There are many studies of violence in marriage and in dating. Methodological differences between studies, however, make it difficult to determine differences in the nature and extent of physical assault between marital status groups. This study analyzed data from two surveys: a study of 526 dating couples at a large midwestern university, and a study of a national probability sample of 5,005 married and 237 cohabiting couples. The results showed that cohabiting couples had a higher rate of assault than did married couples. These findings persisted after controls for age and socioeconomic status were introduced. Violence was also more severe in cohabiting than in married or dating couples. A number of factors may account for the more frequent violence in cohabiting relationships. These include social isolation, the publicity given to wife-beating by the women's movement, questions of autonomy and control, and the investment in the relationship. When age was controlled, dating couples had the lowest violence rate of the three marital status groups. The fact that those who date generally are in a less serious/committed relationship as compared to those who cohabit or are married, may explain the lower rate of dating violence. (Author)