Homo Deus

by Yuval Noah Harari

  What happened here? The left brain, which controls speech, had no data about the snow scene, and therefore did not really know why the left hand pointed to the shovel. So it just invented something credible. After repeating this experiment many times, Gazzaniga concluded that the left hemisphere of the brain is the seat not only of our verbal abilities, but also of an internal interpreter that constantly tries to make sense of our life, using partial clues in order to concoct plausible stories.

  In another experiment, the non-verbal right hemisphere was shown a pornographic image. The patient reacted by blushing and giggling. ‘What did you see?’ asked the mischievous researchers. ‘Nothing, just a flash of light,’ said the left hemisphere, and the patient immediately giggled again, covering her mouth with her hand. ‘Why are you laughing then?’ they insisted. The bewildered left-hemisphere interpreter – struggling for some rational explanation – replied that one of the machines in the room looked very funny.13

  It’s as if the CIA conducts a drone strike in Pakistan, unbeknown to the US State Department. When a journalist grills State Department officials about it, they make up some plausible explanation. In reality, the spin doctors don’t have a clue why the strike was ordered, so they just invent something. A similar mechanism is employed by all human beings, not just by split-brain patients. Again and again my own private CIA does things without the approval or knowledge of my State Department, and then my State Department cooks up a story that presents me in the best possible light. Often enough, the State Department itself becomes convinced of the pure fantasies it has invented.14

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  Similar conclusions have been reached by behavioural economists, who want to know how people take economic decisions. Or more accurately, who takes these decisions. Who decides to buy a Toyota rather than a Mercedes, to go on holiday to Paris rather than Thailand, and to invest in South Korean treasury bonds rather than in the Shanghai stock exchange? Most experiments have indicated that there is no single self making any of these decisions. Rather, they result from a tug of war between different and often conflicting inner entities.

  One groundbreaking experiment was conducted by Daniel Kahneman, who won the Nobel Prize in Economics. Kahneman asked a group of volunteers to join a three-part experiment. In the ‘short’ part of the experiment, the volunteers inserted one hand into a container filled with water at 14°C for one minute, which is unpleasant, bordering on painful. After sixty seconds, they were told to take their hand out. In the ‘long’ part of the experiment, volunteers placed their other hand in another water container. The temperature there was also 14°C, but after sixty seconds, hot water was secretly added into the container, bringing the temperature up to 15°C. Thirty seconds later, they were told to pull out their hand. Some volunteers did the ‘short’ part first, while others began with the ‘long’ part. In either case, exactly seven minutes after both parts were over came the third and most important part of the experiment. The volunteers were told they must repeat one of the two parts, and it was up to them to choose which; 80 per cent preferred to repeat the ‘long’ experiment, remembering it as less painful.

  The cold-water experiment is so simple, yet its implications shake the core of the liberal world view. It exposes the existence of at least two different selves within us: the experiencing self and the narrating self. The experiencing self is our moment-to-moment consciousness. For the experiencing self, it’s obvious that the ‘long’ part of the cold-water experiment was worse. First you experience water at 14°C for sixty seconds, which is every bit as bad as what you experience in the ‘short’ part, and then you must endure another thirty seconds of water at 15°C, which is not quite as bad, but still far from pleasant. For the experiencing self, it is impossible that adding a slightly unpleasant experience to a very unpleasant experience will make the entire episode more appealing.

  However, the experiencing self remembers nothing. It tells no stories, and is seldom consulted when it comes to big decisions. Retrieving memories, telling stories and making big decisions are all the monopoly of a very different entity inside us: the narrating self. The narrating self is akin to Gazzaniga’s left-brain interpreter. It is forever busy spinning yarns about the past and making plans for the future. Like every journalist, poet and politician, the narrating self takes many short cuts. It doesn’t narrate everything, and usually weaves the story only from peak moments and end results. The value of the whole experience is determined by averaging peaks with ends. For example, in the short part of the cold-water experiment, the narrating self finds the average between the worst part (the water was very cold) and the last moment (the water was still very cold) and concludes that ‘the water was very cold’. The narrating self does the same thing with the long part of the experiment. It finds the average between the worst part (the water was very cold) and the last moment (the water was not so cold) and concludes that ‘the water was somewhat warmer’. Crucially, the narrating self is duration-blind, giving no importance to the differing lengths of the two parts. So when it has a choice between the two, it prefers to repeat the long part, the one in which ‘the water was somewhat warmer’.

