Dogs 'Catch' Emotions From People

Like catching the flu, dogs adopt the expressions and emotions of their owners.

Dogs often copy the facial expressions of others, according to a new study that suggests dogs, like humans and other primates, show a phenomenon known as "emotional contagion."

Emotional contagion, which is a basic building block of empathy, is when an individual instantaneously shares the same emotional state of another. Its existence was never fully proven in dogs until now.

Dogs and humans that are closely bonded to each other start to mimic each other for a very useful reason.

Photos: What Your Dog (or Horse) Is Trying to Tell You

"If you live in a group and you share with companions many interests and goals, you must understand his or her emotional state, and the only way to do that is to 'read' his or her behavior and facial and body expressions," explained lead author Elisabetta Palagi.

Palagi, who is president of the Italian Primatological Association, added, "Via emotional contagion, you take part in a social life; you create an emotional bridge between you and others. It is essential for the social life to evolve."

Palagi is also a researcher at the University of Pisa's Natural History Museum as well as at the Institute of Cognitive Sciences and Technologies in Rome. For the study, published in the journal Royal Society Open Science, she and colleagues Velia Nicotra and Giada Cordoni analyzed the behavior of dozens of female and male dogs, representing multiple breeds and ages, at a dog park located in Palermo, Italy.

The researchers documented that in less than one second, many of the dogs would copy the expressions and behaviors of other dogs. For example, if one dog would position his body in a play bow, indicating readiness to play, another would do so near instantaneously. If a dog exhibited a relaxed, open-mouthed face - signifying friend not foe among canines - then the other dog would tend to do the same.

Love Hormone Makes Dogs Even Better Friends

Such mimicry was strongly affected by whether or not the individuals were already familiar and socially bonded with the other. In short, the closer the dog friendship was, the more the two dogs' moods and appearance would be in sync.

Given the closeness of dogs to humans, and with reams of anecdotal evidence, the authors believe that dogs can take on our expressions and feelings too, especially if they are closely bonded to their owners.

"It is an automatic response, similar to that of humans when they see someone crying or smiling," Palagi said, adding that domestication probably even enhanced dogs' natural inclination toward emotional contagion all the more.

Dogs Understand Human Smiles, Scowls

Prior to the new study it was known that human yawning could prompt certain dogs to yawn, but the extent of the mimicry and emotional contagiousness was not known until now. Dog experts contacted by Discovery News were astounded by the new findings.

Marc Bekoff, a professor emeritus of ecology and evolutionary biology at the University of Colorado and the author of "The Emotional Lives of Animals" said that he and his students have conducted decades of research on dog play, "but we hadn't invoked mimicry as one reason they could vigorously play and share intentions to play and maintain the play atmosphere. Now, Dr. Palagi and her colleagues have shown that the ability to maintain a 'play mood' most likely rests on rapid mimicry and emotional contagion."

Sergio Pellis, a professor and board of governors' research chair at the University of Lethbridge's Department of Neuroscience, said, "This is a well thought out paper that is superbly executed and consequently provides very compelling data."

He likened the copycat moods and expressions to playing peek-a-boo with an infant.

Wag The Dog? Tail Monitor Tracks Canine Emotion

"As the cloth is pulled down, the baby smiles, and unless you are a psychopath, you also involuntarily smile; moreover, you feel happy," he said. "While this relationship between action and emotion is well established for humans, rapid facial mimicry has only been recently shown for some other primates, including the work by Palagi and others."

With the new determinations about dogs, Pellis now suspects that other social mammals could reveal such behavior too, so perhaps "Grumpy Cat" really is grumpy, if its owners are often in a bad mood.

Facial expressions among social animals appear to have universal qualities, to the point where humans and other animals can discern how certain species feel just by looking at their faces. That's the suggestion in two new studies -- published in the Journal of Veterinary Behavior and PLOS ONE -- that help explain how humans can have such close, understanding relationships with animals such as dogs and horses, the subjects of the investigations. The research confirmed, through animal behavioral analysis, the underlying meaning of dog and horse facial expressions and also demonstrated that people have a natural knack for figuring out what they mean. For example, "this dog is experiencing a positive emotional state, as his owner has just come back," Emanuela Dalla Costa told Discovery News. She led both studies and is a researcher in the Department of Veterinary Science and Public Health at the Università degli Studi di Milano. She explained that the dog’s eyes are wide open, as is his mouth, yet his facial muscles are somewhat tense. Together, these features and others suggest that he is happy, eager and hopeful.

Why Dogs Find Some Toys Boring

Here is another happy dog. In this case, Dalla Costa explained, the dog's "lips are retracted, but with no exposure of the teeth." The dog is thrilled that its owner has just returned and eagerly looks to the human for guidance.

Dogs Were a Prehistoric Woman's Best Friend, Too

This poor pooch "is tense, due to the departure of his owner," Dalla Costa said. Every part of the dog's face is turned in the direction of his owner's recent exit, maximizing the pup's ability to find him. The dog's eyes and tense mouth convey his worry and loneliness.

The Dog Paddle Is Just an Underwater Jog

This dog's gaze is riveted on its owner, who is holding food. "This emotional condition is considered positive, and we can assume that this dog is happy," said Dalla Costa, adding that "there is no visible tension in the facial muscles." Even though the eyes, ears and face are pointed in one direction, just as they were for the worried and lonely dog in the previous slide, this hopeful canine feels no anxiety.

Dogs Know When You're Sad

Every aspect of this dog’s face communicates concern and worry. "The mouth is opened and the dog is panting," Dalla Costa said. "The dog’s lips are partly drawn back, with no teeth exposure. The facial muscles show some degree of tension, visible through ridges that emerge on the lateral side of the face and near the eyes." His ears are up, yet not fully open, an indication that he’s attentive but also worried.

VIDEO: Dogs Have Feelings, Too

If this dog could talk, the canine would likely be saying, "Oh, please -- feed me." The photo was snapped as the dog looked longingly at its owner, who was holding a favorite food treat. Dalla Costa explained that there is no visible tension in the dog’s face. Its expression cleverly communicates desire and gentleness, while also revealing a sense of hopeful expectation.

Horse expressions, meanwhile, share similar qualities with dogs. This horse, similar to the dogs happily looking at their owners, is attentive and awaiting direction. "The eyes are open and focused on the environment, ears are moving in the direction of sounds, and there is no muscle tension in the mouth," said Dalla Costa.

VIDEO: Why Dogs Spin Before They Poop

This unfortunate horse was photographed while in pain, which, thankfully, turned out to be only temporary. In this moment, however, Dalla Costa noted that the horse's ears are in a sideways position. Its eyes are partially closed, and its "chewing muscles are strained and prominent." Even the horse’s nostrils are stiff over its tightly shut mouth.

While perhaps not as uncomfortable as the previous horse, this horse was also photographed while experiencing temporary, minor discomfort. In this case, the horse’s nostrils are wide open, while its lower lip is drawn back. Even its "ears are held passively backward," Dalla Costa said.

PHOTOS: World's Ugliest Dog Winner for 2014

This horse is completely relaxed. "There is no tension in the mouth and in the chewing muscles," said Dalla Costa. "The nostrils are relaxed." The horse was happy to be chilling out on a pleasant day in an open field.