As with the 'footprint maps', I wonder whether the ability to see analogies, the ability to express meanings in terms of symbolic resemblances to other things, may have been the crucial
software
advance that propelled human brain evolution over the threshold into a co-evolutionary spiral.
Richard-Dawkins-Unweaving-the-Rainbow
What kind of computation must the brain be doing when we throw something at a target, as our ancestors must increasingly have done while they evolved the hunting habit?
One crucial component of an accurate throw is timing.
Whichever arm action you favour, whether underarm lobbing, overarm bowling or throwing, or wristy flicking, the exact moment at which you release your projectile makes all the difference.
Think about the overarm action of a bowler in cricket (bowling differs from baseball pitching in that the arm must remain straight, and this makes it easier to think about).
If you release the ball too soon, it flies over the batsmen's head.
If you let go too late, it digs into the ground.
How does the nervous system achieve the feat of releasing the projectile at exactly the right moment, tailored to the speed of arm movement?
Unlike a lunge with a sword, in which you might steer your aim all the way to the target, bowling or throwing is ballistic.
The projectile leaves your hand and is then beyond your control.
There are other skilled movements, like hammering a nail, which are effectively ballistic, even if the tool or weapon doesn't leave your hand.
All the computation has to be done in advance: 'dead reckoning'.
One way to solve the release timing problem when throwing a stone or a spear would be to compute the necessary contractions of individual muscles on the fly, while the arm was in motion. Modern digital computers would be capable of this feat, but brains are too slow. Calvin reasoned instead that nervous systems, being slow, would be better off with a buffer store of rote commands to the muscles. The whole sequence of bowling a cricket ball, or throwing a spear, is programmed in the brain as a pre-recorded list of individual muscle twitch commands, packed away in the order they are to be released.
Obviously, more distant targets are harder to hit. Calvin dusted off his physics textbooks and worked out how to calculate the decreasing 'launch window' as you try to maintain accuracy for longer and longer throws. Launch window is space jargon. Rocket scientists (that proverbially gifted profession) calculate the window of opportunity during
which they must launch a spacecraft if they are to hit, say, the moon.
Fire too soon, or too late, and you miss. Calvin worked out that for a rabbit-sized target four metres away, his launch window was about 11 milliseconds wide. If he released his stone too soon, it overshot the rabbit. If he held on too long, his stone fell short. The difference between two short and too long was a mere 11 milliseconds, about a hundredth of a second. Being an expert in the timings of nerve cells, this bothered Calvin, because he knew that the normal margin of error of a nerve cell is greater than the launch window. Yet he also knew that good human throwers are capable of hitting such a target at this distance, even while running. I myself have never forgotten the spectacle of my Oxford contemporary the Nawab of Pataudi (one of India's greatest cricketers, even after losing one eye) fielding for the university and throwing the ball with devastating speed and accuracy at the wicket, again and again, even while running at a speed that visibly intimidated the batsmen while raising the game of his team.
Calvin had a mystery to solve. How do we throw so well? The answer, he decided, must lie in the law of large numbers. No one timing circuit can achieve the accuracy of a ! Kung hunter throwing a spear, or a cricketer throwing a ball. There must be lots of timing circuits working in parallel, their effects being averaged to reach the final decision of when to release the projectile. And now comes the point. Having developed a population of timing and sequencing circuits for one purpose, why not turn them to other ends? Language itself relies upon precise sequencing. So does music, dancing, even thinking out plans for the future. Could throwing have been the forerunner of foresight itself? When we throw our mind forward in imagination, are we doing something almost literal as well as metaphorical? When the first word was uttered, somewhere in Africa, did the speaker imagine himself throwing a missile from his mouth to his intended hearer?
My fourth candidate for software that partakes in software/ hardware co- evolution is the 'meme', the unit of cultural inheritance. We've already hinted at it when discussing the epidemic-style 'take-off' of bestsellers. I here draw upon books of my colleagues Daniel Dennett and Susan Blackmore, who have been among several constructive memetic theorists since the word was first coined in 1976. Genes are replicated, copied from parent to offspring down the generations. A meme is, by analogy, anything that replicates itself from brain to brain, via any available means of copying. It is a matter of dispute whether the resemblance between gene and meme is good scientific poetry or bad. On balance, I still think it is good, although if you look the word up on the worldwide web you'll find plenty of examples of enthusiasts getting carried away and going too far. There even seems to be some kind of religion of the meme starting up - I find it hard to decide whether it is a joke or not.
My wife and I both occasionally suffer from sleeplessness when our minds are taken over by a tune which repeats itself over and over in the head, relentlessly and without mercy, all through the night. Certain tunes are especially bad culprits, for example Tom Lehrer's 'Masochism Tango'. This is not a melody of any great merit (unlike the words, which are brilliantly rhymed), but it is almost impossible to shake off once it gains a hold. We now have a pact that, if we have one of the danger tunes on the brain during the day (Lennon and McCartney are other prime culprits), we shall under no circumstances sing or whistle it near bedtime, for fear of infecting the other. This notion that a tune in one brain can 'infect' another brain is pure meme talk.
