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The evolutionary roots of belief

2020; Elsevier BV; Volume: 30; Issue: 17 Linguagem: Inglês

10.1016/j.cub.2020.07.027

1879-0445

Jonathan Birch,

Evolutionary Game Theory and Cooperation

I saw the Lion Man in the British Museum a few years ago, in an exhibition on the theme of ‘living with gods’ (Figure 1). The pictures do not do it justice. It is a 40,000-year-old mammoth-ivory sculpture with the head of a lion and the body of a human, pieced together from fragments found in a German cave. And it is utterly inscrutable. We have no idea who made it or what it meant to its sculptor. Many see a depiction of a non-existent, supernatural being. Then again, there were lions in Europe in the stone age, and shamans have been known to wear lion headdresses. Maybe it depicts a shaman, mid-ritual. The only certainty is that it is a glimpse of a lost and incomprehensible culture, the obvious meaning it once had now an unsolvable riddle. The Lion Man brings out some of the difficult choices faced by anyone who sets out to write about the evolution of ‘belief’. Define the category of ‘belief’ narrowly, so as to include only straightforwardly religious beliefs, and your story starts a few thousand years ago — but it will miss out swathes of relevant prehistory, including objects such as the Lion Man. Define ‘belief’ as broadly as possible (for example, as any representation of the world that is available for the guidance of a wide range of actions) and there will be nothing distinctly human about it at all, given that beliefs in a broad sense are shared by a wide range of other animals. The story Agustín Fuentes wants to tell in Why We Believe is somewhere in the middle: a story about the ancient, but still distinctly hominin, psychological roots of what would eventually become religious belief. This middle ground between belief in the broadest sense and full-blown religious belief is not easy to define. Fuentes offers the following attempt: “belief is the ability to draw on our range of cognitive and social resources, histories and experiences in order to ‘see’ and feel and know ‘something’, and to utterly invest wholly and authentically in it such that it is one’s reality” (p. 177). This is very vague indeed, but it’s hard to imagine a definition that could capture the intended target phenomenon without being vague. I can live with the vagueness, but I’m sceptical of the suggestion that, if we “utterly invest wholly and authentically” in ‘something’, we can make it reality. This is a magic power we do not have. What we can do is create images of what we believe, such as the Lion Man. We can inscribe our ideas, myths, lore and fictions on the walls of caves and into ivory. What we can’t do is bring a non-existent being into existence just by believing in them. The ability to inscribe our ideas on material objects seems likely to have originated in toolmaking. As Fuentes notes (pp. 38–43), the bifacial stone tools of the late Acheulean period around 600,000–300,000 years ago (tools generally known as handaxes and cleavers, although their function is debated) show impressive symmetry and craftsmanship (Figure 2). In modern humans, this kind of toolmaking requires sophisticated cognitive control [1Stout D. Hecht E.E. Evolutionary neuroscience of cumulative culture.Proc. Nat. Acad. Sci. USA. 2017; 114: 7861-7868Crossref PubMed Scopus (57) Google Scholar]. A skilled flint knapper has an inner template of the end-product that they are trying to achieve and a plan or model of how to achieve it. They have internalised technical norms about the correct way to execute particular tasks. There is a dissenting view in which these inner templates and norms were encoded partly genetically in early hominins, like bird songs [2Corbey R. Jagich A. Vaesen K. Collard M. The Acheulean handaxe: more like a bird’s song than a Beatles’ tune?.Evol. Anthropol. 2016; 25: 6-19Crossref PubMed Scopus (50) Google Scholar], but the prevailing view is that they were passed down the generations through social learning — through culture. This does not get us all the way to the Lion Man, but as Fuentes points out (pp. 140–141) we can see some of the ingredients starting to emerge. Even from the late Acheulean there is evidence of different styles of tool at different sites [3Shipton C. White M. Handaxe types, colonization waves, and social norms in the British Acheulean.J. Archaeol. Sci. 2020; 31: 102352Google Scholar]. Groups were starting to diverge, to develop their own distinctive inner templates for handaxes and cleavers. These templates could start to serve as markers of group identity. Meanwhile, the ability to internalise technical norms for precise bodily movements doesn’t have to be limited to toolmaking or tool use: it can be used for dance, for ritual. Group rituals, high in emotional resonance, bond the group together and allow more effective cooperation. Groups can develop shared ways of behaving together and tie their identity as a group to these collective experiences. Once there are rituals, new objects can be specially crafted with these rituals in mind — objects such as the Lion Man perhaps. Fuentes sees toolmaking as part of the story for the origin of belief (in his sense) but far from the whole story. The account that he offers in Why We Believe is compendiously multifactorial, with other factors including cooperative childrearing, extended childhoods, social foraging, defence against predators, expanded brain size and fire. Later there is a role for the domestication of animals and plants, warfare, inequality and hierarchies. The story covers the whole sweep of hominin evolution since our divergence from the other great apes, and most of it is really a story about cognition in general rather than belief in particular. There is a divide in the literature on the