About 23% of Americans actually do attend church "regularly" (two or three times a month or more) according to time diaries (in which people account for 24 hours of recent activity). But 35% to 45% say they attend regularly when asked on surveys.

Does this mean folks in one of the world's self-proclaimed most religious nations (also according to surveys) deliberately fib when they over report church attendance by 10% to 18%?

Not exactly, says Brenner in an interview Wednesday. We're simply re-doing the question in our minds and answering honestly about our self image.

When you ask people if they attended church, they hear that question pragmatically. They reflect on their identity as a religious person and they want to honestly report their identity as a religious person.

So I think they are being honest with how they understand the question: 'Are you the sort of person who attends religious services?' is what they think they hear and they say yes.

Brenner's research, to be published in Public Opinion Quarterly, concludes:

In the U.S., and to a lesser extent in Canada, the gap between what we say and what we do is substantial, and has been so for the last several decades.