Chimp yawns are catching on

If you yawn in a room full of people, there’s a good chance someone else will too – we just can’t help ourselves. The sight of someone yawning often triggers the same reflex in the observer, a phenomenon observed not only in humans, but also in other primates, dogs – even budgies! We react this way involuntarily, without thinking about it, and scientists aren’t entirely sure why. Some argue that it stems from an evolutionary need to synchronize sleep between members of a group, while many have linked it to a species’ capacity for empathy. Now, scientists studying chimpanzees at Burgers’ Zoo, in Arnhem in the Netherlands, have formulated a new theory for this behavioral quirk. 

The zoo’s 15 chimps were each filmed yawning. These videos were then shown to others in the troop, and their individual responses were noted. A pattern emerged: clips of male chimps were more likely to induce yawning than clips of females. As dominant chimps are always male, the researchers concluded that the level of "contagiousness" of a yawn may depend upon the social status of the yawner – the more dominant the chimp, the more likely their yawns are to ripple around the group. Whether this same relationship applies in humans is unclear, but lead researcher Jorg Massen thinks it’s likely, telling New Scientist: “I wouldn’t be surprised if the yawns of President Obama [are] more contagious than those of the average American.” So next time you feel a yawn coming on, have a look to see who "catches" it!