CHICAGO - When it comes to religion, Americans change their affiliation early and often, according to a national study released yesterday.

The findings from the Pew Research Center's Forum on Religion & Public Life show that America's religious landscape is in even greater flux than previously believed.

The report estimates that 47 percent to 59 percent of U.S. adults have changed affiliation at least once. And while most who abandon their childhood faith do so before age 24, many of them change their mind more than once. Most described just gradually drifting away from their childhood faith.

"Because American religion is so diverse, it should not surprise us that reasons people move from one religion to another would also be diverse," said John Green, one of the authors of the report and a senior fellow at the Pew Forum.

America's Catholic bishops pointed to the survey's findings that 68 percent of Catholics have carried the faith from youth to adulthood as a sign of resilience "in the face of something as horrific as the sexual abuse crisis."

Among Protestants who were formerly Catholics, one in five cited the sex-abuse scandal as one of several reasons why they had left the Catholic faith. But only a small number - 2 percent to 3 percent - cited it as the sole reason.

But the survey also found that the Catholic Church has netted the greatest loss because it has not matched its high retention with recruitment compared with other churches. The number of Catholics leaving the church outnumbers joiners by 4-1.

The fastest-growing group - people who describe themselves as unaffiliated - has shown steady gains year to year but less retention as many members of this category are spiritual seekers who eventually find what they're looking for.

About half of the former Protestants and Catholics who are now unaffiliated say they lost religion because they view religious people as "hypocritical, judgmental or insincere."

More than 46 percent said they made the switch because they think institutions focus too much on rules and leaders focus too much on power and money.

While nine out of 10 former Catholics and Protestants gave two or more reasons for leaving the religion of their youth, more than two-thirds said they "gradually drifted away from the religion."

This article includes information from the Washington Post and the Associated Press.