Empathy is an important aspect of humanity's evolution. The following video plays on our basic instincts by creating a global prank of contagious body movements.
Posted just two days ago, the video has garnered well over a million views and something like ten million yawns. Be honest, how many times did you yawn and stretch while watching?
According to CBS News, yawning has a contagious impact on surrounding people and even animals. In fact, if your cat yawns, it could trigger you to follow suit.
A few weeks ago, The Daily Herald ran a Question and Answer with their resident medical know all, Doctor Komaroff, on the cause of yawning. There are physiological purposes for yawns, but another use of the reflex is an evolutionary signal for letting those around you know it's time to hunker down for the night. Like a chain reaction of heavy eyes, a whole tribe could tucker each other out. So if you want someone to pass out, yawn at them.
The maker of the video, Roman Atwood, is a renown internet prank artist. His most popular video prank on Youtube has over over 13 million views: