Christian Agudelo has some insights for you into why we yawn and whether it is contagious.
It is an instinct. All animals do it. Cats are particularly good at it.
We all yawn. Whether we want to or not. We open our mouths and try to swallow air, or at least that is how it seems.
But why do we do it? Is it because we need sleep, or are we hungry or bored? Some experts even say that fetuses yawn.
There are no definitive studies on why humans yawn. But here, Agudelo, an assistant professor of clinical neurology at the University of Miami Miller School of Medicine and co-director of education for the Evelyn F. McKnight Brain Institute, explores the possible reasons for this phenomenon:
What is a yawn?
Yawning is involuntary. Once it starts, we are yawning. It starts with a deep inhalation, our jaw drops, and we take a deep breath and then we stop breathing. It takes seconds. There is a longer than normal pause before we exhale. Your eyes close and then you exhale the air. Everybody does it. There is an audible gasp sometimes but not always. It is very weird.
Does everyone yawn?
Babies yawn; animals yawn. All vertebra yawns. We think fish yawn. It is a behavior that has remained so consistent throughout evolution that it implies that it is somehow very helpful to survival. If racoons yawn and dolphins yawn and humans yawn, then—like sleep—there must be something in our DNA that for some reason this has kept us alive.
Does the body take in more oxygen when we yawn?
I think it has little to do with oxygen. There has been some research that looked at altered oxygenation for people who yawn and there was little evidence that the oxygen level had changed.
Why do we yawn?
Yawning occurs prior to and in anticipation of a near immediate change from a low activity state to a high activity state. It is likely that the magnitude of the anticipated change in activity, consciously or unconsciously, triggers it. An example of this is drowsily watching TV on the sofa late at night. Yawning may occur then because your brain anticipates that you are going to get up and go to bed, which is a massive departure from the drowsy state you are in while passively watching TV on the couch. In this case, yawning is your brain telling you, “GO TO SLEEP!”
Another example is yawning right when you wake up. Maybe you woke up before your body was ready to wake up. Your brain is pulling you back to sleep, but the day is pulling you to wake up. Your brain anticipates the inevitability of the day, and yawns in anticipation of getting up and starting your morning routine. In all these cases, yawning precedes an anticipated change from a relatively low activity or drowsy state to a relatively higher activity state.
What about contagious yawning?
We can all agree that yawning is contagious.
Contagious yawning is a concept written about in different cultures throughout history.
Humanity has observed it independently at multiple times. I believe that contagious yawning is an empathic behavior. I define empathy, in this case, as the ability to approximate someone else’s emotional state in ourselves. We may be aware of empathy as it is happening and be able to use empathy to intellectually understand another person’s emotional state. But empathy need not be a conscious state. Empathy is thought to be a way to learn.
For example, children learn from parents. The most important lessons a parent can impart are those that occur when a parent is emotional: fear, anger, joy, laughter. What to run from and what to run to, those are the most fundamental lessons. A child identifies and codes these lessons with empathy, by feeling what a parent is feeling.
I think yawning is an example of this process and it makes sense in this context. If yawning occurs in preparation of a change in activity level, from low to very high activity, we should be aware when that is happening around us. A child would empathically yawn when their parent yawns, because something is about to happen that is important. They are about to enter sleep or exit sleep, which are moments of greatest vulnerability.
For early humans and animals, they may need to transition from sleep to action immediately. If a child sees that yawn and empathically yawns themselves, they are more likely to learn from the behaviors their parents take to survive the impending attack. Similarly, if early animals and early humans yawned while quietly stalking their prey and before ambushing their dinner with rocks, this is a moment where empathic yawning marks the moment as a learning moment.
Source: University of Miami
