Science Explains What Makes Your Dog So Cute - WSJ

National Dog Day 2021: Science Explains What Makes Your Dog So Cute

The evolution of moveable eyebrows gave dogs those irresistible eyes.

By Jennifer Calfas Updated Aug. 27, 2021 Tap story

What makes your dog so darn cute? Scientists say it’s all about the eyebrows. Research has shown that over thousands of years of domestication, dogs developed moveable brows and other facial features that are attractive to people.

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In fact, “puppy dog eyes'' are a thing today because our ancestors favored canines with expressive eyebrows that make their eyes look bigger over canines with less expressive anatomical features, according to one 2019 study.

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“The most likely evolutionary scenario is that dogs’ ancestor must have, to some extent, expressed characteristics that elicited a caregiving response from humans,” researchers said in the study.

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“Humans then consciously or unconsciously favored and therefore selected for those characteristics, leading to the analogous adaptations we see in dogs today.”

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Dogs and wolves have similar facial muscles—except around the eyes. Dogs’ levator anguli oculi medialis (LOAM) and retractor anguli oculi lateralis (ROAL) muscles help create those expressive eyes, according to the study.

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Wolves can’t do much with their eyes beyond opening and closing them—and squinting. They don’t have the necessary muscles.

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Neither do Siberian huskies. They’re more closely related to wolves than other dog breeds.

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Dogs have also evolved to make eye contact with humans when they need guidance—another thing wolves can’t do. Researchers in the 2019 study have called this kind of eye contact a hallmark of the relationship between dogs and humans.

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Making eye contact with a dog causes humans to release a feel-good hormone called oxytocin, research has shown.

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Beyond giving their owners pleasure, dogs provide them with a number of health benefits, including greater feelings of happiness as well as lower blood pressure.

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Americans own 78 million dogs, with about 44% of households having a loyal companion, according to the American Society for the Prevention of Cruelty to Animals.

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Produced by Chase Gaewski

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