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 Ie when Roxanna falsely believes that her marriage will fail and fears such failure will occur that it actually causes the marriage to fail.
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."[2] 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.
Merton took the concept a step further and applied it to recent social phenomena. In his book Social Theory and Social Structure, he conceives of a bank run at the fictional bank of Cartwright Millingville. It is a typical bank, and Millingville has run it honestly and quite properly. As a result, like all banks, it has some liquid assets (cash), but most of its assets are invested in various ventures. Then one day, a large number of customers come to the bank at once—the exact reason is never made clear. Customers, seeing so many others at the bank, begin to worry. False rumors spread that something is wrong with the bank and more customers rush to the bank to try to get some of their money out while they still can. The number of customers at the bank increases, as does their annoyance and excitement, which in turn fuels the false rumors of the bank's insolvency and upcoming bankruptcy, causing more customers to come and try to withdraw their money. At the beginning of the day—the last one for Millingville's bank—the bank was not insolvent. But the rumor of insolvency caused a sudden demand of withdrawal of too many customers, which could not be answered, causing the bank to become insolvent and declare bankruptcy. Merton concludes this example with the following analysis
