Hawthorne experiment, also known as "lighting experiment", was presided over by Mayo, a professor of psychology at Harvard University, to discuss the influence of working environment on work efficiency. It is divided into four stages: lighting experiment, welfare experiment, interview experiment and group experiment. Its main conclusions are as follows: (1) Workers are social people, not economic people; (2) There are informal organizations in enterprises; (3) Productivity mainly depends on a worker's working attitude and his relationship with people around him.