in what ways do the characters behave in ways that are typical of children, and in what ways us their behavior more typical of adult

Certainly the boys are children. The irony is that they, initially at least, behave like their age. They can't pay attention during meetings, they pick on kids like Piggy, and they light a fire that nearly burns the island down. They constantly obsess about ghosts and "beasties" and are susceptible to simple manipulations. I think only a few boys reflected the world of adults. Piggy tried to model the adult world but was mercilessly mocked for his efforts. Ralph attempted responsible leadership but was cut down at every turn by Jack. Simon, Golding's Christ- figure, tried to convey wisdom but was savagely killed for his efforts.