One crucible for theories of religion is their ability to predict and explain patterns of belief and disbelief. Yet, religious nonbelief is often heavily stigmatized, potentially leading many atheists to refrain from outing themselves even in anonymous polls. We used the unmatched count technique and Bayesian estimation to indirectly estimate atheist prevalence in two nationally representative samples of 2000 U.S. adults apiece.Widely-cited telephone polls (e.g., Gallup, Pew) suggest USA atheist prevalence of only 3-11%. In contrast, our most credible indirect estimate is 26% (albeit with considerable estimate and method uncertainty). Our data and model predict that atheist prevalence exceeds 11% with greater than .99 probability, and exceeds 20% with roughly .8 probability. Prevalence estimates of 11% were even less credible than estimates of 40%, and all intermediate estimates were more credible. Some popular theoretical approaches to religious cognition may require heavy revision to accommodate actual levels of religious disbelief.Keywords: religion; atheism; social desirability; stigma; Bayesian estimation How many atheists are there? 3
How many atheists are there?I am, and I wish I weren't.
Aldous Huxley, Brave New WorldReligion is a core aspect of human nature, yet a comprehensive understanding of religion must also accommodate religious disbelief. Various models seek to explain commonalities in religious cognition (e.g., Boyer, 2008) and the possible adaptive benefits of religious beliefs and practices (e.g., Norenzayan et al., 2014). These models have advanced the naturalistic science of religion, one key challenge in interdisciplinary, consilient approaches to human nature (Wilson, 1999). The scientific success of theories of religion partially hinges on the degree to which they successfully predict and explain the distribution of belief and disbelief. The study of atheists-merely people who disbelieve or lack belief in the existence of God or gods 1 -is thus a central testing ground for basic theory on the origins of religious and supernatural beliefs (Norenzayan & Gervais, 2013). Unfortunately, unbiased answers to some of the most elementary questions regarding belief and disbelief are currently unavailable. Such basic questions as: How many atheists are there?1 As a terminological aside, throughout this paper we use the term "atheist" to refer to people who disbelieve or lack belief in the existence of a god or gods. This definition is standard in the psychology, sociology, and philosophy of religion. Furthermore, it is the definition of "atheist" adopted by the Oxford English Dictionary. Operationally, we thus define people as atheists if they do not indicate belief in a god or gods. We focused on binary classification of atheists not because we necessarily view religious belief as a psychologically binary phenomenon, but rather for direct comparability with existing polling data utilizing binary measurements of this complex construct.How many atheists are there? 4Existing global atheism est...