John Gottman's Relationship Research

Psychologist John Gottman, PhD, of the University of Washington has been researching the relationships of thousands of married couples in his "love lab" in Seattle, Washington since the 1980's. Through careful screening, interviewing, and observation of each couple, Gottman has come up with a system for predicting whether a couple will stay married with up to 95% accuracy.  To do this, Gottman and his team of experts watch the couples' communication patterns and measure physiology (i.e., heart rate, sweating, and skin temperature). The results are then analyzed according to the Specific Affect Coding System (SPAFF), a system that corresponds a number to every possible emotion that can be expressed during conversation. The data from the physiological reactions the couple has throughout the conversation is also factored in. This information is then fed into a complex equation, resulting in a highly accurate prediction of the sustainability of a marriage. 
Gottman's research has gone into great detail about what to look for when assessing a marriage. The SPAFF code uses a range of numbers to interpret facial expressions of the couple as they converse, looking carefully for signs of the Four Horsemen. In as little as three minutes, Gottman is able to thin-slice with relatively high accuracy if a marriage will last based on the scientific measurements and observations made of each couple.
In addition to looking for signs that a relationship may be in trouble, Gottman has done extensive research into what keeps a marriage strong. He has developed a theory for making relationships work, called the Sound Relationship House. The Sound Relationship House consists of seven components of healthy coupledom.