4. Religiously unaffiliated population change
The religiously unaffiliated population is the world’s third-largest religious category and grew the second-fastest between 2010 and 2020.
The American Trends Panel survey methodology Overview Data in this report comes from Wave 166 of the American Trends Panel (ATP), Pew Research Center’s nationally representative panel of randomly selected U.S. adults. The survey was conducted from March 24 to March 30, 2025. A total of 3,605 panelists responded out of 4,045 who were sampled, […]