We've always known that dogs are empathetic to people, but new research has found that dogs are even sensitive to how much we yawn — especially when a canine's owner starts the chain-reaction first.
In a new study published in the PLOS open access journal, researchers from the University of Tokyo set out to determine if the contagious yawning seen in dogs was a response to warm fuzzy empathy, or a response to feelings of stress.
Read more from GlobalPost: Dogs love human parents the same way babies do
Twenty-five test subject canines watched their owner and a stranger both actually yawn, and then mimic a yawn — their behavioral reactions and their heart rates in most of the dogs were then observed and analyzed.
The researchers found that dogs were much more likely to yawn if they saw their owner do it, and were less likely to respond in kind if they saw a stranger carry out the behavior.
Further, they also found the dogs were less likely to yawn if they saw the real thing, while they tended to keep their mouths shut if someone merely mimicked the behavior.
The results are yet more evidence that the common canine is considerably more in tune to humans and human behavior than they're often given credit for, and, according to the researchers, "may indicate that rudimentary forms of empathy could be present in domesticated dogs."
Other research has found that domestic dogs seem to naturally look where humans point, whereas wolves and even chimpanzees don't readily exhibit the same behavior.
Another recent study has found that both human babies and pet dogs exhibit the same "secure base effect" behavior towards their parents or owners, exhibiting more curious and outgoing behavior with their guardian in the room.
Sympathetic yawning in response to a loved one is also seen in people: a study released in 2011 found that humans are more likely to yawn empathetically when they see a family member or a friend do it first. (Beware of family movie nights with a boring film).
"I think what the study does is it supports the idea that empathy is the mechanism that underlies contagious yawns," said Matthew Campbell of Emory University to LiveScience of the behavior. "The idea is that it's the same mechanism by which we catch smiles or frowns or fearful expressions."
Here's a recent TV documentary on the same topic: