Christiana D. Morgan was an American psychologist and a prominent figure in the early development of personality assessment. Born in 1897, she is best known for her work on the Thematic Apperception Test (TAT), a projective psychological test that helps reveal an individual's underlying motives, concerns, and the way they see the social world. Morgan collaborated with Henry A. Murray at Harvard University, where they developed the TAT in the 1930s. Her contributions to psychology extended beyond the TAT, as she also focused on the study of personality and the dynamics of human relationships throughout her career.