It is a well-known phenomenon that people overestimate their capacities on traits that are deemed to be socially desirable. In the US, since being religious is seen as a good thing, people seem to feel obliged to put on a facade.
But it is becoming increasingly clear that Americans are less religious that they claim to be. The Pew survey of religious knowledge in the US says that 4/7 (about 55%) attend church once a week but a University of Michigan examination of actual time diaries kept by people indicate that the figure is only about 25%, much like many European countries, while self reports were about 35-45%. The gap between self-perception and reality in the US was around 18% whereas the highest gaps elsewhere in the world were only about 4-8%, and these were in Catholic countries.
Given that fact, should we believe the Pew results that say that “more than a third (37%) say they read the Bible or other Holy Scriptures at least once a week, not counting worship services”? I find that really hard to believe. The Bible is not a great read, frankly. There are a few occasional well written and poetic passages but most of it consists of turgid prose dealing with dreary lists of rules.
My guess is that even if we use the same inflation factor of two that exists for church attendance to arrive at about 20% for weekly Bible reading, that would still be too high.