By Dr. Becker
Ever heard the expression “Smile, and the world smiles with you”? How about, “Yawn, and your dog yawns with you”?
If you’re like most people, your answers are probably “Yes” to the first question and “Huh?” to the second – especially if you missed my previous article on dog yawns.
Over the last few years, researchers have become quite interested in whether pet dogs “catch” yawns from humans, and if so, what it might tell us about the canine capacity for empathy. The study I wrote about last year was done in Portugal, and more recently, another study on the subject of doggy yawns was conducted in Japan1.
Latest Study Attempts to Determine WHY Dogs Engage in Contagious Yawning
Researchers from the Department of Cognitive and Behavioral Sciences, Graduate School of Arts and Sciences, at the University of Tokyo performed a number of carefully controlled experiments with 25 dogs one year or older and of different breeds.
Prior studies suggesting that dogs, like humans, yawn out of empathy, have been challenged by alternate theories about why the yawning occurs (for example, as a mild distress response). The goal of the University of Tokyo study was to inspire contagious yawning in dogs and then determine what was behind the yawns – empathy, or simply mild distress.
Studies of humans suggest that contagious yawning affects from 45 to 60 percent of adults and is a measure of a person’s social skills and ability to empathize with others. Contagious yawning has also been observed in certain species of primates, including chimpanzees, bonobos and gelada baboons.
The University of Tokyo researchers observed the 25 dogs when their owners and then a stranger yawned, and when both parties fake-yawned. The humans faked yawns by opening and closing their mouths to mimic a yawn, but without making any sound. No treats were given to the dogs in these experiments.
The dogs were placed in a restful environment. "We tried to create a comfortable atmosphere in doing the experiment, and sometimes it was so comfortable for them that they fell asleep," said study author Teresa Romero.
Twenty-one of the 25 dogs also wore heart rate monitors to determine whether they were stressed or anxious, and results showed they were not.
From the study abstract:
“The occurrence of yawn contagion was significantly higher during the yawning condition than during the control mouth movements.”
Translation: The dogs caught real yawns much more often than fake yawns.
“Furthermore, the dogs yawned more frequently when watching the familiar model than the unfamiliar one demonstrating that the contagiousness of yawning in dogs correlated with the level of emotional proximity.”
Translation: The dogs yawned more often after their owners yawned than when a stranger yawned, which means dogs are more apt to catch yawns from people to whom they are emotionally bonded.
“Moreover, subjects’ heart rate did not differ among conditions suggesting that the phenomenon of contagious yawning in dogs is unrelated to stressful events.”
Translation: The dogs wearing heart rate monitors showed they were not physiologically stressed, so their yawning was not a response to distress.
“Our findings are consistent with the view that contagious yawning is modulated by affective components of the behavior and may indicate that rudimentary forms of empathy could be present in domesticated dogs.”
Translation: Evidence is mounting that our canine companions do, in fact, have the ability to empathize with humans, at least at a fundamental level.