The Magic of Reality

by Richard Dawkins

  Why do bad things happen really?

  Why does anything happen? That’s a complicated question to answer, but it is a more sensible question than ‘Why do bad things happen?’ This is because there is no reason to single out bad things for special attention unless bad things happen more often than we would expect them to, by chance; or unless we think there should be a kind of natural justice, which would mean that bad things should only happen to bad people.

  Do bad things happen more often than we ought to expect by chance alone? If so, then we really do have something to explain. You may have heard people refer jokingly to ‘Murphy’s Law’, sometimes called ‘Sod’s Law’. This states: ‘If you drop a piece of toast and marmalade on the floor, it always lands marmalade side down.’ Or, more generally: ‘If a thing can go wrong, it will.’ People often joke about this, but at times you get the feeling they think it is more than a joke. They really do seem to believe the world is out to get them.

  I do a certain amount of filming for television documentaries, and one of the things that can go wrong in filming ‘on location’ is unwanted noise. When an aircraft drones in the distance, you have to stop filming and wait for it to go, and this can be extremely irritating. Costume dramas of life in earlier centuries are ruined by even a trace of aircraft noise. Film people have a superstition that aircraft deliberately choose moments when silence is most important to fly overhead, and they invoke Sod’s Law.

  Recently, a film crew I was working with chose a location where we felt sure there should be a minimum of noise, a huge empty meadow near Oxford. We arrived early in the morning to make doubly sure of peace and quiet – only to discover, when we arrived, a lone Scotsman practising the bagpipes (perhaps banished from the house by his wife). ‘Sod’s Law!’ we all proclaimed. The truth, of course, is that there is noise going on most of the time, but we only notice it when it is an irritation, as when it interferes with filming. There is a bias in our likelihood of noticing annoyance, and this makes us think the world is out to annoy us deliberately.

  In the case of the toast, it wouldn’t be surprising to find that it really does fall marmalade side down more often than not, because tables are not very high, the toast starts marmalade side up and there is usually time for one half-rotation before it hits the ground. But the toast example is just a colourful way to express the gloomy idea that ‘if a thing can go wrong it will.’

  Perhaps this would be a better example of Sod’s Law: ‘When you toss a coin, the more strongly you want heads, the more likely it is to come up tails.’ That, at least, is the pessimistic view. There are optimists who think that the more you want heads, the more likely the coin is to come up heads. Perhaps we could call that ‘Pollyanna’s Law’ – the optimistic belief that things usually turn out for the good. Or it could be called ‘Pangloss’s Law’, after a character invented by the great French writer Voltaire. His ‘Dr Pangloss’ thought that ‘All is for the best in this best of all possible worlds.’

  When you put it like that, you can quickly see that Sod’s Law and Pollyanna’s Law are both nonsense. Coins, and slices of toast, have no way of knowing the strength of your desires, and no desire of their own to thwart them – or fulfil them. Also, what is a bad thing for one person may be a good thing for another. Rival tennis players may both pray fervently for victory, but one has to lose! There is no special reason to ask, ‘Why do bad things happen?’ Or, for that matter, ‘Why do good things happen?’ The real question underlying both is the more general question: ‘Why does anything happen?’

  Luck, chance and cause

  People sometimes say, ‘Everything happens for a reason.’ In one sense this is true. Everything does happen for a reason – which is to say that events have causes, and the cause always comes before the event. Tsunamis happen because of undersea earthquakes, and earthquakes happen because of shifts in the earth’s tectonic plates, as we saw in Chapter 10. That is the true sense in which ‘everything happens for a reason’, the sense in which ‘reason’ means ‘past cause’. But people sometimes use reason in a very different sense, to mean something like ‘purpose’. They will say something like ‘The tsunami was a punishment for our sins’ or ‘The reason for the tsunami was to destroy the strip clubs and discos and bars and other sinful places.’ It is amazing how often people resort to this kind of nonsense.

