What pushes employees to do their best work? Many businesses operate  under the belief that the key to motivating workers is giving them tangible rewards, such as a cash bonus or a corner office.In the book Drive,  business writer Daniel H. Pink argues persuasively that these companies  have it all wrong. He cites a body of behavioral science research that  suggests that optimal performance comes when people find intrinsic  meaning in their work.
See the visual explanation of the theory by Daniel Pink himself.