Plain is the new pretty, a new study has claimed.

Researchers asked men to rank two sets of pictures of women's faces by how attractive they were and combined their answers with a computer model to try and work out what makes women beautiful.

The team found that men prefer a women with a 'simpler' face, which they suggest is because they are easier for our brains to process and store - and some experts even say it could explain why emoticons are so popular.

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Katie Homes is known my many as the classic 'girl next door' and researchers now say they know why we find her relatively plain face more attractive.

WHAT DID THE STUDY FIND? Researchers found that men prefer a women with a 'simple' face, which they suggests is because they are easier for our brains to process. Raises the possibility that symmetrical faces, faces without unusual features, because they are also easier for our brains to process. These findings do support the concept that first impressions are important, as we tend to subconsciously decide if someone is attractive or not before we consciously know it. Advertisement

'Sparseness was found positively correlated with attractiveness as rated by men and explained up to 17% of variance in attractiveness,' the University of Paris team, led by Julien Renoult, the team wrote in the study published by the Royal Society of Open Science.

They created a computer model of the brain's visual cortex to analyze the men's ratings of attractiveness.

'We used an algorithm that models the sparseness of the activity of simple cells in the primary visual cortex of humans when coding images of female faces.'

Using this model, they found that the brain was easier able to process 'simple' and plainer faces without major distinguishing features - giving them a major advantage.

'Our results show that female faces which are rated the most attractive by men should be the most sparsely coded by the primary visual cortex of these men,' they said.

They say the same effect is probably present in most animals.

'Sparseness and more generally efficient neural coding are ubiquitous, occurring in various animals and sensory modalities, suggesting that the influence of efficient coding on mate choice can be widespread in animals.'

'This is a very interesting effect,' University of Queensland School of psychology Professor Bill von Hippel, who was not involved in the study, told News.com.au.

MEN MOST ATTRACTED TO WOMEN IN THEIR 20S - NO MATTER HOW OLD THEY GET In his book Dataclysm: Love, Sex, Race, and Identity - What Our Online Lives Tell Us About Our Offline Selves, author and OKCupid co-founder Christian Rudder used the data preferences found on his dating site to determine that men find women between the ages of 20 and 24 most attractive - no matter how old they get. After [a man] hits thirty, the latter half of [OKCupid's] age range (that is, women over 35) might as well not exist,' Christian explained in an excerpt of his book, which was shared on Jezebel. A majority of the groups of men between the ages of 20 and 50 prefer women to be 20, while 21 was the next highest reported age. And only one age group, 45, chose 24, the highest age reported, as the one that looks best to them. Advertisement

Because we tend to be attracted to simpler images may explain why ubiquitous brands are more popular than complex ones, suggests Von Hippel.

For example, the Nike swoosh or the word Coke are simple images it is easier for us to process and in turn has a more positive affect.

'Think about an emoticon,' says Prof van Hippel.

'You have two dots and a curved line that immediately everyone processes as a smile. It's sparse, it's plain.

'It's familiar, and it's easy to understand.

'The part of the brain processing these things means it is very much an involuntary, automatic, probably largely unconscious reaction. So yes, first impressions are terribly important.'

Although some may think this study suggests women should stop using glowing eye shadows, contouring makeup or ruby red lipstick, think again.

'My guess is lips and cheeks and eyes shaped in a prototypically attractive fashion are very easily processed themselves,' says Prof von Hippel

'So if contouring or lipstick makes it a more prototypical face, I'd imagine that meets the definition of 'simple'.'

Actress Kate Mara is also regarded by many as having a 'plain face'

'Sparseness was found positively correlated with attractiveness as rated by men and explained up to 17% of variance in attractiveness,' the University of Paris team, led by Julien Renoult. Emilia Clarke( pictured) has a plain face without putting makeup on

The French team recruited Caucasian women between the ages of 18 and 26 from France and took their pictures using a Canon EOS 20D camera and a 50 mm lens.

There were 169 men surveyed who were instructed to move a cursor between zero (lowest attractiveness) and 20 (highest attractiveness).

For example, the Nike (right) swoosh or the word Coke are simple images it is easier for us to process and in turn has a more positive affect. 'Think about an emoticon (left),' says Prof van Hippel. 'You have two dots and a curved line that immediately everyone processes as a smile. It's sparse, it's plain

And each male participant was given 30 different faces to rank.

The second part of the study displayed pairs of images to 156 men, who also rated each set based on attractiveness.

Results showed 'that female faces which are rated the most attractive by men should be the most sparsely coded by the primary visual cortex of these men'.

Researchers were asked to rate the faces, which were then analysed to find how plain they were

'The primary visual cortex is a generalist brain region that has been shaped through natural selection and development to process the complex statistics of natural scenes, not to perform a specific task like identifying faces or evaluating their attractiveness,' said the team.

The team found that men prefer a women with a 'simpler' and plain face, such as actress Carey Mulligan (pictured) which they suggest is because they are easier for our brains to process and store.

Professor von Hippel explains that it isn't because humans are simple creatures, it is due to how our brains are so efficient when process information.

These findings do support the concept that first impressions are important, as we tend to subconsciously decide if someone is attractive or not before we consciously know it.