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then. Mendel was working with peas and developing the idea of genetic traits conserved through generations. This is now generally accepted as the mechanism by which evolution works and the idea of genes being passed from parents to children, determining family traits and peculiarities, is a familiar one.

      Genes are the template from which we develop. They influence all aspects of our physical and mental well-being, including our appearance and vulnerability to diseases, our intelligence and personality. They are not the whole story and our environment also plays its part. But genes certainly influence the development of the brain’s structure and the activity of chemical messengers involved in our experience of fear. As explored in more depth in the next chapter, our genes could programme our brains to react to danger.

      Although it may have taken millions of years for the lumbering progress of natural selection to give the world its incredible diversity of species, Nesse points out that individual traits can change much more quickly. Selective breeding of dogs for their temperament, for example, takes just a handful of generations to produce puppies which are either exceptionally easygoing or frantically neurotic.

      But genes may not be our only link to the Stone Age. A chain of people also exists. If we are lucky, we know our parents and their parents and we may be familiar with the two or three, possibly even four generations which preceded us. These generations in turn knew their parents and grandparents and so on back through history. The human links are continuous and it could be that we learn our behaviour from those around us, just as they learnt it from another generation. A kind of cultural rather than genetic transmission of fear could take place.

      Humans have passed on information since we could paint on cave walls and tell stories. Today’s films, books and TV programmes may be efficient ways of relaying a fear of ancient threats. When a writer wants to create a threatening atmosphere, a dark night, a few large spiders and a pair of animal’s eyes usually do the trick. Many ancient threats are symbols or shortcuts to fear and the storyteller only has to mention them to create the desired mood. Cultural learning is powerful and flexible and can quickly shape attitudes in an enduring way.

      The idea was proposed by psychologist Graham Davey from the University of Sussex, and he set out to test it in relation to fear of spiders. Spiders have been embroiled in European culture since the Middle Ages, when they were thought to absorb poisons and to infect any food they touched. They were seen as the forerunners of disease and death during the Great Plague (the discovery that rats’ fleas carried the disease was not made until the nineteenth century). A form of hysteria called tarantulism was even blamed on the spider and only later found to be caused by too much sun. It was not all bad for the spider – tiny ‘money spiders’ were thought to bring financial good luck and cobwebs were used in traditional medicine to bind wounds – but for hundreds of years, in the main, spiders were thought to be highly dangerous and widely feared.

      This thinking was confined to Europe, so if cultural learning is responsible for fear of spiders, Davey reasoned that it should only be widespread in Europeans and their descendants. Observations back him up. In parts of Africa the spider is thought to be wise and local people clean and protect its habitat. Spiders are eaten as a delicacy in areas as diverse as Indo-China, the Caribbean, among the native North Americans and Australian aborigines. Children in Brazil often keep spiders as pets. Hindus in eastern Bengal collect spiders to release at weddings to wish the couple good luck, and in Egypt it is common to put a spider in the bed of a newly married couple.

      Researchers found that the incidence of spider fear in Britain is similar to that in Holland and in the US. So far, so good. Many North Americans are descended from Europeans, so this is not unexpected. The incidence in these countries was higher than in India, as predicted. But, strangely, the incidence in Japan, where there is no particular history of spider fear, is even higher, which tends to weaken the argument.

      Davey’s central point is that it takes countless generations for the biology of a population to change even slightly. Threats would have had to be extremely dangerous and common, killing people in large numbers, for fear reactions to have become biologically programmed. He says we must not ignore the costs of our reactions. Our ancestors might have been well-advised to keep away from poisonous spiders or snakes, but they had to grub through plants to get food. Too much fear of insects would have led to malnutrition if it made people reluctant to look for food. An infant starting to explore its surroundings might be at risk from strangers and suspicion might be appropriate. But strangers are also likely to help a child in trouble and over-reluctance to approach a stranger could be fatal.

      Spiders and snakes may simply have had longer to become embroiled in our culture and inherited learning than modern threats. Guns and electricity outlets have not been around long enough to acquire the symbolic significance that would mark them out as objects to fear. Children may develop fears by absorbing information from the people around them, who are themselves more likely to fear snakes than guns.

      Cultural transmission of fear was a bold challenge to the prevailing view that our thought processes are shaped by strong biological links with our ancient predecessors. It suggested that our fears may have nothing to do with our biology and that perhaps our primitive brain was not, after all, programmed over millions of years. It is possible that we have learned them solely through careful observation of those around us.

      However, this idea has not caught on. Nobody denies the importance of learning, but some of the most exciting research work is attempting to examine the structure and activity in our brains. It seems most likely that genetic and cultural transmission of information work in tandem. We have evolved with a certain biological background which comes to life only in the context of cultural learning. The tendency to fear may be instinctive or hardwired, irrevocably programmed into us as a species. But personal experience and observation of others may be essential before we develop specific fears.

      The idea of flexible learning overlying hardwired fear has been re-explored by evolutionists in recent years. They are delving into aspects of the theory and attempting to test them out in practical, modern ways.

      Animal Instincts

      One of the good things about being an evolutionist is that you can never be definitively contradicted. Most scientists have their best work overturned within their own working life. They spend time trying to disprove other scientists’ ideas but they in turn are usually overtaken by someone else who contradicts or at least refines their work.

      Believing in evolution gives a scientist some respite. Evolution took place over such a phenomenally long time scale that we can never recreate the same conditions and, ultimately, never know anything for certain. It provides a rather luxurious and permanent platform for scientists to stand on.

      This does not mean that we have to accept the evolutionary perspective without question. With some lateral thinking, many ideas stemming from evolution theory can be studied scientifically. For example, evolutionists say that we are more likely to fear ancient rather than modern threats. If this is so, it should hold true for people of different races and cultures since we share the same ancestry and should therefore share the same fear programming.

      A few small studies have produced some evidence for this. Researchers at a mental health clinic in Bangalore, India, found an incidence of phobias only a tenth of that in the West, a rate similar to that in other Indian communities. However, the vast majority of the phobias fitted the evolutionists’ model. Agoraphobia was the most common, closely followed by illness and social phobias. Animal phobias were rare, which is usually the case in clinics catering for people with the most seriously disabling problems. Scottish work found that more than two-thirds of a group’s phobias were relevant to ancient times. A Sri Lankan study used the same method and came up with virtually identical figures. This provides some backing for the idea that people in different parts of the world are similarly attuned to fear threats in the natural world.

      More fundamentally, we cannot apply evolution theory to phobias at all unless we think cautious Stone-Agers were more likely to survive and produce offspring than their fearless friends. Fearfulness should have increased the chances of people passing on their genes to the next generation.

      Coupled

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