Science of Sexy: Why Emilia Clarke Reigns Supreme
Emilia Clarke arrives to the "Terminator Genisys" Los Angeles Premiere on June 28, 2015, in Hollywood, California.
Credit: DFree / Shutterstock.com

It's official: Actress Emilia Clarke is Esquire magazine's "Sexiest Woman Alive."

In many ways, it's not surprising Esquire picked Clarke, who plays the fearless dragon rider and rightful heir to the Iron Throne on Game of Thrones. (And no, it's not just because she's in a state of undress in many episodes of the hit show.)

From her jaw-dropping symmetry to her dewy skin, she has many of the traits that humans have been hardwired to find sexy, scientists say. [Smile Secrets: 5 Things Your Grin Reveals About You]

Youth is beauty

It's probably no surprise that youth is beautiful. Data from the dating website OkCupid reveals that men up to the age of 50 rate women between the ages of 20 and 24 the most beautiful.

"From the time you're 22, you'll be less hot than a 20-year-old, based on this data," Christian Rudder, one of the founders of OkCupid, told fivethirtyeight.com.

While 28-year-old Clarke is past "peak hotness" by that measure, her "baby face" and porcelain-clear skin may give her an edge. Clear and even skin tone makes people look more youthful, while a red, rosy hue — a sign of hemoglobin in the blood — is a sign of health that increases attractiveness, according to a 2011 study published in the Journal of Cosmetic Dermatology.

Bone structure

Like many other beautiful people, Clarke also has incredibly symmetric features.

It's a common trait amongst sex symbols and beauty icons. In the past, scientists thought people were drawn to symmetric faces because symmetry was a marker for good genes. However, a 2014 study published in the journal Proceedings of the Royal Society B found no correlation between the two traits.

Either way, "bottom line, around the world, people regard a very symmetrical face as very attractive," Helen Fisher, an anthropologist at Rutgers University in New Jersey who studies love and attraction, told Live Science.

Women and men alike also tend to prefer features that are not too big or small, but rather average in size, Lisa DeBruine, a psychologist at the University of Glasgow's Face Lab in Scotland, who studies the psychology of attractiveness, previously told Live Science.

Beyond that, the action of sex hormones may play a role in what people consider sexy, Fisher said. When in utero, a fetus's facial development is directed by myriad hormones and chemical signals, including testosterone. High cheekbones are chiseled by testosterone. Though this "T" hormone is most associated with masculinity, it is also present in developing female fetuses. Because testosterone is a caustic substance, high cheekbones can signal a healthy immune system, Fisher previously told Live Science.

On the other end of the spectrum, the sex hormone estrogen, which is typically associated with female sexual features, also molds features that men typically find hot.

"Men tend to be attracted to two kinds of women: high-testosterone women who tend to be taller, have a stronger jaw, a higher forehead," Fisher said. "But they're also very attracted to the high-estrogen type: the puffy lips and very turned-up nose and large eyes in relation to rest of the face."

Clarke, with her pouty lips and high cheekbones, combines traits that men from across the spectrum likely find attractive.

But for those who don't have Clarke's pouty lips or sultry eyes, don't despair. It turns out that beauty really is in the eye of the beholder, and personal tastes vary wildly. A study published Oct. 1 in the journal Current Biology found that identical twins have dramatically different tastes — a sign that life experience, not genetics, plays the biggest role in attraction.

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