The Globe

LIES TO CHIMPANZEES

A central feature of human extelligence is the ability to infer what is going on in another person's mind, to guess what the world looks like from their point of view. Which is what Rincewind is trying to stop the Queen of the Elves from doing. We can't make such inferences with perfect accuracy; that would be telepathy, which is almost certainly impossible, because each brain is wired up differently and therefore represents the universe in its own special way. But we've evolved to be pretty good at guessing.

This ability to get inside other people's heads has many beneficial consequences. One is that we recognise other people as people, not just automata. We recognise that they have a mind, that to them the universe seems just as real and vivid as it does to us, but that the vivid things they perceive may not be the same as those that we perceive. If intelligent beings are going to get along together without too much friction, it's important to realise that other members of your species have an internal mental universe, which controls their actions in the same way that your own mind controls yours.

When you can put yourself inside another person's mind, stories gain a new dimension. You can identify with a central character, and vicariously experience a different world. This is the appeal of fiction: you can captain a submarine, or spy on the enemy, from the safety and comfort of an armchair.

Drama has the same appeal, too, but now there are real people to identify with; people who play a fictional role. Actors, actresses. And they rely even more on getting inside other people's minds, especially the minds of fictional characters. Macbeth. The Second Witch. Oberon.

Titania. Bottom.

How did this ability arise? As usual, it seems to have come about because of a complicity between the internal signal-processing abilities of the brain and the external pressures of culture.

It arose through an evolutionary arms race, and the main weapon in that race was the lie.

The story starts with the development of language. As the brains of proto-humans evolved, getting larger, there was room in them for more kinds of processing tasks to be carried out.

Primitive grunts and gestures began to be organised into a relatively systematic code, able to represent aspects of the outside world that were important to the creatures concerned. A

complicated concept like 'dog' became associated with a particular sound. Thanks to an agreed cultural convention, anyone who heard that sound responded to it with the mental image of a dog; it wasn't just a funny noise. If you try to listen to someone speaking a language that you know, focusing just on the noises that they are making and trying not to pick up the meaning of their words, you'll find that it's almost impossible. If they speak a language far removed from any that you know, however, their speech comes over as a meaningless gabble. It conveys less to you than a cat's miaow.

In the brain are circuits of nerve cells that have learned to decode gabble into meaning. We've seen that as a child grows, it begins by babbling a random assortment of phonemes, the 'units' of sound that a human mouth and larynx can produce. Gradually the child's brain prunes the list down to those sounds that it hears from its parents and other adults. While it is doing that, the brain is destroying connections between nerve cells that seem to be obsolete. Quite a lot of the early mental development of an infant consists of chopping down a randomly connected, all- purpose brain, and pruning it into a brain that can detect the things that are considered important in the child's culture. If the child is not exposed to much linguistic stimulus in early childhood such as a 'feral' child brought up by animals -then they can't learn a language properly in later life. After about the age of ten, the brain's ability to learn language fades away.

Much the same happens with other senses, in particular the sense of smell. Different people smell the same thing differently. To some, a particular odour may be offensive, to others innocuous, and to yet others, nonexistent. As with language, there are cultural biases to certain smells.

The primary function of language -by which we mean 'the main evolutionary trick that made it advantageous, leading to its preservation and enhancement by natural selection' -is to convey meaningful messages to other members of the same species. We do this in several ways: 'body language' and even bodily odours convey vivid messages, largely without our being conscious of them. But spoken language is far more versatile and adaptable than the other kinds, and we are very conscious of what others are saying. Especially when it is about us.

One of the commonest generic evolutionary tricks is to cheat. As soon as a bunch of organisms has evolved some specific ability or behaviour, a new possibility arises: subverting that behaviour. Predictable behaviour patterns provide a natural springboard from which organisms can leap out into the space of the adjacent possible. Bees evolved the abilities to collect nectar and pollen, to feed themselves. Later, we subverted that activity by providing them with better homes than they would find in nature. We get to steal their honey, by providing them with hives as the up-market adjacent-possible homes.

