George Marks / Getty

The countercultural revolution of the 1960s and 1970s threw the American family into chaos. Young adults—educated liberals especially—revolted against the constraints of 1950s family life, engaging seriously with formerly fringe ideas like open marriage and full-time employment for mothers. The old rules were in tatters, and nobody really knew what the new rules were. The likelihood that a given marriage would end in divorce doubled, to 50 percent, between 1965 and 1980.

Academics and pundits of the era generally assumed that the retreat from marriage would continue apace. Some of these analysts focused on culture, arguing that the pursuit of individualism, personal growth, and liberation from traditional constraints would reduce marriage rates and increase divorce rates. Others focused on economics, arguing that the breakdown of traditional gender roles would undermine the division-of-labor benefits of marriage, rendering the arrangement less sensible and less appealing. Cultural and economic analysts often clashed, but they tended to agree that educated liberals would pave the path away from marriage.

Almost nobody anticipated what happened next. After 1980, the likelihood of divorce among college-educated Americans plummeted. Despite their loosened romantic and sexual values, educated liberals became more dedicated to family stability and intensive parenting. They did adopt the beliefs that marriage is optional and divorce is acceptable, but in their personal lives, they also sought to build and sustain an egalitarian, mutually fulfilling marriage. Today, educated liberals certainly value individuality and self-expression, but they tend to pursue family stability as a primary means of realizing those values.

Poorer, less-educated Americans, especially those without a high-school degree, have exhibited the opposite trend. Although they are no less likely to cohabitate today than in previous eras, they are less likely to marry. When they do marry, they are less satisfied and more likely to divorce.

Social analysts have offered three major explanations for these marital difficulties. The first—that less-educated Americans have lost respect for the institution of marriage—is refuted by data. The psychologists Thomas Trail and Benjamin Karney conducted a definitive study asking Americans to indicate their agreement with the statement that “a happy, healthy marriage is one of the most important things in life.” The agreement rates were virtually identical among Americans of all income and education levels—and quite high all around.

The second explanation is that poorer, less-educated Americans have a different, perhaps faulty, vision of how an ideal marriage should work. Given the marital turmoil that started in the 1960s, it was reasonable to hypothesize that different segments of American society would arrive at different visions of the optimal marriage, and that some of these visions might be more conducive to happiness and longevity than others. But here, too, the best evidence suggests that most Americans, across income and education levels, have adopted a new marital ideal in which spouses look to each other not only for love, but also for self-expression and personal growth. Most Americans agree, for example, that “understanding each other’s hopes and dreams” is essential for a successful marriage—much more important than having sufficient savings, sharing values, or having good sex. Americans today want a partner who can help bring out their best self.

The third explanation is that building and sustaining a marriage that meets these lofty aspirations typically requires substantial investments of time, attention, patience, and responsiveness, investments that are harder for poorer, less-educated Americans to make. When life happens—when the car breaks down or a ligament snaps—they are at greater risk for unemployment, eviction, and destitution. They tend to have less control over their schedules and less money to pay a babysitter, so they may struggle to get regular time alone with their spouse. When they find such time, they are more likely to arrive to the conversation feeling emotionally depleted from other stressors, and the topics of discussion—how to stretch the money this month, how to wrangle child care with a demanding work schedule—are often thornier. The evidence is generally supportive of this third explanation: a major reason why the marriages of poorer, less-educated Americans are struggling is that economic realities make it difficult to live up to the new cultural ideal. This struggle is leading many to opt out of marriage altogether and, for those who opt in, to make the path to marital success more challenging.

Education and income are not determinative, of course. Many people with college degrees and good salaries have terrible marriages, and many people without them have excellent marriages. But poorer, less-educated Americans will continue to struggle, on average, until their economic circumstances align better with the nation’s new marital ideal.

Last Friday, the Labor Department reported that employers added over 300,000 jobs in December, and that wages have begun to rise at a good clip. If unemployment stays low and wages grow for the working class and poor, more Americans will be able to reap the benefits of our new marital ideal, enjoying a stable marriage that helps them pursue a meaningful life. If that transpires, educated liberals will indeed have paved the path—not to marital collapse, but to a stable and more fulfilling approach to family life.

This article is adapted from Alexandra Robbins’s new book, Fraternity: An Inside Look at a Year of College Boys Becoming Men.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.