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Professor Richard Dawkins
So much for bones. Now values. We need to establish in Darwinian terms what values are doing for living things. Where bones stiffen limbs, what do values do for their possessors? Having established that the ultimate Darwinian value is gene survival, we are now going to mean something closer to what humans ordinarily mean by values. By values I am going to mean the criteria in the brain by which animals choose how to behave. What are the proximal values in the brain for which animals can be expected to strive, given that the ultimate value is gene survival? The majority of things in the universe don’t actively strive for anything. They just are. I am concerned with the minority that do strive for things, and this minority I shall call value-driven. Some of them are animals and plants, and some are man-made machines – thermostats, heat-seeking missiles. Numerous physiological systems in animals and plants are controlled by negative feedback. There is a target value which is defined in the system. Discrepancies from the target value are sensed and fed back into the system, causing it to change its state in the direction of reducing the discrepancy, until the discrepancy becomes ideally zero. Other value-seeking systems improve with experience. From the point of view of defining values in learning systems, the key concept is reinforcement. Reinforcers are either positive, in which case we call them rewards, or negative punishments. Rewards are states of the world which, when encountered, cause an animal to repeat whatever it recently did; and punishments are the opposite: states of the world which, when encountered, cause an animal to avoid repeating whatever it recently did. The stimuli that animals treat as rewards and punishments are primitive values. Psychologists make a further distinction in primary and secondary reinforcers. Chimpanzees, for example, can learn to work for food as a primary reward, but they will also learn to work for the equivalent of money, which they can then put into slot machines to get food. Some scientists, such as Konrad Lorenz, the grand old man of ethology, have argued that Darwinian natural selection has built in specific rewarding mechanisms, specified differently and in detail for each species to fit its unique way of life. Lorenz believed, for instance, that squirrels had an appetite not just for food, but an appetite to perform the motor patterns of getting food – of cracking nuts in this case – quite independently of the desire to eat them. He would have said that, for a beaver, the act of building a dam has a rewarding value in itself. The nervous system is pre-equipped with the value of liking building dams. Perhaps the most elaborately surprising examples of primary values of this kind come from bird song. Different species of bird develop their songs in different ways, of course. The American Song Sparrow is a fascinating mixture. Young Song Sparrows brought up completely alone end up singing normal Song Sparrow song. So unlike, say Bullfinches, they don’t learn by imitation of other birds, but they do learn. Young Song Sparrows teach themselves to sing by babbling at random and repeating those fragments that sound as a Song Sparrow song ought to sound. There is a template built in of Song Sparrow song genetically specified. You could say that the information of what a Song Sparrow song sounds like is built in by the genes, but note that it is not built in on the motor side. It is not built in as a set of instructions, "Sing like this". It is built in on the sensory side. The instructions are, "Sing at random, until you hear a fragment that sounds like this and then repeat that fragment". So it’s like the rat in the skinner box but, unlike the rat, this reward is highly elaborate and highly specific. It is examples like this that stimulated Lorenz to use the colourful phrase ‘innate schoolmarm’, or innate teaching mechanism, in his various lengthy attempts to resolve the ancient dispute over nativism versus environmentalism. His point was that, however important learning is, there has to be innate guidance of what to learn. In particular, each species needs to be supplied with its own specifications, its own values, specifying what to treat as rewarding and what punishing. "Primary values", Lorenz was saying, "have to come ultimately from Darwinian natural selection". It should follow that, given enough time, we should be able to breed changed values, by artificial selection of the kind we used to breed, say, bulldogs from wolves. We should be able to breed a race of animals that enjoy pain and hate pleasure. Of course, by the animals’ newly evolved definition, this statement is an oxymoron and I have to re-phrase it – by artificial selection, we could reverse the previous definitions of pleasure and pain. The animals so modified would be, of course, less well equipped to survive in the wild than their wild ancestors, just as bulldogs incidentally are for many other reasons. Bulldog puppies can’t be born – they need a caesarean section. Wild ancestors have been naturally selected to enjoy those stimuli most likely to improve their survival. They have been naturally selected to have the right values, the right