Yawning can have multiple causes. Today we gather 5 of the most frequent supported by the scientific community.

The meanings of yawning
Elena Sanz

Reviewed and approved by the psychologist Elena Sanz the 23 November, 2021.

Last update: 23 November, 2021

Yawning is often thought of as an expression of boredom, inattention, and drowsiness. Although this theory is very popular, scientists actually believe that it is the least likely.. Dozens of ideas have been put forward about the functions of yawning, so far without being able to gather enough evidence to consider any as 100% probable.

That is, researchers have found no reasons why we yawn. Yes we have learned some things about it, so that we synthesize in the following lines which are the most accepted theories. We promise you two things: the first is that some of them will surprise you and the second is that before finishing reading this article you will yawn at least once.

Why do we yawn?

As we have already pointed out, scientists have not agreed on the reasons why we yawn. In part, this is because the hypotheses raised have the same number of points in favor as against. Yawning is in itself a mystery, one that we also find in animals.



Indeed, as the evidence, most species of vertebrates yawn. They do it from the fetal stage (something that also happens in humans) until old age. Since the theories outlined for humans do not always apply to animals, some experts indicate that yawning has multifactorial implications in different species.

Because of this, there is no single reason why yawning exists. Animals and humans yawn for different reasons, so action can be motivated by different elements at the same time. With this in mind, we present to you some of the most interesting hypotheses.

1. Stress and fatigue

According to some scientific studies, the origin of yawning could be related to stressful situations and cortisol levels.

A study published in 2011 in the magazine Medical Hypotheses noted that we yawn due to increased levels of cortisol in our body. Cortisol is a hormone produced in the adrenal gland when we are stressed and fatigued. So this would explain why we tend to yawn in these contexts.



Although there is no strong evidence that yawning helps control cortisol levels, it is thought to be a kind of alert to take appropriate action. In small doses, cortisol is healthy, but when it gets out of control it can cause heart problems, sleep disorders, and impair the immune system.

2. Cool the brain

Another well-known hypothesis of why we yawn dictates that has a thermoregulatory function of the brain. Have been made studies and research in animals that support this theory. Apparently, the frequency of yawning increases as the temperature is higher, and this helps to reduce it significantly in the vicinity of the brain.

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Evidence indicates that this also develops in humans. A study published in 2007 in Evolutionary Psychology tested the frequency of yawning while participants held hot and cold compresses to their foreheads. In the second case, the action was much more frequent, which gives us indications of support for this hypothesis.

3. Relieve ear discomfort

Yawning is thought to help alleviate hearing problems experienced during changes in altitude (when flying in an airplane or using the elevator, for example). In theory, this would be achieved by the opening of the Eustachian tubes that is generated after the contraction of the tensor tympanic muscles when yawning.

Studies have supported this hypothesis, so it is one of the reasons why the frequency of yawning increases with rapid changes in altitude. It can also have implications for sharpening hearing sensitivity or for alleviating any type of discomfort that is felt throughout the auditory sensory plane.

4. Boredom

The clearest association with yawning is boredom and monotony. While it is true, it is not the only explanation.

The experts have found a number of physiological changes that occur before, during and after yawning. It is known that right after yawning the heart rate increases, the eye muscles tense and the lung ability is enhanced. The sum of all this produces a general excitement in the body.

What is the cause of this excitement or what is its function? Well, some researchers they have theorized, in line with popular belief, that boredom may be the reason. Indeed, we yawn in contexts in which our attention or interaction is minimal (watching television, for example), so this reaction could help motivate us to stay awake or enhance our attention.

5. Social interaction

It is well known to all that yawning is contagious. This has led to some experts ensure that yawning has an empathic mechanism with prosocial consequences. The levels of empathy can be even higher than those achieved during the laughter interaction.

Therefore, this mechanism could evolve as a tool to promote teamwork, alterity, group rapprochement and as a method of social insertion. The social aspect of yawning is by far the one that generates the greatest intrigue in scientists.

Of course, there are dozens of alternative theories for why we yawn. These are the ones with the highest reputation, at least if we consider the current investigative landscape. Remember that the causes can be multifactorial, so you don’t yawn for just one specific reason.

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