Yawning is an involuntary action that causes us to open our mouths wide and breathe in deeply. It is involuntary, since it occurs even before we’re born: yawning has even been observed in fetuses as young as 11 weeks old. The remarkable 3-D video at the bottom of the post is of a baby yawning in the womb. I was struck at how, while watching it, I couldn’t help yawning myself!
I want to say that yawning is a very deep mystery. I have never heard an explanation for yawning that sounded very convincing. Honest medical professionals will shrug and say that no one really knows why we yawn or why it seems to be so “catching.” Though it does seem related to fatigue, not every who is tired yawns.
“Explanations” abound. Hippocrates thought that the purpose of yawning was to rid the lungs of “bad air” and bring in fresh air. Others have suggested that it helps get more blood to the brain. Still others hold that yawning increases blood oxygen levels and decreases carbon dioxide. But tests don’t really confirm these sorts of things. If you put a person in a room with a high level of CO2 he doesn’t start yawning. And it also doesn’t explain why babies in the womb, who breathe water, would yawn.
Some think yawning helps keep us awake, others that it relaxes us. Some say it helps regulate body temperature. But again, tests using EEGs to monitor brain activity, or tests monitoring body 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, then why do babies alone in the womb yawn? And why do most vertebrates, many of which exhibit little social bonding, yawn?
The current leading theory is that yawning helps to cool the brain. But if that is so, then wouldn’t I yawn a lot when I wear a wool cap indoors? And wouldn’t women who wear wigs or have thick hair weaves be inclined to yawning? But none of this seem to matter.
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.
Personally, I think that whatever its physical causes, yawning is a behavior that helps us to be less hostile. As such, it is a gift of God. When I yawn I am usually relaxed. And when I see other people yawn, even people who get under my skin, there is something humanizing and endearing in it. As I said above, I don’t think that it explains yawning in animals or in its merely physical causes. But for us, yawning helps to humble and humanize us. It tends to display our neediness and to show us as more relaxed and less hostile or arrogant to others.
Why do we yawn? One day we will have to ask God. And here is another mystery to ponder: “Do Jesus and Mary in their glorified bodies in Heaven yawn?” Yes, one day all will be revealed. But for now, live the mystery and accept a very humbling truth: no one knows why we yawn. For now, just thank God for yawning. It is one of life’s little pleasures and one of life’s levelers.
I tell you, I’ve been yawning all through typing this!