Researchers looked at whether or not yawns were contagious between wolves.
Scientists have suggested contagious yawning could be linked to the human capacity for empathy, but little evidence has made this link in animals, PLOS reported.
"On the basis of observational and experimental evidence, several authors have proposed that contagious yawn is linked to our capacity for empathy, thus presenting a powerful tool to explore the root of empathy in animal evolution," the researchers stated in their PLOS ONE study abstract.
Recently researchers documented domestic dogs exhibiting contagious yawning when exposed to human yawns in a lab setting. The researchers were not able to confirm whether the phenomenon has an evolutionary history or developed as a result of human domestication.
In the recent study the researchers observed and recorded yawning in a single pack of 12 wolves at Tama Zoological Park in Tokyo; the study lasted over a five month period in relaxed settings. The exact time of each yawn was recorded as well as the identity of the recent yawner and positioning of subjects surrounding the yawner.
The findings suggest wolves experience the yawn contagion. The strength of the pack member's social bond with the initial yawner was found to positively affect the frequency of contagious yawning. Female wolves also showed faster yawn reaction times and response to social stimuli than males.
Despite the small sample size the results suggest contagious yawning may relate to the wolves' capacity for empathy; other animals may also have the same ability to experience empathy.
"In wolves, as well as in primates and dogs, yawning is contagious between individuals, especially those that are close associates. 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," said Teresa Romero from The University of Tokyo.
