A self-fulfilling prophecy is the sociopsychological phenomenon of someone "predicting" or expecting something, and this "prediction" or expectation coming true simply because the person believes it will and the person's resulting behaviors aligning to fulfill the belief. This suggests that people's beliefs influence their actions. The principle behind this phenomenon is that people create consequences regarding people or events, based on previous knowledge of the subject. A self-fulfilling prophecy is applicable to either negative or positive outcomes. It can be concluded that establishing a label towards someone or something significantly impacts their perception and influences them to establish self-fulfilling prophecy. Interpersonal communication plays a significant role in establishing these phenomena as well as impacting the labeling process. Intrapersonal communication can have both positive and negative effects, dependent on the nature of the self-fulfilling prophecy that a person has on a self-fulfilling prophecy, this will impact their outcome when dealing with self-fulfilling prophecies.
American sociologist W. I. Thomas was the first to discover this phenomenon. In 1928 he developed the Thomas theorem (also known as the Thomas dictum), stating that,
If men define situations as real, they are real in their consequences.
In other words, the consequence will come to fruition based on how one interprets the situation. Using Thomas' idea, another American sociologist, Robert K. Merton, coined the term "self-fulfilling prophecy", popularizing the idea that “a belief or expectation, correct or incorrect, could bring about a desired or expected outcome.” Self-fulfilling prophecies are an example of the more general phenomenon of positive feedback loops.