What social differences create comedy in Twelfth Night?

Maria, Olivia's lady-in-waiting acts often as a balance to
other characters. At the same time, however, Maria's reproofs often give way to humor
and lively wordplay.  Placed against Sir Andrew Aguecheek, Maria generates laughter as
using puns she teases him about his
foolishness:

.
MARIA:Now,
sir, thought is free. I pray you, bring your hand
to the buttery-bar and let
it drink.(65)
SIR
ANDREW:Wherefore, sweetheart? what's your
metaphor?
MARIA:It's
dry, sir.
SIR
ANDREW:Why, I think so: I am not such an ass but I
can
keep my hand dry. But what's your
jest?(70)
MARIA:A
dry jest, sir.
SIR
ANDREW:Are you full of
them?
MARIA:Ay, sir,
I have them at my fingers' ends: marry, now I
let go your hand, I am barren. 
(1.3.64-74)

Maria is very resourceful
and highly energetic, but some of her energies are negative as, for instance, she
considers that her designs may drive Malvolio mad, but decides, "The house will be
quieter." Nevertheless, as she plots with Sir Toby and Sir Andrew against the pompous
Puritan, Malvolio, Sir Toby finds her most amusing, referring to her affectionately as
"a beagle true-bred," a statement that, perhaps, seeks to elevate her social class.Thus,
it is interesting that much of the commentary of characters like Maria who have a lower
position in the society affords the audience its perception of the
play.