Catholic young adults place great importance on marriage but have turned away from church-based ideas of how to make it work, according to a study released last week by the Center for Applied Research in the Apostolate at Georgetown University.

For Catholic members of the “millennial generation,” men and women born between 1982 and 1989, marriage is not to be undertaken lightly. Some 82% of these teens and 20-somethings report that they believe marriage is a lifelong commitment, compared with only 56% of Catholics age 47 to 64—approximately their parents’ generation. Moreover, 84% of these young Catholic adults report concern that “couples don’t take marriage seriously enough when divorce is easily available.” By comparison, only 67% of their parents’ generation agree with this statement.

At the same time, only a quarter of these young adults report that their views about marriage have been formed in significant part by their faith. Indeed, a minority think of marriage as a “vocation” or a “calling from God,” and nearly half of singles say it’s not important that their future spouse be Catholic. Rather, the vast majority of 18- to 25-year-olds report that their spouse must be their “soul mate,” and that falling out of love is an acceptable reason for divorce.

Vanishing Catholic Guilt

On questions about the importance of lifelong commitment in marriage, millennials are more in step with their pre-Vatican II-generation grandparents, but on questions about the influence of Catholic teachings on their views about marriage, young adults agree with their boomer parents.

The study, based on an online survey of more than 1,000 adult Catholics, “paints a mixed picture,” said Archbishop Joseph Kurtz, chairman of the Subcommittee on Marriage and Family Life of the U.S. Conference of Catholic Bishops, which commissioned the report. Catholic youth may have a more conservative outlook on life than their parents’ generation but also an individualized idea of who should set the rules, said Christian Smith, professor of sociology at the University of Notre Dame. “Most

younger Catholics have defined their inner self as the authority, and many freely distance themselves from church practices they don’t believe in.”

Even the concept of “Catholic guilt” seems to have disappeared for younger generations: Catholic youth report no feelings of guilt overall, or about premarital sex or pornography, according to Mr. Smith’s forthcoming article in the Review of Religious Research.

Largely Ineffective

The Georgetown study shows that some 69% of Catholics age 18 to 25 believe “marriage is whatever two people want it to be,” while just over half of their parents’ and grandparents’ generation agreed with that statement. This comes as no surprise to researchers following American family trends. With looser social norms dictating appropriate behaviors for husbands and wives, each couple—regardless of religious affiliation—must settle on their own rules of conduct, argues Stephanie Coontz, author of “Marriage, a History.” But when more issues must be negotiated, she notes, there are more points where negotiations can break down.

While research on other Christian denominations shows similar individualized attitudes about the role of faith in everyday life, the generational differences are more pronounced among Catholics. “Catholic teenagers are the most distanced from the church authorities,” reports Mr. Smith, a fact he attributes to “largely ineffective” modern Catholic religious education.

Cultural Shift

To be sure, some caution is advisable when interpreting generational differences measured at different stages of life: The millennials are just at the beginning of adulthood, so their optimistic and individual-focused opinions may change with their circumstances. “Some of this is useful idealism and some of it is just inexperience,” said Mark Regnerus, associate professor of sociology at the University of Texas at Austin. Still, the cultural shift can’t be ignored, Mr. Regnerus said. “We’ve been swamped by messages of romantic individualism. Those ideas can lead people to marry, but can lead you out of the marriage just as fast when things get tough.”

Although young people often embrace traditional religious ideas to combat the influence of excessive individualism in the culture, they want to construct marriages that are more flexible than in the past, according to Ms. Coontz. But it’s a slippery slope, she says. “Once you start tinkering with the kind of set-in-stone beliefs that used to keep people in the same marriages and at the same jobs for most of their lives, where do you draw the line?”