"If you treat a man as he is, he will remain as he is;
but if you treat him as he were what he ought to be,
he will become what he ought to be and could be"
- Goethe.
What a manager expects of his subordinates and how he treats them will largely determine their performance and career progress. When employees are expected to do little, they tend to do little. But, when they are expected to do much, they tend to fullfill that prophecy.
One characteristic of effective managers is they have the ability to communicate high performance expectations to subordinates that, more often than not, are fullfilled.
Besides, effective managers always establish clear standards (objective and not vague, subjective judgements) of performance and set standards of excellence.