Uncanny Case No. 008: Tanganyika Laughter Epidemic

The Tanganyika Laughter Epidemic occurred in the village of Kashasha, near the border of Tanzania and Uganda. It began at a mission-run boarding school for girls in January 1962, when three students started laughing uncontrollably. The phenomenon spread rapidly, affecting 95 of the 159 pupils, aged 12 to 18. The school was forced to close in March. The laughter spread to nearby villages and lasted for several months, affecting around 1,000 people in total. Symptoms included uncontrollable laughter, crying, and random screaming; it's believed to have been a mass psychogenic illness, or a response to stress.