Many dog owners can recall a time when they were comforted by Fido's eyes or face lick when they were sad. Dogs tend to uniquely respond to human emotions by understanding when their owner is sad or happy. Now, researchers at the University of Vienna in Austria suggest canines not only understand, but also "catch" human emotions and dog emotions; this is known as "emotional contagion."

Previous research has contended dogs are really skilled at picking up what people are feeling just by looking at someone's facial expressions. A 2016 study in Biology Letters found dogs have the ability to integrate visual and oratory inputs to understand and differentiate human emotion from dog emotion. For example, when dogs heard positive sounds, they would look longer to positive faces, both human and dog; negative sounds prompted them to look longer to negative, angry faces.

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Dogs have the ability to combine two different sources of sensory information and perceive the emotion in both humans and dogs.

The new study, published in Animal Contagion, sought to explore whether dogs exhibited a behavioral change in response to emotional sounds in both humans and dogs. A total of 53 dogs (i.e., husky mongrel, golden retriever, airedale terrier etc.) were recruited to listen to recordings of positive and negative sounds from dogs (i.e., playful barks, sad whines); humans (i.e., laughing, crying); and neutral sounds (i.e., rain, crickets chirping) as researchers examined their behavior. Two sessions were done with four trials each with every sessions having four different acoustic sounds playing in the background.

The researchers made several observations after the two sessions. First, dogs reacted differently to emotional sounds than they did to neutral ones by approaching the speaker in the room or looking at their owner when the noise was happy or sad. Moreover, dogs were able to differentiate between sad and happy sounds. Lastly, dogs behaved the same way to the sound of emotion whether it was from a human or a fellow dog.

They wrote that their research “furthermore indicates that dogs recognized the different valences of the emotional sounds, which is a promising finding for future studies on empathy for positive emotional states in dogs.”

These findings suggest dogs are vulnerable to emotional contagion. This enhances their ability to understand their owners when they're happy or sad. A similar 2014 study in Applied Animal Behavior provides evidence dogs do possess empathy, and adjust their behavior based on their owner's behavior.

Dogs' emotional intelligence can be advantageous, and give proof that their love is really unconditional.

Source: Huber A, Barber ALA, Farago T et al. Investigating emotional contagion in dogs (Canis familiaris) to emotional sounds of humans and conspecifics. Animal Cognition. 2017.

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