Science in the Soul Page 6
Continuing our guesswork about the world of our ancestors, the EEA, there are reasons to think that they lived in stable bands, either roving and foraging like modern baboons, or perhaps more settled, in villages like present-day hunter-gatherers such as the Yąnomamö of the Amazon jungle. In either case, stability of grouping means that individuals would tend to encounter the same individuals repeatedly through their lives. Seen through Darwinian eyes, this could have had important consequences for the evolution of our values. In particular, it might help us to understand why, from the point of view of our selfish genes, we are so absurdly nice to each other.
It is not quite as absurd as it might naively appear. Genes may be selfish, but this is far from saying that individual organisms must be harsh and selfish. A large purpose of the doctrine of the selfish gene is to explain how selfishness at the gene level can lead to altruism at the level of the individual organism. But that only covers altruism as a kind of selfishness in disguise: first, altruism towards kin (nepotism); and second, boons given in the mathematical expectation of reciprocation (you help me and I’ll repay you later).
This is where our assumption of life in villages or tribal bands can help – in two ways. First, there would probably have been a degree of inbreeding, as my colleague W. D. Hamilton has argued. Although, like many other mammals, humans go out of their way to combat the extremes of inbreeding, nevertheless neighbouring tribes frequently speak mutually unintelligible languages and practise incompatible religions, which inevitably limits crossbreeding. Assuming various low rates of between-village migration, Hamilton calculated the expected levels of genetic resemblance within tribes as compared with between tribes. His conclusion was that, under plausible assumptions, fellow village members might as well be brothers by comparison with outsiders from other villages.
Such conditions in the EEA would tend to favour xenophobia: ‘Be unpleasant to strangers not from your own village, because strangers are statistically unlikely to share the same genes.’ It is too simple to conclude that, conversely, natural selection in tribal villages would necessarily have favoured general altruism: ‘Be nice to anyone you meet, because anyone you meet is statistically likely to share your genes for general altruism.’*34 But there could be additional conditions in which this would indeed be so, and this was Hamilton’s conclusion.
The other consequence of the village pattern follows from the theory of reciprocal altruism, which received a fillip in 1984 from the publication of Robert Axelrod’s book The Evolution of Cooperation. Axelrod took the theory of games, specifically the game of prisoner’s dilemma, and, abetted by Hamilton,*35 thought about it in an evolutionary way, using simple but ingenious computer models. His work has become well known and I shan’t describe it in detail but summarize some relevant conclusions.
In an evolutionary world of fundamentally selfish entities, those individuals that cooperate turn out to be surprisingly likely to prosper. The cooperation is based not upon indiscriminate trust but upon swift identification and punishing of defection. Axelrod coined a measure, the ‘shadow of the future’, for how far ahead, on average, individuals can expect to continue meeting. If the shadow of the future is short, or if individual identification or its equivalent is hard, mutual trust is unlikely to develop and universal defection becomes the rule. If the shadow of the future is long, relationships of initial trust, tempered by suspicion of betrayal, are likely to develop. Such would have been the case in the EEA if our speculations about tribal villages or roving bands are correct. We therefore might expect to find, in ourselves, deep-seated tendencies towards what may be called ‘suspicious trust’.
We should also expect to find in ourselves special-purpose brain modules for calculating debt and repayment, for reckoning who owes how much to whom, for feeling pleased when one gains (but perhaps even more displeased when one loses), for mediating the sense of natural justice that I have already mentioned.
Axelrod went on to apply his version of game theory to the special case where individuals bear conspicuous labels. Suppose the population contains two types, arbitrarily called the reds and the greens. Axelrod concluded that, under plausible conditions, a strategy of the following form would be evolutionarily stable: ‘If red, be nice to reds but nasty to greens; if green, be nice to greens but nasty to reds.’ This follows regardless of the actual nature of redness and greenness, and regardless of whether the two types differ in any other respect at all. So, superimposed over the ‘suspicious trust’ I have mentioned, we should not be surprised to see discrimination of this kind.
