A new scientific study defines yawning as “a stereotyped orofacial-respiratory behavior characterized by a prolonged jaw gape and coordinated oropharyngeal movements.” We know what yawning is, and we know it can be impolite to yawn while listening to someone speak or perhaps during a sermon. But maybe yawning is good for your health, according to this new study.
Yawning is not confined to humans—mammals, amphibians, reptiles, and other vertebrates also yawn. We think of yawning as accompanied by taking a deep breath, but even marine mammals, including beluga whales, bottlenose dolphins, and dugongs, display a similar action, gaping their mouths even when they’re underwater so they can’t breathe. Yawning must be good for something.
According to the scientific report, most yawns appear to consist of an initial deep inspiration, a pause, and then a rapid expiration. It was suggested that yawning may play a role in regulating blood oxygen levels, brain thermoregulation, or attention/arousal. According to the study, it may also have something to do with cerebral metabolic waste clearance. In other words, it helps clear your brain, so yawning is good for your health.
The movement of cerebral spinal fluid (CSF) contributes to waste removal in the brain. So, if CSF movement is critical to remove metabolic waste from the brain, how does yawning help with that movement? That was what the group’s research sought to find. They said, “The movement of the jaw and the act of inhaling can impact circulation within the skull.”
Furthermore, yawns may be coordinated by a brainstem central pattern generator (CPG), similar to those that control breathing and locomotion. Swallowing is also organized by CPG circuitry, and the researchers found that swallowing is often tied to yawning, since swallowing frequently occurs within seconds after a yawn.
The bottom line, as far as I can understand, is that yawning is good for your health because it helps clear the brain of waste materials. I presume that means when your brain is busy thinking, a yawn becomes necessary to clear out the waste and give room for your brain to keep on thinking. Perhaps if you’re yawning while reading the posts we present on this web page, we are stimulating your brain rather than putting you to sleep. If that is true, I am encouraged because while writing this, I found myself yawning.
I never cease to be amazed at the complexity of life and the human body that God designed, and yawning is just one more thing that amazes me.
— Roland Earnst © 2026
Reference: sciencedirect.com
The cover story of the June (2019) issue of Reader’s Digest lists 50 features of your amazing human body. The article gives some evolutionary guesses as to how some of those features could have developed. We thought it was especially interesting that science has not explained nine of the 50: