What lessons do Scout and Jem learn from their encounter with Mrs. Dubose?
Jem has a blow-out of his temper when Mrs. Dubose, of whom he is terrified, enrages him by insulting Atticus (of whom she is actually a friend, with a mutual, shared respect between them). As a consequence, Jem is compelled to go to her for over a month (a week being added to the originally appointed month) to read to her while she is in a very, very ill condition. During these encounters, Jem learns courage; to control his emotions; to pursue the right course of action even when it is distasteful (or even appalling); and to turn a blind eye to what is distressing. After these encounters Jem learns, the hard way and much against his will, to respect someone with whom he deeply disagrees; to acknowledge and value courage; and to embrace as worthy a different point of view.
Mrs. Dubose was a lady of fiercely staunch Old South habit, expectation and upbringing as illustrated by her tirades to Scout: “Don’t you say hey to me, you ugly girl! You say good afternoon, Mrs. Dubose!” During Jem's quite unsettling reading-aloud encounters with Mrs. Dubose, Jem has to learn physical courage just to mount her "steep steps." As he confides in Atticus, Jem finds the Dubose home "all dark and creepy ... [with] shadows and things on the ceiling...." To forebear in the face of Mrs. Dubose' symptoms of suffering, Jem has to learn moral courage, as Atticus tried to teach him before, by receiving her insults with bold calm and emotional tranquility:
he would gaze at Mrs. Dubose with a face devoid of resentment. ... [H]e had cultivated an expression of polite and detached interest, which he would present to her in answer to her most blood-curdling inventions.
After the encounters with Mrs. Dubose, Jem learned about all-encompassing courage when he understood from Atticus the determination, strength and deeply rooted courage that Mrs. Dubose needed to call up in order to break her morphine habit so that she might pass from her life and "leave this world beholden to nothing and nobody." This lesson changes Jem in a concrete way that manifests in his attitudes and behavior toward Scout, much to her confusion and dismay: "Jem hollered, 'It’s time you started bein‘ a girl and acting right!'"
The cranky, old, racist Mrs. Dubose is sitting on her porch and calls Atticus a “nigger lover” one day as Scout and Jem are passing by her house on the way to town. When Scout and Jem return, Jem destroys Mrs. Dubose’s camellia bushes with the baton he purchased for Scout in town. Jem’s retaliation causes Atticus to agree with her request for Jem's punishment and makes him go to Mrs. Dubose’s house each day to read to her while she is “sick” to help her through her secret struggle. In reality, Mrs. Dubose has an addiction to morphine and has vowed to break her habit before she dies.
Despite her possible symbolic representation of the dying South, Mrs. Dubose teaches Jem about taking responsibility for one’s actions (Jem’s destruction of the bushes) and that there are consequences to actions. Atticus also tells Jem that she is the most courageous person he has ever met, thus teaching them about overcoming obstacles and hardships in life.
I have always encouraged my students to analyze Mrs. Dubose as something more than just an old, mean lady. She is a symbol of the Old South and their racist attitudes. The addiction she is trying to break could be representative of the South’s adherence to racism. As one of the oldest residents of Maycomb, she is signaling the death of the old ways and the emergence of a new generation of people like Jem and Scout who are not racist.
There are a number of lessons learned by Jem which can be credited to his interactions with Mrs. Dubose. Two of the most central lessons are a focus on what courage really is and on empathy. The purpose behind Jem being forced to read to Mrs. Dubose is so that Jem can see what real courage is, not a man with a gun, but anyone who takes on a task where you know you cannot win but you give it your all anyway, as Atticus says to describe what Jem witnessed in Mrs. Dubose' last months alive. In addition, spending time with Mrs. Dubose set up Jem to learn about empathy, the ability to put yourself in another person's shoes and attempt to see the world from their experiences, instead of judging them based on their outward behavior.