proximal values to promote their ultimate value of gene survival and, of course, to treat as painful those stimuli most likely to injure them and prevent their surviving. So injury to the body – puncturing the skin, breaking bones – are all perceived as painful, not for arbitrary reasons, but for good Darwinian reasons. Our artificially selected animals in this hypothetical experiment will enjoy having their skin pierced, will actively seek to break their own bones and will bask in a temperature so hot or so cold as to endanger their survival. And similar artificial selection, I venture, would work with humans. Not only could you breed humans with changed tastes, changed primary values, but you could breed for all sorts of things like callousness, sympathy, loyalty, slothfulness, petty meanness or the protestant work ethic. This is a less radical claim then it sounds, because genes don’t fix behaviour deterministically. They only contribute quantitatively to statistical tendencies, which are already influenced by many other things. Nor does it imply a single gene for each of these complicated things, any more than the feasibility of breeding race horses implies a single gene for speed. In the absence of artificial breeding, our own values are presumably influenced by natural selection under conditions that prevailed in the Pleistocene of Africa and before. Humans are unique in many ways and perhaps the most obviously unique feature is language. Whereas eyes have evolved between 40 and 60 times independently around the animal kingdom, language, as far as we know, has evolved only once. Superficially, language seems to be purely learned, but there is strong genetic supervision of the learning process. The particular language we speak is of course learned, but the tendency to learn language, rather than just any old thing, is inherited and evolved specifically in our human line. We inherit evolved rules for grammar. The exact readout of these rules varies from language to language, but their deep structure is laid down by the genes and presumably evolved by natural selection, just like our bones. Evidence is good that the brain contains a language module, a computational mechanism that actively seeks to learn language, and actively uses grammatical rules to structure it. According to the young and thriving discipline of evolutionary psychology, the language learning module is just an example of a whole set of inherited special-purpose computational modules in the brain – perhaps modules for sex and reproduction; for analysing kinship, which is important for doling out altruism and avoiding incest; for counting debts and policing obligations; for judging fairness and natural justice; perhaps for throwing projectiles accurately towards a target; and for classifying animals and plants. These modules will presumably be mediated by specific built-in values. If we turn our Darwinian eyes on our modern civilised selves and our predilections – our aesthetic values, our capacity for pleasure, our arts, our philosophies – it is important to wear sophisticated spectacles. Don’t ask how a middle manager’s ambitions for a bigger desk and a softer office carpet benefit his selfish genes. Ask instead how these urban partialities might stem from a mental module which was selected to do something else in a very different place and time. For office carpet perhaps (and I really mean perhaps) read soft and warm animal skins whose possession betokened hunting success. A little parable here. We might, on seeing moths flying into candle flames ask, "What is the Darwinian survival value for moths of making burnt offerings of themselves in candle flames?" My point will be that that’s the wrong question to ask. Instead we should be asking, "What’s the survival value of the kind of nervous mechanism which, when there are candles about, has the effect of guiding moths into them?" A possible solution is this. Lots of insects use rays from distant celestial objects as a compass. You can see why this works because the rays from, say, the moon, the stars, or the sun, are hitting us from infinity. They are therefore parallel, and the rule of thumb in the nervous system that maintains a fixed angle relative to these rays will work, and cause the animal to maintain a fixed compass direction. That presupposes that the object is a celestial object, or at least is at optical infinity. A candle is not at optical infinity. The rays radiate out from a central point and, if you follow that same rule of thumb while maintaining an acute angle to the rays, you will describe a neat logarithmic spiral into the candle flame. So the right way to express the story of the moth and the candle flame is not to ask why they kill themselves, but to ask why they maintain a fixed angle relative to light rays. If you put it like that, and think your way back to a time before candles were invented; before artificial close sources of light at night were invented; back to where any source of light had to be at optical infinity, then you will get the right answer. That's the kind of thing we have to do when asking questions about the evolution of human values.
Sustainability Doesn't Come Naturally: A Darwinian Perspective on Values:
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