Joseph Luft was an American psychologist best known for co-developing the Johari Window, a model that helps people understand their interpersonal communication and relationships. He created this tool in 1955 alongside Harry Ingham to illustrate how self-awareness and mutual understanding can improve personal and professional interactions. The Johari Window consists of four quadrants: the open area, blind area, hidden area, and unknown area. Each quadrant represents different aspects of self-awareness and knowledge shared between individuals. Luft's work has had a lasting impact on psychology, communication, and team dynamics, making it a valuable resource in various fields.