The same thing can happen when one is awake. Dennett tells the following anecdote in Darwin's Dangerous Idea (1995):
The other day, I was embarrassed - dismayed - to catch myself walking along humming a melody to myself It was not a theme of Haydn or Brahms or Charlie Parker or even Bob Dylan,- I was energetically humming; 'It takes two to tango' - a perfectly dismal and entirely unredeemed hit of chewing gum for the ears that was unaccountably popular sometime in the 1950's. I am sure I have never in my life chosen this melody, esteemed this melody, or in any way judged it to be better than silence, but there it was, a horrible musical virus, at least as robust in the meme pool as any melody I actually esteem. And now, to make matters worse, I have resurrected the virus in many of you, who will no doubt curse me in days to come when you find yourself humming, for the first time in over thirty years, that boring tune.
For me, the maddening jingle is just as often not a tune but an endlessly repeated phrase, not a phrase with any obvious significance, just a fragment of language that I, or somebody else, has perhaps said at some point during the day. It isn't clear why a particular phrase or tune is chosen but, once there, it is extremely hard to shift. It goes on endlessly rehearsing itself. In 1876 Mark Twain wrote a short story, 'A Literary Nightmare', about his mind being taken over by a ridiculous fragment of versified instruction to a bus conductor with a ticket machine, of which the refrain was
'Punch in the presence of the passenjare'. Punch in the presence of the passenjare Punch in the presence of the passenjare
It has a mantra-like rhythm and I almost dared not quote it for fear of infecting you. I had it going round in my own head for a whole day after reading Mark Twain's story. Twain's narrator finally liberated himself by passing it on to the vicar, who in turn was driven demented. This
'Gadarene swine' aspect of the story -the idea that when you pass a meme to somebody else you thereby lose it - is the only part that does not ring true. Just because you infect somebody else with a meme, does not mean you cleanse your brain of it.
Memes can be good ideas, good tunes, good poems, as well as drivelling mantras. Anything that spreads by imitation, as genes spread by bodily reproduction or by viral infection, is a meme. The chief interest of them is that there is at least the theoretical possibility of a true Darwinian selection of memes, to parallel the familiar selection of genes. Those memes that spread do so because they are good at spreading. Dennett's relentless jingle, like mine and my wife's, was a tango. Is there something insidious about the tango rhythm? Well, we need further evidence. But the general idea that some memes may be more infective than others because of their inherent properties is reasonable enough.
As with genes, we can expect the world to become filled with memes that are good at the art of getting themselves copied from brain to brain. We can notice that some memes, like Mark Twain's jingle, have this property as a matter of fact, though without being able to analyse what gives it to them. It is enough that memes vary in their infectivity for Darwinian selection to get going. Sometimes we can work out what it is that a meme has that helps it to spread. Dennett notes that the conspiracy theory- meme has a built-in response to the objection that there is no good evidence for the conspiracy: 'Of course not - that's how powerful the conspiracy is! '
Genes will spread by reason of pure parasitic effectiveness, as in a virus. We may think this spreading for the sake of spreading rather futile, but nature is not interested in our judgements, of futility or of anything else. If a piece of code has what it takes, it spreads and that's that. Genes can also spread for what we think of as a more 'legitimate' reason, say, because they improve the acuity of a hawk's eyesight. They are the ones that first occur to us when we think of Darwinism. In Climbing Mount Improbable I explained that an elephant's DNA and a virus's are both 'Copy Me' programmes. The difference is that one of them has an almost fantastically large digression: 'Copy me by building an elephant first. ' But both kinds of program spread because, in their different ways, they are good at spreading. The same is true for memes. Jingling tangos survive in brains, and infect other brains, for reasons of pure parasitic effectiveness. They are near the virus end of the spectrum. Great ideas in philosophy, brilliant insights in mathematics, clever techniques for tying knots or fashioning pots, survive in the meme pool for reasons that are closer to the 'legitimate' or 'elephant' end of our Darwinian spectrum.
Memes could not spread but for the biologically valuable tendency of individuals to imitate. There are plenty of good reasons why imitation should have been favoured by conventional natural selection working on genes. Individuals that are genetically predisposed to imitate enjoy a fast track to skills that may have taken others a long time to build up. One of the finest examples is the spread of the habit of opening milk bottles among tits (European equivalent of American chickadees). Milk is delivered in bottles very early to British doorsteps and it usually sits there for a while before being taken in. A small bird is capable of pecking through the lid, but it is not an obvious thing for a bird to do. What happened was that a series of epidemics of bottletop raiding among blue tits spread outwards from discrete geographical foci in Britain. Epidemic is exactly the right word. The zoologists James Fisher and Robert Hinde were able to document the spread of the habit in the 1940s as it radiated outwards by imitation from the focal points where it started, presumably discovered by a few isolated birds: islands of inventiveness and founders of meme epidemics.
Similar stories can be told of chimpanzees. Fishing for termites by poking twigs into a mound is learned by imitation. So is the skill of cracking nuts with stones on a log or stone anvil, which occurs in certain local areas of west Africa but not others. Our hominid ancestors surely learned vital skills by imitating each other. Among surviving tribal groups, stone toolmaking, weaving, techniques for fishing, thatching, pottery, firemaking, cooking, smithwork, all these skills are learned by imitation. Lineages of masters and apprentices are the memetic equivalent of genetic ancestor/descendant lines. The zoologist Jonathan Kingdon has suggested that some of our ancestors' skills began when humans imitated other species. For example, spider webs may have inspired the invention of fishing nets and of string or twine, weaver bird nests the invention of knots or thatching.
