The magic formula

The idea that traits we perceive as beautiful are indicative of health and healthy offspring is also used to explain why we are most attracted to mates who have symmetrical faces.

The human foetus is designed to grow in the womb in two equal parts around the central axis of the spine. These parts should, in theory, be identical but tiny differences, which can be caused by a range of factors including genetic abnormalities and infection, cause the two sides to develop subtle differences.

When viewed in a fully grown human, it’s believed we subconsciously register these minute differences and interpret them as indications of underlying genetic problems. Our predisposition to find symmetrical faces attractive is a subconscious response to fundamental clues about genetic health.

It seems that reoccurring mathematical formulas crop up regularly in studies on beauty. In California, plastic surgeon Dr Stephen Marquardt claims that the formula of beauty is a figure known as the ‘golden ratio’ represented by the Greek letter phi – 1.618.

He believes it crops up all over the ideal human face. He discovered that people deemed beautiful had mouths that were 1.618 times wider than the length of their noses, nostrils 1.618 times wider than the tips of their noses and teeth 1.618 times wider than their height.

Arguably, this number appears in more places in art, music and nature than any other except pi (3.142). Composer Claude Debussy used it in his music and Le Corbusier in his architecture. There are claims the number was used by Leonardo da Vinci in the painting of the Mona Lisa; by the Greeks in building the Parthenon; and by ancient Egyptians in the construction of the Great Pyramid of Khufu.

Other research has found different formulas for ideal facial features. Studies at the University of Toronto found that female faces were judged most attractive when the distance between the eyes and the mouth was roughly 36 per cent of the overall length of the face, and when the distance between the eyes was around 46 per cent of the face’s width.

In a series of studies, students were asked to compare colour photographs of women’s faces. In one photograph the vertical distance between the eyes and mouth and the horizontal distance between the eyes had been doctored. The participants were asked to select the face they found most attractive. In each experiment the face displaying the 36/46 per cent ratios was deemed most attractive.

It is believed that these figures represent a universal average and that we cognitively assess all of the faces we encounter on a daily basis and gravitate toward the ones displaying features nearest to this average.

“We already know that different facial features make a female face attractive such as

The magic 70 per cent formula applies to some of the world’s most beautiful women such as Marilyn Monroe, actress Jessica Alba and supermodel Kate Moss

large eyes or full lips,” says Professor Kang Lee, one of the lead researchers. “The study proves that the structure of faces also contributes to our perception of facial attractiveness.”

The good news for those who do not possess the magic ratio however, is that there are plenty of exceptions to the rule.

For example, actress Angelina Jolie differs from the classic ratio by a few percentage points. The study also discovered that it was