His research addresses questions about interpersonal relationships using methods and models from both social and personality psychology. He is interested in developmental factors that contribute to the functioning of adult romantic relationships. His research also focuses on how narcissistic attributes impact the development of relationships and how such attributes affect important relationship outcomes in ongoing relationships. Because his substantive interests involve processes that occur within relationships and therefore often involve non-independent data, he is particularly interested in analytic models for both cross-sectional and longitudinal dyadic data.