Psychologists have recently given considerable attention to the study of relationship and friendship development, but the contributing social processes have not been examined in relation to each other over time. To examine the effects of disclosure, similarity, equity, and social exchange on satisfaction with a relationship and liking for one's partner over time, 39 pairs of previously unacquainted roommates completed questionnaires at the beginning and end of the school year measuring liking and satisfaction, self-disclosure, similarity, equity, and an index of reward designed to elicit information about the extent to which roommates had helped each other. Results showed that roommates tended to show substantial correlations on many measures, especially in the spring, although as a whole satisfaction decreased from fall to spring. All factors examined were significant predictors of initial liking. While exchange of rewards or resources appeared to be the most important factor over time in determining liking and satisfaction, the correlation between roommates suggests that the nature of the exchange process will change with time. Results also showed that prediction of whether a relationship would continue was just as accurate after 2 weeks as at 6 months, lending support to the importance of first impressions. (JAC)