Why is yawning so contagious?

I yawn, you yawn, we all yawn…but why do we yawn when we see other people yawning? As I’m writing this piece, I’m experiencing a never-ending cycle of yawning. Is this because I’m subconsciously telling myself to yawn? Or is it actually contagious?

What is a yawn?

A yawn is defined as the action of opening the mouth wide with a deep inhalation, usually involuntarily from drowsiness, fatigue or boredom.  According to Neuroscientist and yawn expert, Robert Provine, yawning is ancient and autonomic. It’s autonomic because it roots in the brainstem, way down deep in the levels of the brain, where specific responses are so built-in they can’t even qualify as reflexes.

Yawning is common to many creatures in the animal kingdom.  From lion and monkeys to snakes and fish, but there’s not one defined theory that can explain why this happens.  Many scientists studied yawning, but all of them created their own theories based on personal testing.

What happens when we yawn? 

When we yawn, the powerful stretching of our jaws causes the increase of blood flow in the neck, face, and head. After this happens, the deep intake of oxygen, during a yawn, pushes spinal fluid and blood from the brain.  The cool air that we breathe into our mouths cools these fluids.

 Why do we yawn?

Andrew Gallup, a psychology professor at SUNY College at Oneonta, discovered that yawning may serve as a thermoregulatory mechanism for your body. In other words, Gallup’s theory suggests that yawning is based on the temperature of your body.

Gallup’s theory is that colder air outside cools the brain better than hotter air. The body should, therefore, yawn more when the air is cool, and yawn less when the air warmer. To test this theory, Gallup went to Tucson, Arizona in the winter, where it was 71.6 degrees F outside, and in the summer, when it was 98.6 degrees F outside.

Gallup and his team of researchers asked 80 pedestrians to look at pictures of people yawning. It is well known that people yawn when they see other people yawning. The research concluded that in cooler weather, 45% of people yawned when they looked at the pictures. In the summer, only 24% of people yawned when they looked at the photos. 

Gallup’s research showed that in colder weather, people yawned more. In warmer weather, people yawned significantly less. Gallup’s results on humans had the same results of his previous studies on parakeets and rats.

Gallup’s theory on yawning, being a body temperature controller, can be the perfect explanation for why we yawn right before bed and when we wake up. Right before bed, our brain and body are at the highest temperatures during the circadian rhythm.

With the help of yawning, those temperatures drop as we go deeper into sleep. When we wake up, your body temperature rises rapidly, and you yawn to cool it back down. According to Gallup, we yawn 8 times a day on average.

Empathy Yawning

In a recent study, 60-70% of people find that seeing people yawn in real life, photos, videos and even reading about it, causes them to yawn. One theory suggests that your yawning might be based more on your personality than your sleepiness.

Researchers from the University of Connecticut produced a theory that catching yawns may be an unconscious sign that you’re connected to other people’s emotions. Just like how you might automatically smile, or frown when someone does the same action.  In 2010, these researchers conducted a study where they found that “contagious yawning” didn’t develop in children until they were four. This is the age when kids generally develop empathy skills.

The study also suggested that autistic children, that may have a hard time feeling empathy, were less likely to experience yawning compared to their non-autistic peers. Children who have low-functioning autism were even less likely to have contagious yawning.

A 2015 research report, conducted by Baylor University, showed that people with psychopathic traits are less likely to catch contagious yawning. The researchers gave 135 college students standard psychological personality tests, followed by showing them 10-second video clips of different facial movements including yawning.  The results showed that the less empathy a person had, the less likely they were able to catch a yawn.

Brian Rundle, a psychology, and neuroscience doctoral student from Baylor University said “what we found tells us there is a neurological connection—some overlap—between psychopathy and contagious yawning,” The less empathetic a person was, the less likely they were to be affected by contagious yawning.

Copycat Yawning

Another theory suggests that people yawn subconsciously because they see other people doing it.  Scientists observed contagious yawning in a variety of animals, including chimpanzees, baboons, wolves etc. and found that it is a chance that they just mimic each other. Yawning feels good, so maybe these animals and humans are yawning unknowingly and can’t help it. When you become self-conscious about your yawn, it stops.

Many scientists have been against contagious yawning because they feel there has not been that much research to conclude that it’s true. Rohan Kapitany, a psychologist from the University of Oxford, said: “If we fail to dissect that which we think we know, we might end up with conclusions that do not reflect reality.” Professor Kapitany wants researchers to question the basic features of contagious yawning before a universal conclusion could be thought of.

Yawn Fight or Flight

 Another theory suggests that the amygdala, an area of the brain associated with fear and heightened attention, activates in response to images of yawning. As humans, we yawn when we’re nervous, such as before a sporting performance, but we also yawn when we are bored.

Yawning could be taken as a way for the brain to prepare for “fight or flight”. Contagious yawning could be an evolutionary feature, of animals and humans, that could’ve been used as a survival tactic.

The fact is, there is no clear answer to why we yawn. There are so many theories out there, but none of them have enough concrete evidence to provide a clear enough answer to why it happens. Until we find the exact answer, keep on yawning and keep on sleeping.