7 Astonishing Things Seen By Humankind Only Once

The laughter outburst in Tanganyika (now Tanzania) in 1962.

This case of mass hysteria is not the single one in the world’s history but is the only one that has been recorded.The outburst started on January, 30 in 1962, when three girls — Christian school pupils — started the uncontrollable laughter. The school was closed but the outburst traveled.The phenomenon lasted for 18 months, 14 schools were closed, and more than a thousand people “caught” this epidemic.Some scientists believe that the reason for such an event was due to overly strict rules and teachers. This laughter outburst seems to have been some sort of a protest among children.