What might ‘red’ versus ‘green’ correspond to in real life? Plausibly, own tribe versus other tribe. We have reached, via a different theory, the same conclusion as Hamilton with his inbreeding calculations. So the ‘village model’ leads us, by two quite distinct lines of theory, to expect ingroup altruism jockeying with tendencies to xenophobia.
Now, selfish genes are not conscious little agents, taking decisions for their own future good. The genes that survive are the ones that wired up ancestral brains with appropriate rules of thumb, actions that had the consequence, in ancestral environments, of assisting survival and reproduction. Our modern urban environment is very different, but the genes cannot be expected to have adjusted – there hasn’t been time for the slow process of natural selection to catch up. So the same rules of thumb will be acted out as if nothing had happened. From the selfish genes’ point of view it is a mistake, like our love of sugar in a modern world where sugar is no longer scarce and rots our teeth. It is entirely to be expected that there should be such mistakes. Perhaps, when you pity and help a beggar in the street, you are the misfiring instrument of a Darwinian rule of thumb set up in a tribal past when things were very different. I hasten to add that I use the word ‘misfiring’ in a strictly Darwinian sense, not as an expression of my own values.
So far so good, but there is probably more to goodness than that. Many of us seem generous beyond what would pay on ‘selfishness in disguise’ grounds, even assuming that we once lived in inbred bands who could expect a lifetime of opportunities for mutual repayment. If I live in such a world, I shall ultimately benefit if I build up a reputation for trustworthiness, for being the kind of person with whom you can enter into a bargain without fear of betrayal. As my colleague Matt Ridley puts it in his admirable book The Origins of Virtue, ‘Now, suddenly, there is a new and powerful reason to be nice: to persuade people to play with you.’ He quotes the economist Robert Frank’s experimental evidence that people are good at rapidly sizing up, in a roomful of strangers, who can be trusted and who is likely to defect. But even that is still, in a sense, selfishness in disguise. The following suggestion may not be.
I think uniquely in the animal kingdom, we make good use of the priceless gift of foresight. Contrary to popular misunderstandings, natural selection has no foresight. It couldn’t have, for DNA is just a molecule and molecules can’t think. If they could, they’d have seen the danger presented by contraception and nipped it in the bud long ago. But brains are another matter. Brains, if they are big enough, can run all sorts of hypothetical scenarios through their imaginations and calculate the consequences of alternative courses of action. If I do such-and-such I’ll gain in the short term. But if I do so-and-so, although I’ll have to wait for my reward, it’ll be bigger when it comes. Ordinary evolution by natural selection, though an immensely powerful force for technical improvement, cannot look ahead in this way.*36
Our brains were endowed with the facility to set up goals and purposes. Originally, these goals would have been strictly in the service of gene survival: proximally the goal of killing a buffalo, the goal of finding a new waterhole, the goal of kindling a fire, and so on. Still in the interests of gene survival, it was an advantage to make these goals as flexible as possible. New brain machinery, capable of deploying a hierarchy of reprogrammable subgoals within goals, started to evolve.
Imaginative forethought of this kind was originally usefu
l but (in the genes’-eye view) it got out of hand. Brains as big as ours, as I’ve already argued, can actively rebel against the dictates of the naturally selected genes that built them. Using language, that other unique gift of the ballooning human brain, we can conspire together and devise political institutions, systems of law and justice, taxation, policing, public welfare, charity, care for the disadvantaged. We can invent our own values. Natural selection gives rise to these only at second remove, by making brains that grow big. From the point of view of the selfish genes our brains raced away with their emergent properties, and my personal value system regards this with a distinctly positive sign.
