Testing the investment model of relationship commitment and stability in a longitudinal study of married couples

This study tested Rusbult’s (1980, 1983) investment model of relationship commitment and stability using data from both partners of 3,627 married couples. As pre-dicted, spouses’ satisfaction, investments, and quality of alternatives were unique predictors of their commitment to the marital relationship. Additionally, commitment assessed at the initial testing predicted marital termination or stability 18 months later. Multiple-group path analyses showed that the investment model provided an adequate fit to the data and that the associations among variables were similar for husbands and wives. Limitations of the model as well as directions for future research are consid-ered. This research used the American Couples, 1975-1978, data set [made accessible in 1992, computer data]. These data were collected by Philip Blumstein and Pepper Schwartz and are available through the archive of the Henry A. Murray Research Center of Radcliffe College, Cambridge, Massachusetts (Producer and Distributor). This paper is based on work supported under a National Science Foundation Graduate Fellowship awarded to Emily A. Impett and a UCLA Academic Senate Research Grant to Letitia Anne Peplau. The authors are very grateful to Kevin Kim and Jodie Ullman for statistical consulting and Brian Doss for comments on an earlier draft.