Erik Erikson was a German-American developmental psychologist known for his theory of psychosocial development. He proposed that individuals go through eight stages of development from infancy to adulthood, each characterized by a specific conflict that must be resolved for healthy psychological growth. His work emphasized the importance of social relationships and cultural influences on personality development. Erikson's stages include challenges such as trust versus mistrust in infancy and identity versus role confusion during adolescence. His ideas have influenced various fields, including psychology, education, and counseling, providing a framework for understanding human development throughout the lifespan.