Compare To Kill a Mockingbird and The Scarlet Ibis. How do they explore the ways in which individuals can be limited by society?

If someone in a community does not measure up to everyone else's standards of how to look and behave in "normal" ways, then people's prejudices seem to surface. As a result, the ones who are deemed unusual or different suffer the effects of discrimination and isolation. In both Lee's To Kill a Mockingbird and Hurst's "The Scarlet Ibis," characters who have different challenges or disabilities in life face injustice and harsh treatment at the hands of family and friends who should support them. The "different" characters that come to mind in these stories are Doodle, Boo Radley, and Tom Robinson.  
First, Doodle suffers the effects of discrimination and isolation within his own family because he is born with physical disabilities that not only embarrass his older brother but also discourage his parents. The parents love Doodle and do not mistreat him, but Brother does. Brother's pride leads him to taunt and push Doodle beyond his limitations only so Brother can have the type of sibling he wants and whom society will accept. Brother explains as follows:

The knowledge that Doodle's and my plans had come to naught was bitter, and that streak of cruelty within me awakened. I ran as fast as I could, leaving him far behind with a wall of rain dividing us . . . Soon I could hear his voice no more.

Brother, like society, sometimes does not know how to deal with people's disabilities. Brother does not understand Doodle's limitations; consequently, Brother only knows that he does not want kids at school knowing he has a disabled little brother. The above passage shows Brother leaving Doodle isolated and suffering alone when he needs help. Brother can be compared to society when it turns its back on those who have special needs. 
In To Kill a Mockingbird, Boo Radley and Tom Robinson are treated similarly to Doodle. Boo Radley possibly suffers from social anxiety, and Tom Robinson is black and has a crippled left arm. The community treats Boo Radley as though he is a monster or boogie man, while people treat Tom Robinson with prejudice more for the fact that he is black than for his deformed arm. As a result, Boo hides in his house every day, and Tom is falsely charged with raping a white girl. Because these characters are treated disrespectfully in society, they tend to withdraw or make decisions they otherwise wouldn't in order to please others or to escape society. It is through the characterization and exploration of these characters' lives that profound lessons are learned. For example, Scout paraphrases Mr. Underwood's comments from Maycomb's newspaper after Tom Robinson is killed while trying to escape wrongful imprisonment:

Mr. Underwood didn't talk about miscarriages of justice, he was writing so children could understand. Mr. Underwood simply figured it was a sin to kill cripples, be they standing, sitting, or escaping. He likened Tom's death to the senseless slaughter of songbirds by hunters and children (241).

Mr. Underwood does his best to inform society of its wrongs, but it takes generations' worth of time to change people's minds from such prejudices. Underwood's remarks also point out a common theme between the two stories, which is that it is wrong to hurt someone in any way simply because he or she is different. Not only that, it is wrong to hurt someone who cannot defend himself for herself because of unequal opportunities in life. 
It is interesting to note that Doodle dies running like Tom does, although, it should be noted, Doodle runs to make his brother happy with him and to accept him, and Tom runs to escape injustice. Boo Radley, on the other hand, runs from society by hiding inside of his house and never interacting with anyone in the community. All three characters never seem to find the justice or kindness they deserve. Because Doodle, Boo Radley, and Tom Robinson are never fully accepted within their families or communities, they are limited to living isolated lives both physically and psychologically. Society never accepts them for who they are. As a result, these three characters are not allowed to do anything more than keep running or keep hiding.