"The Psychology of Management" by Lillian Moller Gilbreth is a book published in 1914 that investigates the psychological aspects of scientific management. Gilbreth argues for incorporating the "human element" into management principles, emphasizing workers as individuals with personalities rather than merely economic units. Originally her unpublished doctoral dissertation, the work challenged prevailing management theories by bringing together fundamental elements including individual behavior, group theory, communication, and rational decision-making—establishing it as a pioneering contribution to industrial psychology.