Memes, unlike genes, don't seem to have clubbed together to build large 'vehicles' - bodies - for their joint housing and survival. Memes rely on the vehicles built by genes (unless, as has been suggested, you count the Internet as a meme vehicle). But memes manipulate the behaviour of living bodies no less effectively for that. The analogy between genetic and memetic evolution starts to get interesting when we apply our lesson of 'the selfish cooperator'. Memes, like genes, survive in the presence of certain other memes. A mind can become prepared, by the presence of certain memes, to be receptive to particular other memes. Just as a species gene pool becomes a cooperative cartel of genes, so a group of minds - a 'culture', a 'tradition' - becomes a cooperative cartel of memes, a memeplex, as it has been called. As in the case of genes, it is a mistake to see the whole cartel as a unit being selected as a single entity. The right way to see it is in terms of mutually assisting memes, each
providing an environment which favours the others. Whatever may be the limitations of the meme theory, I think this one point, that a culture or a tradition, a religion or a political complexion grows up according to the model of 'the selfish Cooperator' is probably at least an important part of the truth.
Dennett vividly evokes the image of the mind as a seething hotbed of memes. He even goes so far as to defend the hypothesis that 'Human consciousness is itself a huge complex of memes . . . ' He does this, along with much else, persuasively and at length, in his book Consciousness Explained (1991). I cannot possibly summarize the intricate series of arguments in that book, and will content myself with one more characteristic quotation:
The haven all memes depend on reaching is the human mind, but a human mind itself is an artifact created when memes restructure a human brain in order to make it a better habitat for memes. The avenues for entry and departure are modified to suit local conditions, and strengthened by various artificial devices that enhance fidelity and prolixity of replication: native Chinese minds differ dramatically from native French minds, and literate minds differ from, illiterate minds. What memes provide in return to the organisms in which they reside is an incalculable store of advantages - with some Trojan horses thrown in for good measure . . . But if it is true that human minds are themselves to a very great degree the creations of memes, then we cannot sustain the polarity of vision we considered earlier; it cannot be 'memes versus us,' because earlier infestations of memes have already played a major role in determining who or what we are.
There is an ecology of memes, a tropical rainforest of memes, a termite mound of memes. Memes don't only leap from mind to mind by imitation, in culture. That is just the easily visible tip of the iceberg. They also thrive, multiply and compete within our minds. When we announce to the world a good idea, who knows what subconscious quasi-Darwinian selection has gone on behind the scenes inside our heads? Our minds are invaded by memes as ancient bacteria invaded our ancestors' cells and became mitochondria. Cheshire Cat-like, memes merge into our minds, even become our minds, just as eucaryotic cells are colonies of mitochondria, chloroplasts and other bacteria. This sounds like a perfect recipe for co-evolutionary spirals and the enlargement of the human brain, but specifically what drives the spiral? Where lies the self-feeding, the element of 'the more you have, the more you get'?
Susan Blackmore tackles this question, by asking another: 'Whom should you imitate? ' The individuals who are best at the skill in question, certainly, but there is a more general answer to the question. Blackmore
suggests that you should choose to imitate the best imitators - they are likely to have picked up the best skills. And her next question, 'With whom do you mate? ' is answered in a similar way. You mate with the best imitators of the trendiest memes. So, not only are memes selected for the ability to spread themselves, genes are selected in ordinary Darwinian selection for their ability to make individuals that are good at spreading memes. I do not wish to steal Doctor Blackmore's thunder, for I have been privileged to see an advance draft of her book, The Meme Machine (1999). I will simply note that here we have software/hardware co-evolution. The genes build the hardware. The memes are the software. The co-evolution is what may have driven the inflation of the human brain.
I said that I'd return to the illusion of the 'little man in the brain'. Not to solve the problem of consciousness, which is way beyond my capacity, but to make another comparison between memes and genes. In The Extended Phenotype, I argued against taking the individual organism for granted. I didn't mean individual in the conscious sense but in the sense of a single, coherent body surrounded by a skin and dedicated to a more or less unitary purpose of surviving and reproducing. The individual organism, I arguedd is not fundamental to life, but something that emerges when genes, which at the beginning of evolution were separate, warring entities, gang together in cooperative groups, as 'selfish cooperators'. The individual organism is not exactly an illusion. It is too concrete for that. But it is a secondary, derived phenomenon, cobbled together as a consequence of the actions of fundamentally separate, even warring, agents. I shan't develop the idea but just float, following Dennett and Blackmore, the idea of a comparison with memes. Perhaps the subjective 'I', the person that I feel myself to be, is the same kind of semi- illusion. The mind is a collection of fundamentally independent, even warring, agents. Marvin Minsky, the father of artificial intelligence, called his 1985 book The Society of Mind. Whether or not these agents are to be identified with memes, the point I am now making is that the subjective feeling of 'somebody in there' may be a cobbled, emergent, semi-illusion analogous to the individual body emerging in evolution from the uneasy cooperation of genes.
But that was an aside. I have been looking for software innovations that might have launched a self-feeding spiral of hardware/ software co- evolution to account for the inflation of the human brain. I have so far mentioned language, map reading, throwing and memes. Another possibility is sexual selection, which I introduced as an analogy to explain the principle of explosive co-evolution, but could it actually have driven the inflation of the human brain? Did our ancestors impress their mates by a sort of mental peacock's tail? Was larger brain hardware favoured because of its ostentatious software manifestations, perhaps as
the ability to remember the steps of a formidably complicated ritual dance? Perhaps.
