Why do people yawn? Why is it contagious?

iamme

Lifer
Jul 21, 2001
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Did some Google searching, and couldn't find a conclusive answer. I did find some theories:

The Physiological Theory -- Our bodies induce yawning to drawn in more oxygen or remove a build-up of carbon dioxide. This theory helps explain why we yawn in groups. Larger groups produce more carbon dioxide, which means our bodies would act to draw in more oxygen and get rid of the excess carbon dioxide. However, if our bodies make us yawn to drawn in needed oxygen, wouldn't we yawn during exercise? Robert Provine, a psychologist at the University of Maryland, Baltimore County, and a leading expert on yawning, has tested this theory. Giving people additional oxygen didn't decrease yawning and decreasing the amount of carbon dioxide in a subject's environment also didn't prevent yawning.

The Evolution Theory -- Some think that yawning is something that began with our ancestors, who used yawning to show their teeth and intimidate others. An offshoot of this theory is the idea that yawning developed from early man as a signal for us to change activities.

The Boredom Theory -- In the dictionary, yawning is said to be caused by boredom, fatigue or drowsiness. Although we do tend to yawn when bored or tired, this theory doesn't explain why Olympic athletes yawn right before they compete in their event. It's doubtful that they are bored with the world watching them.

Interesting yawning facts:
  • The average yawn lasts about six seconds.

    Your heart rate can rise as much as 30 percent during a yawn.

    55 percent of people will yawn within five minutes of seeing someone else yawn.

    Blind people yawn more after hearing an audio tape of people yawning.

    Reading about yawning will make you yawn. (This thread will make you yawn.....come on....you know you want to.....)

    Olympic athletes often yawn before competition.

    Research shows that 11-week-old fetuses yawn.

 

Evadman

Administrator Emeritus<br>Elite Member
Feb 18, 2001
30,990
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My god, I did too. No joke.

<edit>
I close my eyes when I yawn.
 

BCYL

Diamond Member
Jun 7, 2000
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71


<< seriously: I yawned when I saw your thread title. >>



Haha me too... seriously...

I was reading iamme's post and yawned... but I didnt even notice it until I see Kyguy's post...
 

BCYL

Diamond Member
Jun 7, 2000
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<< My eyes water alot when I yawn.....do yours? >>



Sometimes... not everytime though...
 

morkinva

Diamond Member
Nov 16, 1999
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I have always wondered why its contageous. I think its the evolutionary theory.
 

Keego

Diamond Member
Aug 15, 2000
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depends if I'm tired or not (water in eyes) if I'm tired, then yes.
 

Joyride

Golden Member
Apr 2, 2001
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Must fight the urge!!!!

Olympic athletes often yawn before competition.

I thought that was due to nerves
 

MikeO

Diamond Member
Jan 17, 2001
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<< My eyes water alot when I yawn.....do yours? >>



Mine does.

Gotta get out of this thread, can't stop yawning :D
 

tcsenter

Lifer
Sep 7, 2001
18,949
573
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<< Why do people yawn? Why is it contagious? >>

There are undoubtedly a few different reasons why we yawn, not just one, and it is strongly 'suggestive'. Just one of thousands of quirky little mysteries...
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
50,419
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rofl.. that's trippy.. I did yawn while reading your post

Yeah, my eyes water when I yawn when I'm tired, too.
 

dude8604

Platinum Member
Oct 3, 2001
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<< seriously: I yawned when I saw your thread title. >>



yeah me too...but after I read part of the thread.
 

LiLRiceBoi

Golden Member
Dec 2, 2000
1,211
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Whoa, I yawned when I read the thread. Thats pretty trippy. Eyes watered and everything.

And I'm STILL yawning :Q
 

BeefJurky

Senior member
Sep 5, 2001
367
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i always figured it was some animal sign of comfort. do you ever yawn when you're nervous? also, if a nervous or scared dog sees you yawn, they calm down. i tried this with my puppy. my neighbors have big dogs that bark at night, and my puppy wouldn't do her thing in the yard before bed with them barking, so i made a big show of yawning in front of her and she wasn't afraid anymore. anyways, that's just mho
 

VirusDub

Golden Member
Aug 29, 2001
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I was proud of myself for not yawning once while reading this thread, but then I yawned as soon as I hit the back button. Dang.
 

Spike

Diamond Member
Aug 27, 2001
6,770
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yawned 3 times while reading this thread

lol!! I was gonna say that