A new study has shown that when a wolf sees other wolf yawning, he yawns too. According to scientists from the University of Tokyo, those family members or friends who are strongly bonded to each other return a yawn with a yawn.

In a recent study, chimpanzees had been shown to share a propensity for contagious yawning. In the recent study, researchers have observed that yawns were contagious among wolves too.

Scientists from the University of Tokyo observed a pack of 12 wolves in Tama Zoological Park over a period of 524 hours. After studying them, scientists have found that yawns were contagious among wolves. About 50% of the wolves had shown the empathetic yawning impulse. There were only 12% solo yawns.

Study has also revealed that female wolves yawn quicker than male wolves. According to researchers, female wolves could be quicker to respond to social stimuli.

A researcher from the University of Tokyo, Teresa Romero, said that yawning is contagious between those who are close to each other. She said, "These results suggest that contagious yawning is a common ancestral trait shared by other mammals and that such ability reveals an emotional connection between individuals".

Researchers have not found the reasons behind the trigger to yawn. According to some scientists, yawning cools the brain since the intake of external temperature. On the other hand, some researchers believe that yawning heighten alertness, which could explain why people yawn during stress.

Teresa Romero wanted to find the difference in the empathetic yawn trigger between wolves and dogs. Some researches show that dogs are the creatures who share the contagious impulse to yawn.

Monique Udell, canine behavior expert, said some past researches have shown that dogs share contagious yawning due to their domestication, but this new study is very different.