You’ve probably heard that yawning is contagious; seeing someone doing it, or even reading about it, can trigger something in your brain that makes you need to yawn. But why do humans yawn? How does yawning look in other species? Those are exactly the questions that Christine Calder, an Assistant Professor in the College of Veterinary Medicine at Mississippi State University, grapples with in her latest article on The Conversation.
Throughout history, there have been many theories on why humans and animals yawn. In 400 B.C., Hippocrates believed yawning removed bad air from the lungs. In the 17th and 18th century, doctors said that yawning increased oxygen in the blood, blood pressure, and heart rate. Now, some are saying that yawning actually cools down the brain. Despite the many theories, there is no definitive answer to why we yawn.
One thing that is clear is that humans are not the only species to yawn. In fact, it occurs in about every species. Not only do animals yawn when they are tired, but they also do it as a threat display.
But why is yawning contagious? Calder asserts that yawning contagion is tied to empathy. “Research on humans tell us that people who are more empathetic tend to be more susceptible to contagious yawning. When you see someone else yawn, the networks in your brain responsible for empathy and social skills are activated,” writes Calder. And this phenomenon may not be limited to humans either. In a 2011 study, multiple dogs yawned in response to a human yawning, although the study could not conclusively prove that canines are susceptible to yawning contagion as humans are.
To read more about the mysteries of yawning in both humans and animals, check out Calder’s full piece here: https://theconversation.com/what-is-it-about-yawning-98292