If you are one of the fortunate humans that share our life with a dog (or a few), you would probably say you know just what your dog wants, needs, or is thinking, by what he “says;” that is, the tone, pitch, volume, and emotional valence of his bark. A recent documentary on the PBS program Nova explored the unique bond between humans and dogs and detailed the research that is proving what dog lovers have suspected all along: Dogs have an uncanny ability to read and respond to human emotions. They are smarter than we ever imagined. Wherever there are humans, there are also dogs. Did you know that there are more pet dogs in the world than there are babies? The bond between humans and their dogs is further strengthened by a release of the same hormone responsible for bonding mothers to their babies.
Even though every dog owner can share stories about how their dog seems to know what they are thinking, even before they are fully aware of their own emotions, science has just now caught up to what we dog owners have already known: dogs are “specially attuned” to humans and our emotions, more than any other species.
Apparently, we show emotions asymmetrically in our faces; meaning, the right side of our face is not an exact mirror of our left side when we express emotions, and in fact, the right side is the more “honestly” emotional side. Humans also innately pick up on this between each other: we have a “left-gaze bias,” meaning that when we look at a person, regardless of whether it’s a picture of someone’s face, or when we see them in person, we look first to the left (the right side of the face), and then scan the rest of the picture or face. It has been assumed that this specific gaze directionality is a uniquely human trait, and is directly linked to reading emotions. (Next time you are at a party, take note of the way people look at you – are those that seem to really “get” you looking with a quick glance to the right side of your face to start, and then looking at you directly?)
Scientists wanted to see if dogs might show a similar pattern when looking at human faces, since they do seem to have this uncanny ability to read our emotions. They devised an experiment in which they showed dogs images on a screen of either human faces, dog faces, or inanimate objects and measured both the movement of their eyes, as well as the duration of their gaze, as they looked at the images. As expected, there was no pattern of looking when shown pictures of dog faces or inanimate objects. Surprisingly, however, dogs’ gazes mimicked human gaze directionality when shown human faces: they looked first to the left (the right side of the human faces). According to the scientists, no other species does this, and no other animal species is so keyed into us. Is this a behavior that evolved in dogs to allow them to bond with humans more closely? It certainly would have a biological advantage: thinking as a dog, “it’s better to approach a human that is calm, relaxed, or happy, than one who is angry, impatient, who could potentially lash out and hurt me!”
However, it’s not just a one-way street with dogs reading our faces and behaving in kind: we also believe we can interpret our dog’s vocalizations. Until recently, scientists have not given any credit to the idea that humans can speak “dog;” however, a recent study in the Journal of Comparative Psychology shows otherwise. Indeed, humans also seem to have an innate ability to interpret the general situational context and underlying message of a dog’s bark. Unfortunately, cat lovers, this phenomenon isn’t generalizable across species: we are much less adept at being able to classify the different kinds of meows (though I’m sure many cat owners would disagree).
You might be able to hold a conversation with your own dog, but how do you do at interpreting the meaning of a random dog’s bark? It won’t be a surprise that we can instinctively identify a warning or aggressive bark – after all, that’s its purpose (Stay away!) but, can you tell the difference between a bark that means: “Wait, don’t go! Don’t leave me alone!” and “Let’s go for a walk”? You can listen to a variety of dog barks, from woofs to whines, and test your “dog whisperer” capabilities via this fun interactive quiz.
“Dogs Decoded” is really fascinating; personally, I learned so much about dog behavior and the special human-dog bond that has evolved over time that I highly recommend every dog lover should watch it. If you didn’t catch the November 9 airing on PBS, you can check it out here, on the Nova website.
Pongrácz, P., Miklósi, Á., Molnár, Cs., and Csányi, V. (2005) Human Listeners Are Able to Classify Dog (Canis familiaris) Barks Recorded in Different Situations. Journal of Comparative Psychology, 119, 136-144.