Despite narcissism's relation with interpersonal dysfunction, surprisingly little empirical research has been devoted to understanding narcissism's effect on intimate relationships in general or marital relationships in particular. The current study addressed this gap using longitudinal data from a community sample of 146 newlywed couples assessed 6 times over the first 4 years of marriage. First, we examined partner characteristics associated with higher levels of narcissism to determine the degree to which couples were matched on narcissism and related traits. Second, we examined how narcissism predicted the trajectory of marital quality over time, testing narcissism's association with initial levels of relationship functioning (the intercept) and changes in relationship functioning (the slope). Results indicated a small degree of homophily but otherwise no clear pattern of partner characteristics for individuals higher in narcissism. Hierarchical linear modeling indicated that wives' total narcissism and entitlement/exploitativeness scores predicted the slope of marital quality over time, including steeper declines in marital satisfaction and steeper increases in marital problems. Husbands' narcissism scores generally had few effects on their own marital quality or that of their wives. These findings are notable in indicating that the effects of personality characteristics on marital functioning may take some time to manifest themselves, even if they were present from early in the marriage. Future research into the mediating psychological and interpersonal processes that link wives' narcissism with poorer marital functioning over time would be valuable.

Although couples' management of differences and problems is widely assumed to be central to the course and outcome of their relationships, some theoretical perspectives hold that marital conflicts increase over the newlywed years, whereas others maintain that couples' problems remain stable. We tested these opposing views by examining changes in marital problems and marital satisfaction over the first 4 years of marriage in a sample of 169 newlywed couples. Although marital satisfaction declined on average, overall levels of marital problems remained stable. Analyses of 19 specific problems generally revealed considerable stability as well, although husbands and wives rated showing affection as increasingly problematic over time. These findings challenge longstanding assumptions regarding the role of accumulating conflict in marital functioning over time and suggest that specific and overall problems in marriage largely remain stable over the newlywed years. Implications for theory and clinical practice are discussed.