
Q. What is a common sign that a marriage/relationship is heading for a breakup, which many people often neglect or don't know?
A. Dr. John Gottman and his team of relationship researchers have identified what they call the Four Horsemen of the Relationship Apocalypse. When these 4 traits appear in a romantic relationship, Dr. Gottman can predict the demise of said relationship with a ridiculously high degree of accuracy (most reports are over 90% accuracy). So if your relationship has these 4 things, it's probably doomed.
The Four Horsemen: Criticism, Contempt, Defensiveness, and Stonewalling - https://www.gottman.com/blog/the-four-horsemen-recognizing-criticism-contempt-defensiveness-and-stonewalling/
2 things that most people don't know is that 1) just having conflict in a relationship or feeling anger is NOT, by itself, a sign that a relationship is heading for a breakup - people have arguments and conflict and feel anger and that's just the nature of interacting with other people in intimate settings, so just having arguments doesn't mean that the relationship is unhealthy or about to end, but that 2) there is a ratio of how *often* or how *much* conflict or unhappiness a relationship can withstand and it's much lower than most people think.
In a relationship, Gottman and other researchers also discovered that there should be a ratio of "negative interactions" to "positive interactions" overall in a relationship that is 1:5. That means that for every bit of ";negative interactions", there should be 5 bits of "positive interactions". Lots of people think that they should stay in relationships until the happiness ratio tips over to where you are unhappy more than half of the time. That's not true.
The Magic Relationship Ratio, According to Science - https://www.gottman.com/blog/the-magic-relationship-ratio-according-science/
So, the predictors of the ending of a romantic relationship are criticism, contempt, defensiveness, and stonewalling. Anger is not among the predictors. If you have these criteria in your relationship more often than 1:5 compared to positive interactions, the relationship is probably on its way out.