Many people will find language itself the most persuasive, as well as the clearest candidate for a software trigger of brain expansion, and I'd like to come back to it from another point of view. Terrence Deacon, in The Symbolic Species (1997), has a meme-like approach to language:
It is not too far-fetched to think of languages a bit as we think of viruses, neglecting the difference in constructive versus destructive effects. Languages are inanimate artefacts, patterns of sounds and scribblings on clay or paper, that happen to get insinuated into the activities of human brains which replicate their parts, assemble them into systems, and pass them on. The fact that the replicated information that constitutes a language is not organized into an animate being in no way excludes it from being an integrated adaptive entity evolving with respect to human hosts.
Deacon goes on to prefer a 'symbiotic' rather than a virulently parasitic model, drawing the comparison again with mitochondria and other symbiotic bacteria in cells. Languages evolve to become good at infecting child brains. But the brains of children, those mental caterpillars, also evolve to become good at being infected by language: co-evolution yet again.
C. S. Lewis, in 'Bluspels and Flalansferes' (1939), reminds us of the philologist's aphorism that our language is full of dead metaphors. In his 1844 essay 'The Poet', the philosopher and poet Ralph Waldo Emerson said, 'Language is fossil poetry. ' If not all of our words, certainly a great number of them, began as metaphors. Lewis mentions 'attend' as having once meant 'stretch'. If I attend to you, I stretch my ears towards you. I 'grasp' your meaning as you 'cover' your topic and 'drive home' your 'point'. We 'go into' a subject, 'open up' a 'line' of thought. I have deliberately chosen cases whose metaphoric ancestry is recent and therefore accessible. Philological scholars will delve deeper (see what I mean? ) and show that even words whose origins are less obvious were once metaphors, perhaps in a dead (get it? ) language. The word language itself comes from the Latin for tongue.
I have just bought a dictionary of contemporary slang because I was disconcerted to be told by American readers of the typescript of this book that some of my favourite English words would not be understood across the Atlantic. 'Mug', for instance, meaning fool, dupe or patsy, is not understood there. In general I have been reassured to find from the dictionary how many slang words are actually universal in the English- speaking world. But I have been more intrigued at the astonishing creativeness of our species in inventing an endless supply of new words
and usages. 'Parallel parking' or 'getting your plumbing snaked' for copulation; 'idiot box' for television; 'park a custard' for vomit; 'Christmas on a stick' for a conceited person; 'nixon' for a fraudulent deal; 'jam sandwich' for a police car; these slang expressions represent the cutting edge of an astonishing richness of semantic innovation. And they perfectly illustrate C. S. Lewis's point. Is this how all our words got their start?
As with the 'footprint maps', I wonder whether the ability to see analogies, the ability to express meanings in terms of symbolic resemblances to other things, may have been the crucial software advance that propelled human brain evolution over the threshold into a co-evolutionary spiral.
In English we use the word 'mammoth' as an adjective, synonymous with very large. Could our ancestors' breakthrough into semantics have come when some pre-sapient poetic genius, struggling to convey the idea of 'large' in some quite different context hit upon the idea of imitating, or drawing, a mammoth? Could that have been the kind of software
advance that nudged humanity into an explosion of software/hardware co-evolution? Perhaps not this particular example, because large size is too easily conveyed by the universal hand gesture beloved of boastful anglers. But even that is a software advance over chimpanzee communication in the wild. Or how about imitating a gazelle to mean the delicate, shy grace of a girl, in a Pliocene anticipation of Yeats's 'Two girls, both beautiful, one a gazelle'? How about sprinkling water from a gourd
to mean not just rain, which is almost too obvious, but tears when trying to convey sadness? Could our remote habilis or erectus ancestors have imagined - and momentously discovered the means to express - an image like the 'sobbing rain' of John Keats? (Though, to be sure, tears themselves are an unsolved evolutionary mystery. )
However it began, and whatever its role in the evolution of language, we humans, uniquely among animal kind, have the poet's gift of metaphor: of noticing when things are like other things and using the relation as a fulcrum for our thoughts and feelings. This is an aspect of the gift of imagining. Perhaps this was the key software innovation that triggered our co-evolutionary spiral. We could think of it as a key advance in the world-simulating software that was the subject of the previous chapter. Perhaps it was the step from constrained virtual reality, where the brain simulates a model of what the sense organs are telling it, to unconstrained virtual reality, in which the brain simulates things that are not actually there at the time - imagination, daydreaming, 'what if? ' calculations about hypothetical futures. And this, finally, brings us back to poetic science and the dominant theme of the whole book.
We can take the virtual reality software in our heads and emancipate it from the tyranny of simulating only utilitarian reality. We can imagine
worlds that might be, as well as those that are. We can simulate possible futures as well as ancestral pasts. With the aid of external memories and symbol-manipulating artifacts - paper and pens, abacuses and computers - we are in a position to construct a working model of the universe and run it in our heads before we die.
We can get outside the universe. I mean in the sense of putting a model of the universe inside our skulls. Not a superstitious, small-minded, parochial model filled with spirits and hobgoblins, astrology and magic, glittering with fake crocks of gold where the rainbow ends. A big model, worthy of the reality that regulates, updates and tempers it; a model of stars and great distances, where Einstein's noble spacetime curve upstages the curve of Yahweh's covenantal bow and cuts it down to size; a powerful model, incorporating the past, steering us through the present, capable of running far ahead to offer detailed constructions of alternative futures and allow us to choose.