Many evolutionary trends have arisen from subversion. So, as the ability to put specific thoughts into the minds of others became established, it was natural for evolution to experiment with methods for subverting that process. You didn't have to put your own genuine thoughts into the minds of others: you could try to put different thoughts there. Perhaps you could gain an advantage by misleading the creatures you were 'communicating' with. The result was the evolution of lying.

Many animals tell lies. Monkeys have been observed making the troupe's 'danger' call-sign.

Then, as the rest of the troupe heads off for cover, the liar grabs the food that they have temporarily abandoned. On a more primitive but just as effective level, mimicry in the animal kingdom is a form of lying. A harmless hover-fly displays the black-and-yellow warning bands of a wasp, telling the lie 'I am dangerous, I can sting'.

As humanity evolved, those monkey lies turned into more sophisticated ape lies, then hominid lies, then human lies. As we became more intelligent, our capacity for telling lies co-evolved alongside another important ability: the ability to tell when someone was lying to you. A monkey troupe can evolve several defences against a member who abuses the danger-signal for his own ends. One is to recognise that this individual can't be trusted, and ignore their calls. The nursery tale of the little boy who cried 'wolf' exposes the dangers inherent in this area, both for the troupe and for the individual. Another is to punish the individual for telling the lie. A third is to evolve the ability to tell the difference between a lying danger-signal and a true one. Is the monkey crying 'danger' staring at someone else's food with a greedy glint in their eye?

Just as there are sound evolutionary reasons for telling lies, so there are sound evolutionary reasons for being able to detect them. If others are trying to manipulate you to their advantage, then it is very probably to your disadvantage. So it is in your best interests to realise that, and avoid being manipulated. The result is an inevitable arms race, in which the ability to tell lies is played off against the ability to detect them. It is no doubt still going on, but already the result is some very sophisticated lying, and some very sophisticated detection. Sometimes the look on a person's face tells us they're telling an untruth; sometimes the tone of voice.

One effective way to recognise a lie is to put yourself inside the other person's mind, and ask yourself whether what they are saying is consistent with what you have convinced yourself they are thinking. For instance, they are saying what a sweet little child you have, but you remember from previous encounters that usually they can't stand kids. Maybe your child is different, of course, but then you notice that worried look in their eyes, as if they'd rather be somewhere else ...

Empathy is not just a nice way to understand someone else's point of view. It's a weapon that you can use to your own advantage. Having understood their point of view, you can compare it with what they're saying, and work out whether to believe them. In this manner, the existence of lies in language's phase space of the adjacent possible encouraged the development of human empathy, and with it, individual intelligence and collective social cohesion. Learning to tell lies was a major step forward for humanity.

We can put ourselves inside the minds of other people with some degree of credibility, because we are people ourselves. We do at least know what it's like to be a person. But even then, we are probably deluding ourselves if we think that we really know exactly what's going on inside someone else's mind, let alone what that feels like to them. Each human mind is wired differently, and is the product of its owner's own experiences. It is even more problematic whether we can imagine what it is like to be an animal. On Discworld, an accomplished witch can put herself inside an animal's mind, as we see, for instance, in this passage from Lords and Ladies: She Borrowed. You had to be careful. It was like a drug. You could ride the minds of animals and birds, but never bees, steering them gently, seeing through their eyes. Granny Weatherwax had many times flicked through the channels of consciousness around her. It was, to her, part of the heart of witchcraft. To see through other eyes ...

... through the eyes of gnats, seeing the slow patterns of time in the fast pattern of one day, their minds travelling rapidly as lightning ...

... to listen with the body of a beetle, so that the world is a three-dimensional pattern of vibrations

...

... to see with the nose of a dog, all smells now colours ...

It's a poetic image. Does a dog 'see' smells? There is a folk belief that smell is far more important to a dog than sight, but this could well be an exaggeration based on the more credible observation that smell is more important to dogs than it is to humans. But even here we must add

'consciously, at least', because we react subconsciously to pheromones and other emotionally loaded chemicals. Some years ago David Berliner was working on the chemicals in human skin, and he left an open beaker containing some skin extracts on the laboratory bench. Then he noticed that his lab assistants were becoming distinctly more animated than usual, with a lot of camaraderie and mild flirtation. He froze the extract and put it away in the laboratory refrigerator for safekeeping. Thirty years later, he analysed the substances in the beaker and found a chemical called androstenone, which is rather like a sex hormone. A series of experiments showed that this chemical was responsible for the animated behaviour. However, androstenone has no smell. What was going on?