  Every time the narrating self evaluates our experiences, it discounts their duration, and adopts the ‘peak-end rule’ – it remembers only the peak moment and the end moment, and evaluates the whole experience according to their average. This has far-reaching impact on all our practical decisions. Kahneman began investigating the experiencing self and the narrating self in the early 1990s when, together with Donald Redelmeier of the University of Toronto, he studied colonoscopy patients. In colonoscopy tests, a tiny camera is inserted into the guts through the anus, in order to diagnose various bowel diseases. It is not a pleasant experience. Doctors want to know how to perform the test in the least painful way. Should they speed up the colonoscopy and cause patients more severe pain for a shorter duration, or should they work more slowly and carefully?

  To answer this query, Kahneman and Redelmeier asked 154 patients to report the pain during the colonoscopy at one-minute intervals. They used a scale of 0 to 10, where 0 meant no pain at all, and 10 meant intolerable pain. After the colonoscopy was over, patients were asked to rank the test’s ‘overall pain level’, also on a scale of 0 to 10. We might have expected the overall rank to reflect the accumulation of minute-by-minute reports. The longer the colonoscopy lasted, and the more pain the patient experienced, the higher the overall pain level. But the actual results were different.

  Just as in the cold-water experiment, the overall pain level neglected duration and instead reflected only the peak-end rule. One colonoscopy lasted eight minutes, at the worst moment the patient reported a level 8 pain, and in the last minute he reported a level 7 pain. After the test was over, this patient ranked his overall pain level at 7.5. Another colonoscopy lasted twenty-four minutes. This time too peak pain was level 8, but in the very last minute of the test, the patient reported a level 1 pain. This patient ranked his overall pain level only at 4.5. The fact that his colonoscopy lasted three times as long, and that he consequently suffered far more pain on aggregate, did not affect his memory at all. The narrating self doesn’t aggregate experiences – it averages them.

  So what do the patients prefer: to have a short and sharp colonoscopy, or a long and careful one? There isn’t a single answer to this question, because the patient has at least two different selves, and they have different interests. If you ask the experiencing self, it will probably prefer a short colonoscopy. But if you ask the narrating self, it will vote for a long colonoscopy because it remembers only the average between the worst moment and the last moment. Indeed, from the viewpoint of the narrating self, the doctor should add a few completely superfluous minutes of dull aches at the very end of the test, because it will make the entire memory far less traumatic.15

  Paediatricians know this trick well. So do vets. Many keep in their clinics jars full of treats, and hand a few to the kids (or dogs) after giving them a painful i
njection or an unpleasant medical examination. When the narrating self remembers the visit to the doctor, ten seconds of pleasure at the end of the visit will erase many minutes of anxiety and pain.

  Evolution discovered this trick aeons before the paediatricians. Given the unbearable torments women undergo at childbirth, you might think that after going through it once, no sane woman would ever agree to do it again. However, at the end of labour and in the following days the hormonal system secretes cortisol and beta-endorphins, which reduce the pain and create a feeling of relief and sometimes even of elation. Moreover, the growing love towards the baby, and the acclaim from friends, family members, religious dogmas and nationalist propaganda, conspire to turn childbirth from a terrible trauma into a positive memory.

  Credit 1.40

  40. An iconic image of the Virgin Mary holding baby Jesus. In most cultures, childbirth is narrated as a wonderful experience rather than as a trauma.

