Robert is an instructor in a music academy. he thinks john, a new student, lacks confidence to perform on stage. therefore, he seldom lets john play on the stage and chooses other students over john. this results in john developing stage fright and losing confidence in his ability to perform on stage. this is an example of

Self-fulfilling prophecy

Explanation:

Self-fulfilling prophecy's about the false perception leads to confirmation. This has happened in many cultures and arts. Many psychologists and researchers found that our beliefs will affect our outcomes.

It happened particularly when we are manifested with our expectations. The placebo effect is the most famous example of a self-fulfilling prophecy. It is an important concept but also used in sociology as well. It was proposed by Robert Merton.  

Thus here John is in self fulfilling stage where he develops fright and losing confidence in his ability

work yay..other than that pretty good actually it hot though (≧▽≦)

ever since wwii tmthey always did hated each other.