Quote 1
"It's right hard to say," she said. "Suppose you and Scout talked colored-folks' talk at home it'd be out of place, wouldn't it? Now what if I talked white-folks' talk at church, and with my neighbors? They'd think I was puttin' on airs to beat Moses."
"But Cal, you know better," I said.
"It's not necessary to tell all you know. It's not ladylike—in the second place, folks don't like to have somebody around knowin' more than they do. It aggravates 'em. You're not gonna change any of them by talkin' right, they've got to want to learn themselves, and when they don't want to learn there's nothing you can do but keep your mouth shut or talk their language." (12.138-144)
Cal doesn't get the privilege of being the same person no matter where she is, because she has to live a double life to fit in. Sometimes, conformity to what everyone else is doing makes more sense. Calpurnia and Atticus offer different models to Jem and Scout of how to deal with a world that can't deal with who people really are. (Extra credit: Check out W.E.B. DuBois's "Of Our Spiritual Strivings" in the "Best of the Web" section for a famous discussion of doubleness and African-American identity.)
Quote 2
"There's some folks who don't eat like us," she whispered fiercely, "but you ain't called on to contradict 'em at the table when they don't. That boy's yo' comp'ny and if he wants to eat up the table cloth you let him, you hear?"
"He ain't company, Cal, he's just a Cunningham-"
"Hush your mouth! Don't matter who they are, anybody sets foot in this house's yo' comp'ny, and don't you let me catch you remarkin' on their ways like you was so high and mighty! Yo' folks might be better'n the Cunninghams but it don't count for nothin' the way you're disgracin' 'em—if you can't act fit to eat at the table you can just set here and eat in the kitchen!"
Calpurnia sent me through the swinging door to the diningroom with a stinging smack. (3.26-29)
Cal's moral lesson here is to respect people's differences, even if you think you're better than them. And acting like you're better than other people is the surest way to show that you're not. This interaction is an early blow against the stereotype that white people have morals but African-Americans don't—and Cal follows it up with a loving "blow" of her own. There's nothing like a smack to make a lesson hit home, right?