  One study conducted at the Rabin Medical Center in Tel Aviv showed that the memory of labour reflected mainly the peak and end points, while the overall duration had almost no impact at all.16 In another research project, 2,428 Swedish women were asked to recount their memories of labour two months after giving birth. Ninety per cent reported that the experience was either positive or very positive. They didn’t necessarily forget the pain – 28.5 per cent described it as the worst pain imaginable – yet it did not prevent them from evaluating the experience as positive. The narrating self goes over our experiences with a sharp pair of scissors and a thick black marker. It censors at least some moments of horror, and files in the archive a story with a happy ending.17

  Most of our critical life choices – of partners, careers, residences and holidays – are taken by our narrating self. Suppose you can choose between two potential holidays. You can go to Jamestown, Virginia, and visit the historic colonial town where the first English settlement on mainland North America was founded in 1607. Alternatively, you can realise your number one dream vacation, whether it is trekking in Alaska, sunbathing in Florida or having an unbridled bacchanalia of sex, drugs and gambling in Las Vegas. But there is a caveat: if you choose your dream vacation, then just before you board the plane home, you must take a pill which will wipe out all your memories of that vacation. What happened in Vegas will forever remain in Vegas. Which holiday would you choose? Most people would opt for colonial Jamestown, because most people give their credit card to the narrating self, which cares only about stories and has zero interest in even the most mind-blowing experiences if it cannot remember them.

  Truth be told, the experiencing self and the narrating self are not completely separate entities but are closely intertwined. The narrating self uses our experiences as important (but not exclusive) raw materials for its stories. These stories, in turn, shape what the experiencing self actually feels. We experience hunger differently when we fast on Ramadan, when we fast in preparation for a medical examination, and when we don’t eat because we have no money. The different meanings ascribed to our hunger by the narrating self create very different actual experiences.

  Furthermore, the experiencing self is often strong enough to sabotage the best-laid plans of the narrating self. For example, I can make a New Year resolution to start a diet and go to the gym every day. Such grand decisions are the monopoly of the narrating self. But the following week when it’s gym time, the experiencing self takes over. I don’t feel like going to the gym, and instead I order pizza, sit on the sofa and turn on the TV.

  Nevertheless, most people identify with their narrating self. When they say ‘I’, they mean the story in their head, not the stream of experiences they undergo. We identify with the inner system that takes the crazy chaos of life and spins out of it seemingly logical and consistent yarns. It doesn’t matter that the plot is full of lies and lacunas, and that it is rewritten again and again, so that today’s story flatly contradicts yesterday’s; the important thing is that we always retain the feeling that we have a single unchanging identity from birth to death (and perhaps even beyond the grave). This gives rise to the questionable liberal belief that I am an individual, and that I possess a consistent and clear inner voice, which provides meaning for the entire universe.18

  The Meaning of Life

  The narrating self is the star of Jorge Luis Borges’s story ‘A Problem’.19 The story deals with Don Quixote, the eponymous hero of Miguel Cervantes’s famous novel. Don Quixote creates for himself an imaginary world in which he is a legendary champion going forth to fight giants and save Lady Dulcinea del Toboso. In reality, Don Quixote is Alonso Quixano, an elderly country gentleman; the noble Dulcinea is an uncouth farm girl from a nearby village; and the giants are windmills. What would happen, wonders Borges, if out of his belief in these fantasies, Don Quixote attacks and kills a real person? Borges asks a fundamental question about the human condition: what happens when the yarns spun by our narrating self cause great harm to ourselves or those around us? There are three main possibilities, says Borges.

  One option is that nothing much happens. Don Quixote will not be bothered at all by killing a real man. His delusions are so overpowering that he could not tell the difference between this incident and his imaginary duel with the windmill giants. Another option is that once he takes a real life, Don Quixote will be so horrified that he will be shaken out of his delusions. This is akin to a young recruit who goes to war believing that it is good to die for one’s country, only to be completely disillusioned by the realities of warfare.

