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.
If men define situations as real, they are real in their consequences.''According to Thomas, people do not react 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 situations. 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:
The parable tells us that public definitions of a situation (prophecies or predictions) become an integral part of the situation and thus affect subsequent developments, This is peculiar to human affairs. It is not found in the world of nature, untouched by human hands. Predictions of the return of Halley’s comet do not influence its orbit. But the rumored insolvency of Millingville’s bank did affect the actual outcome. The prophecy of collapse led to its own fulfillment.
Merton concluded that the only way to break the cycle of self-fulfilling prophecy is by redefining the propositions on which its false assumptions are originally based.
Philosopher Karl Popper called the phenomenon the Oedipus effect.
One of the ideas I had discussed in The Poverty [of Historicism] was the influence of a prediction upon the event predicted. I had called this the “Oedipus effect”, because the oracle played a most important role in the sequence of events which led to the fulfillment of its prophecy. … For a time I thought that the existence of the Oedipus effect distinguished the social from the natural sciences. But in biology, too—even in molecular biology—expectations often play a role in bringing about what has been expected.
In the United States the concept was broadly and consistently applied in the field of public education reform, following the "War on Poverty". Theodore Brameld noted: “In simplest terms, education already projects and thereby reinforces whatever habits of personal and cultural life are considered to be acceptable and dominant.” The effects of teacher attitudes, beliefs and values, affecting their expectations have been tested repeatedly.
The phenomenon of the "inevitability of war" is a self-fulfilling prophecy that has received considerable study.
The idea is similar to that discussed by the philosopher William James as The Will to Believe. But James viewed it positively, as the self-validation of a belief. Just as, in Merton's example, the belief that a bank is insolvent may help create the fact, so too on the positive side, confidence in the bank's prospects may help brighten them. A more Jamesian example: a swain, convinced that the fair maiden must love him, may prove more effective in his wooing than he would had his initial prophecy been defeatist.
Other specific examples discussed in psychology include:
The best known example from Greek legend is that of Oedipus. Warned that his child would one day kill him, Laius abandoned his newborn son Oedipus to die, but Oedipus was found and raised by others, and thus in ignorance of his true origins. When he grew up, Oedipus was warned that he would kill his father and marry his mother. Believing his foster parents were his real parents, he left his home and traveled Greece, eventually reaching the city where his biological parents lived. There, he got into a fight with a stranger, his real father, killed him and married his widow, Oedipus's real mother.
This motif is repeated in other Greek legends, as in Telephus, a son of Hercules prophesied to kill his uncle. His grandfather had him abandoned, which led to his being raised in ignorance of his birth. He met his uncle and his uncle's men, who taunted him with this ignorance, and in anger, he killed his uncle.
The story of Zeus and Chronos is unusual in that Zeus is aware of the prophecy; usually the prophesied child commits the predicted acts in ignorance, whereas Zeus deliberately sets out to overthrow his father in fulfillment of the prophecy. Zeus is also able to forestall similar prophecies for himself. When he hears that Metis's second child will be a son who will destroy him, he tricks and swallows her, preventing her from ever conceiving this son. When he is wooing Thetis, he is warned (by different oracles in different legends, including the titan Prometheus) that her son will be greater than his father, and so marries her off to the mortal Peleus; Peleus's son Achilles then proves to be greater than his father.
Although the legend of Perseus opens with the prophecy that he will kill his grandfather Acrisius, and his abandonment with his mother Danaë, the prophecy is only self-fulfilling in some variants. In some, he accidentally spears his grandfather at a competition — an act that could have happened regardless of Acrisius's response to the prophecy. In other variants, his presence at the games is explained by his hearing of the prophecy, so that his attempt to evade it does cause the prophecy to be fulfilled. In still others, Acrisius is one of the wedding guests when Polydectes tried to force Danaë to marry him, and when Perseus turns them to stone with the Gorgon's head; as Polydectes fell in love with Danaë because Acrisius abandoned her at sea, and Perseus killed the Gorgon as a consequence of Polydectes's attempt to get rid of Danaë's son so that he could marry her, the prophecy fulfilled itself in these variants.
