The Psychology of Management, published in 1914 by Lillian Moller Gilbreth, is a foundational text that applies psychological principles to scientific management, arguing that understanding the "human element"—motivation, individuality, and mental well-being—is crucial for efficiency, not just streamlining tasks. It emphasizes the importance of the mind in directing work, advocating for a human-centered approach that includes worker welfare, training, and incentives.