A self-fulfilling prophecy is when our expectations of another person affect their behavior, causing them to act in accordance with our expectations of them.
a self-fulfilling prophecy?
Xiao Zhang was an ordinary student in Mr. Li's class, but one day an expert in intelligence measurement told Mr. Li that Xiao Zhang had a talent for math. Therefore, Mr. Li paid special attention to Xiao Zhang in math class, and finally, In the exam half a year later, Xiao Zhang's math score had been greatly improved  