A new study found that those who wrote about their rows now and again were more satisfied with married life.
Just three 7-minute essays a year, written from someone else’s perspective, made a difference.
A little homework also boosted feelings of love, passion, intimacy, trust and commitment, the journal Psychological Science reports.
It is thought writing from an outsider’s viewpoint helped people see conflict through fresh eyes.
Researcher Eli Finkel said: “I don’t want it to sound like magic but you can get pretty impressive results with a minimal intervention.”
Experts said the exercise could help a lot of people – as long as they don’t bear grudges and are able to distance themselves from the situation.
Prof. Eli Finkel, of Northwestern University, Illinois, tracked the marriages of 120 couples for two years.
Some had been married for just a few weeks when the study began, others for more than 50 years.
In the second year of the study, half were asked to think about a recent row and write about it from the perspective of a neutral party.
They were encouraged to write about how they could distance themselves in future.
Prof. Eli Finkel estimated each essay took 7 minutes – adding up to 21 minutes over the year.
As previous studies have shown, marital satisfaction fell over the course of the first year.
In those who didn’t do the writing task, it continued to drop during the second year.
But in those who did their homework, satisfaction stabilized. While they didn’t argue any less, their rows caused them less upset.
And there were other benefits. Eli Finkel said: “Not only did the effect emerge for marital satisfaction, it also emerged for other relationship processes – like passion and sexual desire.
“These effects emerged whether people were married for one month, 50 years, or anywhere in between.
“A high-quality marriage is one of the strongest predictors of happiness and health.
“From that perspective, participating in a seven-minute writing exercise three times a year has to be one of the best investments married people can make.”