Only human beings guide their behaviour by a knowledge of what happened before they were born and a preconception of what may happen after they are dead; thus only humans find their way by a light that illuminates more than the patch of ground they stand on. P. B. and J . S. MEDAWAR, The Life Science (1977)
The spotlight passes but, exhilaratingly, before doing so it gives us time to comprehend something of this place in which we fleetingly find ourselves and the reason that we do so. We are alone among animals in foreseeing our end. We are also alone among animals in being able to say before we die: Yes, this is why it was worth coming to life in the first place.
Now more than ever seems it rich to die, To cease upon the midnight with no pain. While thou art pouring forth thy soul abroad In such an ecstasy!
JOHN KEATS, 'Ode to a Nightingale' (1820)
A Keats and a Newton, listening to each other, might hear the galaxies sing.
One way to solve the release timing problem when throwing a stone or a spear would be to compute the necessary contractions of individual muscles on the fly, while the arm was in motion. Modern digital computers would be capable of this feat, but brains are too slow. Calvin reasoned instead that nervous systems, being slow, would be better off with a buffer store of rote commands to the muscles. The whole sequence of bowling a cricket ball, or throwing a spear, is programmed in the brain as a pre-recorded list of individual muscle twitch commands, packed away in the order they are to be released.
Obviously, more distant targets are harder to hit. Calvin dusted off his physics textbooks and worked out how to calculate the decreasing 'launch window' as you try to maintain accuracy for longer and longer throws. Launch window is space jargon. Rocket scientists (that proverbially gifted profession) calculate the window of opportunity during
which they must launch a spacecraft if they are to hit, say, the moon.
Fire too soon, or too late, and you miss. Calvin worked out that for a rabbit-sized target four metres away, his launch window was about 11 milliseconds wide. If he released his stone too soon, it overshot the rabbit. If he held on too long, his stone fell short. The difference between two short and too long was a mere 11 milliseconds, about a hundredth of a second. Being an expert in the timings of nerve cells, this bothered Calvin, because he knew that the normal margin of error of a nerve cell is greater than the launch window. Yet he also knew that good human throwers are capable of hitting such a target at this distance, even while running. I myself have never forgotten the spectacle of my Oxford contemporary the Nawab of Pataudi (one of India's greatest cricketers, even after losing one eye) fielding for the university and throwing the ball with devastating speed and accuracy at the wicket, again and again, even while running at a speed that visibly intimidated the batsmen while raising the game of his team.
Calvin had a mystery to solve. How do we throw so well? The answer, he decided, must lie in the law of large numbers. No one timing circuit can achieve the accuracy of a ! Kung hunter throwing a spear, or a cricketer throwing a ball. There must be lots of timing circuits working in parallel, their effects being averaged to reach the final decision of when to release the projectile. And now comes the point. Having developed a population of timing and sequencing circuits for one purpose, why not turn them to other ends? Language itself relies upon precise sequencing. So does music, dancing, even thinking out plans for the future. Could throwing have been the forerunner of foresight itself? When we throw our mind forward in imagination, are we doing something almost literal as well as metaphorical? When the first word was uttered, somewhere in Africa, did the speaker imagine himself throwing a missile from his mouth to his intended hearer?
My fourth candidate for software that partakes in software/ hardware co- evolution is the 'meme', the unit of cultural inheritance. We've already hinted at it when discussing the epidemic-style 'take-off' of bestsellers. I here draw upon books of my colleagues Daniel Dennett and Susan Blackmore, who have been among several constructive memetic theorists since the word was first coined in 1976. Genes are replicated, copied from parent to offspring down the generations. A meme is, by analogy, anything that replicates itself from brain to brain, via any available means of copying. It is a matter of dispute whether the resemblance between gene and meme is good scientific poetry or bad. On balance, I still think it is good, although if you look the word up on the worldwide web you'll find plenty of examples of enthusiasts getting carried away and going too far. There even seems to be some kind of religion of the meme starting up - I find it hard to decide whether it is a joke or not.
My wife and I both occasionally suffer from sleeplessness when our minds are taken over by a tune which repeats itself over and over in the head, relentlessly and without mercy, all through the night. Certain tunes are especially bad culprits, for example Tom Lehrer's 'Masochism Tango'. This is not a melody of any great merit (unlike the words, which are brilliantly rhymed), but it is almost impossible to shake off once it gains a hold. We now have a pact that, if we have one of the danger tunes on the brain during the day (Lennon and McCartney are other prime culprits), we shall under no circumstances sing or whistle it near bedtime, for fear of infecting the other. This notion that a tune in one brain can 'infect' another brain is pure meme talk.
The same thing can happen when one is awake. Dennett tells the following anecdote in Darwin's Dangerous Idea (1995):
The other day, I was embarrassed - dismayed - to catch myself walking along humming a melody to myself It was not a theme of Haydn or Brahms or Charlie Parker or even Bob Dylan,- I was energetically humming; 'It takes two to tango' - a perfectly dismal and entirely unredeemed hit of chewing gum for the ears that was unaccountably popular sometime in the 1950's. I am sure I have never in my life chosen this melody, esteemed this melody, or in any way judged it to be better than silence, but there it was, a horrible musical virus, at least as robust in the meme pool as any melody I actually esteem. And now, to make matters worse, I have resurrected the virus in many of you, who will no doubt curse me in days to come when you find yourself humming, for the first time in over thirty years, that boring tune.
