But once researchers control for that age variable, it turns out that premarital cohabitation by itself has little impact on a relationship's longevity.
Using meta-analytic methods of current best practices to look across the entire body of published and unpublished evaluation research on premarital education, we found a more complex pattern of results.
A study of married couples revealed that about half the people studied thought negatively about premarital relationships; in general, the female partners were more open to premarital and extramarital relationships.
In contrast, premarital education programs appear to be effective at improving couple communication, with studies that employed observational measures rather than self-report measures producing large effects.
While postnuptial agreements are generally subject to the same notice and recording rules as premarital agreements, the rules for transmutation agreements are slightly different.