Couples who live together before marrying are twice as likely to divorce than those who do not.
Research published this month suggests pre-wedding cohabitees tend to experience greater marital friction and unhappy relationships.
The study of nearly 1,425 American couples, by researchers at Penn State University in Pittsburgh, found about half of cohabiting individuals viewed living together as a means of assessing compatibility before marriage.
The researchers interviewed two sets of couples who married between 1964 and 1980, and 1981 and 1997. In both groups, divorce was more likely for pre-wedding cohabitees.
In the 1964 to 1980 group, 24 per cent of individuals had cohabited prior to marriage, compared with 46 per cent in the latter group. Divorce was 90 per cent higher among the latter group.
The study, "The Relationship Between Cohabitation and Marital Quality and Stability", was published in the Journal of Marriage and the Family.