The Biology Of Beauty

IF WE DID GO COURTING WITH calipers, symmetry isn't all we would measure. As we study each other in the street, the office or the gym, our beauty radars pick up a range of signals. Oddly enough, one of the qualities shared by attractive people is their averageness. Researchers discovered more than a century ago that if they superimposed photographs of several faces, the resulting composite was usually better looking than any of the images that went into it. Scientists can now average faces digitally, and it's still one of the surest ways to make them more attractive. From an evolutionary perspective, a preference for extreme normality makes sense. As Langlois has written, "Individuals with average population characteristics should be less likely to carry harmful genetic mutations."

So far, so good. But here's the catch: while we may find average faces attractive, the faces we find most beautiful are not average. As New Mexico State University psychologist Victor Johnston has shown, they're extreme. To track people's preferences, Johnston uses a computer program called FacePrints. Turn it on, and it generates 30 facial images, all male or all female, which you rate on a 1-9 beauty scale. The program then "breeds" the top-rated face with one of the others to create two digital offspring, which replace the lowest-rated faces in the pool. By rating round after round of new faces, you create an ever more beautiful population. The game ends when you award some visage a perfect 10. (If you have access to the World Wide Web, you can take part in a collective face-breeding experiment by visiting http://www-psych.nmsu.edu/vic/ faceprints/.)

For Johnston, the real fun starts after the judging is finished. By collecting people's ideal faces and comparing them to average faces, he can measure the distance between fantasy and reality. As a rule, he finds that an ideal female has a higher forehead than an average one, as well as fuller lips, a shorter jaw and a smaller chin and nose. Indeed, the ideal 25-year-old woman, as configured by participants in a 1993 study, had a 14-year-old's abundant lips and an 11-year-old's delicate jaw. Because her lower face was so small, she also had relatively prominent eyes and cheekbones.

The participants in that study were all college kids from New Mexico, but researchers have since shown that British and Japanese students express the same bias. And if there are lingering doubts about the depth of that bias, Johnston's latest findings should dispel them. In a forthcoming study, he reports that male volunteers not only consciously prefer women with small lower faces but show marked rises in brain activity when looking at pictures of them. And though Johnston has yet to publish specs on the ideal male, his unpublished findings suggest that a big jaw, a strong chin and an imposing brow are as prized in a man's face as their opposites are in a woman's.

Few of us ever develop the heart-melting proportions of a FacePrints fantasy. And if it's any consolation, beauty is not an all-or-nothing proposition. Madonna became a sex symbol despite her strong nose, and Melanie Griffith's strong jaw hasn't kept her out of the movies. Still, special things have a way of happening to people who approximate the ideal. We pay them huge fees to stand on windblown bluffs and stare into the distance. And past studies have found that square-jawed males not only start having sex earlier than their peers but attain higher rank in the military.