ANN ARBOR—Women are twice as likely as men to file for divorce, and a new University of Michigan study sheds a little light on why.

The study, which followed 355 couples over the course of 16 years, found that while marital tension increased over time, husbands’ tensions increased at a greater rate than wives’ tensions. However, it was increased marital tension among wives that predicted divorce.

Increased tension among wives was particularly problematic for marital longevity when their husbands reported low levels of tension over time.

The study, led by Kira Birditt of the U-M Institute for Social Research, was published in the journal Developmental Psychology.

“The association with divorce was greater if men reported low levels of tension when women reported a higher accumulation of tension,” said Birditt, a research associate professor and lead author of the study. “It could reflect a lack of investment in the relationship on the husband’s part—they might believe it’s unnecessary to change or adjust their behavior.”

The study used data from the Early Years of Marriage Project, which began in 1986. About half of the 355 couples followed were white and half were black. The couples were interviewed between the first four and nine months of their marriage, and again in years 2, 3, 4, 7 and 16 of the project.

Interviewers asked the husbands and wives about their irritation or resentment over the previous month and how frequently they felt tense from fighting, arguing or disagreeing with their spouses.

Women across the study reported higher levels of tension when they entered the marriage. Husbands reported low levels of tension, but their tension increased more over the course of the marriage.

“It could be that wives have more realistic expectations of marriage, while husbands had more idealistic expectations of wives,” Birditt said.

About 40 percent of the 355 couples divorced during the study’s 16-year-period, which matches the national average of the time period, she said.

“These findings are exciting because it’s important to consider both people in the relationship,” Birditt said. “Previous studies have looked at married individuals, but you’re not getting information from both people in the couple. People in the same relationships have different ideas about the quality of their tie.”

More information:

• Study abstract: The development of marital tension: Implications for divorce among married couples
• Kira Birditt