When someone yawns, the reflex is contagious and causes about half of the people who noticed the yawn to do the same. A new study from the University of Tokyo shows that human yawns are also contagious to dogs.

When someone yawns, the reflex is contagious and causes about half of the people who noticed the yawn to do the same.
A new study from the University of Tokyo shows that human yawns are also contagious to dogs.

The study looked at 25 dogs of different breeds, and had their owners yawn at them, followed by having a stranger yawn at them.

The dogs were more likely to yawn when their owner did, but if it was a fake yawn then it was only contagious to a few breeds.

Teresa Romero from the University of Tokyo said: “"Our study suggests that contagious yawning in dogs is emotionally connected in a way similar to humans. (1,3,1) 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.”

14 of the dogs that participated in the study didn’t yawn at all.

Not all people find yawns contagious either, but between 45 and 60 percent of healthy adult people do.

Other primates have also been observed catching contagious yawns from each other.