Yawning is not just contagious in humans, dogs can also start yawning if they see humans doing the same, a new study has said.
According to the study's researchers, the findings suggest that domestic dogs have the capacity for a fundamental form of empathy.
The phenomenon, called contagious yawning, has been found only in humans and other primates such as chimpanzees and is thought to relate to our ability to empathize with others.
Researcher Ramiro Joly-Mascheroni, a psychologist at Birkbeck, University of London first tested the phenomenon in his dog, a Labrador.
Immediately upon yawning himself, Joly-Mascheroni's dog immediately yawned. And sure enough, tests on friends' pups showed similar results.
To reach the conclusion, the furry cast included a wide range of dog breeds from a Greyhound to a Staffordshire Bull Terrier to a Dalmatian.
Twenty nine dogs went through two testing scenarios each lasting five minutes, one in which a human (not the owner) called the dog over and while keeping eye contact with the dog he or she would act out yawns that included the vocal portions.
In the non-yawning scenario, the human went through similar motions, except he or she didn't yawn vocally and instead just opened and closed their mouths.
During the yawn sessions, 21 dogs yawned, while no dogs yawned during the non-yawning scenario. That's compared with 45 percent to 65 percent found from past studies in humans and 33 percent found for chimpanzees.
In addition to yawning, the dogs showed similar reactions to human yawns.
"In the yawning condition, we found the dogs reacted pretty much in the same way," Live Science quoted Joly-Mascheroni, as saying.
"They all acknowledged the yawn in some way either by dropping their ears or turning their heads away," the expert added.