A summary of the findings of the report are:
- On the telephone survey, 36 percent of Americans report attending religious services weekly or more, compared to 31 percent on the online survey.
- Compared to 30 percent of telephone respondents, 43 percent of online survey respondents say they attend religious services seldom or never.
- When interviewed by telephone, fewer than 3-in-10 (29 percent) white mainline Protestants report that they seldom or never attend religious services, compared to 45 percent of white mainline Protestants who took the self-administered online survey.
- Catholics are less than half as likely to report seldom or never attending religious services when responding on the telephone versus online (15 percent vs. 33 percent).
- Nine percent of white evangelical Protestants report they seldom or never attend religious services when speaking with an interviewer by phone, compared to 17 percent who report the same in a self-administered online survey.
- Only 14 percent of black Protestants report seldom or never attending on a telephone survey, compared to nearly one-quarter (24 percent) on the online survey.
- Surprisingly, the social desirability effects are strong among the religiously unaffiliated. While 73 percent say they seldom or never attend religious services in a telephone survey, that number jumps nearly 20 percentage points to 91 percent on an online survey.
- The study also found significant differences between younger and older Americans, as well as among different regions of the country, in the degree to which they inflate religious participation.