The characters in the New Girl are all terrible liars. Nick and Jess fall apart whenever they have to fib—although Nick attempts to keep lies “SSV: Short, simple, vague”, they are easily exposed. And even Schmidt, a relatively deceitful character, undermines his attempt to pose as Mitt Romney’s (Mormon) son when he accidentally accepts a beer.
There is an obvious explanation for this character trait.The inability to lie is a good catalyst that creates plot momentum; sitcoms thrive when characters are forced to confront truths.
But I have a less boring theory. At the beginning of the third season, Schmidt two-times Cece and Elizabeth, two popular female characters. This provoked a huge backlash, with fans complaining that a “wacky, womanising douchebag” was ruining the show. This discomfort with deceit makes sense in the context of the show. Characters who could lie—and get away with it—would be anathema to the fuzzy universe that Zoey Deschanel et al. have constructed. Watching the New Girl is a comfortable, comforting experience. The people are nice, and warm, and friends, and terrible liars.