The thematic apperception test is a projective psychological test used to analyze a person’s underlying motives, concerns, and world view, based on stories that the subject makes up about photographs of people in ambiguous situations. Subjects are shown pictures and asked to tell a story based on what they believe is going on in each picture.
The subject is asked to provide as much detail as possible about the events that might be depicted in the picture, including:

– what is happening at that very moment;
– what has led up to the event depicted in the picture;
– which emotions the characters are feeling and what they are thinking;
– what the outcome of the story is.

The examiner records the stories given by subjects for later assessment and interpretation.
The thematic apperception test was developed by the American psychologists Henry A. Murray and Christiana D. Morgan in the 1930s (1). The reasoning behind the technique is that people tend to interpret ambiguous situations based on and in accordance with their own life experiences and motivations, either consciously or unconsciously. By asking people to tell a story about an ambiguous picture, it was hoped that a person’s psychological defenses could be lowered and sensitive information could be inferred from the information placed in the story created by the subject. For example, in an arson investigation, a suspect might be shown a picture of a man sitting on a bed looking out the window. If the subject was, in fact, the person who had set the fire, the story might be about a man who was feeling remorse for doing something bad, whereas an innocent suspect might make up a story about a man daydreaming about his upcoming vacation in Hawaii.

Source:

1. Morgan, W. (2002). “Origin and History of the Earliest Thematic Apperception test“. Journal of Personality Assessment 79 (3): 422–445.