What is rated as most important for successful marriage by western emerging adults?

Faithfulness is rated as most important for successful marriage by Western emerging adults.

They believe that if you are faithful to your partner, and don't cheat in marriage, your marriage is likely to be successful and last for a long time. For them, it is the most important thing in marriage that is almost sacred. Money, career, children, and all that are important, but not as much as faithfulness.