Most of us have experienced it a handful of times — watching someone near us yawn, and suddenly feeling an almost irresistible urge to do the same. It’s easy to assume that yawning simply boils down to sleepiness, but many of us have experienced this phenomena even when we aren’t feeling tired. It’s so common that many stop and wonder, “wait… is yawning contagious? Can I ‘catch’ a yawn?”
Unsurprisingly, the answer to that question isn’t so simple. Yawning isn’t the common cold and isn’t “contagious” in the traditional sense of the word — but there is a fascinating physiological cause for why one person’s yawn often triggers others’ (and it has almost nothing to do with snoozing).
Let’s explore exactly what’s going on behind this odd phenomena that has us showing off our molars whether or not a nap is on our minds.
Why We Yawn
To understand what’s going on with “contagious” yawning, we need to understand why we yawn, and how it plays into our overall physiology. Even for researchers, however, the function of yawning is still somewhat a mystery — and most scientists can only theorize as to why we have the urge to yawn.
The first and most well-known theory for why we yawn (you guessed it) is feeling sleepy or bored. When we’re tired, we don’t drawn air into our lungs as forcefully or consistently as we do when we are fully alert — so yawning might be our body’s way of replenishing oxygen levels.
The second is that yawning actually helps to “cool” the brain. Scientists theorize that this powerful stretching of the jaw dramatically increases blood flow to our face, head and neck — and when coupled with the drawing in of cool air, yawning helps cool the blood and spinal fluid traveling down from the brain. Some experts suggest this is the reason we tend to yawn more when it’s cold outside.
But many researchers have found that there could be an even more unexpected cause for yawning — one that is more psychological than physiological. According to researcher Dr. Adrian G. Gussisberg of the University of Geneva, yawning may actually have certain social benefits — and could be an unconscious way that we communicate our mental or physical state to others.
It’s for a similar reason that many scientists believe yawning appears to be “contagious” — and why some of those researchers believe yawning may be a connected to an important human trait: empathy.
I Yawn, You Yawn, We All Yawn
Some researchers who study the phenomena of contagious yawning believe that this seemingly innocuous impulse could indicate a person’s level of empathy. It’s a theory supported by a number of studies that find people with higher social competence are more likely to experience contagious yawning.
In fact, an estimated 60-70% of people feel the urge to yawn when seeing someone yawn in real life, when looking at a photo of someone yawning or even just reading about it (have you yawned yet?).
But not everyone is prone to contagious yawning. People who are classified as sociopaths or psychopaths are much less likely to engage in contagious yawning. Since one of the hallmark psychological features of both psychopathic and sociopathic personalities is the inability to recognize and understand the emotions of others, this is consistent with the theory that yawning is an empathetic response.
Yawning Across the Animal Kingdom
It’s not just humans that experience contagious yawning. In fact, scientists have observed contagious yawning in apes, dogs, cats, a small number of birds and even some types of reptiles! It’s especially common in species that live in social groups, where traits like empathy could play a role in survival.
While most animal species will only engage in contagious yawning with other members of the same species, some animals will actually respond to humans’ yawning, too — namely domesticated dogs. Some researchers believe that this stems from dogs’ long-standing connection with human beings. Since dogs evolved in close proximity to humans, they likely have greater empathy for our emotions and feelings.
Don’t buy it? Here’s a fun experiment for pet parents: yawn in full view of your dog and watch to see if your pet returns the favor (spoiler: they usually do).
No matter how you look at it — or why you think contagious yawning happens — there’s no doubt that it’s far from myth. Next time you decide to stretch your jaw wide and take a big gulp of air, look around! You’ll probably find a few others that follow suit.