For me, the maddening jingle is just as often not a tune but an endlessly repeated phrase, not a phrase with any obvious significance, just a fragment of language that I, or somebody else, has perhaps said at some point during the day. It isn't clear why a particular phrase or tune is chosen but, once there, it is extremely hard to shift. It goes on endlessly rehearsing itself. In 1876 Mark Twain wrote a short story, 'A Literary Nightmare', about his mind being taken over by a ridiculous fragment of versified instruction to a bus conductor with a ticket machine, of which the refrain was
'Punch in the presence of the passenjare'. Punch in the presence of the passenjare Punch in the presence of the passenjare
It has a mantra-like rhythm and I almost dared not quote it for fear of infecting you. I had it going round in my own head for a whole day after reading Mark Twain's story. Twain's narrator finally liberated himself by passing it on to the vicar, who in turn was driven demented. This
'Gadarene swine' aspect of the story -the idea that when you pass a meme to somebody else you thereby lose it - is the only part that does not ring true. Just because you infect somebody else with a meme, does not mean you cleanse your brain of it.
Memes can be good ideas, good tunes, good poems, as well as drivelling mantras. Anything that spreads by imitation, as genes spread by bodily reproduction or by viral infection, is a meme. The chief interest of them is that there is at least the theoretical possibility of a true Darwinian selection of memes, to parallel the familiar selection of genes. Those memes that spread do so because they are good at spreading. Dennett's relentless jingle, like mine and my wife's, was a tango. Is there something insidious about the tango rhythm? Well, we need further evidence. But the general idea that some memes may be more infective than others because of their inherent properties is reasonable enough.
As with genes, we can expect the world to become filled with memes that are good at the art of getting themselves copied from brain to brain. We can notice that some memes, like Mark Twain's jingle, have this property as a matter of fact, though without being able to analyse what gives it to them. It is enough that memes vary in their infectivity for Darwinian selection to get going. Sometimes we can work out what it is that a meme has that helps it to spread. Dennett notes that the conspiracy theory- meme has a built-in response to the objection that there is no good evidence for the conspiracy: 'Of course not - that's how powerful the conspiracy is! '
Genes will spread by reason of pure parasitic effectiveness, as in a virus. We may think this spreading for the sake of spreading rather futile, but nature is not interested in our judgements, of futility or of anything else. If a piece of code has what it takes, it spreads and that's that. Genes can also spread for what we think of as a more 'legitimate' reason, say, because they improve the acuity of a hawk's eyesight. They are the ones that first occur to us when we think of Darwinism. In Climbing Mount Improbable I explained that an elephant's DNA and a virus's are both 'Copy Me' programmes. The difference is that one of them has an almost fantastically large digression: 'Copy me by building an elephant first. ' But both kinds of program spread because, in their different ways, they are good at spreading. The same is true for memes. Jingling tangos survive in brains, and infect other brains, for reasons of pure parasitic effectiveness. They are near the virus end of the spectrum. Great ideas in philosophy, brilliant insights in mathematics, clever techniques for tying knots or fashioning pots, survive in the meme pool for reasons that are closer to the 'legitimate' or 'elephant' end of our Darwinian spectrum.
Memes could not spread but for the biologically valuable tendency of individuals to imitate. There are plenty of good reasons why imitation should have been favoured by conventional natural selection working on genes. Individuals that are genetically predisposed to imitate enjoy a fast track to skills that may have taken others a long time to build up. One of the finest examples is the spread of the habit of opening milk bottles among tits (European equivalent of American chickadees). Milk is delivered in bottles very early to British doorsteps and it usually sits there for a while before being taken in. A small bird is capable of pecking through the lid, but it is not an obvious thing for a bird to do. What happened was that a series of epidemics of bottletop raiding among blue tits spread outwards from discrete geographical foci in Britain. Epidemic is exactly the right word. The zoologists James Fisher and Robert Hinde were able to document the spread of the habit in the 1940s as it radiated outwards by imitation from the focal points where it started, presumably discovered by a few isolated birds: islands of inventiveness and founders of meme epidemics.
Similar stories can be told of chimpanzees. Fishing for termites by poking twigs into a mound is learned by imitation. So is the skill of cracking nuts with stones on a log or stone anvil, which occurs in certain local areas of west Africa but not others. Our hominid ancestors surely learned vital skills by imitating each other. Among surviving tribal groups, stone toolmaking, weaving, techniques for fishing, thatching, pottery, firemaking, cooking, smithwork, all these skills are learned by imitation. Lineages of masters and apprentices are the memetic equivalent of genetic ancestor/descendant lines. The zoologist Jonathan Kingdon has suggested that some of our ancestors' skills began when humans imitated other species. For example, spider webs may have inspired the invention of fishing nets and of string or twine, weaver bird nests the invention of knots or thatching.
Memes, unlike genes, don't seem to have clubbed together to build large 'vehicles' - bodies - for their joint housing and survival. Memes rely on the vehicles built by genes (unless, as has been suggested, you count the Internet as a meme vehicle). But memes manipulate the behaviour of living bodies no less effectively for that. The analogy between genetic and memetic evolution starts to get interesting when we apply our lesson of 'the selfish cooperator'. Memes, like genes, survive in the presence of certain other memes. A mind can become prepared, by the presence of certain memes, to be receptive to particular other memes. Just as a species gene pool becomes a cooperative cartel of genes, so a group of minds - a 'culture', a 'tradition' - becomes a cooperative cartel of memes, a memeplex, as it has been called. As in the case of genes, it is a mistake to see the whole cartel as a unit being selected as a single entity. The right way to see it is in terms of mutually assisting memes, each
providing an environment which favours the others. Whatever may be the limitations of the meme theory, I think this one point, that a culture or a tradition, a religion or a political complexion grows up according to the model of 'the selfish Cooperator' is probably at least an important part of the truth.
