I first became interested in the subject of yawning based on this NPR story. The idea that yawning is contagious is not a new idea. Of course, dogs do yawn in response to humans, as do primates. But do they yawn in response to a video?
An interesting paper in the Proceedings of the Royal Society B looks at the question (the paper can be found here – and requires a subscription). PhysOrg.Com has a summary:
Matthew Campbell and colleagues of the Yerkes National Primate Research Center in Lawrenceville, Georgia divided 24 chimps ranging in age from nine to 43 years old into pairs.
Each pair was exposed to animated chimps in two short 3-D videos on a 48-centimetre (19-inch) screen. Only one of the videos showed the animals yawning.
The chimps may doing something deeper than simple imitation, for they may have an emotional tie with the cartoon character, the researchers believe.
“Contagious yawning is controlled by the same mechanism that makes emotions contagious,” the study notes. “Our results strongly suggest an empathetic response to the animations.”