Some animals possess a 'vomeronasal' organ (often called the 'second nose'). This is a small region of tissue in the nose, which detects certain chemicals but is separate from the standard olfactory (smelling) system. The conventional wisdom had long been that humans do not possess a vomeronasal organ, but the curious behaviour of his assistants made the scientist wonder.

Berliner discovered that the conventional wisdom was wrong: some humans, at least, do have a vomeronasal organ, and it responds to pheromones. Those are special chemicals that trigger strong responses in animals, such as fear or sexual arousal. The vomeronasal organ's owners are not consciously aware that they are sensing anything, but boy, do they respond.

This story shows how easily we can get sensations wrong. In this case, you know what it vomeronasally smells like to be a human: you don't feel anything at all, not consciously. But you certainly respond! So your reactions, and what they 'feel like', are very different. The sounds we hear, the sensations of heat and cold on our skin, the smells that assail our nostrils, the unmistakable taste of salt ... all these are qualia, vivid 'feelings' stuck on to our perceptions by our minds to help us recognise them more readily. They have a basis in reality, yes, but they are not real features of the outside world. They must be real features of brain architecture and function, real things happening in real nerve cells, but that level of reality is very different from the level that we perceive.

So we should be suspicious of the belief that we can know what it feels like to be a dog. In 1974 the philosopher Thomas Nagel published a famous essay 'What is it like to be a bat?' in the Philosophical Review, in which he made the same point. We can imagine what it is like to be a human who is behaving -superficially at least -like a bat, but we have no idea what it feels like to the bat, and it is questionable whether human knowledge can ever extend in such a direction.

We probably get bats wrong anyway. We know that bats use echo-location to sense their surroundings, much as a submarine uses sonar. The bat or submarine emits sharp pulses of sound, and hears the returning echoes. From those, it can 'compute' what the sound must be bouncing off. We naturally assume that the bat responds to echoes in the same kind of way that we would: it hears them. We naturally expect the qualia of bat echo-location to be similar to the human qualia evoked by sound-patterns, of which the richest example is music. So we imagine the bat flying along to the accompaniment of incredibly rapid rhythms played on bongo drums.

However, this could be a false analogy. Echo-location is the main sense of a bat, so the 'correct'

corresponding sense of a human is its main sense, which is sight, not hearing. The August 1993 edition of Nature has a picture of a bat on the cover, with the words 'How bats' ears see'. This refers to a technical article, by Steven Dear, James Simmons and Jonathan Fritz, who discovered that the neurons in the part of the bat's brain that processes returning echoes are connected together in a very similar way to those in the human visual cortex. In terms of neural architecture, it looks very much as if the bat's brain uses the echoes to build up an image of its surroundings. Analogously, today's submarines use computers to turn a series of echoes into a three-dimensional map of the surrounding water. Figments of Reality developed this point to give a partial answer to Nagel's question:

[In effect] bats see with their ears, and their sonar qualia might well be like our visual ones.

Intensity of sound might come over to the bat as a kind of 'brightness', and so on. Possibly the bat's sonar qualia 'see' the world in black and white and shades of grey, but they could also pick up and render vivid various more subtle features of sound reflections. The closest analogy in humans is texture, which we sense by touch, but the bat could sense by sound. Soft objects reflect sound less well than hard ones, for instance. So bats may well 'see' textured sound. If so and here our analogy is intended only as a very rough way to convey the idea -the sonar quale for a soft surface might 'look' green to the bat's mind, that for hard ones might look red, that for liquid ones like a colour only bees can see, and so on ...

On Roundworld, such statements are no more than guesswork, supported by analogies of neural architecture. On Discworld, witches know what it feels like to be a bat, or a dog, or a beetle. And Angua the werewolf smells in colours, which is very close to our suggestion that bats hear in images and 'see' textures. But even on Discworld, the witches do not actually feel what it is like to be a bat. They feel what it is like to be a human who has 'borrowed' the sensory organs and neural processing equipment of a bat. It may feel quite different to be a bat when a witch is not hitching a free ride on its mind.

