Though the United States remains a strongly religious nation, the percentage of Americans saying they have no formal religious identity is growing, the authors of a recent survey have concluded.

A national survey of U.S. religious affiliation suggests the existence of a "wide and possibly growing swath of secularism" in the American population.

The American Religious Identification Survey 2001, released by the Graduate Center of the City University of New York (CUNY), also suggests that the proportion of Christians in the U.S. has dropped—from 86 percent in 1990, when the study was first conducted, to 77 percent in 2001.

The survey was based on random telephone interviews from February to June 2001 of more than 50,000 adults. Researchers estimated the responses to be representative of the entire U.S. adult population.

The study was released late in 2001 after the September 11 terrorist attacks in New York and Washington, D.C.—events that, by nearly all accounts, swelled the numbers of people attending religious services.

But Egon Mayer, one of the co-authors of the study, said September 11 had not permanently altered the U.S. religious landscape. Increased attendance at religious services immediately after the attacks did not change the basic religious affiliations that he and co-author Barry Kosmin studied, Mayer said.

"People didn't attend church or synagogue just for religious reasons. They wanted to be around other people," said Mayer. "People probably feel more religious, but whether they have changed behavior is another question."

Another survey, conducted by the Washington-based Pew Forum on Religion and Public Life and released last month, confirmed part of Mayer's contention.

In the Pew study, 78 percent of those ...