The hypothesis by Fincher & Thornhill (F&T) in the target article (see also Fincher & Thornhill 2008) that high levels of popular religiosity are correlated with and perhaps, in part, caused by high disease loads, is a subhypothesis within the larger socioeconomic dysfunctionality hypothesis that proposes that religious supernaturalism tends to suffer serious losses in popularity as general living conditions improve. This uncertainty hypothesis is being supported by a rapidly expanding set of studies, and, as such, strongly contradicts the thesis that supernaturalistic religiosity is the innate, universal human condition (Barber Reference Barber2011); Delamontagne Reference Delamontagne2010; Gill & Lundsgaarde Reference Gill and Lundsgaarde2004; Norris & Inglehart Reference Norris and Inglehart2004; Paul Reference Paul2009; Reference Paul2010a; Reference Paul and Zuckerman2010b; in press; Rees Reference Rees2009; Ruiter & Tubergen Reference Ruiter and Tubergen2009; Verweij et al. Reference Verweij, Ester and Nauta1997; Zuckerman Reference Zuckerman2009).

However, there are certain under-appreciated factors that impact the subject. It has commonly been assumed that levels of supernaturalism are persistently high among “primitive” populations that live under harsh conditions. This appears to not be the case. African Hadza hunter-gatherers are currently living lives not dramatically different than they did in the late Pleistocene. Yet they exhibit minimal religiosity (Barber, in press; Marlowe Reference Marlowe and Kent2002; Reference Marlowe2010; Paul Reference Paul2010a; in press). Although the Hadza fear death, they do not believe in an after-life. In Hadza cosmology the sun is a supernatural entity, but they do not actively worship it or try to influence its actions in their favor. Pre- and post-hunting rituals are absent, and other rituals are limited in scope. Shamans are absent, and the tribe has proved highly resistant to Christian recruitment. Similarly, the Amazonian Piraha are also theistically unconvertible; Everett (Reference Everett2008) found the Piraha to be markedly less religious than devout Christians, especially in their absence of god figures that provide moral guidance.

Preindustrial civilizations have also exhibited strong variations in mass religiosity. The Chinese majority has never developed or adopted major god figures (Yao & Zhao Reference Yao and Zhao2010), and the relatively philosophical civilization appears to have been markedly less pious than neighboring India or pre-Renaissance Europe.

It appears that the high parasite loads and other forms of dysfunction that are continuing to afflict peoples living in undeveloped societies have not consistently forced the development of high levels of religiosity in the population. For example, it is unlikely that the infection, symptom, and mortality rates of the Hadza (Marlowe Reference Marlowe, Ember and Ember2004) are markedly lower than those of other recent hunter-gatherers with much higher levels of supernaturalism. On the other hand, all First-world democracies with historically low levels of socioeconomic dysfunction exhibit historically low levels of religiosity. These patterns suggest that although an inadequate habitat commonly encourages mass religiosity, the effect is not consistent, but that the highest levels of economic and physical security are reliably antithetical to mass religious faith. These hypotheses warrant further research and analysis in a field of human behavior that has not received the full scientific attention it needs.