According to new research, published August 7 in the open access journal PLoS One by Teresa Romero and colleagues from the University of Tokyo, dogs yawn contagiously when they see a person yawn and more frequently respond to their own owner’s yawns than the yawns of strangers.

During the study 25 pet dogs watched their owner and a stranger yawning, or mimicking a yawning movement with their mouth. What was observed was that the dogs yawned more often in response to the actions of their owner rather than a stranger. They also responded less to the mimicked yawns as well, which suggests they have the ability to yawn contagiously.

Previous research has already shown that dogs will yawn in response to human yawns, but what was unclear from that research was whether it was a mild stress response or an empathetic one since yawning can be caused by anxiety. The results of this latest study suggest the yawns are empathetic, as dogs yawn more frequently when their owners’ genuinely yawn than when a stranger does.

The researchers observed no significant difference in heartbeat during the experiments, making it unlikely that their responses were the result of a distress response.

Explaining the significance of the results, Romero says, “Our study suggests that contagious yawning in dogs is emotionally connected in a way similar to humans. Although our study cannot determine the exact underlying mechanism operative in dogs, the subjects’ physiological measures taken during the study allowed us to counter the alternative hypothesis of yawning as a distress response.”

Contagious yawning is known to occur in humans, chimpanzees, baboons and dogs. A study last year found that humans yawn more in response to the yawns of someone they care about.

Elisabetta Palagi, of the Institute of Cognitive Sciences and Technologies in Rome, noted that the study is the first time that scientists have shown contagious yawning occurring between different species.