BrainStuff
Whether the topic is popcorn or particle physics, you can count on BrainStuff to explore -- and explain -- the everyday science in the world around us.

What makes us yawn?

May 7, 20145 min
Yawning is a universal human behavior, yet scientists still don't know exactly why we do it or what purpose it serves. Marshall Brain explores some of the theories behind yawning in this episode.Learn more about advertising on the HowStuffWorks podcasts at www.howstuffworks.com/advertisers.htmAnd to learn about your ad choices when listening to podcasts, visit https://www.howstuffworks.com/privacy.htm#ad-choices