The God Delusion Read online

  GROUP SELECTION

  Some alleged ultimate explanations turn out to be - or avowedly are - 'group-selection' theories. Group selection is the controversial idea that Darwinian selection chooses among species or other groups of individuals. The Cambridge archaeologist Colin Renfrew suggests that Christianity survived by a form of group selection because it fostered the idea of in-group loyalty and in-group brotherly love, and this helped religious groups to survive at the expense of less religious groups. The American group-selection apostle D. S. Wilson independently developed a similar suggestion at more length, in Darwin's Cathedral.

  Here's an invented example, to show what a group-selection theory of religion might look like. A tribe with a stirringly belligerent 'god of battles' wins wars against rival tribes whose gods urge peace and harmony, or tribes with no gods at all. Warriors who unshakeably believe that a martyr's death will send them straight to paradise fight bravely, and willingly give up their lives. So tribes with this kind of religion are more likely to survive in inter-tribal warfare, steal the conquered tribe's livestock and seize their women as concubines. Such successful tribes prolifically spawn daughter tribes that go off and propagate more daughter tribes, all worshipping the same tribal god. The idea of a group spawning daughter groups, like a beehive throwing off swarms, is not implausible, by the way. The anthropologist Napoleon Chagnon mapped just such fissioning of villages in his celebrated study of the 'Fierce People', the Yanomamo of the South American jungle.77

  Chagnon is not a supporter of group selection, and nor am I. There are formidable objections to it. A partisan in the controversy, I must beware of riding off on my pet steed Tangent, far from the main track of this book. Some biologists betray a confusion between true group selection, as in my hypothetical example of the god of battles, and something else which they call group selection but which turns out on closer inspection to be either kin selection or reciprocal altruism (see Chapter 6).

  Those of us who belittle group selection admit that in principle it can happen. The question is whether it amounts to a significant force in evolution. When it is pitted against selection at lower levels - as when group selection is advanced as an explanation for individual self-sacrifice - lower-level selection is likely to be stronger. In our hypothetical tribe, imagine a single self-interested warrior in an army dominated by aspiring martyrs eager to die for the tribe and earn a heavenly reward. He will be only slightly less likely to end up on the winning side as a result of hanging back in the battle to save his own skin. The martyrdom of his comrades will benefit him more than it benefits each one of them on average, because they will be dead. He is more likely to reproduce than they are, and his genes for refusing to be martyred are more likely to be reproduced into the next generation. Hence tendencies towards martyrdom will decline in future generations.

  This is a simplified toy example, but it illustrates a perennial problem with group selection. Group-selection theories of individual self-sacrifice are always vulnerable to subversion from within. Individual deaths and reproductions occur on a faster timescale and with greater frequency than group extinctions and fissionings. Mathematical models can be crafted to come up with special conditions under which group selection might be evolution-arily powerful. These special conditions are usually unrealistic in nature, but it can be argued that religions in human tribal groupings foster just such otherwise unrealistic special conditions. This is an interesting line of theory, but I shall not pursue it here except to concede that Darwin himself, though he was normally a staunch advocate of selection at the level of the individual organism, came as close as he ever came to group selectionism in his discussion of human tribes:

  When two tribes of primeval man, living in the same country, came into competition, if the one tribe included (other circumstances being equal) a greater number of courageous, sympathetic, and faithful members, who were always ready to warn each other of danger, to aid and defend each other, this tribe would without doubt succeed best and conquer the other . . . Selfish and contentious people will not cohere, and without coherence nothing can be effected. A tribe possessing the above qualities in a high degree would spread and be victorious over other tribes; but in the course of time it would, judging from all past history, be in turn overcome by some other and still more highly-endowed tribe.78

  To satisfy any biological specialists who might be reading this, I should add that Darwin's idea was not strictly group selection, in the true sense of successful groups spawning daughter groups whose frequency might be counted in a metapopulation of groups. Rather, Darwin visualized tribes with altruistically co-operative members spreading and becoming more numerous in terms of numbers of individuals. Darwin's model is more like the spread of the grey squirrel in Britain at the expense of the red: ecological replacement, not true group selection.

  RELIGION AS A BY-PRODUCT OF SOMETHING ELSE

  In any case, I want now to set aside group selection and turn to my own view of the Darwinian survival value of religion. I am one of an increasing number of biologists who see religion as a by-product of something else. More generally, I believe that we who speculate about Darwinian survival value need to 'think by-product'. When we ask about the survival value of anything, we may be asking the wrong question. We need to rewrite the question in a more helpful way. Perhaps the feature we are interested in (religion in this case) doesn't have a direct survival value of its own, but is a by-product of something else that does. I find it helpful to introduce the byproduct idea with an analogy from my own field of animal behaviour.

  Moths fly into the candle flame, and it doesn't look like an accident. They go out of their way to make a burnt offering of themselves. We could label it 'self-immolation behaviour' and, under that provocative name, wonder how on earth natural selection could favour it. My point is that we must rewrite the question before we can even attempt an intelligent answer. It isn't suicide. Apparent suicide emerges as an inadvertent side-effect or by-product of something else. A by-product of ... what? Well, here's one possibility, which will serve to make the point.