The tyranny of the texts
I have already disposed of one source of scepticism about my notion of rebellion against the selfish genes. Radical, left-wing scientists wrongly smelled a concealed Cartesian dualism. A different kind of scepticism comes from religious sources. Time and again, religious critics have said to me something like this. It’s all very well issuing a call to arms against the tyranny of the selfish genes, but how do you decide what to put in its place? It’s all very well sitting round a table with our big brains and our gift of foresight, but how are we going to agree on a set of values, how shall we decide what is good and what bad? What if somebody round the table advocates cannibalism as the answer to the world’s protein shortage, what ultimate authority can we call up to dissuade them? Aren’t we going to be sitting in an ethical vacuum where, in the absence of strong, textual authority, anything goes? Even if you don’t believe the existence claims of religion, don’t we need religion as a source of ultimate values?
This is a genuinely difficult problem. I think we largely are in an ethical vacuum, and I mean all of us. If the hypothetical advocate of cannibalism was careful to specify road kills, who are already dead, he might even claim moral superiority over those who kill animals in order to eat them. There are still, of course, good counter-arguments; for instance, the ‘distress to relatives’ argument applies more strongly to humans than to other species; or there’s the slippery slope argument (‘If we get used to eating human road kills, it will be just a short step to…’ and so on).
So, I am not minimizing the difficulties. But what I will now say – and it’s putting it mildly – is that we are no worse off than we were when we relied on ancient texts. The moral vacuum we now feel ourselves to be in has always been there, even if we haven’t recognized it. Religious people are already entirely accustomed to picking and choosing which texts from holy books they obey and which they reject. There are passages of the Judeo-Christian Bible which no modern Christian or Jew would wish to follow. The story of Isaac’s narrowly averted sacrifice by his father Abraham strikes us moderns as a shocking piece of child abuse, whether we read it literally or symbolically.
Jehovah’s appetite for the smell of burning flesh has no appeal for modern tastes. In Judges, chapter 11, Jephthah made a vow to God that, if God could guarantee Jephthah’s victory over the Children of Ammon, Jephthah would, without fail, sacrifice as a burnt offering ‘whatsoever cometh forth of the doors of my house to meet me, when I return’. As luck would have it, this turned out to be Jephthah’s own daughter, his only child. Understandably he rent his clothes, but there was nothing he could do about it, and his daughter very decently agreed that she should be sacrificed. She asked only that she should be allowed to go into the mountains for two months to bewail her virginity. At the end of this time, Jephthah slaughtered his own daughter and turned her into a burnt offering as Abraham nearly had his son. God was not moved to intervene on this occasion.
Much of what we read of Jehovah makes it hard to see him as a good role model, whether we think of him as a factual or fictitious character. The texts show him to be jealous, vindictive, spiteful, capricious, humourless and cruel.*37 He was also, in modern terms, sexist, and an inciter to racial violence. When Joshua ‘utterly destroyed all that was in the city both man and woman, young and old, and ox, and sheep, and ass, with the edge of the sword’, you might ask what the citizens of Jericho had done to deserve such a terrible fate. The answer is embarrassingly straightforward: they belonged to the wrong tribe. God had promised some Lebensraum to the Children of Israel, and the indigenous population was in the way.
But of the cities of these people, which the LORD thy God doth give thee for an inheritance, thou shalt save alive nothing that breatheth;
But thou shalt utterly destroy them; namely, the Hittites, and the Amorites, the Canaanites, and the Perizzites, the Hivites, and the Jebusites; as the LORD thy God hath commanded thee.*38
Now, of course, I’m being terribly unfair. The one thing a historian must never do is judge one era by the standards of a later era. But that is precisely my point. You cannot have it both ways. If you claim the right to pick and choose the nice bits of the Bible and sweep the nasty bits under the carpet, you have sold the pass. You have admitted that you do not, as a matter of fact, get your values from an ancient and authoritative holy book. You are demonstrably getting your values from some modern source, some contemporary liberal consensus or whatever it is. Otherwise by what criterion do you choose the good bits of the Bible while rejecting, say, Deuteronomy’s clear injunction to stone non-virgin brides to death?
