Equation Predicts Marriage
Success or Failure

Mathematics may not seem romantic, but it may be useful for telling whether a marriage will end in divorce, according to researchers at the University of Washington in Seattle. In a study of married couples, a mathematical equation was 94 percent accurate in predicting which ones would divorce.

"I was astonished by the accuracy of the prediction," Dr. James D. Murray told Reuters Health in an interview.

One of the "really exciting" aspects of the model, Murray said, is that it can be used to help couples identify problems in their marriage.

When University of Washington psychologist Dr. John Gottman asked Murray to develop a mathematical model that would predict which marriages would last, Murray thought the idea was "totally ridiculous." But once he started working on the model, Murray said, "I got totally hooked."

The aim was to come up with a system that would quantify the interaction and communication between a married couple, Murray explained.

He and his colleagues viewed 15-minute videotaped conversations of couples talking about a point of contention, such as sex or money. The researchers scored each turn of the conversation.

For example, if a husband raised his eyes during a conversation, several points were deducted. But if a spouse did something positive, such as using humor, then points were added, said Murray, who is an emeritus professor of applied mathematics at the University of Washington and an emeritus professor of mathematical biology at the University of Oxford in the UK.

Murray and his colleagues plotted the scores for each turn in the conversation on a graph. The result was a sort of "cumulative Dow Jones of conversation," said Murray.

Like the stock market average, the conversation ratings "wiggled around" over time, but if they generally rose over time, the marriage was probably in good shape, Murray said. But if the scores had an overall downward trend, the prognosis for the marriage was bleaker, according to Murray.

Along with other information, such as responses to questionnaires filled out by the couples and physiological readings such as pulse rate, the researchers made a prediction on whether a marriage was likely to last.

The study, which has been going on for more than 10 years, includes more than 700 couples who chose to enroll in the study when they applied for a marriage license.

So far, the mathematical model has been 94 percent accurate in predicting which couples will divorce.

Murray and Gottman and co-author Dr. Kristin Swanson presented the results Thursday at the annual meeting of the American Association for the Advancement of Science in Seattle.

Murray said he hopes that the model can be used to help couples identify problems in their relationship that they can try to improve.

"If they don't change certain things, the marriage is unlikely to last," he said.

Murray said that his psychologist colleague Gottman has started using the model with married couples, and the "counseling has been very encouraging."