Studies on the demographics of atheism have concluded that self-identified atheists comprise anywhere from 2% to 11% of the world's population, whereas irreligious individuals comprise anywhere from 10% to 22% of the world's population.[1][2][3][4] Several comprehensive global polls on the subject have been conducted by Gallup International: their 2012 poll found that 13% of respondents were "convinced atheists" and their 2015 poll indicated that 11% were "convinced atheists".[4][5] In Scandinavia and East Asia, and particularly in China, atheists and the nonreligious are the majority.[5] Of the global atheist and nonreligious population, 76% reside in Asia and the Pacific, while the remainder reside in Europe (12%), North America (5%), Latin America and the Caribbean (4%), sub-Saharan Africa (2%) and the Middle East and North Africa (less than 1%).[3] In Africa and South America, atheists are typically in the single digits.[5]
Historical records of atheist philosophy span several millennia. Atheistic schools are found in early Indian thought and have existed from the times of the historical Vedic religion.[6] Western atheism has its roots in pre-Socratic Greek philosophy, but did not emerge as a distinct world-view until the late Enlightenment.[7]
Discrepancies exist among sources as to how atheist and religious demographics are changing. Social scientific assessment of the extent of "atheism" in various populations is problematic. First, in most of the world outside of East Asia most populations are believers in either a monotheistic or polytheistic system. Consequently, questions to assess non belief often take the form of any negation of the prevailing belief rather than an assertion of positive atheism and these will then be accounted accurately to rising "atheism".[8][9][10] According to the 2012 Gallup International survey, the number of atheists is on the rise across the world, with religiosity generally declining.[11] However, other global studies have indicated that global atheism may be in decline due to irreligious countries having the lowest birth rates in the world and religious countries having higher birth rates in general.[