most violently to the outcome. His body jerks when the verdict is read as if he has been stabbed, and he cries at the injustice of what has happened asAtticus and the children walk home.

Yet what Jem expresses openly, Scout feels internally. She is beginning to grow up and learn hard lessons not just about the world but about the evil in her own town, among her own neighbors. For example, she begins to put two and two together when her teacher, Miss Gates, tells them that the persecution of the Jews in Germany is wrong. Miss Gate describes the Jews as religious and hardworking people who are nevertheless not treated equally under the law in Germany. She contrasts this to the US, where, Miss Gates insist, people are treated equally.

Now that she has witnessed injustice in her own country personally, Scout can see the parallels between how blacks are treated and Nazi Germany, as well as her teacher's hypocrisy. She asks Jem:

Well, coming out of the courthouse that night Miss Gates was—she was goin‘ down the steps in front of us, you musta not seen her—she was talking with Miss Stephanie Crawford. I heard her say it’s time somebody taught ’em a lesson, they were gettin‘ way above themselves, an’ the next thing they think they can do is marry us. Jem, how can you hate Hitler so bad an‘ then turn around and be ugly about folks right at home—

Miss Gates might be blind to her own participation in injustice, but Scout no longer can miss the faults in front of her. The trial helps her mature and come of age in understanding the world is sometimes a harsh place.

Following the outcome of the Tom Robinson trial, Scout becomes more aware of the prevalent racism throughout her community. Unlike her brother, who becomes jaded toward his prejudiced community members, Scout gains additional perspective and displays sympathy for the disenfranchised citizens of Maycomb. Before the Tom Robinson trial, Scout hardly recognized the harmful effects of racism throughout her community. She naively followed the culture of Maycomb and did not empathize with African Americans or poor white farmers until she witnessed racial injustice firsthand.

After witnessing an innocent man wrongly convicted of assaulting and raping Mayella, Scout begins to understand the significance of her father's defense. Following Tom's unfortunate death, Scout realizes why Tom never had a chance at winning his case. She also recognizes her community's ignorance regarding race and culture. Scout notices Mrs. Merriweather's blatant prejudice during the missionary circle and also analyzes Mrs. Gates's hypocrisy during a Current Events activity. Scout also begins sharing her father's perspective by applying his life lessons. After she survives Bob Ewell's attack, Scout demonstrates her moral development and maturity by sharing an important lesson that she learned after witnessing Atticus defend Tom Robinson. Scout metaphorically applies Atticus's lesson concerning protecting innocent beings by commenting on the importance of leaving Boo Radley out of the town's limelight. Scout says, "Well, it’d be sort of like shootin‘ a mockingbird, wouldn’t it?" (Lee, 169).

Overall, Scout matures and develops her perspective on life after witnessing the Tom Robinson trial. She begins to recognize hypocrisy and racial prejudice throughout her community and also begins to apply Atticus's earlier life lessons.

Before the verdict is even read, she has a bad feeling, a lonely, isolated feeling. "The feeling grew until the atmosphere in the courtroom was exactly the same as a cold February morning, when the mockingbirds were still."  She knew it was coming, and when Judge Taylor read it aloud, she shut her eyes.  When she opened them, she was in a daze.  She couldn't understand what the judge was saying after her read the verdict, she slowly saw Atticus make his way to Tom and then make his exit.  And she was confused when Reverend Sykes asked her to stand in Atticus' honor.

Scout wasn't upset enough to cry, but she knew that the jurors were wrong.  Scout wasn't old enough to really understand how unfair the verdict was.  Jem was the character who reacted to it.  Harper Lee used Scout as a lens for us to see what she was learning from the scene.  Scout learned that there were people in the community who did what they could to help out.  She learned that from Miss Maudie.  There was never a lot of reaction from Scout when the verdict or Tom's death was mentioned.  But she saw how her family members each reacted, and she learned through them how unfair the world was/is.

The children learn a great deal from the trial. From its outcome, they learn that there is a very ugly side to Maycomb, one that is rooted in the racism of Jim Crow. Their notions of basic justice are proven to be illusions as the jury convicts Tom Robinson despite his obvious innocence. His conviction, in short, is based on the color of his skin. Jem is especially devastated by this realization. After the trial, Scout says:

It was Jem's turn to cry. His face was streaked with angry tears as we made our way through the cheerful crowd. "It ain't right," he muttered, all the way to the corner of the square where we found Atticus waiting.

