Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/PBSDSDonate Several jokes were harmed in the making of this video Don’t miss our next video! SUBSCRIBE! ►► http://bit.ly/iotbs_sub ↓ More info and sources below ↓ T-SHIRTS! http://dftba.com/besmart Laughing is a universal human behavior, one that transcends borders of language and culture. But it's also REALLY WEIRD. Why do we do it? The answer has less to do with humor than you might think Learn more: "Laughter: A Scientific Investigation" by Robert Provine http://amzn.to/1fzZQLy "Ha! The Science of When We Laugh and Why" by Scott Weems http://amzn.to/1etLLyv Have an idea for an episode or an amazing science question you want answered? Leave a comment or check us out at the links below! Follow on Twitter: http://twitter.com/okaytobesmart http://twitter.com/jtotheizzoe Follow on Tumblr: http://www.itsokaytobesmart.com Follow on Instagram: http://instagram.com/jtotheizzoe ----------------- It's Okay To Be Smart is written and hosted by Joe Hanson, Ph.DFollow me on Twitter: @jtotheizzoe Email me: itsokaytobesmart AT gmail DOT com Facebook: http://www.facebook.com/itsokaytobesmart Google+ https://plus.google.com/+itsokaytobesmart For more awesome science, check out: http://www.itsokaytobesmart.com Produced by PBS Digital Studios: http://www.youtube.com/user/pbsdigitalstudios Joe Hanson - Creator/Host/Writer Joe Nicolosi - Director Amanda Fox - Producer, Spotzen IncKate Eads - Producer Andrew Matthews - Editing/Motion Graphics/Animation Katie Graham - Camera John Knudsen - Gaffer Theme music: "Ouroboros" by Kevin MacLeod Other music via APM Stock images from Shutterstock, stock footage from Videoblocks ----------------- More videos: Why Does February Have 28 Days? https://www.youtube.com/watch?v=AgKaHTh-_Gs Why Vaccines Work https://www.youtube.com/watch?v=3aNhzLUL2ys Why Are Some People Left-Handed? https://www.youtube.com/watch?v=NPvMUpcxPSA Where Does the Smell of Rain Come From? https://www.youtube.com/watch?v=lGcE5x8s0B8