Yawning

[deckardcanine]

Why do we yawn? There is not a consensus
In relevant science communities yet.
One popular theory: It cools down the brain, tho
We don’t do it more when we’ve started to sweat.

It once was believed that a yawn helped move oxygen
Into the blood and move CO2 out,
But studies have shown that inhaling each gas makes
No difference for yawning; that theory’s in doubt.

It could be that stretching the lungs and lung tissue
Will quicken your pulse so you feel more awake,
Or maybe a yawn redistributes surfactant
In lungs so deep breaths remain easy to take.

And why’s it contagious in humans? Reportedly,
That doesn’t happen till circa age four,
When children develop the right mental pathways
They need for an adequate empathy score.

Perhaps yawns evolved to communicate something,
Like “This is unpleasant but not a big threat.”
If so, human progress has made it ambiguous,
Hardly a message we’re likely to get.

Whatever it is, we don’t yawn voluntarily;
Don’t take the act as a gesture of scorn.
And please, if you find yourself yawning too frequently,
Talk to a doctor, as specialists warn.