The Thematic Apperception Test (TAT) is a projective psychological test developed in the 1930s at Harvard University. It consists of 31 cards depicting people and scenes that prompt test takers to make up stories about what is happening in the image. The stories are analyzed to understand the test taker's motivations, conflicts, and underlying personality traits. Reliability is high when examiners are well-trained and use consistent analysis methods. Validity depends on the examiner's skill in distinguishing traits influenced by the testing situation from enduring personality characteristics.