In this solo episode, Ethan unpacks what is happening in our brain and our bodies when we laugh. He also goes into all the physical and psychological benefits of laughter. There is even a rant about marines using a baby voice, something for everyone! 

Polyvagal theory: https://the-ccih.com/webzine_post/a-tale-of-three-states/

More about the science of laughter: https://www.bbc.com/news/health-37311320