http://www.mnn.com/family/pets/stori...n-when-we-yawn

If your canine companion has ever yawned after you yawned, it could be because he empathizes with you, according to a new study.

It may seem simple, but the fact that this behavior is contagious is actually quite remarkable because very few animals do it. Yawning itself is rare in the animal kingdom, and besides people and dogs, contagious yawning has been observed only in gelada baboons, stump-tail macaques and chimpanzees.

We know that humans and chimps tend to yawn more with friends and family, suggesting that “catching” someone’s yawn is tied to feelings of empathy, and past research has shown that dogs are more likely to yawn after watching familiar people yawn. However, until recently, it was unclear if dogs’ yawns were tied to empathy.

But a recent study conducted by researchers at Portugal's University of Porto found that dogs yawn even when they hear only the sound of a person yawning, providing the strongest evidence yet that man’s best friend is able to empathize with us.

The team, led by behavioral biologist Karine Silva, selected 29 dogs that had lived with their owners for at least six months. Yawn recordings of the dogs’ owners, an unfamiliar woman and a computer-simulation were played for the animals during two different sessions, and the study found that nearly half of the dogs yawned when they heard a recording of a human yawning. However, the canines yawned five times more often when they heard a human they knew yawning.

"These results suggest that dogs have the capacity to empathize with humans," said Silva, who explained that the close human-animal bond that’s been developed through 15,000 years of domestication “may have fostered cross-species empathy.”