Scientific studies have determined that living organisms are influenced by their environments, and Jem and Scout are no exceptions.  Early in "To Kill a Mockingbird," Scout demonstrates her acquaintance of her surroundings in contrast to her new teacher, who is not from Maycomb.  Miss Caroline is not knowledgeable of such people as Walter Cunningham and his family and she does not understand them as Scout does.  In another instance of the affect of their community, the mystery that surrounds Boo Radley and his house is generated by what the children hear about him.  Because of their learning that Boo is a recluse who does not venture outside, the children play pranks upon the house, luring Boo out.  Since the townspeople derogate the Radleys, Scout, Jem, and Dill feel comfortable ridiculing him, as well.

Certainly Jem's opinion of Mrs. Dubose is different from what he learns about her when his father demands that he read to the old woman after he destroys her camelias.  He, then, understands why she has been so virulent in her speech and manner.  Another example of believing the community's opinions prior to understanding a person comes in the character, Mr. Dolphus Raymond, whom the community ridicule as a drunkard who chooses to live on the wrong side of town with the Negroes.  Later, the children get to know him and make a significant discovery.

Most disturbing to Scout and Jem are the judgments of the community regarding Atticus's defense of Tom Robinson.  Scout is highly offended by the remarks of her cousin Francis regarding this matter.  However, from watching and listening during the trial of Tom Robinson, both Jem and Scout realize that Mayella Ewell lies about Tom, but is afforded credibility because she is white.  Jem and Scout perceive the injustice and hypocrisy in this action, just as Scout perceives earlier the hypocrisy of Aunt Alexandria who puts on airs for her teas and is hypocritical in her charity as the ladies' auxiliary donates to Africans while she will not allow Scout to attend church with Calpurnia.

In the final chapters, Scout and Jem are profoundly moved by the valiant defense that Boo Radley offers them against Bob Ewell. And, they are affected by the charitable act of the sheriff who keeps Boo's slaying of Ewell secret.  The children see the goodness of the community emerge after the shame of the trial.  Tom Robinson has not died in vain, for the sheriff realizes "it is a sin to kill a mockingbird."