By Peggy Fletcher Stack | Salt Lake Tribune

Right after World War II, American Christianity, including Mormonism, flourished. Religion was the rising tide that lifted everyone’s boat.

Now, with devotion to denominations declining, researcher and writer Jana Riess set out to discover where Mormonism fits in the country’s religious landscape.

Is that same exodus happening with members of The Church of Jesus Christ of Latter-day Saints and for the same reasons or has the Utah-based faith bucked the trend?

The answer to these questions and many, many more can be found in Riess’ new book, “The Next Mormons: How Millennials Are Changing the LDS Church.”

The volume, written with political scientist Benjamin Knoll at Centre College in Danville, Ky., includes data from their 2016 Next Mormons Survey, a large-scale, nationally representative study of four generations, including 1,156 current church members and 540 former members, plus 63 in-depth individual interviews.

Riess’ book is a “momentous achievement,” said David Campbell, a Notre Dame professor of political science.

The volume is the “new standard for the empirical study of Mormonism — rigorous but accessible,” Campbell wrote in an email. “It is filled with rich insights, confirming some long-held assumptions about Latter-day Saints’ beliefs and behaviors, but also illustrating where previous assumptions have gone awry.”

The research contributes to many fields, he said, including religious studies, sociology, political science and anthropology.

“The genius of the book is that Jana designed her survey to be relevant to today’s church, which enables her to uncover new and important insights,” he said. “It is as though she created a Mormon MRI: able to see below the surface to understand what LDS folks really think.”

Retired sociologist Armand Mauss seconds that opinion.

It is a “major contribution to the sociology of contemporary American Latter-day Saints,” said Mauss, who lives in Southern California, “both because of its craftsmanship and because of its recency or currency. It will remain relevant for several years to come.”

Cristina Rosetti, a doctoral candidate in religious studies at the University of California, Riverside, notes that many scholars have worked on history rather than “the lived experience of Mormons.”

By contrast, Riess is looking at “people who are alive right now, not people who are dead,” Rosetti said. “It is a revolutionary book for the field.”

Millennial Mormons are, indeed, leaving the church, Riess said on The Salt Lake Tribune’s “Mormon Land” podcast, and at much higher rates than past generations.

“We used to keep about 75 percent of members,” she said. “For millennials, it’s about 46 percent, or less than half.”

That figure parallels what is happening in other faiths.

What kept Southern Baptists and Latter-day Saint numbers growing was their high fertility rates, Riess noted, but family sizes have been dropping in both groups.

Too, in the mid- to late-20th century, the LDS Church’s emphasis on the nuclear family and opposition to homosexuality were “an attractive feature to many Americans,” she said. “Now, it’s a liability.”

The “tenor of the American family has changed,” she said, partially indicated by the “rise of singles.”

That’s why the data’s biggest surprise, Riess said, was coffee.

According to the church’s health code known as the Word of Wisdom, coffee drinking is prohibited and would bar those who drink it from entering the faith’s temples.

But some 40 percent of current millennial and GenXer members said they had had a cup of coffee in the previous six months, Riess reported, including some who reported having a “temple recommend.”

There was a “clear generational divide” in how Latter-day Saints viewed the Word of Wisdom. Older members saw adherence as “essential” to their identity. Youngers saw it as “important, perhaps, but not essential.”

For Knoll, who helped crunch the survey’s numbers and analyze the data, the biggest takeaway was that, though younger members remain relatively conservative and more traditional than other Americans, “they are more socially and politically diverse” than older Latter-day Saints.

Riess’ research found a “lot more support for Democrats among young Mormons than [previous surveys] did,” Campbell said. “One possibility is that there has been a real change: As the Republican Party has embraced Donald Trump, more and more young Mormons are turning away from the GOP. Older Mormons may also have reservations about Trump, but they are more set in their political ways and less likely to drop their Republican identity.”

The greatest insight of this book, the Notre Dame scholar said, “is how Mormons differ by generation, and how younger members of the LDS Church are adapting to a secularizing society.”

The country is “now in a period when Latter-day Saints are again rethinking what it means to be distinctive,” he said, “and young Mormons often differ from their parents and grandparents.”

What this all says to Mauss is that millennial members “define their ‘Mormon’ identity more in terms of social integration and participation with the Saints than in terms of strict compliance with church rules and requirements [as the preceding generations did].” Riess characterized this general posture as “hold[ing] institutional authority more lightly,” he said, which Mauss described as being more “laid back.”

The question “that no one can answer is whether this posture constitutes a kind of ‘new culture,’ which, in time, will come to characterize American Latter-day Saints more generally,” Mauss added, “or whether today’s millennials will eventually ‘mature out’ of this posture and come to resemble culturally the older Saints.”

Riess and Knoll plan to produce a separate book about the former Mormons from the stats they’ve collected.

“We have as much data on them as we do on current members,” Riess said, “but only had one chapter in this book.”

For his part, Campbell would like to see further research into “the continuing reverberations of the LDS Church’s stance on LGBT issues.”

His “hunch,” he said, “is that LDS attitudes on LGBT matters will be much like those toward gender equality: on average, lagging behind the rest of the country, but still moving in the same direction.”

Riess’ book was focused exclusively on U.S. Latter-day Saints, whose experiences likely differ to some extent from international members, so that could be fodder for another survey.

She would love to tackle it, the researcher said, “but it’s extremely expensive and not very feasible for just our small little team to try to mount an international study.”

Mormonism’s future, Riess reasoned, depends on its ability to maintain healthy tensions with the society.

It needs to find “that optimal space where you have enough distinctiveness that you remain attractive, not just blending into every other religion,” she said. “But you’re not so distinctive that you are alienating, especially to young people.”

A healthy religion needs to be both “firm and elastic,” Riess said. “You want to stay apace of the times without compromising what you consider to be your vital integrity as a faith.”

Is she optimistic that Mormonism can manage that?

Yes, Riess said. On good days.