Health & Wellness

Scents and sensitivity: Dogs know when we're happy or angry

Science is proving what pet owners have long believed: Dogs understand what we're feeling. Specifically, dogs can recognize the difference between a happy and an angry human face, a study published Thursday in Current Biology suggests.

University of Veterinary Medicine

It's the first research to show definitively that dogs are sensitive to our facial expressions, says coauthor Ludwig Huber, head of comparative cognition at Messerli Research Institute at the University of Veterinary Medicine, Vienna.

In the Austrian study, 20 pet dogs of various breeds and sizes were taught to play a computer game through a series of exercises. In the first, the dogs were shown two touch screens, one with a circle and one with a square. Through trial and error, they learned that a treat would appear if they chose the right geometrical figure.

Eleven of the 20 dogs were able to catch on to rules of the game and make it to the next phase, where they were shown photos of faces. Half the dogs were rewarded for picking a happy expression and half for choosing an angry expression. The interesting catch: the dogs were shown only the upper half or the lower half of a face.

It was easier to teach the dogs to choose a happy expression than an angry one, suggesting the dogs do indeed understand the meaning behind the expression, Huber says.

As a test, the dogs were then were presented with:

  • the same half of the faces they saw during the training, but from different people
  • the other half of the faces used in training
  • the other half of new faces
  • the left half of the faces used in training

In the vast majority of cases the dogs chose the right answer 70 to 100 percent of the time.

Dogs who had been trained to recognize an expression of anger or happiness on the upper part of a face could identify the same expression when shown only the lower part, and vice versa, Huber says, adding “the only possible explanation is that they recall from memory of everyday life how a whole human face looks when happy or angry.”

Dog owners know their pets not only recognize emotions but also feel empathy.

Delilah, a 3-year-old Chihuahua, always seems to know when her owner Eva Shure is having a bad day.

Courtesy of Eva Shure
Delilah knows when her owner is having a bad day.

Making eye contact and cocking her head to the right, the little dog will stare at Shure's face as if trying to assess her feelings. “It’s weird, I can see her thinking and processing,” says Shure, a 35-year-old New York City business owner. “I’ll say, yeah, it’s not a great day and she’ll come up and sit next to me.”

Beverly Levreault, 57, says her 6-year-old Australian Cattle Dog mix is always tuned in to her moods. “If I’m not feeling well, like when I have the flu, Lacey is definitely lower key and will not leave my side, ” says Levreault, a graphic designer from Williamstown, New York. “If I take her for a walk, she’s not as rambunctious as she usually is.”

Lynette Whiteman says she’s not sure that her 5-year-old Yorkie-Maltese cross is using facial expressions to gauge how she feels. “But she definitely reads my emotions,” says the 58-year-old from Toms River, New Jersey. “I run a therapy dog program and the dogs are just amazing. They go into a room and immediately pick out the person who needs help.”

Behavioral experts say the new findings, while important, wouldn’t surprise anyone with an intimate knowledge of dogs.

Courtesy of Lynette Whiteman
Coco and Lynettte

"This new work continues to build the case for just how sensitive dogs are to our subtle behaviors,” says Dr. Brian Hare, chief scientific officer at Dognition and an associate professor of evolutionary anthropology at Duke University. “This is the strongest evidence yet that dogs are even reading our facial expressions.”

That sensitivity may be the result of generations of selective breeding for a true partner, says Dr. Carlo Siracusa, director of the behavior service at the University of Pennsylvania School of Veterinary Medicine. “We have selected animals that are able to perceive our emotions and communicate with us at a level that no other animal can,” Siracusa says.

Dogs may not talk, but they are very good communicators, says Dr. Nicholas Dodman, a professor in the department of clinical sciences at the Cummings School of Veterinary Medicine at Tufts University and director of the animal behavior clinic at Cummings.

“Just as we are masters of the spoken word, dogs are experts at reading body language,” Dodman says.

“It’s almost impossible to hide your feelings from a dog.”

Turns out, reading facial expressions isn’t the only thing dogs have in common with us.

They can be bitten by the computer gaming bug. “They can really become freaks for it,” Huber says with a chuckle. “They don’t want to stop playing. It’s incredible. They’ll play till they are exhausted and fall asleep.”

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