The concept of fear in Maycomb's small community is applied to anyone or anything that does not conform, is different, or is unfamiliar. Arthur "Boo" Radley and his reclusive lifestyle certainly do not conform to Maycomb's standards, and he is viewed as an outsider in his community. Boo becomes the subject of unflattering rumors, and citizens blame nearly every small crime on him because he is different. At the beginning of the story, Jem, Scout, and Dill subscribe to the rumors and legends surrounding their reclusive, mysterious neighbor and view Boo as a "malevolent phantom."
The children fear Boo because his behavior is extremely odd and significantly different from anyone they've ever met. The children are afraid to step foot in Boo's yard and even run past his home on their way to school. As the novel progresses, the children mature and begin to see Boo Radley in a new, positive light. Jem recognizes that Boo is simply a reclusive, benevolent neighbor and means no harm. Scout eventually feels the same way about Boo and is grateful that he saved their lives.
The fear surrounding Boo Radley's character parallels the community's fear of racial equality and justice. Maycomb's prejudiced town fears that Tom's acquittal will undermine the fabric of their culture and significantly change their community for the worse. Similar to the children's fear of Boo, the prejudiced citizens' fear is also irrational and unreasonable. Using Boo Radley and Tom Robinson, Harper Lee underscores the importance of not fearing the unknown, exercising perspective, and being tolerant.