Botox and even permanent tattoos to accentuate brow arch and fullness.

'Narcissists behave aggressively when pursing potential mates and enjoy successfully securing short-term partners,' said Dr Giacomin.

'Their eyebrows could signal this prowess to others.'