Researchers at the University of Michigan and Stony Brook University interviewed 123 couples in their seventh year of marriage and again nine years later.
"These findings show directly, for the first time, that not only conflicts but also simple boredom with the relationship can shape relationships over the long term," said Terri Orbuch, a research professor at U-M Institute for Social Research and Institute for Research on Women and Gender.
Orbuch collaborated on the new study, which is published in the journal Psychological Science, with lead author Irene Tsapelas and Arthur Aron of Stony Brook University.
The researchers examined boredom in predicting relationship quality over nine years. They focused on years seven and 16 among a representative sample of black American and white American couples in the Detroit area.
Both individuals in each couple were of the same race and entering into their first marriages, and the wife was younger than 35 years old.
Participants were asked "During the past month, how often did you feel that your marriage was in a rut, or getting into a rut, that you do the same thing all the time and rarely get to do exciting things together as a couple?"
Other questions asked how satisfied they were in the marriage and directed them to select a picture that best described how close they were with each other.
The study indicated that greater boredom in year seven predicted significantly less satisfaction at year 16. In addition, greater satisfaction in year seven did not significantly predict less boredom in year 16.
Being bored with the marriage undermines closeness, which in turn reduces satisfaction, Orbuch said.
"It suggests that excitement in relationships facilitates or makes salient closeness, which in turn promotes satisfaction in the long term," she said.
Couples can reduce boredom by participating together in exciting activities. The closeness may lead to greater satisfaction, partner responsiveness, commitment and trust, the researchers said.
Psychological Science: http://www3.interscience.wiley.com/cgi-bin/fulltext/122306789/HTMLSTART