Scientists first thought that yawning was designed to keep the brain cool. It turns out that there is a connection between the susceptibility for contagious yawning and empathy. Humans, who had better performance in cognitive building block tests, also yawned contagiously more often. See if watching these animals makes you yawn.
Here’s another video of two chimpanzees who yawn after seeing video clips of chimps from their own social group. Chimps also yawn just after watching familiar and unfamiliar humans doing it, but unfamiliar chimps and baboons failed to cause contagious yawning. Credit: M. Campbell and F. de Waal 2014 Yerkes National Primate Research Center/Emory University.
If you didn’t yawn, it’s okay. Researchers discovered that the closer you are to someone emotionally or genetically, the more likely it is that you’ll yawn after seeing them yawn.