See those sweet, doleful eyes? Wolves don't have the facial muscles to accomplish that look. Humans began breeding the ability for dogs like Evie, a terrier mix, to gaze soulfully into a person's eyes some 30,000 years ago.
Courtesy Ryan Pollyea
Dogs like Daisy, a black Labrador mix, have "fast-twitch" facial muscles that today's wolves don't have. Those muscles allow dogs to quickly respond to us in ways that mimic an infant's face, boosting the release of oxytocin, the "love" hormone.
Courtesy Zac May
Dogs like Garrus, a Husky Border collie mix, have perfected the begging look. "Dogs are unique from other mammals in their reciprocated bond with humans which can be demonstrated though mutual gaze, something we do not observe between humans and other domesticated mammals such as horses or cats," said Anne Burrows, a professor in the department of physical therapy at Rangos School of Health Sciences at Duquesne University in Pittsburgh.
Courtesy Cat Meyers
Eevee, a corgi who always begs for food, is using a muscle that wolves don't have to raise an inner "eyebrow." That allows her to show the whites of her eyes, making her more expressive (and successful in tugging at humans' heartstrings).
Courtesy Skye Huang
"Sweet Dora the Giant Puppy," as her mom calls her, is a 1-year-old Great Pyrenees who enjoys playing in the mud and begging for cheese.
Courtesy Julia Meo
Molly, a cockapoo mix, is using her facial muscles to look like humans do when they are sad, "making (dogs) irresistible and resulting in a nurturing response from humans," said Madisen Omstead, laboratory manager for the Rangos School of Health Sciences department of physical therapy.
Courtesy Ryan Pollyea
People are still unconsciously selecting "puppy dog eyes" in their choice of pet today, experts say. Kimchi, a chocolate Labrador that's 1 ½ years old, is begging to get on her person's bed for a nap.
Courtesy Pascale Sauvage
A 2013 study found dogs like Nasus (pictured here) who use sweet expressions more frequently "were rehomed more quickly than less expressive dogs, reinforcing this type of evolutionary scenario," Omstead said. Nasus, who is a Formosan Mountain Dog from Taiwan, was a rescue.
Courtesy Nic Phelps
Nymeria, a year-old Husky mix who is deaf, uses her puppy dog eyes to woo her person into giving her extra love and playtime.
Courtesy Nic Phelps
Siberian huskies, which are more closely related to wolves than many other breeds, may not have these extra muscles, experts say. (We beg to differ when it comes to this 10-year-old Siberian husky, Delilah.)
Courtesy Brawner Raymond
Revan, whose name comes from Star Wars "Darth Revan." is a Foxhound Coonhound mix adopted as a stray. He is "totally begging to have the kids take that thing off his head," said his mom.
Courtesy Cat Meyers
Look at Edison, a miniature Australian shepherd! Many dogs have another muscle, called the retractor anguli oculi lateralis muscle, which pulls the corners of the eyelids towards the ears, in effect producing what humans would call an "eye smile." A 2019 study found that, while wolves had a bit of this muscle fiber, most domesticated dogs had a more fully developed muscle and used it frequently.
