Ever wondered why we yawn and why it is contagious?

The reflex epidemic action of yawning! Your mouth is wide open, and eardrums are stretched. You are either too tired, sleepy or bored. All you want is some time for yourself. Yawning is an activity to rejuvenate the brain.Yawning is so infectious that even if you see a stranger yawn, you cannot stop from grabbing a yawn for yourself.

The moment you get bored, yawning is triggered. Not only humans but animals also experience yawning. Thus, it a universal phenomenon.

So why do we yawn?

It's because when we are sleepy, tired or bored, we breathe more slowly. The brain and body are not able to have ample amount of oxygen. So, the brain makes us take an extra breath. This breath is deeper and longer, called a yawn. Yawn helps us to take in more oxygen and release carbon dioxide fully.

Another theory is that yawning stretches the lungs and lung tissue. Stretching and yawning may be a way to flex muscles and joints, increase heart rate, and feel more awake.

Why yawning is contagious?

Does looking at this image of a person yawning make you yawn? About half of adults yawn after someone else yawns due to a universal phenomenon called “contagious yawning.” Catching yawns may be an unconscious sign that you're attuned to other people's emotions, in the same way you might automatically smile or frown at someone when they do the same to you.

Researchers from the University of Connecticut backed up this theory in a small 2010 study, where they found that most children did not begin so-called "contagious yawning" until they were around four years old—generally the age when empathy skills begin to develop.

But contrary to this, a new study from Duke University suggests that contagious yawning is not strongly related to variables like empathy, tiredness, or energy levels.

But, there is still no reason that is 100% responsible for yawning. A lot of research is underway to get the best possible answer.

Now some interesting facts about yawning.

1. We spend around 400 hours of our life, yawning!

2. Yawning is ubiquitous in humans. Even when we are not born, we yawn. Studies have shown that even 11-week-old fetuses yawn. Yawning is a part and parcel of human life.

3. Ever felt the urge to yawn and stretch your arms together, right after waking up? Well, you have experienced pandiculation. This is a kind of reflex action when you want to stretch your body just after waking up, in order to re-energize your body and make it alert.

4. Yawns last an average of 6 seconds, and on average, men yawn longer than women. During that 6 seconds, the heart rate can increase by as much as 30 percent.

5. It is studied that on an average, a person will muster up to 240,000 in a lifetime. Wow, that's a huge number.

6. One function of yawning is to cool down an overheated brain, which allows us to think more clearly and have better concentration. So don't worry about yawning during tests, or before athletic competitions. It'll probably help!

7. While yawning is a normal bodily activity, too much yawning might mean that you are suffering from an underlying medical condition. Excessive yawning is one of the ‘rare’ symptoms of heart conditions, as oscitation is a result of vagus nerve reaction. Too much Yawning might signify brain illnesses as well.

Sources: one, two, three, four, five