Why Do We Yawn?

Why Do People Yawn?

Yawning is often contagious
Yawning is often contagious | Source

The Hows and Whys of Yawning

What do you think of when someone yawns and stretches? Is the first word that comes to mind pandiculation? It isn’t for me but, pandiculation is the act of yawning and stretching together.

Yawning is usually associated with boredom or being tired. Yawning is known to be contagious and suggestive. You may even have the deire to yawn just by reading this. It is hard to suppress a yawn because it is mostly involuntary. Usually we can’t control or suppress the urge to yawn.


If you think about yawning you may very well start yawning. Yawning is usually triggered by something or someone else.

Scientists believe a brain mechanism detects someone yawning and the process begins to make us yawn. There are other theories that we yawn in order to get more oxygen to our brains, but scientific tests have shown that people will yawn even if they have 100% oxygen.

Why is Yawning Contagious?

Yawning also has aspects of syncronized behavior, it is a biological way that nature initiates a chain reaction within a species. Yawning, it is believed,brings on some kind of changes in the body and this synchronization makes everyone in the vicinity do it at the same time. Yawning may serve a purpose of creating increased mental awareness and group vigilance.

Evolutionary design may help explain why yawning is contagious. But modern science has yet to explain why this is so. Some theories suggest that yawning is a way of communicating to others that there are changes in the environment or internal biological conditions.

There Are Many Thoughts About Why We Yawn

Many people think yawning is a sign of tiredness. It may be, and it also may be a way to go from sleepiness to alertness. It may be a way of changing our state of awareness.s

Science knows that yawn creates neurochemical changes in the brain. Some research has said that it keeps the brain from overheating. Tests have revealed that we won’t yawn if the temperature is too cold to prevent thermal shock to our brains.

Yawning has also been noted to precede seizures and migraine headaches and increased yawning has been associated with multiple sclerosis and in people with brain damage. Excessive yawning may be a sign of something going on health-wise and more research needs to be done to gain a better understanding.

It is believed the hypothalmus plays a role in our yawns, where chemical messengers induce yawns. Chemicals in the brain such as dopamin, oxytocin, ACTh, and glycine spur on our stretching and yawning behavior.

Animals Yawn Too!

In utero, as early as the first trimester of development, unborn babies are yawning.

Many other species yawn also. Almost all vertebrae yawn. Reptiles, fish, birds, and mammals all yawn similarly. It is believed that yawning may be a vestige from our evolutionary ancestors.

Systematic yawning is similar across all species. It is consistent among systematic and coordinated with cyclic rhythms of feeding, reproduction, sleep and arousal. It is believed that yawning helps maintain homeostasis regarding these behaviors. Animals that are known to sleep a lot, yawn less than those that sleep 8-12 hours, and alternative their activities between active and inactive periods.

Predatory animals and primates yawn more often following a circadian rhythm. People yawn 5-15 times a day. We yawn more frequently after we wake up than before we go to sleep

What Science Knows About Yawning

Why we yawn is not completely understood, but science knows it has more to do than just because we are tired or bored. The biology of yawning has to do with lower oxygen levels in our lungs. During normal at rest breathing we do not use a good part of of our lung capacity. We generally us the air sacs at the bottom of our lungs, the alveoli. If these tiny sacs don’t get fresh air, they partially collapse and can get stiff. This prompts our brain to signal the body to sigh or yawn to get more in air into our lungs. But this does not explain everything about yawning. In the womb, fetuses have been observed to yawn. Yawning also is associated with multiple sclerosis and some other medical symptoms, all of which are not explained by medical science.


Some scientists connect yawning to the hypothalmus part of the brain. The hypothalmus is related to our metabolism, our heart rate and blood pressure, sexual behavior and feeding.

Some scientists believe yawning is connected to the hypothalmus. The hypothalmus is involved with our metabolic balance, our blood pressure, heart rate, feeding, and sexual behavior. “Yawning, they believe, is connected to a group of neurons related to social behavior. At the time these neurons get activated, yawning occurs.

Yawning Facts

Yawning facts:

  • the average yawn lasts about 6 seconds
  • in human beings, yawns can occur as early as approximately the 11th week in utero
  • Yawning is associated with the hypothalmus in the brain

It is believed we start to catch yawns at about the age of 4or 5 years old. This age is around the time when we begin to develop the ability to identify another person’s emotions properly. Studies have shown that people who are susceptible to contagious yawning are better at inferring what others are thinking from their faces.

Most animals, including snakes and fish yawn, but it is only contagious in humans, primates and, according to a recent study, dogs.

Observing 29 dogs placed in a room with a yawning man found that 21 of the dogs (72%) also started to yawn.The dog that was the top yawner was a Border Collie, who yawned 5 times within a few minutes.
The researchers,said the skill may allow the pet to build stronger bonds with their owners.

Theories About Yawning

There are no definitive answers as to why people yawn. No one knows for sure why people yawn.

Theories about yawing:

  • Yawning is an involuntary reflex that helps control the levels of our carbon dioxide and oxygen levels. Many studies have shown that when we breathe in more oxygen, it doesn’t decrease yawning. Breathing in more carbon dioxide also doesn’t bring on more yawning.


