It is easy to make someone seem evil or bad if you don’t know them well or at all. You can convince yourself of things about them that aren’t true, and
it is easier if you have no evidence against these things. In the case of racism, people thought that black people were not the same as them and they were inferior, but getting to know someone makes you realize that they are like you. In the movie, Jackie’s teammates saw that he was just as good at baseball as them, and that he didn’t treat other players the way they treated him. That made it hard for them to see him as bad, so they accepted him onto the team. In order to initiate the change of thinking, the person that they are prejudiced towards might treat them kindly, or they realize all the good things about the person. Prevention of racist thinking needs to start early. Take for example the kid in the stands surrounded by people against Jackie. Pretty soon he started yelling at him to get off the field with the other people. To prevent racism, one must see the good in everyone and not let the majority influence your thinking.