A 26-year longitudinal study of married couples finds that women who initially have close relationships with their parents-in-law are more likely to get divorced 16 years down the road.

The NIH-funded study—soon to be published in the journal Family Relations—began in 1986 and followed 373 couples ages 25 to 37. Lead researcher and University of Michigan psychologist Terry Orbuch asked each participant to rate the closeness of their relationship with their in-laws on a scale of one to four.

The study found that couples where the husband reported feeling close to his wife's family were 20% less likely to get divorced over the next 16 years. However, couples where the wife reported feeling close to her husband's family were 20% more likely to get divorced.

According to Orbuch, the difference may have a lot to do with identity and boundaries. For example, a wife who feels close to her husband's parents may have trouble establishing certain boundaries and, over time, may regard even well-intentioned advice as meddling.

"Because relationships are so important to women, their identity as a wife and mother is central to their being," Orbuch says, adding, "They interpret what their in-laws say and do as interference into their identity as a spouse and parent."

Meanwhile, men tend to put their identity as a provider ahead of their identity as a father and husband. As a result, when husbands feel close to their in-laws, "These ties connect the husband to the wife… They say, 'Your family relationships are important to me because you are important to me. I want to feel closer to them because it makes me feel closer to you,'" Orbuch concludes (Bernstein, Wall Street Journal, 11/27).