Donald Super developed one of the most influential career development theories. He proposed that career development occurs in five life stages: growth, exploration, establishment, maintenance, and decline. At each stage, individuals face developmental tasks related to self-concept and career decision making. Super also developed the concept of a "life-career rainbow" to illustrate how careers and self-concept evolve over the lifespan through experiences. His work emphasized that career choices express self-concept and that individuals seek career satisfaction by developing roles that allow them to implement their evolving self-view.