What was the unwritten social code that Mayella broke in To Kill A Mockingbird?
This whole discussion got started when Scout wanted to invite Walter Cunningham for dinner. Aunt Alexandra, who represents the social mores of the town, said that there is no way he can come over to dinner. When Scout asks why, Aunt Alexandra tells her,
"...they're not our kind of folks." (pg 224)
Scout, who has been raised in a non-prejudicial home, still doesn't understand. Finally Aunt Alexandra says,
"Because--- he--- is--- trash, that why you can't play with him. I'll not have you around him, picking up his habits and learning Lord- knows- what." (pg 225)
Scout becomes very angry, and she turns to Jem for advice, something she often does. Jem has been thinking hard since the trial, trying to figure out why good men would convict Tom Robinson and condemn him to death. When Scout asks him about Aunt Alexandra's strict rules, Jem tells her,
"There's four kinds of folks in the world. There's the ordinary kind like us and the neighbors, there's the kind like the Cunninghams out in the woods, the kind like the Ewell's down in the dump, and the Negroes." (pg 226)
He placed them in that order. He had to clarify that this was according to Maycomb County when Scout asked about the Chinese and the Cajuns. He added,
"....our kind of folks don't like the Cunninghams, the Cunninghams don't like the Ewells, and the Ewells hate and despise the colored folks." (pg 226)
Although the children try think it out logically, there is no logic to it. Mayella broke the social code by inviting a black man into her home and coming on to him. Tom Robinson knew it was wrong on many levels and so did she. Bob Ewell could not have it out in the town that his daughter had associated with a black man, so he filed rape charges on Tom. Mayella could not have the townspeople think she was attracted to a black man, so she lied on the stand and called them names when she felt Atticus was pressuring her.