Task: Question Answering
Input (English): Context: An experiment was carried out at British school into the performance of new pupils. At the start of the year, the pupils were each given a _ , ranging from "excellent prospect" to "unlikely to do well". These were totally untrue ratings and did not reflect how well the pupils had previously performed. However, these ratings were given to the teachers. At the end of the year, the experimenters compared the pupils' performance with the ratings. Despite their real abilities, there was an astonishingly high connection between performance and ratings. It seems that people perform as well as we expect them to. The Self-fulfilling Effect is also known as the Pygmalion Effect. This comes from an old Greek story. The story was also the basis of George Bernard Shaw's play "Pygmalion", later turned into the musical "My Fair Lady". In Shaw's play, Professor Henry Higgins claims he can turn a Cockney flower girl, Eliza Doolittle into a duchess. But, as Eliza herself points out to Higgins' friend Pickering, it isn't what she learns or does that determines whether she will become a duchess, but how she's treated. The implication of the Pygmalion Effect for leaders and managers is massive. It means that the performance of your team depends less on them than it does on you. The performance you get from people is no more or less than what you expect, which means you must always expect the best. As Goethe said, "Treat a man as he is and he will remain as he is. Treat a man as he can and should be and he will become as he can and should be." 
 Question: What's the passage mainly about?
Output (English): the self-fulfilling effect.