In the study, researchers at the University of Denver (DU) also found that couples, who lived together before engagement and then married, reported a lower satisfaction in their marriages.

The study was conducted by Galena Rhoades, senior researcher, Scott Stanley, research professor, and Howard Markman, professor of psychology.

"We think that some couples who move in together without a clear commitment to marriage may wind up sliding into marriage partly because they are already cohabiting," Rhoades said.