Dill’s reaction to the turtle and Mr. Gilmer’s cross-examination of Tom Robinson both demonstrate the sensitivity he has compared to Jem and Scout.
When Jem suggests striking a match under a turtle’s shell to make him come out, Dill objects. He considers it “hateful.” Jem doesn’t see why. It just “persuades” him.
"How do you know a match don't hurt him?"
"Turtles can't feel, stupid," said Jem.
"Were you ever a turtle, huh?" (ch 1)
Dill’s sensitivity to the turtle’s feelings demonstrates both naiveté and maturity. He is empathetic enough to know that you should not tease a turtle, which shows maturity, but also does not see what Jem and Scout see, which is that cruelty is common.
When Dill cries at Tom Robinson’s trial, Scout and Jem also do not understand why. Mr. Dolphus Raymond does. Like Dill, he finds it upsetting to his stomach to see racism in action. He does not just accept it as some people do.
"You aren't thin-hided, it just makes you sick, doesn't it?" (ch 19)
Raymond tells Dill that he agrees. He does not appreciate how Mr. Gilmer was treating Tom either, calling him “boy” and treating him rudely. He understands that Dill sees what most of the grown adults do not.
Like the turtle, Tom Robinson is being treated cruelly. Dill is aware of this. Scout and Jem seem relatively unaware, but in different ways. Jem assumes that Tom will be acquitted, and Scout assumes that this is just the way things are. Dill ‘s reaction demonstrates that the future of Maycomb is in the children, who may see things differently.