Rather, the new Baylor Religion Survey documents a trend that can be seen in cities and towns throughout the country: the rising number of evangelical churches that have nothing to do with traditional denominations.
The Baylor Religion Survey, which claims to probe deeper into facets of American religion and spirituality than previous studies, found roughly 30 million Americans, or 10.8 percent, claim no religious affiliation.
A whopping 100 million people - 33.6 percent - however, claimed affiliation with churches that researchers deemed Evangelical.
The results of the survey were shared with religion writers from throughout the country at a meeting of the Religion Newswriters Association in Salt Lake City last week, but were not publicly released until Monday.
Other surveys in previous years had shown a growing percentage of Americans with no religious affiliation. That number grew from 8 percent in 1988 to 14.3 percent in 2004, according to one prominent study.
Researchers from the Baylor Institute for Studies of Religion, however, said they now believe those results were skewed.
It has to do with how many follow-up questions you ask, said Kevin Dougherty, a Baylor sociology professor and one of the survey's authors. "The inability to name a larger denomination has been seen as boosting the percentage of people who have no religion in our society," he said.
The Baylor survey asked not just the respondents' denomination, but the name of a church they attend.
"There are a growing number of congregations that have distanced themselves from denominations," he said.
Greg Johnson, a Utah evangelical who runs the interdenominational group Standing Together, said the survey results don't surprise him.
Megachurches, with thousands of members, are springing up constantly across the United States, he said. "What's being swallowed up are the liberal denomination churches, which are in sharp decline."
The church Johnson attends in Salt Lake City, K2, has grown to more than 1,000 members in two years' time, he said.
"The great appeal for a lot of these kinds of churches is they are very practical, very relational, very appealing to the masses . . . They've got good music, good sermons," Johnson said.
The Baylor study conducted by Gallup in fall 2005 collected written surveys from 1,721 respondents who answered 350 questions ranging from beliefs about God to religious consumerism.
The survey even attempted to gauge belief about the paranormal, such as aliens and Bigfoot, and tried to learn whether believers' faith was rocked by the novel The DaVinci Code, which claimed biographical details for Jesus that Christians have found scandalous.
Though the researchers identified more than a third of respondents as "Evangelical," less than 15 percent of the respondents put that label on themselves.
That fewer people would claim the label "Evangelical" is not surprising to Johnson. More might consider themselves simply Christian or Bible-believing, because the word Evangelical has come to almost mean right-wing in political terms, he said.
Those who are not part of any particular church are not necessarily without spiritual belief, the survey found.
Of the 30 million Americans not affiliated with a church, 62.9 percent said they believe in God or some higher power, while 37.1 percent said they do not believe.
The survey also attempted to gather the most detailed information ever about how Americans see God, said Christopher Bader, a Baylor sociology professor and survey author. He and colleague Paul Froese are working on a book about America's four Gods - the four ways Americans view God - and how they affect culture and politics.
The highest percentage of Americans, 31.4 percent, believe in a Type A God, who is highly involved in their daily lives and world affairs, but also angry and capable of meting out punishment. Another 23 percent believe in a Type B God, who is likewise engaged, but less willing to condemn or punish individuals.
Sixteen percent believe in a Type C God, who does not interact with the world and is unhappy about the current state of affairs. Another 24.4 percent believe in a Type D God, who is not active in the world and is more the disinterested cosmic force that set the laws of nature in motion.
"This is terribly important because it can predict all kinds of things about an individual," Froese said. "A person's opinion of God relates to their world view, their morality, their political views."
As for The DaVinci Code, by author Dan Brown, Christians should not worry that it will empty the pews, Bader said.
It seems many people who read the book show a tendency to believe in the paranormal.
As for space aliens, nearly 25 percent of the survey respondents said they believe some UFOs are probably alien spaceships, and nearly 18 percent said they believe creatures such as Bigfoot and the Loch Ness Monster will one day be discovered.