In "The 7 Habits of Highly Effective People", Stephen Covey gives an anecdote about a computer error in England in which a group of 'bright' students are accidentally labelled as 'dumb' and a group of 'dumb' students are labelled as 'bright'.
The mistake is discovered after a period of time and the students are tested. It turns out that the dumb students are now classified as 'bright' as well. The moral of the story is that people rise to the level expected of them.
This anecdote can be found, with minor variations, in many places on the internet:
Have any scientifically valid studies been done which support or disprove this claim?