section_path: Classification/Demographic classification
section_name: Demographic classification
paragraph_text: Demographic classification
  
  The five largest religious groups by world population, estimated to account for 5.8 billion people and 84% of the population, are Christianity, Islam, Buddhism, Hinduism (with the relative numbers for Buddhism and Hinduism dependent on the extent of syncretism), and traditional folk religions.
  
  A global poll in 2012 surveyed 57 countries and reported that 59% of the world's population identified as religious, 23% as not religious, 13% as convinced atheists, and also a 9% decrease in identification as religious when compared to the 2005 average from 39 countries. A follow-up poll in 2015 found that 63% of the globe identified as religious, 22% as not religious, and 11% as convinced atheists. On average, women are more religious than men. Some people follow multiple religions or multiple religious principles at the same time, regardless of whether or not the religious principles they follow traditionally allow for syncretism. Unaffiliated populations are projected to drop, even when taking disaffiliation rates into account, due to differences in birth rates.
  
  Scholars have indicated that global religiosity may be increasing due to religious countries having higher birth rates in general.