Supplementary reading. The biology of beauty

THE BIOLOGY OF BEAUTY

It’s widely assumed that ideas of beauty vary from era to era and from culture to culture. But studies have established that people everywhere – regardless of race, class or age – share a sense of what is attractive. And though no one knows just how our minds translate the sight of a face or a body into rapture, new studies suggest that we judge each other by rules we’re not even aware of. We may admire Kim Bessinger’s legs or Arnold’s biceps, but it isn’t to say that beauty is all that matters in life. Most of us manage to find jobs, attract mates and bear offspring despite our physical imperfections. But everyone wants to be good-looking.

One key to physical attractiveness is symmetry; humans, like other species, show a strong preference for individuals whose right and left sides are well matched.

Biologists have long used symmetry to measure what’s known as development stability. Scientists found that the bugs with the most symmetrical wings did best in the competition for food and mates. When the researches started noting similar trends in other species, they turned their attention to people.

Working together with psychologists, scientists started measuring the body symmetry of hundreds college-age men and women. They have measured an index of asymmetry of the feet, ankles, hands, wrists, elbows and ears. Then they asked the person to fill out a confidential questionnaire covering every aspect of his life. They were not disappointed. For both men and women, greater symmetry predicted a larger number of friends and sex partners.

That was just the beginning. From what they knew about other species, scientists predicted that women would be more sexually responsive to symmetrical men, and that men would exploit that advantage. They surveyed 86 couples and found that symmetrical men are less attentive to their partner and more likely to cheat them. Women showed no such tendency. Further studies showed that facial symmetry is also associated with health. The least symmetrical have the most physical complaints and show more anger, jealousy and withdrawal.