Self-fulfilling prophecy

A self-fulfilling prophecy is a prediction that directly or indirectly causes itself to become true, by the very terms of the prophecy itself, due to positive feedback between belief and behavior. Although examples of such prophecies can be found in literature as far back as ancient Greece and ancient India, it is 20th-century sociologist Robert K. Merton who is credited with coining the expression "self-fulfilling prophecy" and formalizing its structure and consequences. In his book Social Theory and Social Structure, Merton gives as a feature of the self-fulfilling prophecy: eg. when Roxanna falsely believes that her marriage will fail and fears such failure will occur that it actually causes the marriage to fail.

The self-fulfilling prophecy is, in the beginning, a false definition of the situation evoking a new behaviour which makes the original false conception come 'true'. This specious validity of the self-fulfilling prophecy perpetuates a reign of error. For the prophet will cite the actual course of events as proof that he was right from the very beginning.

In other words, a prophecy declared as truth when it is actually false may sufficiently influence people, either through fear or logical confusion, so that their reactions ultimately fulfill the once-false prophecy.

Robert K. Merton's concept of the self-fulfilling prophecy stems from the Thomas theorem, which states that "If men define situations as real, they are real in their consequences." According to Thomas, people react not only to the situations they are in, but also, and often primarily, to the way they perceive the situations and to the meaning they assign to these perceptions. Therefore, their behavior is determined in part by their perception and the meaning they ascribe to the situations they are in, rather than by the situations themselves. Once people convince themselves that a situation really has a certain meaning, regardless of whether it actually does, they will take very real actions in consequence.