Conflict is a part of most romantic relationships—and in a certain sense, if there are no arguments there may not be enough at stake. Yet certain types of chronic arguing can be a sign of abuse or dysfunction. Some psychologists point to a qualitative difference between conflict driven by disagreement and that driven by contempt. Psychologist John Gottman popularized this distinction with his suggestion that contempt is the greatest single predictor of a failed marriage, and is “poisonous to a relationship because it conveys disgust.”

So how do we learn to fight in a constructive way? We can strive to remember that regardless of an argument’s apparent subject, there are often undercurrents in which both parties are trying to defend essential parts of themselves. Dr. Gottman desc...