Why is there such a magical result? What matters is the teacher's expectation. Teachers believe in the expert's conclusion and that the designated children have a bright future, so they place higher expectations on them, put more enthusiasm into them and give them more encouragement. In turn, these children's self-confidence has been enhanced, so they make progress faster than other 80% students.
This experiment tells us that encouraging others with a positive attitude may lead to improvement in a positive direction; On the contrary, negative and excessive criticism and attacks will also lead to elimination, especially for those minors who lack self-control ability.
Positive encouragement is a kind of goodwill, and too much criticism and blow is a kind of malice. Successful educational methods are mostly based on understanding, respect and concern, and are a kind of "good" education. Because good is huge energy, and evil is also huge energy, which can change the "magnetic field" around you.