New evidence suggests couples who marry without ever having cohabited divorce at a lower rate, even when they marry before the age of 30.

Writing in the Wall Street Journal, researchers Brad Wilcox and Lyman Stone say there is an interesting exception to the conventional wisdom that waiting until 30 to marry is best, if you want to avoid divorce.

“In analyzing reports of marriage and divorce from more than 50,000 women in the U.S. government’s National Survey of Family Growth (NFSG), we found that there is a group of women for whom marriage before 30 is not risky: women who married directly, without ever cohabiting prior to marriage. In fact, women who married between 22 and 30, without first living together, had some of the lowest rates of divorce in the NSFG”.

While the idea that cohabitation is risky is surprising to some, they write that a growing body of research indicates that Americans who live together before marriage are less likely to be happily married and more likely to land in divorce court.

“In looking at the marital histories of thousands of women across the U.S., we found that women who cohabited were 15% more likely to get divorced. Moreover, a Stanford study indicates that the risk is especially high for women who cohabited with someone besides their future husband. They were more than twice as likely to end up in divorce court”, they write.