Dr. Rensis Likert developed the principle of supportive relationships in 1961 which emphasizes supportive relationships within work groups and open communication. He identified four systems of management - exploitative/authoritative, benevolent/authoritative, consultative, and participative - with the participative system considered the most productive where groups are involved in decision making and communication is open. The document provides examples of each system and suggests improvements for an event based on Likert's principle.