What does Scout learn about mob mentality?

In Chapter 16, Scout learns a lesson about mob mentality from her father, Atticus. The next day after Walter Cunningham and the Old Sarum bunch attempted to harm Tom Robinson outside of the Maycomb County jailhouse, Atticus explains to his children Walter's reasoning. Atticus tells Scout that Walter Cunningham is still a good man and that he has blind spots just like everybody else. When Jem says that Walter would have killed Atticus, Atticus disagrees and tells him that when he's older, he'll understand people a lot better. Atticus tells Scout and Jem that Walter was part of a mob last night, and that people act differently when they get around others. He tells them that mobs are always made up of individuals, and they should never forget that. Just because Walter was influenced by his peers does not make him a bad person. Scout learns that mobs can influence individuals to act differently, and that peer pressure can negatively impact a person's reasoning. Scout also learns that she should not judge a person simply because they were involved in a mob.