In To Kill a Mockingbird, what effect did Scout have on the mob in Chapters 15-16?
As the mob gathers at the jail, Scout is surprised to discover that she knows some of these men. She recognizes Mr. Cunningham, the father of little Walter Cunningham, who she had over to her house for lunch one day. So, being innocent, and recognizing a face in a crowd, she starts talking to him. "Hey, Mr. Cunningham. How's your entailment gettin' along?" She is making small talk with an angry mob that had come to take Tom Robinson from the jail and do who-knows-what to him.
This throws the entire feeling of the mob off; Mr. Cunningham is embarrassed. He is transformed from a faceless mobster who will set aside any morals or principles to act with the crowd on his fears, to a real human being that a small girl knows and is concerned about. Scout forces these men to ask themselves if they would be willing to commit this violence in front of a young girl, and it paints a stark contrast to their everyday selves. They see themselves through Scout's eyes: normal, kind, civil members of society. This humanizing of the mob immediately has an impact, and the end result is that the mob disperses, with no harm done. Scout, through her child-like innocence and polite concern, saves the moment.
Scout is able to quell the mob's violent spirit. When she sees the mob gathering in front of the jailhouse, she recognizes Mr. Cunningham and speaks to him about his entailment (a legal matter in which Mr. Cunningham is receiving help from Atticus). She then mentions Walter, Mr. Cunningham's son and one of her schoolmates, and explains that she invited Walter home for dinner once. She asks Mr. Cunningham to say hello to Walter for her, and then she goes back to speaking about the entailment, which she thinks will interest Mr. Cunningham. Finally, after not knowing how to react, Mr. Cunningham bends down and says to Scout, “I’ll tell him you said hey, little lady." He then tells the mob to disperse. Scout has effectively caused the mob to quiet their anger and dispelled their violent intentions by reminding them that Atticus is a father and that Mr. Cunningham is too. By asking Mr. Cunningham innocent questions, she has broken the mob's murderous spirit.