Later he compares his realization to a caterpillar emerging from the safety of its cocoon, suggesting that for him, coming to grips with racism, and evil, more generally, is part of growing up. The injustice of the decision becomes complete shortly thereafter, when everyone learns that Tom was shot to death in an escape attempt from prison.

But the trial teaches the children something else. This is that their father is a good man, the type who nobly takes on a righteous cause even though he recognizes the consequences (and perhaps the futility of it). They are proud of Atticus, who grows to an almost saintly status in their minds. This is quite the departure from their attitude earlier in the book, where Scout describes Atticus as a sort of feeble old man. So in this sense To Kill a Mockingbird is as much about the maturation of two children as it is about the injustice of Jim Crow.

Scout and Jem learn that while there are a lot of racists in Maycomb, not everyone is racist.  They also learn that people are complicated but generally have good intentions.

Before the trial, Atticus expressed concern to his brother Jack about how the trial would affect Scout and Jem.  He knew that they would hear a lot of talk, about him and about the trial.  His children would have to mature a little early.  A rape trial is a very grown-up thing.

You know what’s going to happen as well as I do, Jack, and I hope and pray I can get Jem and Scout through it without bitterness, and most of all, without catching Maycomb’s usual disease. Why reasonable people go stark raving mad when anything involving a Negro comes up, is something I don’t pretend to understand… (Ch. 9) 

When the Cunningham mob comes to lynch Tom Robinson, both Scout and Jem intervene.  They learn that the Cunninghams are not bad people, but they just got carried away. Atticus tells them that most people are well-intentioned.  This later pans out when Atticus tells them that two Cunninghams would have hung the jury, because they were open-minded and willing to accept that Robinson was innocent after hearing the evidence.

Scout and Jem do not become racists, despite Scout using the N-word.  She is just repeating what others said.  Jem certainly is no racist.  He strongly believes that Tom Robinson will be acquitted.  However, another thing that Scout and Jem learn is that the world is not always fair.  Even with Atticus’s evidence that Tom Robinson could not have caused Mayella’s injuries, he is convicted. 

Scout and Jem also learn that race relations in Maycomb or more complicated than they thought.  During the trial, they meet Dolphus Raymond, who pretends to be drunk all of the time because he is living with a black woman and they have children.  Maycomb tolerates him because he is from a wealthy family. 

In a reflection that shows her growing understanding of the world, Scout realizes that Maycomb's reaction to Mayella’s relationship with Tom Robinson is different than Dolphus Raymond’s with his wife because Mayella is poor. 

She couldn’t live like Mr. Dolphus Raymond, who preferred the company of Negroes, because she didn’t own a riverbank and she wasn’t from a fine old family. Nobody said, “That’s just their way,” about the Ewells. Maycomb gave them Christmas baskets, welfare money, and the back of its hand. (Ch. 19) 

Jem determines that there are four kinds of people in Maycomb.  “Normal” people like the Finches, the Cunningham types, the Ewell types, and “the Negroes.”  This is the understanding of race and class relations he has developed from the trial.

Tom has taught Scout that the citizens of Maycomb may not really be the "best folks in the world" after all.

What has happened to poor Tom Robinson in the Maycomb county courtroom causes Scout to realize that good does not always conquer evil; further, Tom's cruel treatment by Mr. Gilmer and the jury has also taught Scout about the racial bias that exists in her environment. Indeed, Tom has taught Scout that one may be in the right, but still may be found guilty by those in power in order to satisfy their own desires.

From her witnessing of the proceedings of the trial of Tom Robinson, Scout begins to know the adult world of Maycomb as she becomes aware that there are things about her environment which differ greatly from her earlier perceptions. For instance, from listening to some of her father's cases, she is shocked that Mayella and even her dissolute father would lie under oath, yet they are somehow afforded some credibility by the jury. In addition, the gratuitous cruelty of the Ewells toward the man who was so kind to Mayella shocks her. Yet, somehow, the Ewells are also afforded more credibility than Tom is when he testifies honestly.
Thus, the most defining lesson for Scout is the mounting proof of racial bias toward the one-armed Tom who could not possibly have beaten Mayella as charged, while a reprobate like Ewell is allowed his lie. Further, when Tom is put on the stand, he ingenuously states that he felt sorry for Mayella, who has no one to aid her at her house, and helped her by breaking up a chiffarobe. Hearing this, Mr. Gilmer counters with vitriolic innuendos about Tom's expression of pity:

"You felt sorry for her, you felt sorry for her?" Mr. Gilmer seemed ready to rise to the ceiling.

