Jane Loevinger was an American psychologist best known for her work in personality development and ego psychology. She developed the Loevinger Sentence Completion Test, a tool designed to assess an individual's level of ego development through their responses to incomplete sentences. Her research focused on how people grow and change over time, emphasizing the importance of understanding personality in a developmental context. Loevinger's theories proposed that individuals progress through a series of stages in their moral and psychological development. Her work has influenced various fields, including psychology, education, and counseling, providing insights into how people perceive themselves and their relationships with others.