In the early 1990’s in Vienna the biological anthropologist Karl Grammer and his colleagues noticed that symmetrical scorpion flies attract more mates than asymmetrical ones. On the hunch that what’s true for the courting of scorpions might also be true for the courting of humans, they examined perceptions of symmetry in people and learned that symmetry was one of the features we associate with beauty. Not just “we” in Vienna, but people all over the world. In one of their studies, people from South Africa and Austria judged the same Japanese women to be attractive.
Though until the 1990’s there had been little research on the science of beauty—the topic was considered politically incorrect during the 1960’s and 1970’s—Grammer spent the next 15 years studying what we think of as beautiful and how beauty drives much of our behavior, from who we court to how we dress to what we buy to adorn ourselves. After reading in a recent issue of Nature an interview with Grammer, in which he identifies “eight pillars of beauty,” I began to wonder how he and others had arrived at this list and how robust the research has been.
The best answer I’ve found is their review of their work published in 2003, titled “Darwinian Aesthetics: sexual selection and the biology of beauty.” Over 140 references, mostly from the previous 15 years, convinced me they had plenty of good company in a wide range of disciplines who had published in sound scientific journals. And they summarize the evidence for and against their assertions, suggesting they have done their homework on both sides of the arguments. Here are a few notes on how they elaborate on these eight pillars of beauty.
Symmetry. Nature has selected against asymmetries since the beginning of reproduction. Asymmetric gametes (the organisms after the sperm and egg meet and start multiplying) don’t survive. All plants and animals that survive show features of symmetry, and among primates obvious asymmetries usually lead to harsh exclusion by all but the most compassionate groups. Symmetry also favors efficient movements, which for most species is essential to survival.
Youthfulness. It is no accident that our icons of beauty tend to be in their reproductive years, between the late teens to the late forties. Babies and children can be “cute,” but they don’t evoke the power of youthful beauty. The elderly too can be attractive, but often in ways that retain the features of their youth. The pitch from plastic surgeons and cosmetologists is that they can help you prolong the appearance of your youth.
Averageness. We have learned to be wary of the extremes of human appearance as indicators of risky genes. And the circuits in our brains for recognizing faces and bodies operate on prototypes. Faces and bodies that don’t fit the general rules of our prototypes trigger alarm or indifference. Try turning a picture of a face upside down and see how long it takes you to recognize it. So we are programmed to be attracted to people who fit our concept of average humanness.
Sexual dimorphism. Clarity of gender and readiness for reproduction have driven our sense of what makes a woman or a man attractive. The broad male chin signals ample testosterone, but too broad a chin may signal too much aggression, a disadvantage in caring for the offspring. The high cheekbones and smaller chins and lower facial features that signal ample estrogen differentiate the fertile woman from the undeveloped girl or boy. The body shape of the fertile woman also signals adequate storage for estrogen in breasts and hips. The recent effort to consider gender along a continuum instead of a binary phenomenon poses a challenge to this feature of beauty.
Body scents. Did you know that women show a distinct preference for the body scents of “symmetric men” during the ovulatory phase of the menstrual cycle? If you know some symmetric men who don’t smell so hot, imagine what “asymmetric” men smell like! Sorry, we haven’t yet evolved beyond such animalistic things as pheromones. Maybe some day soon.
Movement. We can quickly identify a person’s gender by watching gait. How a person moves also tells us something about age, health, and ability to compete against others. No wonder dance plays a ritual role in most cultures. No wonder we’re fascinated by the movements of our young and often attractive athletes.
Skin complexion and hair texture. One of the better outward indicators of the state of a person’s immune system is the state of his skin and hair. Blemishes and hair loss often reflect difficulty with parasites. When choosing a mate, you’re choosing your mate’s parasites too. Make sure he or she has good control over those buggers.
Why eight pillars of beauty, and not seven or ten? That number seems to be a moving target that depends on the state of the research. When Grammer and colleagues published their review in 2003, they devoted some ink to the role of the voice in attractiveness, but there has been little research about the effect of voices on perceptions of beauty, so this gap in research apparently dropped it from the list. More recent research about skin complexion and hair texture as indicators of immune function has added those two “pillars” to the list. Science is always remodeling its house.
In the next blog, we’ll wonder aloud what this list tells us about how our highly evolved sense of beauty draws us so powerfully to the less human marvels of rainbows and songbirds and Beethoven’s seventh symphony and the mesmerizing shape of an egg.