Science has done a terrific job of answering some of the world’s most difficult questions, but certain mysteries still elude researchers. How does gravity work? Can your pet fish really predict an earthquake? Why do we yawn so much? Here’s what we don’t know and how close we are to figuring it out.
1. Why Do We Yawn?
Theories about why we yawn are as common as grumpy toddlers at nap time, but two explanations seem plausible after experimental tests. One is that yawns help cool the brain and optimize its performance. Psychologists at the State University of New York at Albany say it explains why we yawn when we’re drowsy: Like the fan in a computer, the yawn kicks in when our performance starts lagging.
But if yawns are our brains’ way of kick-starting their efficiency, why is yawning contagious? The brain-cooling camp suggests that it’s a way to maintain group vigilance and safety. When a member of a pack yawns, signaling that he is not functioning at his best, the whole group may need to yawn for a collective cognitive boost.
That’s not the only theory floating around, though. Another explanation contends that contagious yawning builds and maintains empathy between yawners. A sympathetic yawn signals an appreciation and understanding of someone else’s condition and subconsciously says, “Me too, buddy.” So which story is the accurate one? Scientists aren’t ready to declare a winner yet—they need a little time to sleep on it.