Why Yawning is Contagious? Here is the Science.

Why Yawning is Contagious? Here is the Science.

Ohh, Really? Is it an only sign of fatigue or does it have any physiological significance? There must be a science behind it. Let us find out.

Yesterday, I was talking with my friend over an important note and I yawned in between. He got angry and but in no time he also started to yawn. That intrigued me to write this article today.

In childhood, you might have observed that if you yawn in class, you’ll probably notice a few other people will start yawning, too. From unborn babies to the oldest person – everybody yawns. Animals do it, too. But no one knows why exactly?

Why do people yawn?

Why do we yawn is a mysterious theory. Many texts have different theories to prove the process. Here, we tried to bring some of the most accepted ones.

Theory 1

Yawning is observed to be the reflex of your brain that induces to wake you up or make you more alert. Some hormones released to increase the heart rate and alertness when tired or bored — if only for a brief time. It forces blood toward your face and brain to increase alertness (1).  

Related read l Know more about your nervous system, organs, and function

Theory 2

The motion helps stretch the lungs and their tissues and allows the body to flex its muscles and joints that increase heart rate, and feel more awake.

Theory 3

The yawning is a protective reflex to redistribute the oil-like substance called surfactant that helps keep lungs lubricated inside and keeps them from collapsing.

Theory 4

Either voluntarily (on purpose) yawn and also involuntarily (not on purpose), yawning could be the result of trying and equalizing the pressures within your ear – Just like when changing elevation rapidly as in an airplane.

Theory 5

If we are getting bored or tired, we just don’t breathe as deeply as we usually do. In such a scenario, our bodies take in less oxygen because our breathing has slowed.
Therefore, yawning helps us bring more oxygen into the blood and move more carbon dioxide out of the blood.

Yawning, then, would be an involuntary reflex that helps us control our oxygen and carbon dioxide levels.

Related read l Why Pulse Oximeter is a must for you

Sounds good, but other studies have shown that breathing more oxygen does not decrease yawning. Likewise, breathing more carbon dioxide does not increase yawning. It is considered logical but the theory faces disapproval.

Theory 6

A study published in 2014 in the journal Physiology & Behavior looked at the yawning habits of 120 people and found that yawning occurred less during the winter.

The theory claims that yawning is a motion to regulate brain temperature. If the brain’s temperature gets too far outside of the norm, inhaling air can help cool it down.  It is the most scientifically backed theory (2).  

Why yawning is contagious

There are many mysteries in health medicine, but one human and animal behavior that has been observed for years but is poorly understood is yawning.

Study 1

The study ‘a neural basis for contagious yawning’ has been published in the academic journal Current Biology.

According to the experts at the University of Nottingham, the human propensity for contagious yawning is triggered automatically by primitive reflexes in the primary motor cortex – an area of the brain responsible for motor function.

And, the contagious yawning is an automatic imitation of another’s yawn. It is triggered involuntarily when we observe another person does (3).

To test the link, they recruited 36 adults to help with their study. The participants were shown showing someone else yawning through video clips and were instructed to either resist yawning or to allow them to yawn.

Their yawns and stifled yawns were counted, in addition, the intensity of each participant’s perceived urge to yawn was continuously monitored.

Using electrical stimulation they were also able to increase the urge to yawn. The research has shown that yawning is contagious and the ‘urge’ is increased by trying to stop yourself.

The propensity for contagious yawning is determined by cortical excitability and decreased physiological inhibition of the primary motor cortex.

Study 2

According to a study published in the journal Personality and Individual Differences, the more empathetic you are, the more likely you are to yawn when someone else does.

The study looked at 135 college students, their personalities, and how they reacted to different facial movements.

The study shows that if you are very close to a person emotionally, you will yawn if they do. The closer one is to the person who yawns, the more likely one is to yawn as well.

And, the rank order of this suggestion is family, friend, and stranger. It’s a good thing that you’re showing empathy and bonding towards them.

How to stop yawning?

Even if you are thinking of it can get you yawning. And, no matter how hard you try to avoid or stifle it, you cannot alter the propensity to yawn.

Here, I am sharing few add-on points if you want to skip yawning at social settings.

  1. Start to take a deep breath.  Nasal breathing exercises like inhale and exhale is helpful in skipping a yawn.
  2. Try moving to get rid of feelings of tiredness, boredom, and stress. Move. Move. And just move to be alert and awake.
  3. Try to cool yourself down. Drinking cool water or chilled snacks such as fruit or baby carrots might help.

However, if you feel like yawning, go ahead and complete the motion. Do not try to stop or terminate it forcibly.

Related read l 60-seconds spoon test to diagnose your health status

What is excessive Yawning a sign of?

When the act of yawning occurs repeatedly or in close succession can cause excessive yawning. It means taking in a deep breath more often, generally more than a few times per minute (4).

Changes in a sleep-wake cycle, such as shift work or travel across time zones could be the only reason we know for excessive yawning. However, there are several physiological and emotional reasons too.

Physical causes;

  • Heart disease: The vagus nerve acting on blood vessels can stimulate excessive yawning. This is called a vasovagal reaction and could the indicator that you have a heart problem.
  • Poor blood circulatory problems like chronic venous insufficiency
  • Hypothyroidism (low production of thyroid hormones)
  • Medication used to treat depression, anxiety, or allergies
  • Multiple sclerosis (disease that affects the brain and spinal cord causing weakness, coordination, balance difficulties, and other problems) Seizure activity (may occur before or after)
  • Taking in too much caffeine or going through an opiate detox

Emotional or psychological disturbances;

In some cases, yawning excessively can be a symptom of a serious or life-threatening condition that should be immediately addressed and evaluated. They include;

  • Exacerbation of chronic obstructive pulmonary disease (COPD, includes emphysema and chronic bronchitis)
  • Seizure
  • Stroke

What are the potential complications of yawning excessively?

Because yawning excessively can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage.

  • Absenteeism from work or school
  • Difficulty performing daily tasks
  • Inability to participate normally in activities
  • Poor quality of life
  • Progression of symptoms
  • Withdrawal or depression

Ask yourself several questions related to your yawning excessively;

• Are you yawning too often? And, from when did you observed it?
Do you have a sleep problem? How much sleep are you getting each day?
• Are you on medication for the other condition?
• Does excessive yawning have a pattern?

Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care provider design specifically for you to reduce the risk of potential complications.  


To yawn is a normal reflex, although it is poorly understood. However, if you experience it in excess for no apparent reason, it is wise to visit your physician and make sure there is nothing going on that is abnormal.

Yes, it is contagious. When I started writing on this topic, I don’t remember how many times I yawned. How many times have you yawned while reading this article? We hope not many!