Cluster analysis was applied to the marital reports of 99 husbands and wives (from 104 families) obtained when their firstborn sons were 10, 27, 36, and 60 months of age to identify distinct patterns of change in marital functioning. Husband-love and wife-conflict scores revealed 3 distinct change patterns-stays good, bad to worse, and good gets worse-which afforded the opportunity to address 2 distinct questions, the 1st dealing with the correlates of consistently good and poor functioning marriages and the 2nd with what distinguishes marriages that initially functioned similarly (and well) but proceeded to develop in distinctively different ways. Results show, consistent with related findings from a study of newlyweds (B. Karney & T. Bradbury, 1997), that the answer to the 1st question is found in enduring personality traits of spouses, whereas the answer to the 2nd is found in observed marital dynamics (reflecting coparenting processes).