Positive psychology at work. Discovering the happiness advantage ; The happiness advantage at work ; Change is possible -- Seven principles. Principle #1. The happiness advantage ; Principle #2. The fulcrum and the lever ; Principle #3. The Tetris effect ; Principle #4. Falling up ; Principle #5. The Zorro circle ; Principle #6. The 20-second rule ; Principle #7. Social investment -- The ripple effect. Spreading the happiness advantage at work, at home, and beyond.