When a smile becomes an occupational hazard

Have you ever found it hard to keep up a smile at work? If so, spare a thought for staff in the Japanese service sector, who since the 80's have been trained to smile as much as possible throughout the day. The nation's perma-grin is starting to take its toll on its workers, predominantly younger women. Suppressing their emotions all day means they find it hard to turn off the smile and manage emotions when they leave for the day, leading in severe cases to stress and depression. Leo Lewis has the story in The Times