Yawn
Latest research awakens debate over why people can’t keep their mouths closed
Scratching relieves an itch, sneezing clears out the nose and drinking relieves thirst. And yawning … does something.
Researchers have been trying to finish that sentence for centuries. This involuntary, obvious and sometimes contagious behavior afflicts most humans — even those still in the womb — multiple times a day. Yawning isn’t even restricted to people: Snakes, ostriches, hedgehogs and fish have been spotted throwing their mouths open for a satisfying yawn. Yet for a behavior so commonplace, the yawn is still a big, gaping mystery.
“Every single day, every person on the planet yawns,” says behavioral biologist Andrew Gallup of Princeton University. “Yet we have no idea why it is we do it.”