Even though we can't be certain what it feels like to be an animal, or another person, the attempt has several uses. As we said, the ability involved here is empathy: being able to understand what another person feels like. We've already seen that this is an important social skill, and that the same ability, deployed in a different way for a different purpose, gives us a chance to detect that someone else is lying to us. If we put ourselves inside their heads and realise that what they are saying is different from what we believe they are thinking, then we suspect them of lying.

The word 'lie' has negative overtones, deservedly so, but what we're talking about here can be constructive as well as destructive, and often is. For the purposes of the present discussion, a lie is anything contrary to the truth, but it's not at all clear what 'the truth' is, or even whether there is only one of it, as the word 'the' would seem to indicate. When two people have a row, it is generally impossible for either of them, or anyone else, to figure out exactly what really happened. Our thoughts are tainted by perceptions. This is unavoidable, because what we think of as being 'real' is what our minds make of what comes from the sense organs: fudged, tuned, and mangled by a succession of interpretations by different bits of brain, plus some wallpaper additions. We never know what is really out there around us. All we know is what our minds construct from what our eyes, ears and fingers report.

Not to put too fine a point on it, those perceptions are lies. The vivid universe of colour that our brain derives from the light that falls on our retinas does not really exist. The redness of a rose is derived from its physical features, but 'being red' is not a physical feature as such. 'Emitting light of a certain wavelength' gets closer to being a physical feature. However, the vivid redness that we 'see' does not correspond to a specific wavelength. Our brains correct the colours of visual images for shadows, light reflected on to parts of the image by other parts of a different colour, and so on. Our sensation of redness is a decoration added to the perception by our brain: a quale.

So what we 'see' is not an accurate perception of what is there, but a mental transform of a sensory perception of what is there.

To a bee, that same uniformly red rose may look very different, with obvious markings. The bee

'sees' in ultraviolet, a wavelength outside our range of perceptions. The rose emits a whole distribution of wavelengths of light; we see a small part of that, and call it reality. The bee sees a different part and responds to it in its own beelike way, using the markings to land on the flower and collect nectar, or to dismiss it from consideration and fly on to the next possibility. Neither the bee's perception, nor ours, is the reality.

In Chapter 24 we explained that our minds select what they perceive in more ways than just passively ignoring signals that our senses can't pick up. We fine-tune our senses to see what we want them to see, hear what we want them to hear. There are more nerve connections going from the brain to the ear than there are from the ear to the brain. Those connections adapt the ear's ability to perceive certain sounds, maybe by making it more sensitive to sounds that could represent danger and less sensitive to sounds that don't really matter much. People who are not exposed to certain sounds as children, when their ears and brains are being tuned to pick up language, cannot distinguish them as adults. To the Japanese, the two phonemes 'l' and 'r' sound identical.

The lies that our senses tell us are not malicious. They are partial truths rather than untruths, and the universe is so complicated, and our minds are so simple in comparison, that the best we can ever hope for is half-truths. Even the most esoteric 'fundamental' physics is at best a half-truth.

Indeed, the more 'fundamental' it becomes, the less true it gets. It is therefore no surprise that the most effective method we have yet devised for passing extelligence on to our children is a systematic series of lies. It is called 'education'.

We can hear the hackles rising even as we write, as quantum signals echo back down the timelines from future readers in the teaching profession turning to this page. But before hurling the book across the room or sending an offended e-mail to the publisher, ask yourself just how much of what you tell children is true. Not worthy, not defensible: true. At once you'll find yourself on the defensive: 'Ah, yes, but of course children can't understand all of the complexities of the real world. The teacher's job is to simplify everything as an aid to understanding ...' Quite so.

