Why Do We Yawn? Here Is The Sleepy Science Behind It

Have you ever realized how easily influenced we can be to yawn? Have you ever asked yourself why we yawn in the first place? Did you know that by just reading the word "yawn" you can trigger the need to yawn? Yes, yawn monkey, yawn! But really, chances are by the time you've reached this sentence, if you have not already yawned, you can feel a growing need to yawn beneath your ribs and in the back of your throat.

In order to figure out why it is that we yawn, scientists like to look at what exactly a yawn is. Well, physically, a yawn is an involuntary deep breath that's drawn from the belly and causes us to open our mouths wide to let in as much air as possible and fill out lungs to capacity. Beneath the skin, a yawn cases the blood to oxygenate, it can increase the heart rate up to 30 percent and in return make you feel significantly more awake at simulated afterward.

There are many theories about why we yawn. There are evolutionary theories that in the past have suggested that yawning was a way for our ancestors to show their teeth, puff up their chest and intimidate predators. But newer theories suggest that yawning was a way for our ancestors to break tension and show their vulnerability and humanity to others. Medical scientists have theories about yawning as a pre-programmed method of waking up the body and mind when you're feeling sleepy or bored. Another theory is that we yawn to cool our brains when we're in situations or environments that typically warm the brain. While no theory has yet be crowned the winning theory, they're all based off of fascinating observations that teach us more about ourselves as a species than as bored or warm headed humans.

Here are some fun facts about yawning to "bore" your friends with:

Babies Yawn Before Birth


Babies experience their first involuntary breaths in the womb starting in their second trimester at just 11 weeks. (We still don't know why exactly they do this and what benefits they receive from doing it.)

Copy Cat Yawning


Kids under the age of five rarely experience copy cat yawning. It's only after the age of five that the yawns of family and peers can trigger their own yawns. This might be because this is the age that children begin to develop empathetic behavior, and yawning is an empathetic action.

Ancient Greek Theory


Hippocrates believed that yawning helped expel toxic waste from the body. It was his belief that when the body was filled with too much carbon dioxide or sickness or bad energy, the body would pull in fresh air and push out all of the waste.

Form Of Communication


Many researchers believe that the fact that we can trigger each other's yawns means that it might have been a primitive form of communication. While we don't know exactly what type of information it would have been used to communicate, stress, hunger and exhaustion and possible theories.

Brain Temperature


To encourage the theories of brain cooling as the function for yawning, it's been proven that the temperature of the brain is cooler after a yawn. Note that the brain is typically on the warmer side when you're exhausted, sleep deprived or stressed. Makes sense, huh?

OK, my jaw is killing me from writing this article. How many times have you yawned?

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