Moderator and mediator effects in dyadic research: Two extensions of the actor-partner interdependence model

Two extensions of the Actor-Partner Interdependence Model (e.g., Kenny, 1996) incorporating moderators and mediators are presented. Both models, called the Actor-Partner Moderator Model and the Actor-Partner Mediator Model, allow the analysis of moderator and mediator effects within dyads. In addition to a brief guidance on analyzing the moderator model with regression analyses, advice is given for applying the bootstrap method using structural equation analyses. Different indicators are considered for assessing the mediation. The two models are illustrated using data from 198 couples on daily stress, relationship quality. depressed mood and sexual dysfunctions. Regression and bootstrap analyses based on the Actor-Partner-Moderator Model support the hypothesis that relationship quality moderates the association between daily hassles and sexual dysfunctions. Using the Actor-Partner Mediator Model. structural equation modelling analyses support the assumption that depression mood mediates the relation between daily hassles and relationship quality. In conclusion, the utility, merits and limits of the models are discussed.