THE HUMAN ANIMAL

Inherently Beautiful

Francis Galton loved photography and hated criminals. As a man of means, he combined these passions with a hope to both develop technical skills and provide a service to society. Using the best technology of the day, and a captive and thus patient subject pool, Galton set out to reveal the essential criminal face.

This was a tall order, and one made no easier given the state of photography in the late 1800s. Galton—a versatile scientist and inventor—designed his own equipment and perfected a method of combining the likenesses of different subjects into a single blended image. The logic, like the eventual images, was flawless: superimposing images would allow for meaningless variation to drift into the background, while pulling essential similarities to the foreground.

Surely what shone through should be the pure criminal essence. With the prototypical criminal face thus identified, trials could be sped up, and individuals might even be sequestered before they fulfilled their criminal destiny. But that isn’t what happened. When Galton completed his task, he was surprised to find that the prototypical criminal face was . . . beautiful. He had become the accidental father of a new approach to understanding which features humans find attractive.

When the images were combined, each individual’s small imperfections—wrinkles, scars, or blemishes—disappeared from the final photo. The resulting composite faces appeared youthful and healthy. Humans find these characteristics especially attractive, as they indicate fertility.

And it isn’t surprising that we are attracted to traits indicating fertility. From an evolutionary perspective, choosing a partner is particularly important. Not only should we be attracted to fertile individuals, but we should also be attracted to individuals with the best genes.

But how do you infer someone’s genetic quality just by looking at the person? Again, Galton’s prototypical criminal face suggests an answer. One variation that faded to the background in the composite images was the slight deviation we all have from bilateral symmetry. The resulting image was of a highly symmetrical face. Many biologists today think that symmetry is a reliable external indicator of good genes.

Research has shown that we rate highly symmetrical faces more attractive, that we are more committed to highly symmetrical partners, and even that sex with a symmetrical partner is more fulfilling. Some provocative data even suggest that the willingness to cheat on a partner is influenced by that person’s degree of symmetry relative to the prospective lover’s.

Our choice of mate, of course, is based on a suite of characteristics, not just facial attractiveness. Moreover, our choices differ according to our gender, our age, our experiences, and our current and long-term goals. But to the extent that faces matter, Galton’s accidental uncovering of traits that we commonly associate with attractiveness remains significant.

As a means of identifying criminal facial types, his photographic technique became as irrelevant as another one of his ideas: eugenics, a field with its own well-earned social stigma. But in fairness to Galton, I should point out that he also invented twin studies, developed statistical techniques, showed how fingerprints could be classified for forensics, produced the first weather map, and much more.

But for a biologist like myself who both adores and is fascinated by the human animal, his lasting message is especially satisfying. Galton was the first to use science to show that when you look at enough of us, and allow the variation to fade to the background, what emerges is undeniable: as a collective, humans are inherently beautiful.

PHILIP STARKS, an associate professor of biology at Tufts, studies the social behavior of animals, with an emphasis on insects.