According to my observation and knowledge, the cause of the existence of stereotypes and prejudices in our group in our society is that people do not know each other very well. They simply relied on their common sense or what others told them to judge others, rather than knowing people on their own and lack of education. There are many ways to resolve stereotypes. First of all, put yourself in their shoes. Like in the video, because the teacher made the children experience how they feel when they judge others, so they know how others feel and they know not to prejudice others. Second, let people in. Get to know them. When you felt insecure about other people, go and say hello and get to know them. Maybe you have some misunderstanding about them. Lastly, be polite. Don't easily believe what others say