Dark Roasted Blend: The Weirdest Examples of Mass Hysteria:
Things supposedly started innocently enough. Kashasha, near Lake Victoria in Tanzania in 1962: One girl in a boarding school there told another girl a joke. Maybe, "Have you heard the one about?" or "A Jew, an Indian, and Herbert Hoover walk into a bar …" or "Take my wife, please … " Whatever the setup, the delivery, or punch line, the result was laughter. Whether it was a giggle, a guffaw, a chortle, a snort is irrelevant. The listener found it funny.
But then things went dark, weird, and creepy: one girl laughed, but then so did another, and then another, and then another, and then another.
After exposure, the incubation period from nothing to hysteria was short, from a few hours to a couple of days. There was no fever, no physical symptoms, just laughter and occasional crying between short moments of exhausted recuperation. When victims were restrained they sometimes became violent.
No one knew what to do. The school administrators were puzzled, local doctors were confused. Trying to put a lid on the phenomena, the administrators shut the school down.
But that was too little, too late: Whatever it was began to spread. It infected other schools and worked its way into the village, seemingly carried by infected students. It traveled to another village 20 miles away, and another 55 miles from Kashasha.