What follows is the answer to an essay question our daughter sent in to school for her Physiology and Health exam:

Question: What are three characteristics of a successful marriage?

Answer:

Three characteristics of a successful marriage are:

Good communication. Couples need to be able to share their feelings and express their needs and concerns. 

Emotional maturity.  People who are emotionally healthy try to understand their partner's needs and are willing to compromise.  

Similar values and interests. When couples share attitudes about the importance of good health, spirituality, ethical standards, morality, family, and friendships, they spend more time together, which strengthens marriage. 

From the mouths of babes. That about sums it up.  : )