Why Are We Yawning?

Yawning could be used to reposition our jaws or stretch facial muscles.

Yawning is an unconscious and uncontrollable gesture that all humans make. And not just humans:  many vertebrate animals and almost all mammals do. But why are we yawning?

Yawning involves opening your mouth wide, inhaling deeply, then releasing a little less air and closing your mouth. Besides, it is accompanied by a subtle closing of the eyes, tearing and a slight increase in saliva,  among other things.

All cultures have their own idea of ​​yawning. The most normal is to think, in a popular way, that one yawns out of fatigue, boredom  and even out of hunger. However, that does not explain why the rest of the animals do it.

Yawning has been present almost since the first moments of our life, when we are babies. But, oddly enough,  scientists continue to study the possible reasons for these yawns. Here we will explain the current theories circulating on this subject.

Why are we yawning?

The hypothesis that is currently the most popular is that  yawning allows us to cool our brains. It would be like a natural refrigeration system, like any electrical appliance.

This is a curious theory that has been reinforced from some recent studies from Princeton University. This study claims that  when we yawn, membranes in our nasal sinuses move.

The nasal sinuses are cavities in our skull that contain air. The fact that these membranes move when we yawn suggests that they act like little fans. They would allow air to circulate better to our brain and cool it.

This theory also makes sense because our brain is one of the organs that needs the most energy. Its functioning produces heat in the skull, so  yawning could be a very useful mechanism to stabilize its temperature and be able to work properly.

Why are we yawning: are there other hypotheses?

In addition to this brain refrigeration theory, many others seek to explain the function of our yawns. Another theory indicates that  when we yawn, we are “repositioning” our mandibles. In other words, it’s a way of getting our skull bones back into proper position.

Moreover, as you have surely noticed,  when we yawn, we open our ears. This happens because the pressures between the inside and outside of the ear balance out. So it could all be linked.

Yawning can be used to put us on alert

In some animals, it has been observed that yawning appears in the face of a threat. This happens for example in lemurs. So, when we yawn, it is possible that we are trying to increase our concentration. Thanks to this, we could better cope with threats or challenges.

This gesture could be associated with anxiety. In fact, it has been detected that when we yawn, cortisol levels subtly rise in our blood. Cortisol is the hormone that increases in stressful situations.

We yawn to increase the oxygen level

Some scientists argue that yawning  is a mechanism in our brain to increase the concentration of oxygen in the blood. According to this theory, our brain would send signals to yawn when it detects low concentrations of this gas.

Do we yawn out of empathy?

You don’t have to be a scientist to see that  yawns are “contagious”. When someone yawns near you, it’s very common that you end up doing it too.

This is apparently due to mirror neurons. These are neurons that could be responsible for empathy. In other words, they are the ones that allow us to put ourselves in the other person’s shoes and feel the same as them, even if we are not going through the same situation.

To conclude

Yawning is an involuntary gesture; we do not yet know very well its biological function. Nevertheless, the latest research indicates that it is a way for our bodies to keep our brains in optimal temperature conditions.