Henry Murray was an American psychologist best known for his work in personality theory and projective testing. He developed the Thematic Apperception Test (TAT), a tool used to assess an individual's personality through storytelling based on ambiguous images. His research focused on understanding human motivation and the complexities of personality. Murray was also a key figure at Harvard University, where he contributed to the field of psychology during the mid-20th century. He emphasized the importance of understanding individual differences and the role of social and environmental factors in shaping behavior. His work laid the foundation for future studies in personality psychology.