Why Do People Yawn When They’re Bored or Tired?

Imagine you're sitting in a classroom and the teacher talks for what feels like forever. You feel sleepy, and suddenly, you yawn. It's almost like your brain said, 'I need more oxygen!' Yawning might help you stay awake or make you more alert. And sometimes, when you see someone else yawn, you feel like you want to yawn too! Scientists think this is because of how our brains work together in groups, it’s like a little brain chat.