This chapter describes key advances in understanding the effects of conflict behavior in couple relationships. We illustrate that (1) most types of couple conflict behavior are not routinely harmful or beneficial, (2) understanding what constitutes harmful or beneficial conflict behavior requires identifying the reasons conflict behavior affects actors and their partner, and (3) these differing functions mean that the effects of conflict behavior vary according to contextual factors-qualities of the situation, actor, partner, and external environment-which all interact to predict communication effectiveness. We conclude that managing conflict effectively requires enacting a range of different behaviors depending on the needs and demands of the situation. We then present a new model of calibrated dyadic communication that considers how these varying factors infuse the communication process to affect communication effectiveness and conclude by highlighting the implications the model has for future research.