What is yawning?

MISSISSIPPI – You know the feeling. It's impossible to resist. You just need to yawn.

A yawn consists of an extended yawning followed by a faster closing. In mammals and birds, a long breath and shorter expiration follow the gaping mouth, but in other species such as fish, amphibians and snakes, there is no breath

. happen?

In the past, people have had a lot of badumptions. From 400 BC BC, Hippocrates thought that yawning removed bad air from the lungs before fever. In the 17th and 18th centuries, doctors believed that yawning increased oxygen in the blood, blood pressure, heart rate and blood flow itself. More recently, the consensus has shifted to the idea that yawning cools the brain, so when ambient conditions and brain temperature increase, yawning episodes increase.

Despite all these theories, the truth is that The function of a yawn.

What we do know is that yawning occurs in almost all species. It happens when an animal is tired. It can be used as a threat in some species. Yawning can occur in times of social conflict and stress, what researchers call displacement behavior

and this open mouth can be contagious, especially in social species such as humans, chimpanzees, bonobos, macaques and wolves. Watching someone yawn – heck, even reading about yawning – can cause you to yawn yourself. Why?

Human research tells us that people who are more empathetic tend to be more susceptible to contagious yawning. When you see someone else yawning, the networks in your brain responsible for empathy and social skills are activated

Is yawning contagious for dogs too? In 2011, British biologists tested a contagious yawn between people and the best friend of man. Although 5 of the 19 dogs studied yawned in response to a yawn from an unknown person, the researchers could not prove that the yawning was contagious.

In 2013, cognitive-behavioral scientists from the University of Tokyo again tested contagious yawning. canines while controlling stress. This time, researchers found that dogs were more likely to yawn in response to a familiar person. They concluded that dogs can "catch" a yawn from humans and that yawning is social behavior rather than stressful.

In 2014, psychologists from the University of Nebraska observed contagious yawning in shelter dogs. They found that some dogs that yawned when exposed to yawning had high levels of cortisol – an indicator of stress. Cortisol stress hormone levels have not increased in dogs who have not yawned in response to a human yawn. This discovery suggests that some dogs find human yawning stressful and others do not. More research is needed to evaluate this aspect of the dog-human relationship.

So, the jury is still on the true why yawns. But when it's inter-species yawning, you can collect your own anecdotal data. Try an experiment at home: yawn and see if your animal bounces.

Christine Calder, Assistant Clinical Professor of Behavior, College of Veterinary Medicine, Mississippi State University

This article was originally published on The Conversation. Read the original article.