Analyzing change at the dyadic level: the common fate growth model.
For the study of growth in dyads, methods have been developed to analyze growth at the level of the dyad members. In this article, we present a novel approach that we call the Common Fate Growth Model (CFGM). This model permits an analysis of growth at the level of the dyads when members are either distinguishable (e.g., heterosexual couples) or indistinguishable (e.g., lesbian couples). To estimate the model, we describe the use of structural equation modeling (SEM) for both distinguishable and indistinguishable members. For indistinguishable members and small groups, such as families, we provide details for the use of multilevel SEM (MSEM). For both SEM and MSEM, we address the issue of measurement invariance (MI) and the estimation of group-level means. The models are illustrated with data from couples collected at seven measurement occasions. To aid the estimation of the models, Mplus code and Amos setups are provided.