The power of the mighty yawn is great: Reading about yawns, seeing someone yawn, watching videos of people yawning, and eventhinkingabout yawns can cause just about everybody to succumb to one themselves, says Robert Provine, Ph.D., author ofCurious Behavior: Yawning, Laughing, Hiccuping, and Beyond.
But when it comes to the exact scientific reason for the reaction—and what the heck it accomplishes anyway—there’s still some debate.
Here’s everything you ever wanted to know about your yawns. (We’ll give you a second to open wide and inhale.)
Yawns Are NOT:
An Oxygen Booster
You might think that when you breathe in oxygen and carbon dioxide, you’ll yawn more. “But recent research actually suggests that oxygen intake decreases rather than increases after yawning,” says Andrew Gallup, Ph.D., a biopsychologist at SUNY Oneonta.
A Learned Behavior
Babies begin yawning in the first trimester of their development, says Provine. At birth, you’re already a yawning pro. (And maybe a great athlete: You Could Be an Olympic Champion, If You Have the Right Birthday.)
Yawns MAY Be:
A Cool-Down for Your Noggin
Yawning could function as your head’s chill pill. Like the fan in your computer, yawning lowers your brain’s temperature for optimum performance, says Gallup. Yawning frequency rises initially when the temperature in your skull elevates.
Yawning once can cool your head by 0.2 degrees Fahrenheit, while excessive yawning drops the temp by 0.7 degrees.
A Wakeup Call
A poorly timed yawn can be really embarrassing in certain situations—like at a funeral. But the common belief is true: You yawn more when you’re bored or drowsy, says Provine.
Some researchers say yawns are beneficial in moments when your full attention is needed and your focus wanders. Yawns can help you to dig in and increase your level of alertness.
Contagious yawns may exist to heighten the awareness of others. Birds in small groups yawn to keep each other alert, according to Gallup’s research. He thinks humans do it, too: It’s the idea of collective vigilance—a “we’re all in this together” mentality that keeps groups safe. If we’re all yawning away, we’re all more attentive. So letting out a yawn during your next office meeting may actually keep everyone more engaged.
A Shift in Your Mode
Athletes yawn before a big competition and paratroopers do it before their first jump, says Provine. Those guys definitely aren’t bored, indicating yawns don’t just happen when things are dull. Yawns increase when your body is in transition, like when you wake up in the morning or go to sleep at night, says Provine.


I will soon yawn in ASO VILLA !

Cool! I've always been wondering what opening my mouth wide and making that funny sound does to my body.

waoh!!! **** yawn ****