Dennett vividly evokes the image of the mind as a seething hotbed of memes. He even goes so far as to defend the hypothesis that 'Human consciousness is itself a huge complex of memes . . . ' He does this, along with much else, persuasively and at length, in his book Consciousness Explained (1991). I cannot possibly summarize the intricate series of arguments in that book, and will content myself with one more characteristic quotation:
The haven all memes depend on reaching is the human mind, but a human mind itself is an artifact created when memes restructure a human brain in order to make it a better habitat for memes. The avenues for entry and departure are modified to suit local conditions, and strengthened by various artificial devices that enhance fidelity and prolixity of replication: native Chinese minds differ dramatically from native French minds, and literate minds differ from, illiterate minds. What memes provide in return to the organisms in which they reside is an incalculable store of advantages - with some Trojan horses thrown in for good measure . . . But if it is true that human minds are themselves to a very great degree the creations of memes, then we cannot sustain the polarity of vision we considered earlier; it cannot be 'memes versus us,' because earlier infestations of memes have already played a major role in determining who or what we are.
There is an ecology of memes, a tropical rainforest of memes, a termite mound of memes. Memes don't only leap from mind to mind by imitation, in culture. That is just the easily visible tip of the iceberg. They also thrive, multiply and compete within our minds. When we announce to the world a good idea, who knows what subconscious quasi-Darwinian selection has gone on behind the scenes inside our heads? Our minds are invaded by memes as ancient bacteria invaded our ancestors' cells and became mitochondria. Cheshire Cat-like, memes merge into our minds, even become our minds, just as eucaryotic cells are colonies of mitochondria, chloroplasts and other bacteria. This sounds like a perfect recipe for co-evolutionary spirals and the enlargement of the human brain, but specifically what drives the spiral? Where lies the self-feeding, the element of 'the more you have, the more you get'?
Susan Blackmore tackles this question, by asking another: 'Whom should you imitate? ' The individuals who are best at the skill in question, certainly, but there is a more general answer to the question. Blackmore
suggests that you should choose to imitate the best imitators - they are likely to have picked up the best skills. And her next question, 'With whom do you mate? ' is answered in a similar way. You mate with the best imitators of the trendiest memes. So, not only are memes selected for the ability to spread themselves, genes are selected in ordinary Darwinian selection for their ability to make individuals that are good at spreading memes. I do not wish to steal Doctor Blackmore's thunder, for I have been privileged to see an advance draft of her book, The Meme Machine (1999). I will simply note that here we have software/hardware co-evolution. The genes build the hardware. The memes are the software. The co-evolution is what may have driven the inflation of the human brain.
I said that I'd return to the illusion of the 'little man in the brain'. Not to solve the problem of consciousness, which is way beyond my capacity, but to make another comparison between memes and genes. In The Extended Phenotype, I argued against taking the individual organism for granted. I didn't mean individual in the conscious sense but in the sense of a single, coherent body surrounded by a skin and dedicated to a more or less unitary purpose of surviving and reproducing. The individual organism, I arguedd is not fundamental to life, but something that emerges when genes, which at the beginning of evolution were separate, warring entities, gang together in cooperative groups, as 'selfish cooperators'. The individual organism is not exactly an illusion. It is too concrete for that. But it is a secondary, derived phenomenon, cobbled together as a consequence of the actions of fundamentally separate, even warring, agents. I shan't develop the idea but just float, following Dennett and Blackmore, the idea of a comparison with memes. Perhaps the subjective 'I', the person that I feel myself to be, is the same kind of semi- illusion. The mind is a collection of fundamentally independent, even warring, agents. Marvin Minsky, the father of artificial intelligence, called his 1985 book The Society of Mind. Whether or not these agents are to be identified with memes, the point I am now making is that the subjective feeling of 'somebody in there' may be a cobbled, emergent, semi-illusion analogous to the individual body emerging in evolution from the uneasy cooperation of genes.
But that was an aside. I have been looking for software innovations that might have launched a self-feeding spiral of hardware/ software co- evolution to account for the inflation of the human brain. I have so far mentioned language, map reading, throwing and memes. Another possibility is sexual selection, which I introduced as an analogy to explain the principle of explosive co-evolution, but could it actually have driven the inflation of the human brain? Did our ancestors impress their mates by a sort of mental peacock's tail? Was larger brain hardware favoured because of its ostentatious software manifestations, perhaps as
the ability to remember the steps of a formidably complicated ritual dance? Perhaps.
Many people will find language itself the most persuasive, as well as the clearest candidate for a software trigger of brain expansion, and I'd like to come back to it from another point of view. Terrence Deacon, in The Symbolic Species (1997), has a meme-like approach to language:
It is not too far-fetched to think of languages a bit as we think of viruses, neglecting the difference in constructive versus destructive effects. Languages are inanimate artefacts, patterns of sounds and scribblings on clay or paper, that happen to get insinuated into the activities of human brains which replicate their parts, assemble them into systems, and pass them on. The fact that the replicated information that constitutes a language is not organized into an animate being in no way excludes it from being an integrated adaptive entity evolving with respect to human hosts.
Deacon goes on to prefer a 'symbiotic' rather than a virulently parasitic model, drawing the comparison again with mitochondria and other symbiotic bacteria in cells. Languages evolve to become good at infecting child brains. But the brains of children, those mental caterpillars, also evolve to become good at being infected by language: co-evolution yet again.
