America’s Yellowstone Park discovered that signs reading ‘Please don’t litter’ actually caused littering to increase. The words weren’t ‘positive’ enough, so they changed the signs to the more engaging, ‘People who love the environment take their litter home’ – and more people started taking their litter home. (Merci, Le Nic)
Take a look at ‘Nudge’ by Richard Thaler and Cass Sunstein for more on this insight. The book shows how people often behave irrationally, and offers some gentle ‘nudging’ techniques for making them behave more responsibly and sensibly.
For example, the bosses at Amsterdam’s Schiphol airport, fed up with urine all over their floors, painted black flies in the centre of the urinals. By giving men something to aim at, accuracy was dramatically improved.