How Do Expectations Affect Performance?

Sometimes parents set high expectations for their child. There are reasons for high expectations. 1. They want to use their children's talent to brag about; using their children's talent to show that their children are the best. 2. They want the best for their children. 3. They want their children to be the prodigy of the future. However, despite the fact that parents want the best for their children, the fact that they want to brag about is the most. I know a child, whose mother trained him since he was in elementary school. Finally, their pay has returns. That child skipped a grade and his mother started to brag about it. That child doesn't have a good class grade for every class, but he had a good grade on SAT. His mother brag about is how amazing and smart her child is, scoring so high on SAT, and she is proud to have a son like that. All these annoyed me. This is an example of how a mother expected her son to do well in school, but he didn't. If his mother finds out what is going on with him, she must be pissed.