Wherever this contemporary liberal consensus may come from, I am entitled to appeal to it when I explicitly reject the authority of my ancient text – the DNA – just as you are entitled to appeal to it when you implicitly reject your – rather less ancient – texts from human scriptures. We can all sit down together and work out the values we want to follow. Whether we are talking about four-thousand-year-old parchment scrolls, or four-thousand-million-year-old DNA, we are all entitled to throw off the tyranny of the texts.
AFTERWORD
Although the onus is not on me to say where religious people find the modern consensus whereby they decide which are the good verses of the Bible and which the horrible ones, there is nevertheless a genuinely interesting question lurking here. Where do our twenty-first-century values come from, as opposed to the relatively nasty ones of earlier centuries? What has changed, such that in the 1920s ‘votes for women’ was a daringly radical proposal, leading to riots in the streets, whereas now to forbid women the vote is regarded as an obvious outrage? Looking back to earlier centuries, Steven Pinker’s The Better Angels of our Nature and Michael Shermer’s The Moral Arc document inexorable improvements in our values. Improvements by whose standards? By the standards of modern times, of course – a line of reasoning which, although circular, is not viciously so.
Think of the slave trade, think of killing as a spectator sport in the Roman Colosseum; of bear-baiting, burning at the stake, treatment of prisoners including prisoners of war before the Geneva Convention. Think of warfare itself, and consider the wholesale and deliberate bombing of cities in the 1940s against the fact that modern air forces feel the need to apologize when civilian targets are accidentally hit. The moral arc shows some erratic zigzagging, but the trend is unmistakably in one direction. Whatever caused the change, it wasn’t religion. But what was it?
‘Something in the air’? That sounds mystical but it can be rendered in sensible terms. I liken the process to Moore’s Law, which states that computer power has increased over the decades at a lawful rate, though nobody really knows why. Well, we understand it in a general way, but we don’t know why it is so beautifully lawful (a straight line when plotted on a logarithmic scale). For some reason improvements in hardware and software, themselves the summed effects of lots of different kinds of detailed improvements, in different companies in different parts of the world, come together to yield Moore’s Law. What are the equivalent trends that sum up to make the Shifting Moral Zeitgeist, with its overall unidirectional (albeit slightly more erratic) line? Again, the onus is not on me to name them, but I would guess it’s some combination of the following:
legal decisions in courts of law;
speeches and votes in parliaments and houses of
congress;
lectures, papers and books by moral and legal philosophers;
journalistic articles and newspaper editorials;
everyday conversations at dinner parties and in pubs, on radio and television.
This all leads to an obvious next question. Whither the moral arc in future decades and centuries? Can you think of something that we accept with equanimity in 2017 but future centuries will regard with the same revulsion as we, today, view the slave trade or the railway wagons bound for Belsen and Buchenwald? I don’t think it requires much imagination to think of at least one candidate. Don’t the Belsen-bound railway wagons come, unwelcome, to mind when you drive behind one of those closed-in trucks with bewildered, fearful eyes peering through the ventilation slats?
* * *
*1 The Oxford Amnesty Lectures are an annual series, given in the Sheldonian Theatre in aid of Amnesty International. Each year the lectures are collected in a book, edited by an Oxford academic. In 1997 the convenor and editor was Wes Williams and the chosen theme was ‘the values of science’. Among the lecturers were Daniel Dennett, Nicholas Humphrey, George Monbiot and Jonathan Rée. Mine was the second of the series of seven and the text is reproduced here.
*2 Had Sam Harris’s thought-provoking book The Moral Landscape been published at the time of this lecture, I would have deleted ‘strongly’. Harris makes a persuasive case that there are some actions, for example infliction of acute suffering, which it would be perverse to deny are immoral, and that science can play a crucial role in identifying them. A worthwhile case can be made that the fact–value distinction has been oversold. (For full publication details of books referred to in the text and notes, please see the bibliography at the back of this volume.)