A self-fulfilling prophecy is a prediction that directly or indirectly
causes itself to become true. Although examples of such prophecies can be
found in human 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:

" 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.[1] "

In other words, a true prophetic statement - a prophecy declared as truth
when it is not - may sufficiently influence people, either through fear or
logical confusion, so that their reactions ultimately fulfill the false
prophecy.

[edit] History of the concept
Robert K. Merton's concept of the self-fulfilling prophecy stems from the
Thomas theorem, which states that:

turtoni wrote: