3 Strange Cases of Mass Hysteria

Can a group of people develop a weird symptoms but it spreads not through air or fluids? These cases of mass hysteria might be conditions all in their heads. Want to help solve a cold case? Join ‪@CriminallyListed‬ membership and proceeds from that will go to help solve a cold case through genetic genealogy. [0:17] The Tanganyika Laughing Epidemic [4:48] The Le Roy Tics [9:42] The Dancing Plague of 1518