The self-fulfilling prophecy is a statement that alters actions and therefore comes true. For example, a person stating “I’m probably going to have a lousy day,” might alter his actions so that such a prediction is fulfilled by his actions. This may be an unconscious gesture. A person who might espouse a self-fulfilling prophecy in a positive way “I’m going to have a great day,” might act in ways that will actually make this prediction true.

The self-fulfilling prophecy actually predates its name. Early examples of the self-fulfilling prophecy are the Greek myths surrounding Oedipus. Oedipus fulfills the oracle’s prophecy that he will kill his father and marry his mother, by striving to avoid the prophecy. This can be called a self-fulfilling prophecy because it is Oedipus’ actions that make the prophecy true.

Robert Merton, a 20th century sociologist, actually coined the term of self-fulfilling prophecy. In his definition, in the book Social Theory and Social Structure published in 1949, the prophecy or prediction is false but is made true by a person’s actions. In the modern sense the prophecy has neither false nor true value, but is merely a possibility that is made into probability by a person’s unconscious or conscious actions.

Examples of the modern self-fulfilling prophecy abound in literature. For example, the Harry Potter series finale now revolves around Lord Voldemort hearing a partial version of a prophecy that he then made true by attacking Harry. In the attack, which failed, Voldemort transferred some of his powers to Harry, making the two equal, with an equal outcome when they face each other and battle to the death.

While the modern self-fulfilling prophecy echoes the past, most would agree that the normal use of the term translates to attitude about events to come. While one’s attitude cannot necessarily influence the larger things, such as a hurricane or the possibility of an earthquake, one’s attitude can influence the smaller things, like the way we relate to other people and their responses to us.

Additionally, interpretations of things like "good" and "bad" tend to be weighted by one’s expectations. The person, who is going to have a bad day for example, might miss the bus because he is grumbling about the evil portents for the day. He might seem negative or depressed at work, which might fuel nasty responses from co-workers. As the day gets worse, the person may then return home to fighting children, an unmade dinner or a fight with a spouse. All things will be interpreted in a negative light.

Conversely, the person who is going to have a good day, might miss the bus, but then get a ride from a friend, in which a useful conversation takes place. Even if a co-worker seems nasty, the person might negotiate the situation to come to a healthy resolution. If the children are fighting at home, this might be an opportunity to use one’s parenting skills, and an uncooked dinner might mean a chance to get one’s favorite pizza. The positive self-fulfilling prophecy allows one to shift interpretation of events.

Understanding positive attitudes and the self-fulfilling prophecy are now particularly helpful in dealing with long-term mental illness like anxiety disorder, or chronic pain. Cognitive behavioral studies have shown that perception and prediction of an illness’ course tends to influence experience of the illness. Cognitive behavioral therapy focuses on learning to alter perception to reduce chronic pain, or events like panic attacks. In this way, understanding of the self-fulfilling prophecy has led to greater success in treating difficult illnesses.