  Maybe it is a hangover from childhood. Child psychologists have shown that very young children, when asked why certain rocks are pointy, reject scientific causes as an explanation and prefer the answer: ‘So that animals can scratch themselves when they get itchy.’ Most children grow out of that kind of explanation for the pointy rocks. But quite a lot of adults seem unable to shake off the same kind of explanation when it comes to major misfortunes like earthquakes, or good fortune such as lucky escapes from earthquakes.

  What about ‘bad luck’? Is there such a thing as bad luck, or indeed good luck? Are some people luckier than others? People sometimes talk of a ‘run’ of bad luck. Or they will say, ‘So many bad things have happened to me lately, I’m due for a piece of really good luck.’ Or they may say, ‘So-and-so is such an unlucky person, things always seem to turn out badly for her.’

  ‘I’m due for a piece of good luck’ is an example of a widespread misunderstanding of the ‘Law of Averages’. In the game of cricket, it often makes a big difference which team bats first. The two captains toss a coin to decide who gets the advantage, and each team’s supporters very much hope their captain will win the toss. Before a recent match between India and Sri Lanka, a Yahoo web page posed the question:

  ‘Will Dhoni [the Indian captain] be lucky once again with the toss?’

  Of the answers they received, the following was chosen as ‘Best Answer’:

  ‘I firmly believe in the law of averages, so my bet is on Sangakkara [the Sri Lanka captain] being lucky and winning the much hyped toss.’

  Can you see what rubbish this is? In a series of previous matches, Dhoni had won the toss every time. Coins are supposed to be unbiased. So the misunderstood ‘Law of Averages’ ought to see to it that Dhoni, having been lucky so far, should now lose the toss, to redress the balance. Another way to put this would be to say that it was now Sangakkara’s turn to win the toss. Or that it would be unfair if Dhoni won the toss yet again. But the reality is that, no matter how many times Dhoni has won the toss before, the chances that he will win it again this time are always 50:50. ‘Turns’ and ‘fairness’ simply don’t come into it. We may care about fairness and unfairness, but coins don’t give a toss! Nor does the universe at large.

  It is true that if you toss a penny 1,000 times, you’d expect approximately 500 heads and 500 tails. But suppose you’ve tossed the penny 999 times and it’s so far come up heads every time. What would you bet for the last toss? According to the widespread misunderstanding of the ‘Law of Averages’, you should bet on tails, because it is tails’ turn, and it would be so unfair if it came up heads yet again. But I would place my bet on heads, and so would you if you were wise. A sequence of 999 heads in a row suggests that someone has tinkered with the penny, or with the method of tossing it. The misunderstood ‘Law of Averages’ has been the ruin of many gamblers.

  Admittedly, with hindsight you can say, ‘Sangakkara was very unlucky to lose the toss, because it meant that India batted on a perfect pitch and that helped them to amass a huge score.’ There is nothing wrong with that. All you are saying is that this time around winning the toss really made a difference, so whoever won the toss on this particular occasion was very lucky to have done so. What you should not say is that because Dhoni has won the toss on many occasions before, it is Sangakkara’s turn this time! Nor should you ever say something like this: ‘Dhoni happens to be a good cricketer, but the real reason we should make him captain is that he is very lucky at winning the toss.’ Luck with coin tosses is not something that individual people possess. You can say of a cricketer that he is a good batsman or a bad bowler. You cannot say t
hat he is good at winning tosses, or bad at winning tosses!

  For just the same reason, it is complete nonsense to think you can improve your luck by wearing a lucky charm around your neck. Or by crossing your fingers behind your back. These things have no way of influencing what happens to you unless it is by some effect on how you feel: giving you added confidence that calms your nerves before a tennis serve, for example. But that is nothing to do with luck; that is psychology.

  True, some people are described as ‘accident prone’. This is fine, if it only means something like ‘clumsy’, or especially likely to fall over or otherwise suffer misfortune. If you want a really funny example of ‘accident prone’, see the hilarious film The Pink Panther, starring Peter Sellers as Inspector Jacques Clouseau. Inspector Clouseau continually has embarrassing and amusing accidents, but that is because he is a habitual bungler, not because he has constant bad ‘luck’, which is how some people use the phrase. (By the way, do try to see the original Pink Panther film itself, not the later run of inferior films with similar titles like Son of Pink Panther, The Pink Panther’s Revenge and so on, which it spawned.)

