In a survey of 2,000 Americans on gratitude, some 80 percent agreed that receiving gratitude makes them work harder, but only 10 percent managed to express gratitude to others every day. "Thanks"—whether sent up, down, or sideways—was rarely heard.

The Wall Street Journal reports that being appreciated is one of the great motivators on the job, even better than money. Researchers at the London School of Economics analyzed more than 50 studies that looked at what gets people charged up at work. They concluded that we give our best effort if the work gets us interested and excited, if we feel that it's providing meaning and purpose, and if others appreciate what we're doing.

Two business professors designed a study in which they asked professionals to advise students about the cover letters they were using to apply for jobs. After receiving the suggestions, the students asked for help with another letter. Some 32 percent of the professionals agreed. But when students added a single line to their note about the first feedback—"Thank you so much! I am really grateful!"—a full 66 percent of the advisers agreed to help again. A simple expression of gratitude doubled the response.