FOR the female half of the population, it may bring a satisfied smile. Scientists have found that evolution is driving women to become ever more beautiful, while men remain as aesthetically unappealing as their caveman ancestors.

The researchers have found beautiful women have more children than their plainer counterparts and that a higher proportion of those children are female. Those daughters, once adult, also tend to be attractive and so repeat the pattern.

Over generations, the scientists argue, this has led to women becoming steadily more aesthetically pleasing, a “beauty race” that is still on. The findings have emerged from a series of studies of physical attractiveness and its links to reproductive success in humans.

In a study released last week, Markus Jokela, a researcher at the University of Helsinki, found beautiful women had up to 16% more children than their plainer counterparts. He used data gathered in America, in which 1,244 women and 997 men were followed through four decades of life. Their attractiveness was assessed from photographs taken during the study, which also collected data on the number of children they had.

This builds on previous work by Satoshi Kanazawa, an evolutionary psychologist at the London School of Economics, who found that good-looking parents were far more likely to conceive daughters. He suggested this was an evolutionary strategy subtly programmed into human DNA.

He cited two findings from the Longitudinal Study of Adolescent Health, a US government-backed study that is monitoring more than 15,000 Americans. The measurements include objective assessments of physical attractiveness.

One finding was that women were generally regarded by both sexes as more aesthetically appealing than men. The other was that the most attractive parents were 26% less likely to have sons.

Kanazawa said: “Physical attractiveness is a highly heritable trait, which disproportionately increases the reproductive success of daughters much more than that of sons.

“If more attractive parents have more daughters and if physical attractiveness is heritable, it logically follows that women over many generations gradually become more physically attractive on average than men.”

In men, by contrast, good looks appear to count for little, with handsome men being no more successful than others in terms of numbers of children. This means there has been little pressure for men’s appearance to evolve.

The findings coincide with the bicentenary of the birth of Charles Darwin, whose theory of evolution first described the forces that shape all species.

Even he, however, might have been surprised by the subtlety of the effects now being detected by researchers looking into human mating.

The heritability of attractiveness is widely accepted. When Elizabeth Jagger became a model, her mother, the former model Jerry Hall, said: “It’s in her genes.”

Women may take consolation in the finding that men are subject to other types of evolutionary pressure.

Gayle Brewer, a psychology lecturer at the University of Central Lancashire, said: “Men and women seek different things in their partners.

“For women, looks are much less important in a man than his ability to look after her when she is pregnant and nursing, periods when women are vulnerable to predators. Historically this has meant rich men tend to have more wives and many children. So the pressure is on men to be successful.”

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