The Power of Physical Beauty Is More Than Skin Deep

How attractive you are may seem the kind of superficial issue that few serious scientists would spend time studying. Increasingly, however, it is being seen as a profound question that deserves serious investigation. Indeed, recent findings suggest it could be a linchpin of evolutionary theory.

Psychological studies since the 1970s have established that the physically attractive are more successful at job interviews, judged to have higher IQs, seen as more socially skilled and thought to be superior at all sorts of tasks such as teaching, even piloting aircraft. Beautiful children are punished less by adults and pretty people attract more lenient sentences in court – so check your make-up before stepping into the dock.

We seem to be born with a beauty instinct. Research has shown that even babies prefer an attractive adult face rather than an ugly one, and that adults decide whether the face they are looking at is attractive or not in around one tenth of a second (100 milliseconds).

Since the 1990s, when these experiments were done by scientists, this figure has stood as a kind of world record for love at first sight but now it seems that we can become enraptured with another with a briefer glance than even a baby's eye-blink. Prof Ingrid Olson from the Centre for Cognitive Neuroscience at the University of Pennsylvania and Christy Marshuetz of Yale University recently published data which demonstrate that we can judge an attractive face when it's presented so quickly we can't even consciously note it.

Their study, published in the journal Emotion, involved asking people to rate the attractiveness of a face presented to them so briefly – 13 milliseconds – that viewers were often not even consciously aware they had actually seen the face – yet they were still able reliably to agree on its attractiveness afterwards. So science can confirm not only that love at first sight exists, it can even quantify it more precisely than any romantic poet has ever managed – love can take hold within 13 thousandths of a second.

These astonishing figures suggest to scientists that who we are attracted to may have much less to do with individual choice and taste, and much more to do with unconscious biological or brain programming: evolution has designed us this way.

Darwin's theory of evolution has two main driving forces – ''survival of the fittest" is perhaps the most widely known but there is another plank of evolution, which Darwin himself originally proposed, which can be abbreviated to ''survival of the fanciest".

The term that evolutionary biologists prefer to use is "sexual selection" and the idea is if a bird, such as a peacock for example, has an incongruously large tail that hampers flight, but yet is highly attractive to the opposite sex, then the genes of these attractive, cumbersomely tailed birds will be more likely to be transmitted to the next generation relative to their stubby-tailed peers. There is therefore an evolutionary pressure to be attractive to the opposite sex.

The findings of one of the largest experiments in the science of attractiveness conducted by myself in 2007 with The Daily Telegraph Newspaper and website challenge current thinking about the differences between men and women.

Around four thousand people took part in the web experiment and survey and while some revelations are obvious - in the case of men, being rich, powerful, smart and funny helps, and the more attractive the woman you are pursuing, the more these factors matter to her. Some are less obvious: women rate being good in bed as more desirable in a possible partner than men do!

The woman's face deemed the most beautiful by survey - by just over half of the men rating the five photographs presented to them - was that of the youngest, aged 19. Women, however, plumped for the second oldest man, aged 29, as the most attractive.

This tallies with what one would expect from evolutionary theory: what we mean by beauty is a person who sends out signals that they are fertile, have "good" genes to pass on to our children and in so doing assist the dissemination of our own DNA - in other words all attraction is determined by the "selfish gene".

Because women have a shorter reproductive life span, males are predicted to be lured primarily by visual cues that signal high fertility, such as youth, and biological fitness indicated by physical flawlessness.

As predicted by evolutionary theory, the women that rated themselves as most attractive were teenagers, while nine per cent fewer women between 26 and 35 years rated themselves as most attractive.

Evolutionary strategy also predicts that whom we go for is influenced by our assessment of our own value in the "market place". Women are more likely than men to shun the most attractive partner even if they believe they could secure him, because of fears that while he may be a great date, in the longer run he may be less likely to remain faithful and helpful.

Men are more predictable, going for the most physically gorgeous woman regardless of their ability to keep hold of such a desirable mate.

While it could be predicted that women would value being good with children as more important than men do in determining gorgeousness, it may come as a shock to discover that the women we surveyed rate being good in bed as more important than men do.

The one per cent of women who had slept with more than 51 partners rated their own desirability very high indeed at 7.27 on a scale of 1-10. This is intriguing, as traditional psychological thinking had been that women who ''sleep around'' have low self-esteem. However, this score for self-rated attractiveness backs recent research that reveals a new breed of woman whose predatory approach to sex is similar to the male mindset.