Why do we yawn?
Brain's Cool-Down
Why do we yawn?
You're sitting in class, or maybe curled up on the couch after dinner, when it happens — your jaw drops open like a trapdoor, your face scrunches up, and out comes a giant, unstoppable yawn. What just happened? Why did your body hijack your face like that?
For a long time, scientists thought yawning was your body's way of grabbing extra oxygen — like your brain was running low on air and needed a top-up. But here's the twist: when researchers measured people's oxygen levels before and after yawning, nothing changed. Yawning doesn't actually get you more oxygen. So that theory got tossed out.
