A new study shows that one in seven Americans will exaggerate how often they attend religious services when asked by a pollster over the phone, versus answering the same question in an online survey.

The Public Religion Research Institute (PRRI) presented a research paper on May 17 that showed that every age group, religious affiliation, and race overstated their religious participation when asked in a telephone survey.

The study, titled "I Know What You Did Last Sunday: Measuring Social Desirability Bias in Self-Reported Religious Behavior, Belief, and Belonging," asked random persons identical questions regarding their belief in God, religious service attendance, and affiliation. The study was presented at the American Association of Public Opinion Research.

"I Know What You Did Last Sunday" showed that over the phone, 30 percent of respondents said that they seldom or never attend religious services, but online, this selection rose to 43 percent. There were also higher numbers of weekly or occasional religious service attendance when participants were asked online compared to over the phone.

Catholics were the most likely to exaggerate church attendance. 15 percent told phone interviewers that they rarely or never attended church, but over 30 percent admitted so online. White Mainline Protestants and young adults also tended to overstate more than other subgroups.

Americans who do not belong to a church also inflated their attendance. 73 percent said they seldom or never attend religious service when asked over the phone, but this number rose to 91 percent when respondents self-reported online.

The results show that although the country is becoming more secular, the appearance of religious participation is still important to Americans.

"The existence of religious participation inflation demonstrates that church attendance remains a strong social norm in the U.S.," Robert P. Jones, co-author of the study and CEO of PRRI, said in a press release.

"The impact of these norms– what social scientists call 'social desirability bias'– is that respondents talking to live interviewers on the telephone are less willing to admit lower levels of participation in an activity deemed to be socially good. Respondents completing the survey privately online are less apt to feel this pressure."

Simply put, "very few people are willing to admit that they never attend religious services, even though many of us don't," said Daniel Cox, co-author of the study, and PRRI's Director of Research.