Why Is Yawning Contagious?

You've probably yawned at least once since this started. Here's the real science of why a yawn spreads, and whether a fake one can do it. Your brain catches yawns through the part of it that controls movement, and trying to resist only makes the urge stronger. 0:00 The word that started it 0:51 Part 1: Why do you yawn at all? 2:17 Part 2: Why do you catch it? 4:04 Try it: hold a yawn for 5 seconds 4:28 Part 3: Does it mean anything? 5:29 Can you fake a yawn? 6:32 What you can do 7:20 Recap Sources: Brown et al. (2017), Current Biology: https://doi.org/10.1016/j.cub.2017.07... Bartholomew & Cirulli (2014), PLoS ONE: https://doi.org/10.1371/journal.pone.... Norscia & Palagi (2011), PLoS ONE: https://doi.org/10.1371/journal.pone.... Massen & Gallup (2017), Neuroscience & Biobehavioral Reviews 80, 573–585 Gallup & Gallup (2007), Evolutionary Psychology 5(1), 92–101 Provine, Tate & Geldmacher (1987), Behavioral and Neural Biology 48, 382–393: https://pubmed.ncbi.nlm.nih.gov/3120687/ Provine (1986), Ethology 72, 109–122 Guggisberg et al. (2010), Neuroscience & Biobehavioral Reviews: https://doi.org/10.1016/j.neubiorev.2... Joly-Mascheroni, Senju & Shepherd (2008), Biology Letters: https://pmc.ncbi.nlm.nih.gov/articles... Wegner et al. (1987), JPSP ("white bear"): https://doi.org/10.1037/0022-3514.53.1.5 Animated with code; narration by text-to-speech.