Why do We Yawn?
Is Yawning Contagious?
Did you ever wonder why you yawn? If you are with someone else who yawns, the chances are they will yawn also. Is yawning infectious? Really, the answer is yes; it often is very infectious. When we see someone yawn or even hear them yawn over the phone, we often yawn also.
Do you ever yawn when on an airplane to relieve ear discomfort? This is a benefit of yawning. Contagious yawning may be a way to keep us alert.
Essentially we are all the same when it comes to instinctive behaviors and yawning is one of those behaviors. Scientists really do not know very much about yawning, except that it is an involuntary action. Robert Provine, a developmental neuroscientist at the University of Maryland has proven that 11 week old fetuses yawn, so it is a normal human reflex and age is not a cause of yawning.
Why Do We Yawn?
Physical Effects of Yawning
From a physical standpoint, yawning causes us to open our mouths wide and take in a deep breath. Other parts of the body are also involved in the yawn. The jaw drops open to allow more air to enter into the lungs, the abdominal muscles flex pushing the diaphragm down.
The diaphragm is a large dome-shaped skeletal muscle extending across the bottom of the rib cage, which actually separates the thoracic cavity with the abdominal cavity and is moving with each breath.Your heart rate may rise by 30 percent during yawning. It is also a way to stretch the muscles. Did you know that yawning can also be a sign of sexual arousal?
Boredom, drowsiness and fatigue are known to bring on a yawn. We often cover our mouths when yawning in public to not offend another individual. Yawning is natural, and the facts are scientists do not know for sure why we yawn.
Saberttooth Tiger and Caveman
An individual that suddenly has excessive yawning, even when tired, can indicate a serious problem. It may be caused by what is known as a vasovagal reaction. This reaction happens when the vagus nerve (this nerve runs from the brain to the heart and stomach) interacts with some of the blood vessels.
This reaction can indicate an impending heart attack, a sleeping disorder to bleeding around the large aorta artery. It is appropriate to consult a physician if you have been yawning much more frequently for no apparent reason.
Why do We Yawn?
The most common theories include:
- There is a physiological theory that states a yawn is induced to remove a build-up of carbon dioxide in our bodies by breathing in more oxygen. This theory might explain why we yawn in groups in a closed in class room for instance. This poses the question, "Why don’t we yawn during exercise?" We certainly need more oxygen during exercise. Actually, this theory has also been tested by Robert Provine. Giving people more oxygen and reducing carbon dioxide did not prevent yawning at all in his studies.
- Then, there is the evolution theory. Some people believe that our ancestors in the early ages yawned to intimidate others by showing their teeth. That seems a bit bizarre, but a theory none-the-less.
- Yawning may also be a territorial reflex. Yawning often makes the body look bigger as arms are outstretched and the mouth is open. When humans witness an animal yawning the first thing they notice is the animal’s teeth and any threat.
- The boredom theory seems to be a more relevant one. While we do tend to yawn more when we are tired or bored, this theory does not explain why Olympians yawn right before competing in their athletic event. Also, why do dogs yawn right before they attack? I do not think they are bored.
- Another more recent theory states people yawn more when their brains are warmer. Then, it would seem they are yawning to cool off their brains. This theory was also tested by having subjects breathe through their noses. They also pressed hot and cold compresses against their foreheads to try to cool down their brains. Cool brains think more clearly, which is the reason this theory is being tested. Dr.Gallup of the State University of New York in Albany tested this theory. The subjects of this experiment were all in one room while others looked through a one way mirror and counted the number of yawns. The results of this study found that yawning was almost eliminated for those breathing through their noses with cool compresses on their foreheads. Dr.Gallup surmised yawning keeps us more alert.
All God’s Creatures Yawn
All vertebrates, including fish, lizards and snakes yawn, however, only human beings, chimps and dogs experience contagious yawns.
Another study explored why yawning might be contagious and they linked it to empathy or a form of social bonding. Kids do not experience contagious yawns until approximately four years of age. Children with autism seldom yawn, particularly in the more severe cases. Scientists think the study of yawning might help their understanding of developmental disorders
Sleep Music to Relax and Rewind - "The Path" or to Yawn
Now that I have yawned for the past hour while writing this hub, I hope that each of you stayed awake and enjoyed this information about yawning. We know it is natural to yawn and perhaps it is good to not get too overheated.
Do you find yourself yawning when others yawn?
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.