If you're a person who dislikes confrontation, arguments are most likely not your thing. While most people don't really like to argue (attorneys notwithstanding), arguments can serve a useful purpose. They can clear the air, alleviate a misunderstanding, settle a difference of opinion, or perhaps allow us to agree to disagree.For writers, our characters' arguments can be especially useful. Sure, they can do all of the above, but they can serve other purposes as well.
Arguments can show a character's true colors. Just like us, characters can say things in the heat of the moment they wouldn't say any other time. Since the only way readers can get to know a character is by what's shown on the page, arguments give readers insight into how a character handles conflict, show what happens when she gets angry or flustered and drop some not-so-subtle hints about what pushes her buttons.
Arguments can illustrate a relationship between two characters. While this is true for any kind of dialogue, it's especially true when emotions are running high. Two co-workers who get along just fine when they can retreat to their individual cubicles might interact completely differently when thrown together in a high-stakes meeting. Whether it's a mother and daughter, brother and sister or husband and wife doing the arguing, listening in can give a reader a lot of information about the state of the relationship.
Arguments can advance the plot. Just as in real life, what happens during an argument influences what happens after the argument. Do the characters kiss and make up? Does one character storm out? Stay in the room, but return only stony silence? Does someone say something that lingers in the air long after the argument has ended? Cross a line? All these things influence what will happen the next time the characters see one another, along with many other conversations that take place with characters who were not a part of the argument. One well-written argument can influence pages and pages of interactions (or entire seasons of a television show).
Arguments can nudge a character to grow. Arguments rarely arise out of thin air. If what happens before the argument is a preface, what follows is a sort of epilogue. Tidy resolutions lead to little change in characters or their interactions, but a simple misunderstanding, left uncorrected, can lead to soul-searching, avoidance, or any number of actions on the part of both the offended character and the one who offended her. And a big blow up? That can lead a character to rethink everything he or she thought to be true, creating the kind of internal conflict that drives story.
Whether confrontational or non-confrontational by nature themselves, writers of fiction need to make peace with confrontation on the page in order to give both their readers and their characters the kind of story they deserve. As a Jersey girl trained as a counselor, I'm very much a clear-the-air kind of girl, which might just give me a head start. But, truth be told, my characters are usually running the show.