The Science of Why We Yawn

[Please note that this page contains affiliate links. If you choose to purchase after clicking a link, I may receive a commission at no extra cost to you.]

Some people yawn a lot, and others seldomly do.

Although yawning often can lead to awkward situations, like social situations.

For example, suppose someone is telling a person an important story, and the listener is constantly yawning. The storyteller might feel that the other person is bored and could care less about the conversation.

Therefore, learning the science of why we yawn is critical from a psychological perception.

The Brain Cooling Hypothesis

A recently published study in the scientific journal Communications Biology (Massen et al., 2021) tests an exciting hypothesis: The brain cooling hypothesis.

The brain cooling hypothesis suggests that we yawn to cool our brains.

According to this hypothesis, deep inhalation and muscular contraction are to flush hotter blood from the brain and replace it with colder blood.

Brain cooling is vital as too much heat from nerve cell activity, and the surrounding temperature can weaken brain function because of overheating.

The Largest Yawning Study Ever

The yawning brain cooling hypothesis proposes that animals with big brains with more nerve cells do it a lot more often and longer, as a bigger brain needs more effort to cool down than a smaller brain.

The researcher who conducted the study performed the most widespread analysis of yawning ever done to test this.

The researchers looked at 1291 different videos of yawns made by humans and non-human animals from 101 different species (46 bird species and 55 mammal species) and determined the length of each one.

In addition, this study included data from many other animals like cats, rats, chimpanzees, hyenas, owls, parrots, and ravens. These videos were done in zoos, during observations, or were obtained from internet sites.

The scientists obtained data on the brain size and the amount of the species from studies done previously.

The Study Results

The researchers discovered a significant, statistically meaningful association between yawning length and brain size as well as the amount of brain nerve cells.

Bigger-brained animals with more nerve cells had yawned a lot longer than animals with smaller brains with fewer nerve cells. This connection was discovered in both birds and mammals.

The study findings show strong evidence to back up the brain cooling hypothesis.

Furthermore, these results indicate that yawning is an older evolutionary mechanism to help prevent your brain from overheating across all animal species.

The Results of Chronic Yawning

The study shows that there are no negatives attached to yawning a lot. On the contrary, it’s a normal body function that helps with proper brain function.

The stereotype of people yawning well conversating are not interested in the conversation or bord is false. In contrast, this study shows that people do it to keep their brains working correctly and critically during a conversation.


Massen, J.J.M., Hartlieb, M., Martin, J.S. et al. Brain size and neuron numbers drive differences in yawn duration across mammals and birds. Commun Biol 4, 503 (2021).

Alpha Brain
Onnit Alpha Brain (30ct) Nootropic Brain Booster Supplement For Memory, Focus, and Mental Clarity with Bacopa, AC11, Huperzine A, L-Tyrosine, and Vitamin B6

Dean Mathers


Leave a Reply

Your email address will not be published.