  Pollyanna and paranoia

  So, we have seen that bad things, like good things, don’t happen any more often than they ought to by chance. The universe has no mind, no feelings and no personality, so it doesn’t do things in order to either hurt or please you. Bad things happen because things happen. Whether they are bad or good from our point of view doesn’t influence how likely it is that they will happen. Some people find it hard to accept this. They’d prefer to think that sinners get their come-uppance, that virtue is rewarded. Unfortunately the universe doesn’t care what people prefer.

  But now, having said all that, we should pause for thought. Funnily enough, I have to admit that something a bit like Sod’s Law is true. Although it is definitely not true that the weather, or an earthquake, is out to get you (for they don’t care about you, one way or the other), things are a bit different when we turn to evolution. If you are a rabbit, a fox is out to get you. If you are a minnow, a pike is out to get you. I don’t mean the fox or pike thinks about it, although it may. I’d be equally happy to say that a virus is out to get you, and nobody believes viruses think about anything. But evolution by natural selection has seen to it that viruses, and foxes, and pikes, behave in ways that are actively bad for their victims – behave as though they are deliberately out to get them – in ways that you couldn’t say of earthquakes or hurricanes or avalanches. Earthquakes and hurricanes are bad for their victims, but they don’t take active steps to do bad things: they don’t take active steps to do anything, they just happen.

  Natural selection, the struggle for existence as Darwin called it, means that every living creature has enemies that are working hard for its downfall. And sometimes the tricks that natural enemies use give the appearance of being cleverly planned. Spider webs, for example, are ingenious traps laid for unsuspecting insects. A fearsome little insect called an ant lion digs booby traps for its prey to fall into. The ant lion itself sits under the sand at the bottom of the conical pit that it digs, and seizes any ant that falls into the pit. Nobody is suggesting that the spider or the ant lion is ingenious – that it has thought up its cunning trap. But natural selection makes them evolve brains that behave in ways that look ingenious to our eyes. In the same way, a lion’s body looks ingeniously designed to bring about the doom of antelopes and zebras. And we can imagine that, if you were an antelope, a stalking, chasing, pouncing lion might seem out to get you.

  It’s easy to see that predators (animals that kill and then eat other animals) are working for the downfall of their prey. But it’s also true that prey are working for the downfall of their predators. They work hard to escape being eaten, and if they all succeeded the predators would starve to death. The same thing holds between parasites and their hosts. It also holds between members of the same species, all of whom are actually or potentially competing with one another. If the living is easy, natural selection will favour the evolution of improvements in enemies, whether predators, prey, parasites, hosts or competitors: improvements that will make life hard again. Earthquakes and tornadoes are unpleasant and might even be called enemies, but they are not ‘out to get you’ in the same ‘Sod’s Law’ kind of way that predators and parasites are.

  This has consequences for the sort of mental attitude that any wild animal, such as an antelope, might be expected to have. If you are an antelope and you see the long grass rustling, it could be just the wind. That’s nothing to worry about, for the wind is not out to get you: it is completely indifferent to antelopes and their well-being. But that rustle in the long grass could be a stalking leopard, and a leopard is most definitely out to get you: you taste good to a leopard and natural selection favoured ancestral leopards that were good at catching antelopes. So antelopes and rabbits and minnows, and most other animals, have to be constantly on the alert. The world is full of dangerous predators and it is safest to assume that something a bit like Sod’s Law is true. Let’s put that in the language of Charles Darwin, the language of natural selection: those individual animals that act as though Sod’s Law were true are more likely to survive and reproduce than those individual animals that follow Pollyanna’s Law.