The story of Romulus and Remus is another example. According to legend, a man overthrew his brother, the king. He then ordered that his two nephews, Romulus and Remus, be drowned, fearing that they would someday kill him like he did to his brother. The boys were placed in a basket and thrown in the Tiber River. A female wolf found the babies and raised them. Later, a shepherd found the twins and named them Romulus and Remus. As teenagers, they found out who they were. They killed their uncle, fulfilling the prophecy.
The story of the Death of Baldr in Norse mythology provides another example of a self-fulfilling prophecy. The young god Baldr, the most beautiful, kind and wise of the gods, has a prophetic dream of his own death. He told his mother Frigg about it, and she was so distraught at the thought of her own son dying that she made every object on earth take a vow not to hurt her son. As nothing could now injure Baldr, the gods started hurling objects at him for entertainment, only to see every object bounce of him without a scratch. This soon became the favourite pastime of the gods.
Jealous of Baldrs newfound popularity, Loki the trickster, went to Frigg in disguise to find out if there was anything that could hurt Baldr. He found out that Frigg had not asked the mistletoe to make the vow, thinking that it was too non-threatening and unimportant to ask. Loki proceeded to make a magical spear from the plant (in some versions it was an arrow). Loki gave the spear to Baldrs blind brother Höðr, who proceeded to hurl the spear at Baldr, killing him instantly. Thus the prophecy of Baldrs dream was fulfilled.
Many fairy tales, such as The Devil With the Three Golden Hairs, The Fish and the Ring, The Story of Three Wonderful Beggars, or The King Who Would Be Stronger Than Fate, revolve about a prophecy that a poor boy will marry a rich girl (or, less frequently, a poor girl a rich boy). This is story type 930 in the Aarne-Thompson classification scheme. The girl's father's efforts to prevent it are the reason why the boy ends up marrying her.
Another fairy tale occurs with older children. In The Language of the Birds, a father forces his son to tell him what the birds say: that the father would be the son's servant. In The Ram, the father forces his daughter to tell him her dream: that her father would hold an ewer for her to wash her hands in. In all such tales, the father takes the child's response as evidence of ill-will and drives the child off; this allows the child to change so that the father will not recognize his own offspring later and so offer to act as the child's servant.
In some variants of Sleeping Beauty, such as Sun, Moon, and Talia, the sleep is not brought about by a curse, but a prophecy that she will be endangered by flax (or hemp) results in the royal order to remove all the flax or hemp from the castle, resulting in her ignorance of the danger and her curiosity.
Shakespeare's Macbeth is another classic example of a self-fulfilling prophecy. The three witches give Macbeth a prophecy that Macbeth will eventually become king, but the offspring of his best friend will rule instead of his afterwards. Macbeth tries to make the first half true while trying to keep his bloodline on the throne instead of his friend's. Spurred by the prophecy, he kills the king and his friend, something he never would have done before. In the end, the evil actions he committed to avoid his succession by another's bloodline get him killed in a revolution. The later prophecy by the first apparition of the witches that Macbeth should "Beware Macduff" is also a self-fulfilling prophecy. If Macbeth had not been told this, then he might not have regarded Macduff as a threat. Therefore he would not have killed Macduff's family, and Macduff would not have sought revenge and killed Macbeth.
Oleg of Novgorod was a Varangian prince who ruled of the Rus people during the early tenth century. As old East Slavic chronicles say it was prophesied by the pagan priests that Oleg would take death from his stallion. To avoid this he sent the horse away. Many years later he asked where his horse was, and was told it had died. He asked to see the remains and was taken to the place where the bones lay. When he touched the horse's skull with his boot a snake slithered from the skull and bit him. Oleg died, thus fulfilling the prophecy. In the Primary Chronicle, Oleg is known as the Prophet, ironically referring to the circumstances of his death. The story was romanticized by Alexander Pushkin in his celebrated ballad "The Song of the Wise Oleg". In Scandinavian traditions, this legend lived on in the saga of Orvar-Odd.