“These younger unaffiliated adults are very nonreligious,” said Daniel Cox, PRRI’s research director. “They demonstrate much lower levels of religiosity than we see in the general population,” including participation in religious rituals or worship services.

A growing tide of young Americans is drifting away from the religions of their childhood — and most of them are ending up in no religion at all.

One in four young adults choose “unaffiliated” when asked about their religion, according to a new report from the Public Religion Research Institute and Georgetown University’s Berkley Center for Religion, Peace & World Affairs.

But most within this unaffiliated group — 55 percent — identified with a religious group when they were younger.

“These younger unaffiliated adults are very nonreligious,” said Daniel Cox, PRRI’s research director. “They demonstrate much lower levels of religiosity than we see in the general population,” including participation in religious rituals or worship services.

Some of them will return to their faiths as they age, “but there’s not a lot of evidence that most will come back,” added Cox, who said the trend away from organized religion dates back to the early 1990s.

The study of 2,013 Americans ages 18-24 focused on the younger end of the cohort commonly known as the “Millennials” or “Generation Y,” which generally includes young adults as old as 29. Interviews were conducted between March 7 and 20.

Across denominations, the net losses were uneven, with Catholics losing the highest proportion of childhood adherents — nearly 8 percent — followed by white mainline Protestant traditions, which lost 5 percent.

Among Catholics, whites were twice as likely as Hispanics to say they are no longer affiliated with the church.

White evangelical and black denominations fared better, with a net loss of about 1 percent. Non-Christian groups posted a modest 1 percent net increase in followers.

But the only group that saw significant growth between childhood and young adulthood was the unaffiliated — a jump from 11 percent to 25 percent.

The study also posed a wide range of questions to the group, from their views on the Tea Party to labor unions to same-sex marriage.

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