  • Another theory believes that yawning stretches the lungs and the lung tissues. This may increase our heart rate and make us feel more alert and awake.


  • Another theory states that yawning is a protective reaction to distribute surfactant, an oil like substance through the lungs to keep them lubricated and avoid the lungs from collapsing.


  • Yawning is related to boredom. In a study of 17-19 year old students was done to compare the yawns of these students, who watched music videos compared to the students who watched a mundane color test bar pattern. The students yawned nearly 6 times in an half hour. Those who watched the music video yawned a little more than 3 times in an half hour time period. The yawns were also noted to be longer with the color pattern video. It also seemed that male students held their yawns longer than female students.


  • Some scientists believe yawning may be a gesture ofl empathy. Scientists believe that contagious yawning – yawning after someone else does – is a sign of being keenly interested in the first person’s thoughts and feelings. Italian researchers who observed more than 100 men and women from four continents as they went to work, ate in restaurants and sat in waiting rooms. When one of the volunteers yawned, the researchers noted whether anyone within a 10ft area ‘caught’ the yawn – and yawned within the next three minutes. Their results showed that race and gender had no effect on whether the uncontrollable urge to yawn was passed on. But how well the two people knew each other did. A reciprocal yawn was most likely to occur among family members, then friends, then acquaintances. The phenomenon was least common among strangers


  • One theory states that yawning may be an evolutionary trait that developed early in the human development of man. It is believed the contagious yawn led the group to become more vigilant towards predators and alert to danger


  • Only about half of adult humans are prone to contagious yawning. In his tests it was found that people who are more susceptibility to contagious yawning is connected to people’s success on a face recognition task. Those who are less likely to yawn contagiously tend to score higher on a measure of schizotypal disorder, a personality disorder characterized by a need for social isolation.


  • Additional studies used functional MRI, (fMRI) to take images of the brains as they watch another person yawning. It was found that this experience of yawning triggers neural activity in the part of the brain that has to do with social awareness and empathy.

The Reasons We Yawn Are Not Yet Known

The mystery of yawning has yet to be solved. The are many theories that abound about this very human action. An average yawn lasts 6 seconds.


Hearing someone talk about a yawn, thinking about a yawn, seeing someone yawn makes us yawn. It is involuntary and uncontrollable, and it happens to all of us, all the time, even serveral times a day.


My apologies, if this article caused you to yawn, just as long as it didn’t put you to sleep. One day perhaps, we will understand the meaning of why we yawn, and with that uncover even greater secrets that will benefit mankind.

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Comments 13 comments

beingwell profile image

beingwell 4 years ago from Bangkok

I yawn whenever i see someone yawns. Darn! Haha!


billybuc profile image

billybuc 4 years ago from Olympia, WA

very interesting....I knew practically none of that. Thanks for the education.


Ruby H Rose profile image

Ruby H Rose 4 years ago from Northwest Washington on an Island

What a great "yawn" read! No, seriously, it is a marvelous hub. A great subject, weird that no one knows why. Thumbs up!


Twilight Lawns profile image

Twilight Lawns 4 years ago from Norbury-sur-Mer, Surrey, England. U.K.

Voted UP and interesting, and if there had been a FASCINATING button to press, I would have.

Great... I mean GREAT hub.


kashmir56 profile image

kashmir56 4 years ago from Massachusetts

A very interesting hub,thanks for helping me learn more about yawning ! Well done !

Vote up and more !!!


Greensleeves Hubs profile image

Greensleeves Hubs 4 years ago from Essex, UK

Interesting to read this toknowinfo. I've always wondered exactly why it is that yawning is contagious, whereas other regular body reflexes and responses to internal or external conditions, such as coughs, hiccups and sneezes, tend not to be contagious. Voted up.


toknowinfo profile image

toknowinfo 4 years ago Author

@Beingwell, since you yawn whenever you see someone yawn, you must be a very empathetic person!

@Billy, I take great joy in educating you about things you didn't know.

@Ruby, Thanks for the kind words. I am glad you enjoyed this hub.

@Twilight, Gee I am so complimented that you found this fascinating. I am so glad you stopped by, it has been a while, and it is good to see you again.

@Tom, I am glad you liked my hub and as always I so appreciate your kind comments and up votes.

@Greensleeves, You are so right, yawning is so distinctly different than other body reflexes. Science knows yawning serves some purpose, but has yet to discover it. Thanks for the up votes.


rwelton profile image

rwelton 4 years ago from Sacramento CA

Everyone in our family (including the cat) yawns pretty much every day. Very interesting.

rlw


toknowinfo profile image

toknowinfo 4 years ago Author

Hi RW, Who yawns first the cat or someone in your family?


rwelton profile image

rwelton 4 years ago from Sacramento CA

The cat, of course, and then we all follow!.

rlw


kissayer profile image

kissayer 4 years ago from Sydney, Australia

As a nanny you would not believe how many times I get asked this question - now I can teach them why :P Excellent info!


toknowinfo profile image

toknowinfo 4 years ago Author

Well that just shows what an empathetic family you are!


toknowinfo profile image

toknowinfo 4 years ago Author

Hi Kristy, I am so glad I can give you info that is practical for you to use. Thanks for stopping by.

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