Grayson West
A yawn might seem simple, but it’s tied to far more than sleepiness. There are many surprising reasons behind this everyday reflex, and some will change how you think about your body. Keep reading to uncover the 10 unexpected science behind yawns.
Yawns Have A Precise Duration
The average duration of a yawn is about 6 seconds, and you cannot stifle a yawn once it begins. Scientists call this a “fixed action pattern” that must run its complete course. Give it a try next time to see it for yourself.
Yawning Cools Your Brain
Sometimes, the body feels the need to yawn when the brain is a little warm. Opening your jaw and taking a deep breath of air increases blood flow and air circulation, eventually bringing your brain’s temperature down.
Your Heart Rate Jumps During A Yawn
As you yawn, your heart rate jumps up noticeably, prompting you to become more alert. The sudden burst of energy is accompanied by the tensing of muscles in your face and neck, with some people also experiencing their ears “popping” as a result.
Yawning Begins In The Womb
Long before a baby takes its first breath, it learns to yawn in the womb. A baby’s yawn is a part of their brain and lung maturation. At about 24 weeks of development, it emerges as a vital milestone.
Contagious Yawning Is A Social Phenomenon
Have you ever seen someone yawn and then suddenly feel the need to do it yourself? That’s because yawning is contagious. It’s directly linked to seeing or simply thinking about others yawning. Interestingly, people with higher empathy tend to catch yawns easily.
Yawning Does Not Oxygenate Your Blood
Contrary to old beliefs, yawning does not help you get more oxygen. Scientists have known for decades that breathing and yawning are managed by separate parts of the brain. In fact, Psychologist Robert R. Provine’s laboratory experiments show that changing oxygen or carbon dioxide levels does not trigger a yawn at all.
Animal Yawns Are Also Common
Humans aren’t the only creatures that yawn. Yawning has been observed in birds, other mammals, and some reptiles. Animals have even shown yawn contagion between different species—as fish and budgerigars yawn, they occasionally trigger it in their tankmates or flock.
Excessive Yawning Can Signal Medical Issues
Yawning is usually a normal reaction, but excessive yawning can also hint at a serious health condition. For example, nerve stimulation during a cardiac event may increase yawning. Plus, it has been associated with other neurological disorders as well. So, if you’re yawning more than normal, it’s a good idea to check with a doctor.
Lungs Benefit From Yawns
As you yawn, the deep breath you take quietly encourages healthy lung function. Yawns actually help coat the tiny air sacs in your lungs called alveoli with a substance that keeps them open. This promotes better lung health.
Stress Can Also Trigger Yawning
Your body releases cortisol, the stress hormone, just before you yawn, and the surge sometimes triggers a yawn when you’re stressed or anxious. It can also happen right before you give a speech. The yawning frequency also increases as stress levels do.