Dogs yawn along with their owners, according to a new study by researchers at the University of Tokyo in Japan. They found dogs are more likely to yawn with their owner than with strangers.
The team tested 25 dogs and recorded their heart rates as they yawned with their owners and as they yawned with strangers. They saw dogs responding more frequently with familiar humans. Dogs also reacted differently to fake yawns created by controlled mouth movements.
"Similarly to humans, in both species the closer the social bond between individuals, the more likely they would yawn when the other yawned," the researchers said in their study, published in the peer-reviewed science journal PLOS ONE.
A previous study had found that dogs' yawns were related to stress, whereas the new study showed heart rates in dogs to be stable.
According to the scientists, the new findings were indicative of dogs' ability to empathize with humans, especially with their owners.
Contagious yawning is also noted in humans and primates. About 45 to 60 percent of human adults are affected by other people's yawns, according to the study.