Yawning Science: Gallup's Cold Pack Test, Paratroopers and Penguin Love

SPEAKER_1 (0:00)

Have you ever noticed that you yawn when you're completely and hopelessly bored in a meeting?

SPEAKER_2 (0:05)

Oh, absolutely, the classic mid-afternoon office yawn.

SPEAKER_1 (0:08)

Right, but then military paratroopers also yawn right before they jump out of an airplane.

SPEAKER_2 (0:14)

Which is such a wild contrast when you really picture it.

SPEAKER_1 (0:16)

It is, just picture that for a second. On one side, you have someone struggling to keep their eyes open in a swivel chair, just staring at a spreadsheet.

SPEAKER_2 (0:24)

Yeah, trying not to pass out.

SPEAKER_1 (0:26)

Exactly, and on the other side, you've got someone standing at the open door in an aircraft. They're experiencing extreme life or death nervousness.

SPEAKER_2 (0:34)

Total adrenaline.

SPEAKER_1 (0:35)

So how can the exact same biological response signal both ultimate mind numbing boredom and extreme adrenaline fueled readiness?

SPEAKER_2 (0:44)

I mean, it feels like a massive biological contradiction, doesn't it?

SPEAKER_1 (0:48)

Totally.

SPEAKER_2 (0:48)

You'd really think the body would have two very different mechanisms for, I'm falling asleep and I'm about to fall out of the sky.

SPEAKER_1 (0:55)

You really would. So today, we are taking a deep dive into the surprisingly complex and honestly kind of bizarre world of chasmatology.

SPEAKER_2 (1:04)

Which just to clarify for everyone is the actual scientific study of yawning. Yes.

SPEAKER_1 (1:09)

The mission today is to just unpack this everyday bodily function for you. I mean, it only lasts about six seconds, but it connects us to our evolutionary past, our capacity for human epathy and basically the rest of the animal kingdom.

SPEAKER_2 (1:23)

It's a huge topic. But to really wrap our heads around this, we have to start by defining what a yawn actually is.

SPEAKER_1 (1:29)

Okay. Let's lay the groundwork.

SPEAKER_2 (1:31)

Scientifically, it's known as oscillation and it's crucial to separate a true yawn from just opening your mouth to take a deep breath.

SPEAKER_1 (1:38)

Right. They aren't the same thing.

SPEAKER_2 (1:40)

Not at all. A yawn is a highly specific, hardwired vertebrate reflex. It operates in these really distinct phases.

SPEAKER_1 (1:47)

Walk us through the phases.

SPEAKER_2 (1:49)

So it begins with a long, slow inhalation and a gradual gaping of the mouth. Then you hit this climax, the acme, which involves a massive, involuntary stretching of muscles.

SPEAKER_1 (2:00)

It really is involuntary once it starts. You can't just stop it halfway easily.

SPEAKER_2 (2:05)

Exactly. And finally, it ends with a rapid exhalation and muscle relaxation.

SPEAKER_1 (2:09)

And it is so deeply ingrained in our hardware that you don't even have to be born to do it.

SPEAKER_2 (2:14)

Yeah, that part is fascinating.

SPEAKER_1 (2:16)

Right. Like, fetuses have actually been captured on 40 ultrasounds, yawning in the womb at just 30 weeks.

SPEAKER_2 (2:22)

It's incredible.

SPEAKER_1 (2:23)

So, it's fundamental to the human operating system from the very beginning. Whatever this auscitation thing is doing, it's critical.

SPEAKER_2 (2:30)

Which means we need to look at the physical mechanics of the action to understand why an unborn baby and a paratrooper are both doing it.

SPEAKER_1 (2:37)

Yeah, what's actually happening under the hood?

SPEAKER_2 (2:39)

Well, we have to clear up a major misconception right out of the gate. And it starts by looking really closely at what a yawn actually does to your physical body.

SPEAKER_1 (2:47)

I mean, when I yawn, it genuinely feels like a full body event, even if I'm just sitting perfectly still in a chair. It feels like my entire head and neck are engaged.

SPEAKER_2 (2:57)

That's because they are. Doing a yawn, the muscles around your airway are stretched to their absolute limit. Really? Yeah. And this includes the muscles you use for chewing and swallowing. Because of these incredibly strong repositioning muscle movements, your airway, meaning your throat and your lungs, literally dilates to three or four times its original size.

SPEAKER_1 (3:15)

Wait, three or four times?

SPEAKER_2 (3:17)

Three or four times.

SPEAKER_1 (3:19)

That is a massive physiological shift for something that takes like five or six seconds.

SPEAKER_2 (3:24)

It's a huge physical exertion for the body.

SPEAKER_1 (3:26)

And here's a detail that I completely resonated with when looking into the sources for this deep dive. You know that rumbling sound you hear in your head when you take a really deep satisfying yawn?

SPEAKER_2 (3:37)

Oh yeah, I know exactly what you're talking about.

SPEAKER_1 (3:39)

It sounds almost like a rushing wind deep inside your ears.

SPEAKER_2 (3:43)

Well, most people assume that sound is just the physical air rushing down into their lungs.

SPEAKER_1 (3:47)

I totally thought it was air.

SPEAKER_2 (3:48)

Yeah, almost everybody does, but it's not.