An extensive new survey by the Pew Forum on Religion & Public Life details the religious affiliation of the American public and explores the shifts taking place in the U.S. religious landscape. Based on interviews with more than 35,000 Americans age 18 and older, the U.S. Religious Landscape Survey finds that religious affiliation in the U.S. is both very diverse and extremely fluid.

     More than one-quarter of American adults (28%) have left the faith in which they were raised in favor of another religion– or no religion at all. If change in affiliation from one type of Protestantism to another is included, roughly 44% of adults have either switched religious affiliation, moved from being unaffiliated with any religion to being affiliated with a particular faith, or dropped any connection to a specific religious tradition altogether.

     The survey finds that the number of people who say they are unaffiliated with any particular faith today (16.1%) is more than double the number who say they were not affiliated with any particular religion as children. Among Americans ages 18-29, one-in-four say they are not currently affiliated with any particular religion.

See: http://religions.pewforum.org/pdf/report-religious-landscape-study-key-findings.pdf