  Artificial light is a recent arrival on the night scene. Until recently, the only night lights on view were the moon and the stars. They are at optical infinity, so rays coming from them are parallel. This fits them for use as compasses. Insects are known to use celestial objects such as the sun and the moon to steer accurately in a straight line, and they can use the same compass, with reversed sign, for returning home after a foray. The insect nervous system is adept at setting up a temporary rule of thumb of this kind: 'Steer a course such that the light rays hit your eye at an angle of 30 degrees.' Since insects have compound eyes (with straight tubes or light guides radiating out from the centre of the eye like the spines of a hedgehog), this might amount in practice to something as simple as keeping the light in one particular tube or ommatidium.

  But the light compass relies critically on the celestial object being at optical infinity. If it isn't, the rays are not parallel but diverge like the spokes of a wheel. A nervous system applying a 30-degree (or any acute angle) rule of thumb to a nearby candle, as though it were the moon at optical infinity, will steer the moth, via a spiral trajectory, into the flame. Draw it out for yourself, using some particular acute angle such as 30 degrees, and you'll produce an elegant logarithmic spiral into the candle.

  Though fatal in this particular circumstance, the moth's rule of thumb is still, on average, a good one because, for a moth, sightings of candles are rare compared with sightings of the moon. We don't notice the hundreds of moths that are silently and effectively steering by the moon or a bright star, or even the glow from a distant city. We see only moths wheeling into our candle, and we ask the wrong question: Why are all these moths committing suicide? Instead, we should ask why they have nervous systems that steer by maintaining a fixed angle to light rays, a tactic that we notice only where it goes wrong. When the question is rephrased, the mystery evaporates. It never was right to call it suicide. I
t is a misfiring byproduct of a normally useful compass.

  Now, apply the by-product lesson to religious behaviour in humans. We observe large numbers of people - in many areas it amounts to 100 per cent - who hold beliefs that flatly contradict demonstrable scientific facts as well as rival religions followed by others. People not only hold these beliefs with passionate certitude, but devote time and resources to costly activities that flow from holding them. They die for them, or kill for them. We marvel at this, just as we marvelled at the 'self-immolation behaviour' of the moths. Baffled, we ask why. But my point is that we may be asking the wrong question. The religious behaviour may be a misfiring, an unfortunate by-product of an underlying psychological propensity which in other circumstances is, or once was, useful. On this view, the propensity that was naturally selected in our ancestors was not religion per se; it had some other benefit, and it only incidentally manifests itself as religious behaviour. We shall understand religious behaviour only after we have renamed it.

  If, then, religion is a by-product of something else, what is that something else? What is the counterpart to the moth habit of navigating by celestial light compasses? What is the primitively advantageous trait that sometimes misfires to generate religion? I shall offer one suggestion by way of illustration, but I must stress that it is only an example of the kind of thing I mean, and I shall come on to parallel suggestions made by others. I am much more wedded to the general principle that the question should be properly put, and if necessary rewritten, than I am to any particular answer.

  My specific hypothesis is about children. More than any other species, we survive by the accumulated experience of previous generations, and that experience needs to be passed on to children for their protection and well-being. Theoretically, children might learn from personal experience not to go too near a cliff edge, not to eat untried red berries, not to swim in crocodile-infested waters. But, to say the least, there will be a selective advantage to child brains that possess the rule of thumb: believe, without question, whatever your grown-ups tell you. Obey your parents; obey the tribal elders, especially when they adopt a solemn, minatory tone. Trust your elders without question. This is a generally valuable rule for a child. But, as with the moths, it can go wrong.

  I have never forgotten a horrifying sermon, preached in my school chapel when I was little. Horrifying in retrospect, that is: at the time, my child brain accepted it in the spirit intended by the preacher. He told us a story of a squad of soldiers, drilling beside a railway line. At a critical moment the drill sergeant's attention was distracted, and he failed to give the order to halt. The soldiers were so well schooled to obey orders without question that they carried on marching, right into the path of an oncoming train. Now, of course, I don't believe the story and I hope the preacher didn't either. But I believed it when I was nine, because I heard it from an adult in authority over me. And whether he believed it or not, the preacher wished us children to admire and model ourselves on the soldiers' slavish and unquestioning obedience to an order, however preposterous, from an authority figure. Speaking for myself, I think we did admire it. As an adult I find it almost impossible to credit that my childhood self wondered whether I would have had the courage to do my duty by marching under the train. But that, for what it is worth, is how I remember my feelings. The sermon obviously made a deep impression on me, for I have remembered it and passed it on to you.

  To be fair, I don't think the preacher thought he was serving up a religious message. It was probably more military than religious, in the spirit of Tennyson's 'Charge of the Light Brigade', which he may well have quoted:

  'Forward the Light Brigade!'

  Was there a man dismayed?

  Not though the soldiers knew

  Some one had blundered:

  Theirs not to make reply,

  Theirs not to reason why,

  Theirs but to do and die:

  Into the valley of Death

  Rode the six hundred.

