Americans are by all measures a deeply religious people, but they are also deeply ignorant about religion.
Researchers from the independent Pew Forum on Religion and Public Life phoned more than 3,400 Americans and asked them 32 questions about the Bible, Christianity and other world religions, famous religious figures and the constitutional principles governing religion in public life.
On average, people who took the survey answered half the questions incorrectly, and many flubbed even questions about their own faith. Those who scored the highest were atheists and agnostics, as well as two religious minorities: Jews and Mormons. The results were the same even after the researchers controlled for factors like age and racial differences.
"Even after all these other factors, including education, are taken into account, atheists and agnostics, Jews and Mormons still outperform all the other religious groups in our survey," said Greg Smith, a senior researcher at Pew.
That finding might surprise some, but not Dave Silverman, president of American Atheists, an advocacy group for nonbelievers that was founded by Madalyn Murray O'Hair.
"I have heard many times that atheists know more about religion than religious people," Silverman said. "Atheism is an effect of that knowledge, not a lack of knowledge. I gave a Bible to my daughter. That's how you make atheists."
Among the topics covered in the survey were: Where was Jesus born? What is Ramadan? Whose writings inspired the Protestant Reformation? Which biblical figure led the exodus from Egypt? What religion is the Dalai Lama? Joseph Smith? Mother Theresa? In most cases, the format was multiple choice.
The researchers said the questionnaire was designed to represent a breadth of knowledge about religion but was not intended to be regarded as a list of the most essential facts about the subject. Most of the questions were easy, but a few were difficult enough to discern which respondents were highly knowledgeable.
On questions about the Bible and Christianity, the groups that answered the most right were Mormons and white evangelical Protestants. On questions about world religions, like Islam, Buddhism, Hinduism and Judaism, the groups that did the best were atheists, agnostics and Jews.
One finding that may grab the attention of policy makers is that most Americans wrongly believe that anything having to do with religion is prohibited in public schools. An overwhelming 89 percent of respondents, asked whether public school teachers are permitted to lead a class in prayer, correctly answered no. But fewer than one in four knew that a public school teacher is permitted "to read from the Bible as an example of literature." And only about one third knew that a public school teacher is permitted to offer a class comparing the world's religions.
The survey's authors concluded that there was "widespread confusion" about "the line between teaching and preaching."
Smith said the survey appeared to be the first comprehensive effort at assessing the basic religious knowledge of Americans, so it is impossible to tell whether they are more or less informed than in the past.
The phone interviews were conducted in English and Spanish in May and June. There were not enough Muslim, Buddhist or Hindu respondents to say how those groups ranked.
Clergy members who are concerned that their congregants know little about the essentials of their own faith will no doubt be appalled by some of these findings:
• 53 percent of Protestants could not identify Martin Luther as the man who started the Protestant Reformation.
• 45 percent of Catholics did not know that their church teaches that the consecrated bread and wine in holy communion are not merely symbols but actually become the body and blood of Christ.
• 43 percent of Jews did not know that Maimonides, one of the foremost rabbinical authorities and philosophers, was Jewish.
The question about Maimonides was the one that the fewest people answered correctly. But 51 percent knew that Joseph Smith was Mormon, and 82 percent knew that Mother Theresa was Roman Catholic.