Arguments
Funny enough, John Krasinski and Rainn Wilson actually got into the habit of giving each other lines during Jim and Dwight’s arguments to use for the other’s character. So, essentially, their lines came from one another.
Actors And Writers
The producers of the show found it important to hire actors who could also write well. Mindy Kaling, Paul Lieberstein, B.J. Novak and Michael Schur all wrote and produced for the show. Steve Carrell, Rainn Wilson, John Krasinski, Ed Helms, and Brian Baumgartner wrote some episodes.