The belle curve: why all men love a waistline (allegedly)

Psychologists have defined the shape of beauty, writes Anna Maxted

BEAUTIFUL, sexy women come in all shapes and sizes. For every man who goes for the voluptuous type, such as Anna Nicole Smith, the lavishly endowed American model, there is another who prefers the waiflike elfin look: Audrey Hepburn, Kate Moss, Twiggy. Just a matter of personal taste, surely . . .

Not according to Dr Devendra Singh, a psychologist at Texas University. Dr Singh has spent the past five years researching the correlations between body shape, health and perceptions of beauty. His conclusions are that Anna Nicole Smith and Twiggy have one attribute in common: their sizes may be completely different but both have waists that are noticeably narrower than their hips. This he identifies as their WHR - waist-hip ratio. And this is what makes men find them attractive. The lower curves of an hourglass figure signify fertility and men are biologically programmed to react accordingly. In fact, says Dr Singh, all men, everywhere, regardless of age or culture, are drawn to the hourglass shape in the female figure. It is the universal standard of beauty, he claims.

Dr Singh's findings are based on studies of males from Africa, the Azores, Hong Kong, India, the Netherlands and the United States. Volunteers were given a selection of photographs of female bodies of different shapes and sizes and asked to rank them according to physical beauty. "They all selected the same women," Singh says. "They all seemed to like women with a low waist-to-hip ratio. We wanted to see how early it starts. In America and India eight-year-old boys selected the same women as the grown-ups. They looked at the women and said: "That's the one that's beautiful." He compares this apparent instinct with people's innate liking for sugar: "You don't have to teach a kid to like chocolate.''

But surely different cultures place different values on female shape and size? Dr Singh, whose claims were reported in the New Scientist, believes culture is secondary to genetically conditioned behaviour. "In countries such as India and Africa the volunteers' first choice was the normal-weight woman, their second choice was the fatter and their third choice the skinnier woman. In America and Europe, they picked the normal weight woman, then the underweight woman and finally the overweight one." The magic WHR figure is calculated by dividing a woman's waist circumference by that of her hips. A ratio of 1.0 would be a female with a waist the same size as her hips. The ratio can vary from a curvy 0.67 to an almost tubular 0.9.

John Manning, of Liverpool University's Department of Environmental and Evolutionary Biology, also studies body shape, and describes Dr Singh's research as "very valid".

"If you look at Miss Americas over the past 30 to 40 years, their body weight has gone down but their waist-hip ratio remains the same. Singh has found that this ratio is related to fertility. Women with low WHRs are most fertile because they tend to produce more oestrogen."

This fits the Darwinian notion that males unconsciously look for signs of fertility in females as, in evolutionary terms, there is no point in choosing a sterile mate.

Manning's own research attempts to determine a link between a woman's shape and the sex of her offspring. He studied 84 mothers and found those with thicker waists produced marginally more sons than daughters. This suggests, says Manning, that if a woman's bloodstream contains a lot of testosterone she'll be more tubular and less fertile than her voluptuous, oestrogen-rich counterpart, but more likely to have male children.

Women are unlikely to greet the idea that there is a "correct" female shape with whoops of joy. Dr Singh dismisses charges of body fascism, maintaining that the desirable shape is indicative of good health. But this cuts no ice with Dr Phyllis Lee, biological anthropologist at Cambridge University. "Total and utter nonsense," she says, tartly.

She points out that while women with greater deposits of fat on their hips may theoretically be more capable of sustaining a pregnancy (in conditions where food was limited the reserves can be mobilised for producing milk), this does not necessarily mean they are able to ovulate. "I don't know what the waistline has to do with it," she says. Manning's survey, she believes, is no more than "pure speculation. They tested 84 women and I don't think the results are statistically significant. I'm not sure testosterone thickens the waist. It tends to increase muscle fibre density rather than fat storage."

Women of all shapes and sizes, take heart.