Why do we yawn?

What are the reasons of constant yawning? Is it a sign of disease? Read the article to learn it.

Some people far from medicine consider that yawning is a sign of drowsiness or boredom. Actually it is an uncontrollable reflex of organism, which can be shown for the most different reasons. For example, why we do it when someone else yawns? Find the answer below.

Why do we yawn

  • Though many researches are devoted to studying of the reasons of why do we yawn, scientists can't still agree about it main appointment. Long time it was considered that yawning results from the lowered content of oxygen in blood: by means of a deep breath the organism does an oxygen drink. However scientists have refuted this theory as a result: it became clear that if to give to the yawning person more oxygen or to air a stuffy room, he wouldn't stop yawning.

Why do yawn 3

  • According to other theory, the person yawns to cool a brain. The experiments made by American scientists shown that examinees with cold compress on forehead yawned when viewing videos with the yawning people less often, than examinees with a warm compress or without it. Those participants of experiment who were asked to breathe only a nose yawned also less often: at such breath, more cool blood comes to brain, than at breath with mouth.

yawn when tired

  • One more purpose of yawning is a need to stretch and relax clamped muscles when tired. First of all it is muscles of throat and tongue, and also a muscle of all body: for this reason people often stretches. Such warm-up for muscles in combination with cooling of a brain helps to encourage an organism and to bring it to ready action state. Therefore, yawning often arises when people are nervous before some responsible action: students yawn before examinations, parachutists before a jump, and actors before performance. For the same reason people yawn when they want to sleep or miss: yawning helps to encourage a sleepy brain and grown dumb muscles.

yawn when someone else does

READ ALSO: Why do we dream? – 5 top theories

  • Also it is useful to yawn during flights by plane. It helps to get rid of the feeling of congestion of ears arising at take-off or landing because of difference of pressure on both sides from eardrum. As the throat by means of special channels connects to cavity of a middle ear, it helps to level pressure in ears.

yawn when others do

  • Yawning is a very infectious phenomenon. People begin to yawn not only when someone else does, but also while watching video or photos of the yawning people. Moreover, often it is enough to person to read or think about yawning to begin to yawn. However not all possess ability to mirror yawning: researches of children with autism have shown that they, unlike healthy children, don't catch yawning during viewing video when others do. Also children who are younger than five years aren't inclined to mirror yawning. They are not capable to empathize others yet. What communication between susceptibility to infection with yawning and ability to empathy is explained with?

yawning so much

So-called mirror neurons are the reason of it. These neurons located in cerebral cortex of person, other primacies and some birds have some kind of empathy: they are excited when the person watches actions, which someone makes. Mirror neurons define ability to imitation (for example, when studying modern languages) and to empathy: thanks to them, we not simply notice an emotional condition of other person, but also actually endure it. Mirror yawning is one of examples of such imitative behavior. According to scientists, imitative yawning arose in evolution of primacies for coordination of actions of social groups. When one of members of group yawned at sight of danger, its state was transferred to everyone, and the group came to ready for action.

Why do we yawn 1

  • In 2011 Italian scientists shown that infectivity of yawning serves as a measure of emotional proximity of people. In experiments mirror yawning most often arose at close relatives and friends. Distant acquaintances caught yawning less often, and absolutely seldom this behavior arose at people unfamiliar with yawning person. At the same time a sex and nationality didn't influence on this tendency anyway.

Why do we yawn 2

  • Long frequent yawning can be a symptom of various diseases, for example: violations of thermal control of body, problems with dream, an elevated pressure, thrombosis of arteries or damages of trunk of brain where there is a respiratory center. Besides, too frequent yawning can arise at increased uneasiness or depression. At this same time in blood is observed high level of cortisol – stress hormone. Therefore, if you yawn so much, it is worth seeing a doctor to check heart, blood vessels and pressure. For a start, it is possible to try to sleep properly and cease to be nervous.


Many believe that the first researcher of the phenomenon of yawning 2,500 years ago, Hippocrates was. The famous Greek physician believed that yawning helps the body to get rid of bad air, especially at elevated temperatures.

"Like large amounts of steam escaping from the boilers with boiling water that has accumulated in the body air escapes from the mouth when the body temperature rises," wrote Hippocrates.

Different versions of this explanation prevailed in Europe until the nineteenth century when scientists assumed that yawning helps the breath, activating the flow in the circulatory system oxygen and stimulating the withdrawal of the carbon dioxide.

If it was actually, probably, people would yawn more or less regularly, depending on the level of oxygen and carbon dioxide in the ambient air.

Answered 1 year ago.
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