Yawns Keep You Awake?
If there's one thing that narks a scientist it's when someone asks them a straightforward question like "why do we yawn?" and they haven't got a decent answer. Cue a myriad different hypotheses being bandied around like billy-o. Riaz Bhunnoo reports on a new one - yawning keeps you awake.
It’s Monday morning and you’re absolutely shattered. You’ve managed to struggle into work but your eyelids weigh heavily in protest. You unleash an enormous yawn and, at that exact moment, your colleagues follow suit. Without realising it, you’ve initiated a contagious yawn. But why do we even yawn in the first place? New research suggests it is designed to keep you awake rather than send you to nod.
Yawning is an involuntary action that we start doing even before we are born. Strangely, animals such as snakes and birds also yawn from time to time. The yawn causes you to open your mouth wide and take a deep inhalation of breath; your abdominal muscles flex and your diaphragm pushes down.
Researchers from the University of Albany in New York have suggested that the yawn is actually designed to keep you awake, rather than signalling the need for sleep. They reckon that yawning cools the brain, making it work more efficiently and keeping you alert. Contagious yawning affects approximately half of the adults in the world. Simply seeing or hearing someone yawn can trigger this, as can reading about it (cue yawn…now).
The brain cooling theory also provides a possible explanation for contagious yawning. The scientists think that when we yawn we are taking part in an ancient hardwired ritual that evolved to help groups stay awake and detect danger. Dr Gordon Gallup, a leading researcher at the University of Albany, said: "We think contagious yawning is triggered by empathic mechanisms which function to maintain group vigilance." This might explain why paratroopers report a tendency to yawn just before jumping out of a plane.
Some other theories have recently emerged for contagious yawning. One theory points to an unconscious herding effect in which the yawn helps to communicate with those around us – similar to how birds change direction at the same time whilst flying in groups. Another theory suggests that yawning indicates your level of alertness to the rest of the group and enables the coordination of sleeping times; your initial yawn suggests to others that its time for forty winks and those that agree with you yawn back in approval.
Despite the many theories, there are still no definitive scientific explanations for why we yawn or why it's contagious. If you haven’t yawned once whilst reading this article then you’re probably already asleep...
Get more articles from Riaz or stick to the sleepy science:
- Interesting - Can you catch a yawn?
- Cool - Top ten things science can't explain
- Grouchy - Not a morning person? Here's why
- You shouldn't laugh but... - Narcoleptic dogs
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