People enter into a marriage optimistically.  However, many marriages fail as couples engage in ineffective patterns of relating, conflicts become habitual and lead to a gradual withdrawal of esteem and caring for each other. Here are some of the most troublesome things that many of couples do, not intentionally, but because they don't evaluate their relationships for problems or do not know how to change their patterns of conflictual communication.

1. Avoid conflict.   
Avoiding conflict requires stuffing anger, which leads to numbing of all feelings. A genuinely passionate partnership requires occasional conflict, not terminal niceness.

2. Escalate conflict.   
Conflict, skillfully handled, is one of the keys to a great relationship. Out-of-control conflict is an excuse for physical, verbal, or psychological abuse. Partners who take turns being angry and schedule their fights seem to work things out. Take turns being angry!... meaning that both have the right to anger, not just one partner.

3. Avoid each other.   
Occasional withdrawal is healthy. Habitual withdrawal or withholding is death to healthy partnership.

4. Criticize.   
Critical speaking or thinking is hard on a relationship. Criticism is usually a sign of that the criticizing partner is seeing things in his partner that he doesn't like about himself. It is OK to ask your partner to change behavior, but not OK to criticize. There is a difference.

5. Show contempt.   
Contempt is criticism escalated to mental abuse. A contemptuous statement attacks the being of the other. For example, "What's the matter with you anyway? You never get it right."

6. React defensively.   
Most of us experience some fears or relating and defensiveness naturally accompanies fear. Skillful partnering skills allow both partners to feel safe enough to lower their defenses.

7. Deny responsibility.   
When I deny my responsibility for my part of the issue, I wind up blaming my partner and trying to change him or her. The blamed partner will generally refuse to change, even if the change is needed.

8. Rewrite history.   
Emphasizing mostly the negative experiences in a partnership is a predictor for future breakdown. All partnerships have their difficult times. Partners that stay together are proud of their ability to weather the stormy seas and are warmed by their memories of the happy times spent on tropical beaches. Partners likely to separate tend to remember the difficult times and use those memories as evidence that they are a poor match.

9. Permit abuse.   
Part of healthy loving is to be tough when needed. A partner who abuses physically, mentally, or spiritually is begging to be called to accountability. Permitting a partner to continue to abuse, is responsible for it as he/she cooperates with and enables that abuse.

10. Change partners.  
We instinctively choose partners that push our hot buttons, reminding of our wounds and undeveloped traits. Refusing to heal old wounds and develop the missing parts of us will almost certainly lead to another repetition of the same issues with another partner.

Adapted from
John Gottman, Why Marriages Succeed or Fail