Laughter is the best medicine. Ask anyone. Well, maybe not a doctor. At the very least, laughter is a great way to pull a reader into your story, to make them connect with your characters, and to strike the perfect pitch and tone. But using humor effectively is fiction is no laughing matter (see how easy it is to botch it?)
There is a great difference between making a reader laugh with a character and making the reader laugh at a character (WARNING: Literary references ahead). We laugh with Huck Finn when he outwits the King and the Duke, but we laugh at the grandmother in “A Good Man Is Hard to Find” when she leads the family astray, only to realize the house she wanted to visit was in Tennessee instead of Georgia. By laughing with a character we as readers are drawn to them, and we feel a connection with them through shared experience. But when a writer directs us to laugh at a character, we laugh because of the distance between us and that character. We know more than they do, we know better than they do, and we know what is to come better than they do. The humor arises from the reader being distanced from the actions within the story, rather than from situations where the reader feels like they are right there on the page.
Now I’m not claiming that you should never make a reader laugh at your characters. Flannery O’Connor uses this technique well in “A Good Man Is Hard to Find”. We laugh because we can see the grandmother for the nasty, nasty woman that she is. This suits the writer’s purpose and fits well within the story. But it is Flannery O’Connor after all.
Whether you are making your reader laugh with or at your characters, it is important to be sure that there is a purpose to your humor beyond being funny just for the sake of it. This is an important point for short stories, which have a very limited amount of time to make their point. It is less of an issue in a novel, though still worth considering. If your humor can advance the story or connect the reader to a character as well as making the reader laugh, then you’ll have a powerful story as opposed to just showing off how clever you are.
Few things draw a reader into fiction more than humor, but it can backfire if not used wisely. As Uncle Ben says, “With great power comes great responsiblity.” So make them laugh (or groan), but be aware of how and why you are doing it.