James K. McNulty, an associate professor of psychology at Florida State University, and colleagues studied 135 heterosexual couples who had been married less than six months and then followed up with them every six months for four years.
The study, published in the journal Science, found the feelings the study participants verbalized about their marriages were unrelated to changes in their marital happiness over time.
Instead, it was the gut-level negative evaluations of their partners that they unknowingly revealed during a baseline experiment that predicted future happiness, the study said.
"Everyone wants to be in a good marriage," McNulty said in a statement. "And in the beginning, many people are able to convince themselves of that at a conscious level. But these automatic, gut-level responses are less influenced by what people want to think. You can't make yourself have a positive response through a lot of wishful thinking."
The researchers asked the subjects to verbalize their relationship satisfaction and the severity of their specific relationship problems.
The researchers then flashed photos of the participants' spouses on a computer screen for one-third of a second, followed by a positive word like "awesome" or "terrific" or a negative word like "awful" or "terrible." The subjects had to press a key on the keyboard to indicate whether the word was positive or negative.
The researchers used specialized software to measure reaction time.
"It's generally an easy task, but flashing a picture of their spouse makes people faster or slower depending on their automatic attitude toward the spouse," McNulty said. "People who have really positive feelings about their partners are very quick to indicate that words like 'awesome' are positive words and very slow to indicate that words like 'awful' are negative words."
People with positive gut-level attitudes were really good at processing positive words but bad at processing negative words when those automatic attitudes were activated. The opposite was also true.
When a spouse had negative feelings about a partner that were activated by the brief exposure to the photo, they had a harder time switching gears to process the positive words.
The researchers found the respondents who unwittingly revealed negative or lukewarm attitudes during the implicit measure -- the gut-level attitudes -- reported the most marital dissatisfaction four years later.