This document discusses several important management theories and approaches: - The human relations movement focused on social and psychological factors, unlike classical theorists who focused only on work. Theories discussed motivation, groups, and leadership. - Early motivation theorists like Maslow and McGregor developed needs hierarchy and assumptions (Theory X/Y) models to understand what drives human behavior. - Systems theory views organizations as open systems that receive inputs, convert them, and provide outputs to the environment, with feedback. Contingency approaches suggest the best structure depends on an organization's environment and circumstances.