Do they deliberately write funny lines for these types of films?

*spoiler below*


When she and her daughter are attacked, the psycho yells gaspingly:
"You know what this is? This is a family argument!"
Do writers deliberately write lines like these to be humorous, or are we supposed to be frightened by them?


"I'd say this cloud is Cumulo Nimbus."
"Didn't he discover America?"
"Penfold, shush."