This neutral interviewing method produced far fewer professions of church attendance. Compared to the "time-use" technique, Presser and Stinson found that nearly 50 percent more people claimed they attended services when asked the type of question that pollsters ask: "Did you attend religious services in the last week?"
In a more recent study, Hadaway estimated that if the number of Americans who told Gallup pollsters that they attended church in the last week were accurate, about 118 million Americans would be at houses of worship each week. By calculating the number of congregations (including non-Christian congregations) and their average attendance, Hadaway estimated that in reality about 21 percent of Americans attended religious services weekly—exactly half the number who told pollsters they did.
Finally, in a brand new paper, Philip Brenner at the University of Michigan's Institute for Social Research compared self-reported attendance at religious services with "time-use" interviews in the United States, Canada, the Netherlands, Germany, France, Norway, Finland, Slovenia, Italy, Spain, Austria, Ireland, and Great Britain. Brenner looked at nearly 500 studies over four decades, involving nearly a million respondents.
Brenner found that the United States and Canada were outliers—not in religious attendance, but in overreporting religious attendance. Americans attended services about as often as Italians and Slovenians and slightly more than Brits and Germans. The significant difference between the two North American countries and other industrialized nations was the enormous gap between poll responses and time-use studies in those two countries.
Why do Americans and Canadians feel the need to overreport their religious attendance? You could say that religiosity for Americans is tied to their identity in a way that it is not for the Germans, the French, and the British. But that only restates the mystery. Why is religiosity tied to American identity?
Historians will point to the European roots of North American colonization. Many European settlers came to the New World in search of religious freedom, presumably because they cared more intensely about religion than did the brethren they left behind.
Perhaps. That answer feels unsatisfactory. I don't think religious intensity necessarily explains how religiosity becomes part of one's identity. Canada and the United States are quite different today in terms of their religious intensity and the importance they attach to the role of religion in public life, yet citizens in both countries greatly exaggerate their church attendance.
Whatever the reason for the disparity, here's the bottom line: For many Americans, church attendance is a central part of their lives. For others, it's a waste of time. If you're in either of these groups, more power to you. But in the spirit of Christmas and the truthteller whose message we celebrate, surely believers and atheists can agree on what to tell folks who talk Jesus but walk Santa: Enough with the two-faced posturing.
Correction, Dec. 23, 2010: This article originally contained an incorrect description of C. Kirk Hadaway's study. (Return to the corrected sentence.)