evolution of human cognition between accounts that privilege one factor, such as joint intentionality [4Tomasello M. A Natural History of Human Thinking. Harvard University Press, Cambridge, MA2014Crossref Google Scholar], and accounts that present us with swirling feedback loops of interconnected causes. Fuentes is on the latter side. One drawback to this approach is that it becomes hard to see what is distinctive about Fuentes’s account in comparison with other multifactorial big pictures, such as Kim Sterelny’s The Evolved Apprentice [5Sterelny K. The Evolved Apprentice: How Evolution Made Humans Unique. MIT Press, Cambridge, MA2012Crossref Google Scholar]. Another drawback is that it becomes hard to tease out precise, testable predictions. If an account has one big empirical conjecture at its core, it is easier to test. An example is Cecilia Heyes’s account of the origins of human cognition in Cognitive Gadgets [6Heyes C. Cognitive Gadgets: The Cultural Evolution of Thinking. Harvard University Press, Cambridge, MA2018Crossref Google Scholar], which hinges on the big empirical conjecture that the mechanisms of cultural learning are themselves culturally inherited. I couldn’t find anything that plays the same role for Fuentes’s book — no big conjecture on which everything else hinges. It’s an account in which everything matters and everything is interrelated — and that’s a hard hypothesis to test. Full-blown religious belief is only discussed towards the end of the book, and the discussion is surprisingly brief: a single chapter of 25 pages. Fuentes takes a hands-off approach to the specific beliefs of particular religions, arguing that attempts to give evolutionary explanations of specific beliefs lead nowhere. Is he giving up too easily? The ‘big gods’ hypothesis [7Norenzayan A. Big Gods: How Religion Transformed Cooperation and Conflict. Princeton University Press, Princeton, NJ2015Google Scholar], which posits that a shared belief in an all-powerful, divine enforcer of social norms helps stabilise more complex societies, is singled out for special criticism (pp. 138–140). And indeed, a high-profile recent study suggests that belief in ‘big gods’, although correlated with social complexity, follows rather than precedes complex societies [8Whitehouse H. François P. Savage P.E. Currie T.E. Feeney K.C. Cioni E. Purcell R. Ross R.M. Larson J. Baines J. et al.Complex societies precede moralizing gods throughout world history.Nature. 2019; 568: 226-229Crossref PubMed Scopus (61) Google Scholar]. Still, haven’t we learnt something by articulating and testing a clear hypothesis? Fuentes is sceptical of attempts to explain specific beliefs because he is “fully comfortable leaving open the possibility that some form of transcendent revelation plays a role in a religion’s particular beliefs” (p. 146). I would say that this too is a hypothesis on which evidence can be brought to bear. One piece of evidence is that the beliefs associated with different religions are often incompatible, so they can’t all be divinely revealed truth. In at least some cases it will be necessary to explain away the appearance of transcendent revelation. But once one grants the need for such an explanation, there is no good reason to exempt one’s own religious beliefs from its scope. Of course, these debates have been running for hundreds of years and can’t be settled here. There are also chapters on the evolution of economies and the evolution of love. What are they doing in this book? The thought is that they crucially involve belief in the sense that we have been discussing. Consider money. When you take a piece of metal and stamp an emperor’s face on it, you are inscribing a myth onto a material object. Economies don’t work because of the intrinsic value of a coin or a piece of paper: they work because the coins and pieces of paper are symbols that inspire confidence that debts will be honoured. Money is not a ritual object, but it shares important features with ritual objects. We believe in it, and our belief in it is central to our identity and our social organisation. The chapter goes on to critique the allegedly widespread belief in capitalist societies that economic self-interest is ‘natural’ for humans. A worthy endeavour, but I couldn’t help but notice that, as soon as the topic is something other than religion, Fuentes is happy to explain — and criticise — specific beliefs. Then we come to the chapter on love. The connection between love and belief is not obvious, but it is there if you look hard enough. To love someone, perhaps you have to believe that they are worthy of love. I can sympathise with people I think don’t deserve my sympathy, but can I love them? Love it seems involves belief — for me, at least. More generally, belief makes possible a whole range of complex, partly cognitive emotions, including guilt (which involves the belief that one is guilty), sexual jealousy (which involves the belief that a relationship is threatened) and indignation (which involves a belief that one has been wronged). Beliefs inhabit our emotions as constituent parts, and these complex, belief-involving emotions are at the core of human relationships. Fuentes argues for the plausible idea that love has its origins in pair-bonding mechanisms that initially regulated the mother–child relationship but that, in humans, have expanded out to encompass a large in-group — and maybe, if we try hard enough, the rest of the world as well. In sum, Why We Believe provides a wide-ranging discussion of the distinctive features of human belief: our capacity to form beliefs about non-existent beings, and our capacity to inscribe our beliefs on the world in countless ways. Religion is a manifestation of that capacity, but it is not the only one. Readers with an interest in the origins of human cognition will find it a stimulating book.