The video at the bottom of the post is a remarkable 3-D video of a baby yawning in the womb. I was struck at how, while watching it, I began to yawn as well.
I want to say, that yawning is a very deep mystery. I have never heard an explanation for yawning that sounded very convincing. Frankly, honest medical people will shrug and say, no one really knows why we yawn, or why the practice is so catchy. It does seem related to fatigue but not every who is tired yawns.
“Explanations” abound. Hippocrates thought that yawning was to rid the lungs “bad air,” and bring in fresh air. Other have thought it helped get more blood to the brain. Still others hold that yawning helps increase blood oxygen levels and decrease carbon dioxide. But tests don’t really confirm these sorts of things. Put a person in a room with high CO2 and they don’t start yawning. And that surely doesn’t explain why babies who breathe water would yawn in the womb.
Some think yawning helps keep us awake, others think it helps relax us. Some say it helps regulate body temperature. But again tests such using EEGs to monitor brain activity, or taking temperature just don’t confirm this.
Still others think the behavior is related to imitation, empathy and social bonding behavior. But if that is so why do babies alone in the womb yawn? And why do most vertebrate animals, many of which exhibit little social bonding. yawn?
So you see, one of the most common human behaviors is deeply mysterious. We just don’t know why we yawn, or why the behavior is contagious. It is one of life’s imponderables.
One day we will have to ask God. Another mystery to ponder, do Jesus and Mary in their glorified bodies in heaven yawn? Yes, one day all will be reveled. For now, live the mystery and humbly accept a very humbling truth: no one knows why we yawn.
I tell you, I’ve been yawning all through typing this!