Heathen America?

I'd say the 26% figure is probably more accurate.

How many Americans go to church regularly?

If you listen to the answers provided by major opinion research firms, the answer usually hovers around 40%. (National Opinion Research Center: 38%; Institute for Social Research’s World Values: 44%; Barna: 41%; National Election Studies: 40%; Gallup: 41%.)

But in recent years this consensus has been challenged. It seems that it’s more accurate to say that 40% of Americans claim to attend church regularly.

In 1998, sociologist Stanley Presser at the University of Michigan—whose “research focuses on questionnaire design and testing, the accuracy of survey responses, and ethical issues stemming from the use of human subjects”—co-authored a study entitled: “Data Collection Mode and Social Desirability Bias in Self-Reported Religious Attendance,” American Sociological Review, v. 63 (1998): 137-145 (with L. Stinson). Comparing diaries with actual attendance, they made the estimate that the actual percentage of Americans attending church from the mid-1960’s to the 90’s was about 26%.