Can YOU identify these stars from just their lips? Scientists say plump pouts like the Kardashians' aren't the most desirable while Holly Willoughby and Taylor Swift have a perfect pair

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Researchers have identified a 'golden ratio' for a mathematically perfect pout.

Despite the growing popularity of top lip fillers among women keen to emulate the Kardashians' pillowy pouts, the study indicates that a lower lip 47 per cent larger than the top lip is actually a preferable shape.   

Experts performed a detailed analysis of 50 years of fashion photographs in Vogue magazine to hit on the so-called 'golden ratio', after identifying facial traits shared by celebrated beauties through the decades.

The scientists noted the recurring link between the size of a model's top lip compared with the proportions of the bottom.  

See if you can single out the stars with the most enviable lips from the pictures - as well as those whose pouts are too full to make the grade (scroll down for answers)

Can you guess the celebrity from their lips? 1: A good girl gone bad. 2: A pop princess. 3: A lively actress. 4: An on-screen jailbird. 5: A singer who likes to roar. 6: A reality TV princess. 7: An Oscar hopeful. 8: A black swan. 9: A body conscious reality star. 10: A famous little sister. 11: Taylor Swift's BFF. 12: A daytime TV queen

Identification of the perfect lip shape began with research by experts at the University of Southern California, who trawled back issues of the style bible over the past 50 years.

Hundreds of images of lips were digitally scanned and their precise surface area measured in order to build a database of how the dimensions may have changed over the course of five decades. 

Lead scientist Dr Prem Tripathi found there was a recurring link between the size of a model's top lip compared to the proportions of her bottom lip. 

And the most common upper lip to lower lip ratio was 0.68, meaning the women celebrated by the style bible all had lower lips 47 per cent larger than their top lip.

Taylor Swift's pout is mathematically perfect as one can get according to experts who assessed hundreds of images with the golden ratio

Fellow pop stars Rihanna (left) and Solange (right) also both possess lips that are 47 per cent larger than their top lip 

While the purpose of Dr Tripathi's research was to identify how lip dimensions have changed, experts now say the fact that so many models possess this 'golden ratio' proves that it's the most desirable lip shape for women. 

The figure could now be utilised by cosmetic doctors wishing to achieve the perfect ratio through simple lip filler injections. 

Leading UK aesthetic surgeon Dr Navid Jallali says the data provided by this survey could provide a technical blueprint for lips that are the easiest on the eye. 

Dr Jallali, a consultant cosmetic and reconstructive surgeon based in London, said: 'This study is interesting for a number of reasons. 'Firstly, it appears to disprove the theory that the craze for fuller lips is a modern one.

'This data shows that magazine editors have always been keen to portray women with a nice pout. There's nothing new about this at all. 

'And the study also appears to quantify the ideal lip proportions among fashion models, with the bottom lip being significantly larger than the model's top lip. 

'On a scientific level, this isn't surprising. 

Singer Katy Perry, award-winning actress Emma Stone and Hollywood starlet Blake Lively join the top ten list

Everyone's favourite daytime television host makes an appearance alongside some of the most glamorous women in entertainment 

'When it comes to beauty, there are special ratios that exist in nature and repeat themselves over and over again, defining what we regard as pleasurable to look at. 

THE GOLDEN RATIO EXPLAINED 

The most common upper lip to lower lip ratio in the study was 0.68

Expressed as the ratio '1 to 1.618', it appears over and over again in nature and it also appears to grow organically.

It marks the proportions of a person's hand compared to their forearm, as well as the distance between a persons three knuckles on each finger.

Scientifically put, the golden ratio is found when we divide a line into two parts so that: the longer part divided by the smaller part is also equal to the whole length divided by the longer part. 

It's also found in da Vinci's 'The Last Supper' mural painted back in 1499. 

'The 15th Century Renaissance painter Leonardo da Vinci was one of the first people to realise this, and wrote about a 'golden ratio', or the 'divine proportion', which he utilised when sketching his subjects.

'And we surgeons can also use this information to make sure lip filler injections are used to naturally compliment a woman's existing facial features, rather than just opting to make both lips look as plump as possible. 

'It's about striving for beauty, rather than just saying 'bigger is better' with no thought for how it impacts on the overall aesthetics.' 

While precise figures are not kept, cosmetic clinics in Britain have reported a steep rise in enquiries about lip filling injections since 2015 - some even suggesting a 70 per cent increase. 

Dr Jallali adds: 'After all, thinning lips are a natural consequence of growing older and the issue can be exacerbated in those who smoke. 

'We can make subtle, natural changes to keep someone looking and feeling great.'  

Head and neck surgeon Dr Tripathi, whose results were published in the journal JAMA Facial Plastic Surgery, explained: 'A cursory glance through Vogue leaves the reader with a variety of shiny, lip-centric images of fashion models.

Khloe Kardashian and her sister Kylie Jenner are known for their ultra plump pouts, but experts say that their luscious lips are not the most attractive 

Oscar-winning Natalie Portman's well-proportioned pout signifies desirability which is part of the calculation

Singer Selena Gomez petite features are perfectly balanced with her pout, while actress Laverne Cox has a stunning pair

'Studying magazine photographs provides a means to analyse trends for a lengthy period. 

'And in the present study we analysed 50 years of fashion model photographs in Vogue magazine to identify if the "desirable" features of the lip have trended toward a fuller aesthetic. 

'While there was no statistically significant increasing trend or strong correlation in the upper-lip surface area or the lower lip surface area, the mean upper-lip to lower-lip surface area ratio was 0.68, representing a 46 per cent larger lower lip compared with the upper lip.'