Those simplifications are lies, within the meaning we are currently attaching to that word. But they are helpful lies, constructive lies, lies that even when they are really very wrong still open the door to a better understanding next time round. Consider, for example, the sentence 'A

hospital is a place where people are sent so that the doctors can make them better'. Well, no sensitive adult would wish to tell a child that sometimes people go into hospital alive and come out dead. Or that often it's not possible to make them better. For a start, the child may have to go into hospital at some stage, and too big a dose of truth early on might make it difficult for the parents to persuade them to do so without making a fuss. Nonetheless, no adult would consider that sentence to be an accurate statement of what hospitals are really about. It is, at best, an ideal to which hospitals aspire. And when we justify our description on the grounds that the truth would upset the child, we are admitting that the sentence is a lie, and asserting that social conventions and human comfort are more important than giving an accurate description of what the world is about.

They often are, of course. A lot depends on context and intention. In Chapter 4 of The Science of Discworld we called these helpful untruths and half-truths 'lies-to-children'. They must be distinguished from the much less benevolent 'lies-to-adults', another word for which is 'politics'.

Lies-to-adults are constructed with the express purpose of concealing intentions; their aim is to mislead. Some newspapers tell lies-to-adults; others do their best to tell truths-to-adults, although they always end up by telling adult versions of lies-to-children.

In the twenty-fifth Discworld novel The Truth, journalism comes to the Disc, in the form of William de Worde. His career begins with a monthly newsletter sent to various Discworld notables, usually for five dollars each month, but in the case of one foreigner for half a cartload of figs twice per year. He writes one letter, and pays Mr Cripslock the engraver in the Street of Cunning Artificers to turn it into a woodcut, from which he prints five copies. From these small beginnings emerges Ankh-Morpork's first newspaper, when de Worde's ability to sniff out a story is allied to the dwarves' discovery of movable type. It is rumoured that the dwarves have found a way to turn lead into gold -and since the type is made of lead, in a way they have.

The main journalistic content of the novel is a circulation battle between de Worde's Ankh- Morpork Times, with its banner 'THE TRUTH SHALL MAKE YOU FREE', and the Ankh- Morpork Inquirer (THE NEWS YOU ONLY HEAR ABOUT). The Times is an upmarket broadsheet, running stories with headlines like 'Patrician Attacks Clerk With Knife (He had the knife, not the clerk)', and checking its facts before publishing them. The Inquirer is a tabloid, whose headlines are more of the 'ELVES STOLE MY HUSBAND' kind, and it saves money by making all the stories up. As a result, it can undercut its upmarket competitor when it comes to price, and the stories are much more interesting. Truth eventually prevails over cheap nonsense, however, and de Worde learns from his editor Sacharissa a fundamental principle of journalism:

'Look at it like this,' said Sacharissa, starting a fresh page. 'Some people are heroes. And some people jot down notes.'

'Yes, but that's not very—'

Sacharissa glanced up and flashed him a smile. 'Sometimes they're the same person,' she said.

This time it was William who looked down, modestly.

'You think that's really true?' he said.

She shrugged. 'Really true? Who knows? This is a newspaper, isn't it? It just has to be true until tomorrow.'

Lies-to-children, even the broadsheet newspaper sort, are mostly benign and helpful, and even when they are not, they are intended to be that way. They are constructed with the aim of opening a pathway that will eventually lead to more sophisticated lies-to-children, reflecting more of the complexities of reality. We teach science and art and history and economics by a series of carefully constructed lies. Stories, if you wish ... but then, we've already characterised a story as a lie.

The science teacher explains the colours of the rainbow in terms of refraction, but slides over the shape of the rainbow and the way those colours are arranged. Which, when you come to think of it, are more puzzling, and more what we want to know about when we ask why rainbows look like they do. There's a lot more to the physics than a raindrop acting as a prism. Later, we may develop the next level of lie by showing the child the elegant geometry of light rays as they pass through a spherical raindrop, refracting, reflecting, and refracting back out again, with each colour of light focused along a slightly different angle. Later still, we explain that light does not consist of rays at all, but electromagnetic waves. By university, we are telling undergraduates that those waves aren't really waves at all, but tiny quantum wave-packets, photons. Except that the 'wave-packets' in the textbooks don't actually do the job ... And so on. All of our understanding of nature is like this; none of it is Ultimate Reality.