John Gottman, Ph.D. has studied marriage relationships with more scientific rigor than just about anyone. If you and your spouse sit in his lab and have a conversation about a disagreement in your marriage, he can tell whether the marriage will last another 5 years with 90% accuracy in just 15 minutes (80% accuracy in five minutes!).
He has identified what he calls the four horsemen (taken from the four horsemen of the apocalypse found in the book of Revelation in the Bible). When any of these are habitually present in your marriage, you cannot continue your current relationship patterns and reasonably expect to keep your marriage/family together.
The four horsemen are: