An old Chinese saying: “Don’t treat others in the way you won’t want to be treated.” It is cross-cultural wisdom, for there is similar teaching in the Bible. “So in everything, do to others what you would have them do to you － Matthew 7:12.” “Mirror effect” in psychology claims that we get to know ourselves by noting others’ reactions to our actions. The principle is obvious. The action I expect the person in the mirror to do, I must do the action first. In human relationships, we do to others what we would have them do to us. When I expect others to be sincere, I must be sincere first. Interestingly, the “mirror effect” has another interpretation. “How we expect a person will shape the person over time.” In an experiment, a class of students with similar English proficiency was randomly assigned to two English teachers with similar teaching experience. But one was told he was teaching students with high English skills, while the other was told that his assigned students were weak in English. At the end of the semester, the student’s performances in the two classes were significantly different. It demonstrates the power of prejudice. It also tells us that our expectation for the kids shapes the kids.