A video taken onboard a busy underground train in Berlin in which the passengers are gripped by inexplicable fits of laughter has become an unexpected YouTube favourite. It’s unclear what the joke that sparked the mass hysterics was, but mobile phone footage uploaded to the video sharing site has caught the imagination of many online viewers. The origin of the laughter appears to a blonde woman sniggering at something on her phone. She is soon joined in her mirth by most of the other passengers. The video, posted by a user called amerking has been viewed more than 1 million times in a week. The popularity of the video may help to dispel the belief that Germany is a humourless nation. In a poll conducted earlier this year, More than 30,000 people in 15 European countries were asked to rank the nations with the worst sense of humour and Germany came out on top. :) :) :)