What We Know About Why Couples Get Divorced

One thing Brad and Angelina have in common with ordinary American divorces: about two in three are initiated by women.

Angelina Jolie and Brad Pitt

Photographer: Axelle/Bauer-Griffin/FilmMagic via Getty Images

More than 800,000 American couples get divorced each year. Some, such as the reported divorce of Angelina Jolie and Brad Pitt, will get a bit more attention than others. But one fact remains true about all types of marriage: About half end in divorce.

The number of divorces in the U.S. soared in 1970s and 1980s as the Baby Boom generation entered adulthood. More recently, the annual divorce rate has fallen—but that’s largely because fewer people are getting married and doing so at later ages. Assuming Millennials follow more or less the same pattern as their Boomer parents, about half of American marriages will continue to end in divorce, according to a recent estimate by University of Maryland sociology professor Philip Cohen.

Sociologists have spent decades trying to understand why so many marriages end. New research suggests the reasons for divorce are changing, as the roles of men and women changed at work and home. 

Multiple studies have found that about two-thirds of all divorces are initiated by women. “We sometimes have the idea that it’s always men leaving women, but that’s only a third of cases,” said New York University sociology professor Paula England.

But just because you filed the paperwork doesn’t mean you somehow “caused” the divorce, England noted. “She may be leaving because he had an affair,” she said. Or, “he was unemployed and got violent.” (Same-sex marriage was not legal nationwide until last year, so almost all academic studies of divorce look only at heterosexual couples.)

A 17-year study asked more than 2,000 people about their marriages. If the couples got divorced—and, from 1980 to 1997, 274 did split up—they were asked: “What do you think caused the divorce?” In one 2003 study, researchers put those answers into 18 categories:

Infidelity was the most common cause cited by women, while men most commonly said the couple was incompatible. That’s not enough for sociologists, who want to know the deeper reasons why so many marriages have stopped working.

Some factors can make divorce more likely without being a direct cause of breakup. For example, gender roles can affect a couple's likelihood of divorce, even if violating traditional roles isn’t as dangerous for a marriage as it used to be.

While couples that married before 1975 were more likely to split up if they divided housework equally, a study in last month's American Sociological Review found that housework hasn’t been much of a factor for marriages that started since then.

The expectations on men in a marriage have changed less over the past four decades, according to the study by Alexandra Killewald, a Harvard University professor. Men are still expected to be the breadwinners, she found; couples were one-third more likely to break up if husbands weren’t working.

Women, meanwhile, are more likely to get divorced if they have jobs. But according to a 2011 study in the American Journal of Sociology, this has less to do with traditional gender roles and more to do with independence. Having a job “increases divorce because it provides a way for women deeply unsatisfied with their marriages to support themselves outside marriage,” it reported.

Americans are getting divorced a lot more frequently than they did 50 years ago, but that’s not necessarily because they’re less happy. They may just have more ways to escape from unhappy marriages.

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