Partner effects in relationship research: Conceptual issues, analytic difficulties, and illustrations

This article discusses the conceptual meaning of partner effects, which occ ur when one person is affected by the behavior or characteristics of his or her partner. We show that partner effects can be used to validate the pres ence of a relationship and can elaborate the particular nature of that rela tionship. We discuss possible moderation of partner effects and show that m any theoretical variables in relationship research (e.g., similarity) can b e viewed as the interactions of partner effects with other variables. We pr esent three extended examples that illustrate the importance of partner eff ects.