But even after controlling for education, race, age, and gender, people who live together are 1.8 times more likely to report violent arguments than married people. It matters a great deal, however, whether cohabiting couples have definite plans to marry. Engaged cohabitors are no more likely to report violence than married couples, but cohabitors with no plans to marry are twice as likely to report couple violence as either married or engaged couples. Women in uncommitted cohabiting relationships seem to be especially at risk of violence directed toward them. The well-being of married and engaged cohabiting couples is substantially higher on this dimension than uncommitted cohabiting couples.
Some researchers suggest that commitment to the relationship and to the partner reduces violence.
These differentials seem to support that view. According to the 1992 National Health and Social Life Survey, cohabiting men and women make love on average between seven and seven and a half times a month, or about one extra sex act a month than married people. But cohabiting men and women are less likely than those who are married to be monogamous, although virtually all say that they expect their relationship to be sexually exclusive. Renata Forste and Koray Tanfer find in the National Survey of Women that four percent of married women had a secondary sex partner compared to 20 percent of cohabiting women and 18 percent of dating women. Women's behavior changed dramatically when they married, with a huge decline in the chances of having a secondary sex partner.