Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Naïve and ironic? Cue Scout, talking about Aunt Alexandra.
I never understood her preoccupation with heredity. Somewhere, I had received the impression that Fine Folks were people who did the best they could with the sense they had, but Aunt Alexandra was of the opinion, obliquely expressed, that the longer a family had been squatting on one patch of land the finer it was. (13.28)
Well, when you put like that, it doesn't actually make much sense. Scout describes her understanding of her aunt's belief in literal terms: sure, you could come up with flowery words about how it's about stability, a family putting down roots and becoming leaders in the community as time passes, but really it's just about a group of people getting there first and holding on to what they've got. So while Scout herself is naïve in the way she narrates what's going on, the overall effect is ironic: mocking established beliefs by portraying them in an absurd way.