Answer: At the beginning of the novel, Scout, Dill, and Jem have a firm and uncomplicated idea of what’s good and what’s bad, but by the end of the novel, they’ve all lost their innocence and have come to a more complex understanding of how people and the world work.
Step-by-step explanation: Comically the novel demonstrates how innocent Scout was to believe Jem’s unfounded claim that the teaching method Miss Caroline promotes is called the Dewey Decimal System although, in reality, it is a system of organizing a library. She considers her and Jem’s snowman as an “Absolute Morphodite” (morphodite means a hermaphrodite, a plant or animal with both male and female sex organs). The children also firmly believe that Boo Radley is a zombie-like figure who eats small mammals or, possibly, is dead and stuffed up the chimney of the Radley house. The children’s innocence is represented by these instances of misunderstandings or far-fetched superstitions.
Tom Robinson’s trial marks the end of Scout and Jem's innocence. Jem in particular struggles to understand how such a thing could’ve happened. As the children grew, they lost their capacity to mourn over injustices like Robinson's trial. They learn to conform to adult rules of polite society that forbid reactions like that. They abide by the prejudices of the society which discourages that kind of compassion directed toward black people.