The concept of beauty is complicated. Beauty is both a biological feature and a subjective perception. Thanks to cosmetics companies, modeling campaigns, and photoshopped magazines, we are constantly being shown the “perfect” face. 

Bella Hadid, sister to model Gigi Hadid and face of Dior perfumes, has been praised for her symmetrical face since her modeling career started in 2012. Hadid has always been universally acknowledged as beautiful by fans and magazines—and now by science.

Randy Thornhill and Steven W. Gangestad, entomologist and evolutionary biologists, published a study on this in 1993, finding that those with a more “average” face process a more diverse set of genes, linked to survival due to their bodies understanding a larger variety of proteins. 

Everyone is a makeup of two parent’s DNA formation, but not every gene functions the same. Some are dominant and others are recessive; like brown hair as opposed to blond. Evolutionarily, physical attractiveness was thought to be an indication of good health, fitness, and fertility. People with these qualities appear to the public as more sexually attractive because they would make a good partner. 

In ancient Greece, artists were treated as inventors. They created many of the techniques for painting and sculpting the perfect figure that we still see today, including the “golden ratio” which mathematically calculates the symmetry and proportion of a person’s face to optimize attractiveness. 

Since then, beauty standards have evolved a bit, but not as much as one would think. Facial symmetry is still one of the largest universal attractive scales that scientists have studied. Plastic surgeon Dr. Julian De Silva created the “beauty phi” based on initial ancient Greek ideals of symmetry. He runs the Center for Advanced Facial Cosmetic and Plastic Surgery in London. 

While studying a number of celebrities from around the world, Bella Hadid was found to have a 94.35 percent perfect face, according to the “beauty phi” algorithm. All measurable characteristics of her face rank about 88 percent “perfect,” with her chin scoring a whopping 99.7 percent. But De Silva isn’t the first to apply these ancient symmetrical standards to modern beauty standards. 

Kendra Schmid, professor of biostatistics at the University of Nebraska, appeared on the Oprah Winfrey Show in 2009 to explain the sex-appeal of facial symmetry. She said that the ideal facial height is about 1 ½ times its width. Ears should be the same length as the nose. The face should make three equal horizontal quadrants, with the eyes and bottom of the nose as inner points. It’s the same way that people draw or sketch the baseline of portraits, before adding in an individual’s features of when imagining a hypothetical person. It stems from the original rules of Greek art.

But you don’t have to be Bella Hadid to reap the benefits of symmetrical beauty. In fact, averageness is proven more common to have symmetry. So perhaps Bella Hadid is just the highest percentage of average? I would personally like to think so.