The Graphic of the Week highlights data from PRRI’s newest study, “I Know What You Did Last Sunday: Measuring Social Desirability Bias in Self-Reported Religious Behavior, Belief, and Belonging,” which finds that Americans tend to exaggerate how often they attend religious services. By comparing survey modes, the study concludes that Americans are more likely to report higher levels of religious participation when polled by live interviewers on the telephone than they are when completing a self-administered online survey.

On the telephone, 30 percent of Americans overall say they seldom or never attend religious services; that number jumps to 43 percent when Americans respond online.

The inflation of religious participation varies considerably among religious groups. Catholics and white mainline Protestants are more likely than white evangelical Protestants and black Protestants to over report their religious participation. When interviewed by telephone, fewer than 3-in-10 (28 percent) white mainline Protestants say they seldom or never attend religious services, compared to 45 percent in the self-administered online survey. Catholics are about half as likely to report seldom or never attending religious services when responding on the telephone versus online (15 percent vs. 33 percent). Among white evangelical Protestants, the differences are less stark: when speaking with a live interviewer, 9 percent report they seldom or never attend religious services compared to 17 percent who report the same in a self-administered survey. Among black Protestants, 14 percent say they seldom or never attend religious services in a telephone survey, compared to 24 percent on an online survey.

The study also found significant differences between younger and older Americans, as well as among people living in different regions of the country, in the degree to which they inflate religious participation. For more information about the study, click here.