  Our ancestors spent much of their time in mortal danger from lions and crocodiles, pythons and leopards. So it probably made sense for each person to take a suspicious – some might even say paranoid – view of the world, to see a likely threat in every rustle of the grass, every snap of a twig, and to assume that something was out to get him, a deliberate agent scheming to kill him. ‘Scheming’ is the wrong way to look at it if you think of it as deliberate plotting, but it is easy to put the idea into the language of natural selection: ‘There are enemies out there, shaped by natural selection to behave as though they were scheming to kill me. The world is not neutral and indifferent to my welfare. The world is out to get me. Sod’s Law may or may not be true, but behaving as if it is true is safer than behaving as if Pollyanna’s Law is true.’

  Maybe this is one reason why, to this day, many people have superstitious beliefs that the world is out to get them. When this goes too far, we say they are ‘paranoid’.

  Illness and evolution – work in progress?

  As I said, predators aren’t the only things that are out to get us. Parasites are a more sneaky threat, but they are just as dangerous. Parasites include tapeworms and flukes, bacteria and viruses, which make a living by feeding off our bodies. Predators such as lions also feed off bodies, but the distinction between a predator and a parasite is usually clear. Parasites feed off still-living victims (though they may eventually kill them) and they are usually smaller than their victims. Predators are either larger than their victims (as a cat is larger than a mouse) or, if smaller (as a lion is smaller than a zebra), not very much smaller. Predators kill their prey outright and then eat them. Parasites eat their victims more slowly, and the victim may stay alive a long time with the parasite gnawing away inside.

  Parasites often attack in large numbers, as when our body suffers a massive infection with a flu or cold virus. Parasites that are too small to see with the naked eye are often called ‘germs’, but that’s rather an imprecise word. They include viruses, which are very very small indeed; bacteria, which are larger than viruses but still very small (there are viruses that act as parasites on bacteria); and other single-celled organisms like the malarial parasite, which are much larger than bacteria but still too small to be seen without a microscope. Ordinary language has no general name for these larger singled-celled parasites. Some of them can be called ‘protozoa’, but that’s now rather an outdated term. Other important parasites include fungi, for example ringworm and athlete’s foot (big things like mushrooms and toadstools give a false impression of what most fungi are like).

  Examples of bacterial diseases are tuberculosis, some kinds of pneumonia, whooping cough, cholera, diphtheria, leprosy, scarlet fever, boils a
nd typhus. Viral diseases include measles, chickenpox, mumps, smallpox, herpes, rabies, polio, rubella, various strains of influenza and the cluster of diseases that we call the ‘common cold’. Malaria, amoebic dysentery and sleeping sickness are among those diseases caused by ‘protozoa’. Other important parasites, larger still – large enough to be seen with the naked eye – are the various kinds of worms, including flatworms, roundworms and flukes. When I was a boy living on a farm, I would quite often find a dead animal like a weasel or a mole. I was learning biology at school, and I was interested enough to dissect these little corpses when I found them. The main thing that impressed me was how full of wriggling, live worms they were (roundworms, technically called nematodes). The same was never true of the domesticated rats and rabbits we were given to dissect at school.

  The body has a very ingenious and usually effective system of natural defence against parasites, called the immune system. The immune system is so complicated that it would take a whole book to explain it. Briefly, when it senses a dangerous parasite the body is mobilized to produce special cells, which are carried by the blood into battle like a kind of army, tailor-made to attack the particular parasites concerned. Usually the immune system wins, and the person recovers. After that, the immune system ‘remembers’ the molecular equipment that it developed for that particular battle, and any subsequent infection by the same kind of parasite is beaten off so quickly that we don’t notice it. That is why, once you have had a disease like measles or mumps or chickenpox, you’re very unlikely to get it again. People used to think it was a good idea if children caught mumps, say, because the immune system’s ‘memory’ would protect them against getting it as an adult – and mumps is even more unpleasant for adults (especially men, because it attacks the testicles) than it is for children. Vaccination is the ingenious technique of doing something similar on purpose. Instead of giving you the disease itself, the doctor gives you a weaker version of it, or possibly an injection of dead germs, to stimulate the immune system without actually giving you the disease. The weaker version is much less nasty than the real thing: indeed, you often don’t notice any effect at all. But the immune system ‘remembers’ the dead germs, or the infection with the mild version of the disease, and so is forearmed to fight the real thing if it should ever come along.