  And there is a third option, much more complex and profound. As long as he fought imaginary giants, Don Quixote was just play-acting, but once he actually kills somebody, he will cling to his fantasies for all he is worth, because they are the only thing giving meaning to his terrible crime. Paradoxically, the more sacrifices we make for an imaginary story, the stronger the story becomes, because we desperately want to give meaning to these sacrifices and to the suffering we have caused.

  In politics this is known as the ‘Our Boys Didn’t Die in Vain’ syndrome. In 1915 Italy entered the First World War on the side of the Entente powers. Italy’s declared aim was to ‘liberate’ Trento and Trieste – two ‘Italian’ territories that the Austro-Hungarian Empire held ‘unjustly’. Italian politicians gave fiery speeches in parliament, vowing historical redress and promising a return to the glories of ancient Rome. Hundreds of thousands of Italian recruits went to the front shouting, ‘For Trento and Trieste!’ They thought it would be a walkover.

  It was anything but. The Austro-Hungarian army held a strong defensive line along the Isonzo River. The Italians hurled themselves against the line in eleven gory battles, gaining a few kilometres at most, and never securing a breakthrough. In the first battle they lost 15,000 men. In the second battle they lost 40,000 men. In the third battle they lost 60,000. So it continued for more than two dreadful years until the eleventh engagement, when the Austrians finally counter-attacked, and in the Battle of Caporreto soundly defeated the Italians and pushed them back almost to the gates of Venice. The glorious adventure became a bloodbath. By the end of the war, almost 700,000 Italian soldiers were killed, and more than a million were wounded.20

  After losing the first Isonzo battle, Italian politicians had two choices. They could admit their mistake and sign a peace treaty. Austria–Hungary had no claims against Italy, and would have been delighted to sign a peace treaty because it was busy fighting for survival against the much stronger Russians. Yet how could the politicians go to the parents, wives and children of 15,000 dead Italian soldiers, and tell them: ‘Sorry, there has been a mistake. We hope you don’t take it too hard, but your Giovanni died in vain, and so did your Marco.’ Alternatively they could say: ‘Giovanni and Marco were heroes! They died so that Trieste would be Italian, and we will make sure they didn’t die in vain. We will go on fighting until victory is ours!’ Not surprisingly, the politicians preferred the second option. So they fought a second battle, and lost another 40,000 men
. The politicians again decided it would be best to keep on fighting, because ‘our boys didn’t die in vain’.

  Credit 1.41

  41. A few of the victims of the Isonzo battles. Was their sacrifice in vain?

  Yet you cannot blame only the politicians. The masses also kept supporting the war. And when after the war Italy did not get all the territories it demanded, Italian democracy placed at its head Benito Mussolini and his fascists, who promised they would gain for Italy a proper compensation for all the sacrifices it had made. While it’s hard for a politician to tell parents that their son died for no good reason, it is far more difficult for parents to say this to themselves – and it is even harder for the victims. A crippled soldier who lost his legs would rather tell himself, ‘I sacrificed myself for the glory of the eternal Italian nation!’ than ‘I lost my legs because I was stupid enough to believe self-serving politicians.’ It is much easier to live with the fantasy, because the fantasy gives meaning to the suffering.

  Priests discovered this principle thousands of years ago. It underlies numerous religious ceremonies and commandments. If you want to make people believe in imaginary entities such as gods and nations, you should make them sacrifice something valuable. The more painful the sacrifice, the more convinced people are of the existence of the imaginary recipient. A poor peasant sacrificing a priceless bull to Jupiter will become convinced that Jupiter really exists, otherwise how can he excuse his stupidity? The peasant will sacrifice another bull, and another, and another, just so he won’t have to admit that all the previous bulls were wasted. For exactly the same reason, if I have sacrificed a child to the glory of the Italian nation, or my legs to the communist revolution, it’s enough to turn me into a zealous Italian nationalist or an enthusiastic communist. For if Italian national myths or communist propaganda are a lie, then I will be forced to admit that my child’s death or my own paralysis have been completely pointless. Few people have the stomach to admit such a thing.