Yawning when you see someone else yawn is thought to signal empathy. About half of all people do it contagiously. Now researchers have confirmed what many pet owners have long suspected: Dogs, too, are contagious yawners.
In a series of experiments carried out on two dozen breeds, from poodles to pit bulls, researchers found that when a dog watched either a stranger or its owner yawn, the dog was far more likely to yawn in response to its owner. Dogs in the study also demonstrated that, for the most part, they could not be duped. They responded frequently to genuine yawns, but less so to fake yawns in which people simply stretched and then opened and closed their mouths without making noise.
Imaging studies show that in people, contagious yawning activates brain regions involved in imitation, social behavior and empathy. But contagious yawning is not distinctly human. It has been demonstrated in birds, apes and most vertebrate species. One study showed that chimpanzees exposed to videos of other yawning chimps will inevitably yawn themselves.
Previous studies have suggested that dogs could “catch” the yawns of sleepy people. But if so, it was not clear why. Some researchers called it a sign of the bonding between man and his best friend. Others argued that perhaps the behavior in dogs was just a result of mild stress or anxiety.
In the new study, which was published in the journal PLoS One, the scientists had the dogs wear heart rate monitors, which indicated that stress did not play a role. That the dogs were more frequently influenced by the yawns of their owners than those of strangers, the researchers said, suggesting that empathy and “emotional proximity” were the more likely factors.
“Dogs are unusually skilled at reading human social and communicative behaviors,” they wrote. “Thus, it is not surprising that they are also able to ‘catch’ human yawns.”
THE BOTTOM LINE
Studies suggest that yawning between dogs and their owners may be contagious.