Big Gods: How Religion Transformed Cooperation and Conflict, presents an empirically grounded rational reconstruction detailing the role that belief in “big gods” (i.e., omniscient, omnipresent, and omnipotent gods) has played in the formation of society from a cultural-evolutionary perspective. Ara Norenzayan’s primary thesis is neatly summed up in the title of the book: religion has historically served—and perhaps still serves—as a building block and maintenance system in societies around the world. This thesis consists of eight central claims, which Norenzayan defends by drawing on empirical research from fields such as archaeology, sociology, cognitive science, and the psychology of religion. In the author’s own words the eight claims are, “1. Watched people are nice people. 2. Religion is more in the situation than in the person. 3. Hell is stronger than heaven. 4. Trust people who trust God. 5. Religious actions speak louder than words. 6. Unworshipped Gods are impotent Gods. 7. Big Gods for Big Groups. 8. Religious groups cooperate in order to compete” (p. xiii). These argument about the societal roles of religious ideas are also embedded in a theory of religion that posits religion as the product of a “powerful combination of genetic and cultural evolution” (p. 9).

Despite being about religious ideas, Norenzayan devotes significant attention to the question of how atheists (and other nonreligious individuals) fit into the narrative. Three points may be of particular interest on this note. First, as stated in the first two central claims above, people—religious or otherwise—behave more cooperatively when they feel as though they are being watched. The cues that trigger this feeling can be as simple as pictures of eyes; one need not believe that pictures can see to nevertheless be affected by them. Furthermore, psychological experiments have shown that exposure to religious stimuli (e.g., words) increase prosocial behaviour even among nonbelievers. Indeed, there is scant evidence that religious individuals are any more virtuous than their secular counterparts. Atheists, then, fit into Norenzayan’s story in much the same way that devout believers do. However, Big Gods also focuses on prejudice against atheists, a topic Norenzayan claims is “one of the least appreciated or understood prejudices in the modern world”. Drawing from several experiments, he takes great care to argue that distrust and discrimination against religious nonbelievers is not simply reducible to “imagined dissimilarity, xenophobia, or general fear of otherness” (p. 76), rather, the specific content of belief (or lack thereof) in big gods is key. As Norenzayan claims in his eight-point summary, there is a link between belief in big gods and trust, the flip side of which is that nonbelievers are untrustworthy. From this point, it is easy to see that atheists are currently still fighting an uphill battle amidst other kinds of cultural pluralism. The third way in which secularism features is in the research on how “gods and governments may be interchangeable” (p. 88). Norenzayan notes that while religious authorities may have been responsible for the world we live in today, secular authorities (i.e., courts, police, etc.) may provide at least an equal footing in encouraging and supporting cooperation and adherence to societal norms. Indeed, the establishment and prevalence of strong secular authorities in some countries may also reduce the anti-atheist prejudice described earlier (pp. 88–93).

There are moments in which Norenzayan strays too far into speculative areas, often in unnecessary comments. He claims, for example, that “reason, logic, or science have little to give us when we face intense anxieties about death, chaos, loneliness, or meaninglessness”(p. 186). This may or may not be true as a metaphysical statement, but Norenzayan provides no evidence for it as an empirical statement. Certainly, if—as Norenzayan argues—big gods can serve both as a source of strength and strife, depending on individuals’ or communities’ interpretations and emphases, the same might be said for various forms of secular rationalism. Who is to say, for example, that the belief in literal immortality offered by many religious traditions is any more comforting than the symbolic immortality offered by the scientific claim that matter is indestructible? It is an empirical question, not to be rhetorically presupposed. Finally, besides the descriptive and explanatory claims of the book, Big Gods also makes a methodological contribution to the field by way of lamenting researchers’ reliance on so-called WEIRD people—Western, Educated, individuals from Industrialized, Rich and Democratically-governed countries—as research subjects. Norenzayan is not the first to make this point, but his pleas for research on non-WEIRD samples are certainly welcome if we are to make generalisable theoretical claims about religion.

Big Gods provides a dynamic look at the interplay between belief in God and the lack of a belief in God. It synthesizes research from multiple disciplines in a palatable and coherent way painting a picture of religions’ role in the formation of the society we know and live in today. Norenzayan weaves the thread of both secular and religious societal forces together to tell a tale of how religions with big gods transformed conflict and cooperation, and also of how secular alternatives are on the rise and present a highly promising means with which to sustain and further advance such cooperation and hopefully stem conflict.