The Public Religion Research Institute (PRRI) recently conducted a survey of the US population and have published the study’s results as I Know What You Did Last Sunday: Measuring Social Desirability Bias in Self-Reported Religious Behavior, Belief, and Belonging. In the results the folks at PRRI have determined from a random sampling that people in the US, across the spectrum, over report their religious participation when asked over the phone, as opposed to answering the same questions about religious attendance, affiliation, salience and belief in God in an online survey. Those most likely to inflate? Young adults, Catholics and white mainline Protestants. The area most likely to be under reported when queried by phone, seldom or never attending religious services.