Why Do We Yawn?Source: Wikimedia
A yawn is a deep breath that is taken within a normal breathing cycle, usually with the mouth wide open, presumably to maximise the body’s capacity to feed the lungs with greater levels of oxygen. If you have been spending hours gambling online or playing video games, then yawning is probably a sign that you ought to take a break and do something else for a bit. That said, yawning does not only occur after we have been relatively sedentary for a period of time. We can sometimes yawn simply because others around us are doing so. Indeed, reading about yawning, according to certain studies, has been shown to lead to an increased likelihood that you will yawn. So, if you are yawning whilst reading this article, then it is not because it is boring – it is because of the subject matter. In fact, yawning is a fascinating topic, largely because we really know so little about it.
What Are the Theories Around Yawning?
The ancient Greeks thought that the yawn was the body’s way to get more oxygen to the brain and remove what they referred to as bad air. Although this might have something to it, you could get the same effect by consciously breathing more deeply, of course. As such, it is said to be an involuntary action, a bit like your heartbeat. However, this doesn’t take into account environmental impacts on yawning fully. For example, we are more likely to yawn when we are bored. A lack of stimulation will often lead to a yawn or two no matter how much we try to stifle them. Equally, it does not deal with the idea that yawning is a contagion. If we see a person – or an animal for that matter – yawning, then we are also more likely to join in.
One idea that has been put forward about yawning is that it is a way of staying awake. The theory takes into account the idea that we yawn more when we are tired. By re-oxygenating the blood supply, the idea is that we are trying to stop ourselves from falling asleep. However, there is not much evidence that yawning actually makes us feel more awake and responsive so it is more likely that the act is something that simply follows on as a result of drowsiness. All we can say for sure is that certain drugs – such as oxytocin, for example – result in an increased rate of yawning so there is something going on at a physiological level.Source: Wikimedia
Are There Benefits to Yawning?
If we rule out the theory that yawning keeps us more alert, then it could be something that used to be of benefit to us but which, through evolution, is no longer advantageous. Some people certainly see it as an evolutionary throwback but that still does not explain why animals, especially mammals, do it either. Some scientific research has indicated that a deep yawn may equalise the pressure of the inner ear. It does this by opening the Eustachian tube up which connects the ear to the throat. Perhaps that is why so many people yawn when their flight is about to land? There again, it could be that passengers are simply tired after a long flight.
Yawning may help to remove debris around the tonsils, thereby helping you to breathe more easily. Some people also claim that it has a similar effect on the lungs, increasing oxygen transfer to them. It could even prevent a lung collapse in certain circumstances. However, the biggest known benefit of yawning is that it sends a social signal that we are feeling sleepy. It is, therefore, a way to indicate to others that we are settling down for sleep and so should they. This may explain why there is a contagion around yawning. The more we do it, so the more others join in, helping groups to all go to sleep together without disturbing one another. If you think about early man, sharing a cave for shelter, a social mechanism – like a yawn – that signal the end of the day could have great benefits for ensuring everyone enjoys adequate sleep ready for the next day’s activities.