Researchers may have found the answer to the age-old question, “Why do we yawn?” We yawn when we’re tired, when we wake up, when we’re bored, and even when we’re anxious, but do we know why we yawn? Researchers from SUNY Oneonta, along with the University at Vienna in Austria and Nova Southeastern University in Florida, believe to have found that why through identifying a link between the events that make us likely to yawn and thermoregulation, or brain cooling.
Their explanation: we yawn to cool the brain.
This is contrary to a widely held theory that it is to increase oxygen supply, even though previous research shows no association between yawning and blood oxygen levels.
A new study says yawning means your brain is overheating. Whew, I thought it had something to do with me sticking my head in the microwave.
— Stephen Colbert (@StephenAtHome) May 8, 2014
Our brains experience a change in temperature when we sleep, have anxiety, or are aroused. Subsequently, we are prone to yawn during these same situations, setting forth the researchers’ theory. The researchers then drew from this theory that yawning should be easily manipulated by a change in temperature, thus lowering the temperature of our brains- which should in turn cause us to yawn.
Jorg Massen and Kim Dusch of the University of Vienna measured contagious yawning frequencies of random pedestrians walking in Vienna, Austria during the winter and summer months. Next, they conducted an identical study in Arizona of pedestrians in a dry climate. Both sets of pedestrians were then asked to report on their own yawning behavior.
They found that the people in Vienna yawned more in the summer than in the winter, while the people in Arizona yawned more in the winter than in the summer. Evidently, it was not the seasons that made the difference, but that contagious yawning was controlled in an “optimal thermal zone” or a range of ambient temperatures close to 20 degrees Celsius (about 68 degrees Fahrenheit.) However, contagious yawning decreased when the temperatures were high in the summer in Arizona and close to freezing in the winter in Vienna.
Jorg Massen explains that where yawning is used to cool the brain, yawning is not functional when the surrounding temperatures are as hot as the human body, and might not be necessary or may even be detrimental to your health when it’s freezing outside.
There have been many studies that test whether yawning is contagious while only emphasizing emotional-cognitive and interpersonal influences. This new study seeks to uncover the underlying reason for yawning and suggests that yawning is spread through behavior, or brain cooling, via contagious yawning.
Top photo: Techcetera.com