58% of couples have premarital sexual intercourse, on average with 5 partners. Twenty-three percent had sex only with the person they married. That group had significantly greater marriage quality.

Thirty-five percent of those who had lived with arrangements pre-marriage had high-quality marriages but forty-two percent of those who had not lived with a romantic partner had high-quality marriages.

“Prior relationship experience leaves some kind of imprint on us that we carry forward,” Dr. Rhoades said. “We compare new partners to old partners.”

Although sexual intercourse before marriage does not necessarily ruin marriages, with the high rate of divorce today, this does suggest strongly that conscientiousness may still be the key to developing a great marriage.