For Tom, a "colored man," to feel sorry for a white woman is an egregious social mistake because this action implies that he feels himself superior to her. 

...nobody liked Tom Robinson's answer. Mr. Gilmer paused a long time to let it sink in.

Finally, Scout learns the deeper meaning of her father's words about it being a sin to kill a mockingbird. That is, the innocent Tom is shot trying to escape from prison after his conviction that comes as a result of a trial that has been nothing less than a travesty of justice. For, while in the courtroom, Tom has learned that he has been convicted before the start of the proceedings in the "secret courts of men's hearts." Therefore, after his conviction, he despairs of any hope for winning an appeal, and out of desperation, he tries to escape and is killed, having been shot an excessive seventeen times. 

Scout has one revelation about the Tom Robinson case just as she is entering the courthouse prior to the start of the trial in Chapter 16.

As Scout, Jem, and Dill make their way into the courthouse with the rest of the spectating crowd, Scout gets separated from the boys while trying to make her way to the staircase. In her moment of separation, Scout "found herself in the middle of the Idlers' Club"; the "Idlers' Club is Maycomb's name for a group of elderly men "who had spent their lives doing nothing and passed their twilight days doing the same on pine benches" in the town square. As frequenters of the town square, they are also frequent spectators of the courtroom, who often express their opinions about courtroom proceedings.

While in the midst of the Idlers' Club, Scout overhears them having an interesting conversation about her father. One man expresses his objection to Atticus's intentions to truly defend Tom Robinson, whereas a second man responds by saying, "Lemme tell you somethin' now, Billy ... you know the court appointed him to defend this nigger" (Ch. 16). The news that Atticus was appointed by the court to defend Robinson hit home with Scout. Up to this point, she had been wondering why Atticus had been so willing to face so much ridicule just to defend a "nigger," and the man's comment helps Scout understand at least some of Atticus's moral obligation, as she expresses in the following:

This was news, news that put a different light on things: Atticus had to, whether he wanted to or not. I thought it odd that he hadn't said anything to us about it—we could have used it many times in defending him and ourselves. He had to, that's why he was doing it, equaled fewer fights and less fussing. (Ch. 16)

In other words, Scout has learned for the first time that Atticus was commanded by the judge to defend Tom Robinson. Therefore, she has come to understand part of Atticus's moral obligation to defend Robinson—he was doing so because he was commanded to do so. The understanding helps eliminate at least some of the confusion that had been weighing on Scout's mind since Chapter 9. Since that chapter, Scout has been wondering why Atticus is so willing to face so much persecution. Yet, being young, she is only able to see a small part of his moral obligation. Scout still fails to understand that Atticus has to defend Robinson not so much because he was commanded to by the judge but because he has an ethical responsibility to adhere to the principle of "innocent until proven guilty" and give every defendant the best defense possible, regardless of race.

There is actually some seemingly contradictory evidence concerning how Scout first learned that Atticus is appointed to defend Tom Robinson at his trial in To Kill a Mockingbird. In Chapter 9, Scout is deliberately eavesdropping on Atticus' conversation with Uncle Jack. Atticus tells Jack that

"... John Taylor pointed at me and said ' You're It.' "

Apparently Scout does not understand this reference that Judge Taylor has assigned Atticus to the case, rather than Atticus seeking it out on his own. In Chapter 16, however, Jem, Scout and Dill all sneak down to the courthouse where they overhear several men discussing the trial. When they hear Atticus' name mentioned, they pay closer attention. Scout learns that

     "... you know the court appointed him to defend this nigger."
     "Yeah, but Atticus aims to defend him. That's what I don't like about it.
     This was news, news that put a different light on things...

This is Scout's first inkling that her father was appointed to the case, despite what she had overheard at Finch's Landing.