C. S. Lewis, in 'Bluspels and Flalansferes' (1939), reminds us of the philologist's aphorism that our language is full of dead metaphors. In his 1844 essay 'The Poet', the philosopher and poet Ralph Waldo Emerson said, 'Language is fossil poetry. ' If not all of our words, certainly a great number of them, began as metaphors. Lewis mentions 'attend' as having once meant 'stretch'. If I attend to you, I stretch my ears towards you. I 'grasp' your meaning as you 'cover' your topic and 'drive home' your 'point'. We 'go into' a subject, 'open up' a 'line' of thought. I have deliberately chosen cases whose metaphoric ancestry is recent and therefore accessible. Philological scholars will delve deeper (see what I mean? ) and show that even words whose origins are less obvious were once metaphors, perhaps in a dead (get it? ) language. The word language itself comes from the Latin for tongue.
I have just bought a dictionary of contemporary slang because I was disconcerted to be told by American readers of the typescript of this book that some of my favourite English words would not be understood across the Atlantic. 'Mug', for instance, meaning fool, dupe or patsy, is not understood there. In general I have been reassured to find from the dictionary how many slang words are actually universal in the English- speaking world. But I have been more intrigued at the astonishing creativeness of our species in inventing an endless supply of new words
and usages. 'Parallel parking' or 'getting your plumbing snaked' for copulation; 'idiot box' for television; 'park a custard' for vomit; 'Christmas on a stick' for a conceited person; 'nixon' for a fraudulent deal; 'jam sandwich' for a police car; these slang expressions represent the cutting edge of an astonishing richness of semantic innovation. And they perfectly illustrate C. S. Lewis's point. Is this how all our words got their start?
As with the 'footprint maps', I wonder whether the ability to see analogies, the ability to express meanings in terms of symbolic resemblances to other things, may have been the crucial software advance that propelled human brain evolution over the threshold into a co-evolutionary spiral.
In English we use the word 'mammoth' as an adjective, synonymous with very large. Could our ancestors' breakthrough into semantics have come when some pre-sapient poetic genius, struggling to convey the idea of 'large' in some quite different context hit upon the idea of imitating, or drawing, a mammoth? Could that have been the kind of software
advance that nudged humanity into an explosion of software/hardware co-evolution? Perhaps not this particular example, because large size is too easily conveyed by the universal hand gesture beloved of boastful anglers. But even that is a software advance over chimpanzee communication in the wild. Or how about imitating a gazelle to mean the delicate, shy grace of a girl, in a Pliocene anticipation of Yeats's 'Two girls, both beautiful, one a gazelle'? How about sprinkling water from a gourd
to mean not just rain, which is almost too obvious, but tears when trying to convey sadness? Could our remote habilis or erectus ancestors have imagined - and momentously discovered the means to express - an image like the 'sobbing rain' of John Keats? (Though, to be sure, tears themselves are an unsolved evolutionary mystery. )
However it began, and whatever its role in the evolution of language, we humans, uniquely among animal kind, have the poet's gift of metaphor: of noticing when things are like other things and using the relation as a fulcrum for our thoughts and feelings. This is an aspect of the gift of imagining. Perhaps this was the key software innovation that triggered our co-evolutionary spiral. We could think of it as a key advance in the world-simulating software that was the subject of the previous chapter. Perhaps it was the step from constrained virtual reality, where the brain simulates a model of what the sense organs are telling it, to unconstrained virtual reality, in which the brain simulates things that are not actually there at the time - imagination, daydreaming, 'what if? ' calculations about hypothetical futures. And this, finally, brings us back to poetic science and the dominant theme of the whole book.
We can take the virtual reality software in our heads and emancipate it from the tyranny of simulating only utilitarian reality. We can imagine
worlds that might be, as well as those that are. We can simulate possible futures as well as ancestral pasts. With the aid of external memories and symbol-manipulating artifacts - paper and pens, abacuses and computers - we are in a position to construct a working model of the universe and run it in our heads before we die.
We can get outside the universe. I mean in the sense of putting a model of the universe inside our skulls. Not a superstitious, small-minded, parochial model filled with spirits and hobgoblins, astrology and magic, glittering with fake crocks of gold where the rainbow ends. A big model, worthy of the reality that regulates, updates and tempers it; a model of stars and great distances, where Einstein's noble spacetime curve upstages the curve of Yahweh's covenantal bow and cuts it down to size; a powerful model, incorporating the past, steering us through the present, capable of running far ahead to offer detailed constructions of alternative futures and allow us to choose.
Only human beings guide their behaviour by a knowledge of what happened before they were born and a preconception of what may happen after they are dead; thus only humans find their way by a light that illuminates more than the patch of ground they stand on. P. B. and J . S. MEDAWAR, The Life Science (1977)
The spotlight passes but, exhilaratingly, before doing so it gives us time to comprehend something of this place in which we fleetingly find ourselves and the reason that we do so. We are alone among animals in foreseeing our end. We are also alone among animals in being able to say before we die: Yes, this is why it was worth coming to life in the first place.
Now more than ever seems it rich to die, To cease upon the midnight with no pain. While thou art pouring forth thy soul abroad In such an ecstasy!
JOHN KEATS, 'Ode to a Nightingale' (1820)
A Keats and a Newton, listening to each other, might hear the galaxies sing.
