Using an implicit task, scholars used two experiments, how people automatically responded to words, to predict break-ups. They showed it was easier to link words referring to their partner to words with pleasant or unpleasant meanings, a harbinger of couples about to split up.

Most of the time happiness determination in relationships involves asking people but surveys have little value there. Finland always tops 'happiest country' charts even though they aren't happy at all, they just have cultural sisu and claim they are happy when asked.
But people may not really know how happy they are, says Ronald D. Rogge, of the University of Rochester, and "to make things worse, a lot of people don't want to tell you if they're starting to feel less happy in their relationship."

So he and his colleagues Soonhee Lee and Harry T. Reis turned to a technique often used to assess racism and bias, other feelings people have trouble admitting to themselves and to researchers.

The 222 volunteers in their study were all involved in a romantic relationship. Each volunteer supplied the partner's first name and two other words that related to the partner, like a pet name or a distinctive characteristic. Then they watched a monitor as three types of words were presented one at a time – good words (like peace, vacation, or sharing), bad words (such as death, tragedy, and criticizing), and partner-related words (names or traits).



There were two different kinds of tests: one where the volunteer was supposed to press the space bar whenever they saw either good words or partner-related words, and one where the combination was bad words and partner words. The idea is to get at people's automatic reactions to the words – if they have generally good associations with their partners, they should be able to do the first task more easily than the second.

The researchers found that volunteers who found it easy to associate their partner with bad things and difficult to associate the partner with good things were more likely to separate over the next year. The researchers also asked volunteers to report on the strength of their relationships at the start of the study – and found that the new test did a much better job of predicting breakup.

"It really is giving us a unique glimpse into how people were feeling about their partners – giving us information that they were unable or unwilling to report," says Rogge.
Citation: Lee, S., Rogge, R. D.,&Reis, H. T. (2010). Assessing the Seeds of Relationship Decay: Using Implicit Evaluations to Detect the Early Stages of Disillusionment: Using Implicit Evaluations to Detect the Early Stages of Disillusionment. Psychological Science, 21(6), 857-864. https://journals.sagepub.com/doi/10.1177/0956797610371342