  (One of the earliest and scratchiest recordings of the human voice ever made is of Lord Tennyson himself reading this poem, and the impression of hollow declaiming down a long, dark tunnel from the depths of the past seems eerily appropriate.) From the high command's point of view it would be madness to allow each individual soldier discretion over whether or not to obey orders. Nations whose infantrymen act on their own initiative rather than following orders will tend to lose wars. From the nation's point of view, this remains a good rule of thumb even if it sometimes leads to individual disasters. Soldiers are drilled to become as much like automata, or computers, as possible.

  Computers do what they are told. They slavishly obey any instructions given in their own programming language. This is how they do useful things like word processing and spreadsheet calculations. But, as an inevitable by-product, they are equally robotic in obeying bad instructions. They have no way of telling whether an instruction will have a good effect or a bad. They simply obey, as soldiers are supposed to. It is their unquestioning obedience that makes computers useful, and exactly the same thing makes them inescapably vulnerable to infection by software viruses and worms. A maliciously designed program that says, 'Copy me and send me to every address that you find on this hard disk' will simply be obeyed, and then obeyed again by the other computers down the line to which it is sent, in exponential expansion. It is difficult, perhaps impossible, to design a computer which is usefully obedient and at the same time immune to infection.

  If I have done my softening-up work well, you will already have completed my argument about child brains and religion. Natural selection builds child brains with a tendency to believe whatever their parents and tribal elders tell them. Such trusting obedience is valuable for survival: the analogue of steering by the moon for a moth. But the flip side of trusting obedience is slavish gullibility. The inevitable by-product is vulnerability to infection by mind viruses. For excellent reasons related to Darwinian survival, child brains need to trust parents, and elders whom parents tell them to trust. An automatic consequence is that the truster has no way of distinguishing good advice from bad. The child cannot know that 'Don't paddle in the crocodile-infested Limpopo' is good advice but 'You must sacrifice a goat at the time of the full moon, otherwise the rains will fail' is at best a waste of time and goats. Both admonitions sound equally trustworthy. Both come from a respected source and are delivered with a solemn earnestness that commands respect and demands obedience. The same goes for propositions about the world, about the cosmos, about morality and about human nature. And, very likely, when the child grows up and has children of her own, she will naturally pass the whole lot on to her own children - nonsense as well as sense - using the same infectious gravitas of manner.

  On this model we should expect that, in different geographical regions, different arbitrary beliefs, none of which have any factual basis, will be handed down, to be believed with the same conviction as useful pieces of traditional wisdom such as the belief that manure is good for the crops. We should also expect that superstitions and other non-factual beliefs will locally evolve - change over generations - either by random drift or by some sort of analogue of Darwinian selection, eventually showing a pattern of significant divergence from common ancestry. Languages drift apart from a common progenitor given sufficient time in geographical separation (I shall return to this point in a moment). The same seems to be true of baseless and arbitrary beliefs and injunctions, handed down the generations - beliefs that were perhaps given a fair wind by the useful programmability of the child brain.

  Religious leaders are well aware of the vulnerability of the child brain, and the importance of getting the indoctrination in early. The Jesuit boast, 'Give me the child for his first seven years, and I'll give you the man,' is no less accurate (or sinister) for being hackneyed. In more recent times, James Dobson, founder of today's infamous 'Focus on the Family' movement,* is equally acquainted with the principle: 'Those who control what young people are taught, a
nd what they experience - what they see, hear, think, and believe - will determine the future course for the nation.'79

  * I was amused when I saw 'Focus on your own damn family' on a car bumper sticker in Colorado, but it now seems to me less funny. Maybe some children need to be protected from indoctrination by their own parents (see Chapter 9).

  But remember, my specific suggestion about the useful gullibility of the child mind is only an example of the kind of thing that might be the analogue of moths navigating by the moon or the stars. The ethologist Robert Hinde, in Why Gods Persist, and the anthropologists Pascal Boyer, in Religion Explained, and Scott Atran, in In Gods We Trust, have independently promoted the general idea of religion as a by-product of normal psychological dispositions -many by-products, I should say, for the anthropologists especially are concerned to emphasize the diversity of the world's religions as well as what they have in common. The findings of anthropologists seem weird to us only because they are unfamiliar. All religious beliefs seem weird to those not brought up in them. Boyer did research on the Fang people of Cameroon, who believe . . .

  . . . that witches have an extra internal animal-like organ that flies away at night and ruins other people's crops or poisons their blood. It is also said that these witches sometimes assemble for huge banquets, where they devour their victims and plan future attacks. Many will tell you that a friend of a friend actually saw witches flying over the village at night, sitting on a banana leaf and throwing magical darts at various unsuspecting victims.

  Boyer continues with a personal anecdote:

  I was mentioning these and other exotica over dinner in a Cambridge college when one of our guests, a prominent Cambridge theologian, turned to me and said: 'That is what makes anthropology so fascinating and so difficult too. You have to explain how people can believe such nonsense.' Which left me dumbfounded. The conversation had moved on before I could find a pertinent response -to do with kettles and pots.