Paying people to do something they already enjoy can make them do less of i. In t classic demons, children w drew will were rewa for dra, and wh the rew stopped th drew less than children who had never been paid at all. The explanation usually offered is that the payment supplies a reason, and a reason once supplied replaces the one that was already there. The effect is small and unreliable, and it is strongest where interest was high to begin with.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.