Nesse carried out an interesting exercise in which he listed the physical and social dangers that would have threatened early humans. Physical dangers included accidents, disease, starvation, predators, hostile humans; social dangers included rejection, attacks on status or disruption of relationships. Modern anxiety disorders correspond well with these ancient threats. The hunter-gatherer’s proper fear of predators could have become today’s animal phobia; storage of food in times of plenty to ward off starvation could have become hoarding; cleaning rituals and taboos to ward off disease or contamination could have become obsessive-compulsive disorder. The hunter who sensibly stayed at the home base while a hungry lion roamed may have become today’s agoraphobic, highly reluctant to go out.
Responses that may once have been life-saving reactions have become inappropriate. Fear of heights, once a proper respect for the danger of a high cliff, is now a nuisance if it translates into fear of bridges or high-rise apartments. Reluctance to approach spiders may have been wise, and still is in some parts of the world. But fear of spiders in countries like Britain, where none is harmful, is widespread, and serves no useful purpose.
Nesse’s point is that today’s anxiety reactions would often have been essential in the Stone Age. There is nothing essentially wrong with the reactions, they are just too easily triggered for life today. It is a helpful idea. Fear of danger is a natural response and one which in other circumstances, thousands of years ago, might have protected us rather than blighted our lives.
The Evolution of Fear
The idea that we are attuned to life on the African plains makes a wonderful story, but most of us do not feel much like Stone-Agers. We have adapted to many changes even in the last few decades; we are more or less at ease with cars and aeroplanes, computers, dishwashers and foreign holidays. How come our fears lag so far behind?
Can we really blame our prehistoric ancestors for our fear of snakes and spiders? Fear may be contagious but evolution demands that it is passed down for tens of thousands of years. It is asking rather a lot for fear to survive intact so long. Diseases have died out in that time, whole species have become extinct. Yet evolutionists say that our fears of heights and the dark have remained unchanged since our predecessors in the Stone Age were trying to get back to their caves at night.
Charles Darwin first introduced evolution to the public in the mid nineteenth century. Some of his basic ideas were old, even then; Charles’s grandfather, Erasmus Darwin, had been one of several advocates of the theory in the eighteenth century. Charles Darwin himself became convinced during a five-year voyage through the southern hemisphere on HMS Beagle. He watched species of animals change gradually from island to island as the boat moved south. But it was his observations in the Galapagos Islands that were critical to forming his theories. Finches and giant tortoises varied slightly but predictably from island to island and the local people could always tell where a particular bird or tortoise belonged. It seemed that all the variations of these creatures must have had a common ancestor.
It took Darwin twenty years to publish The Origin of Species, possibly in part because he anticipated and dreaded the uproar it would cause. The book is packed with examples of evolving creatures: ants and bees, horses and zebras, birds, fish and plants. Darwin defined the process of natural selection as ‘the slow and gradual accumulation of numerous, slight, yet profitable variations’. If a tiny random change in an individual gives it an advantage over other members of the species it is more likely to survive, reproduce and pass the adaptation on to its offspring. The offspring in turn are more successful than those without the adaptation and over many generations more and more of the population are born with this small advantage. In the same way, variations which give their carriers a disadvantage are eliminated.
Natural selection works to produce gradations in animals’ instincts as well as in their physical features, Darwin said. Nesting birds, for instance, have an instinctive fear of most of their enemies, strengthened by their own experience and by the sight of fear in other birds. But they are slow to develop a fear of humans. According to Darwin, large birds in highly populated countries like England are wilder than small birds because they have been persecuted by humans. In uninhabited islands, large birds have no more fear than small birds. Magpies and hooded crows are wary in England but, in Darwin’s time at least, magpies were tame in Norway as were hooded crows in Egypt.
Darwin omitted humans from his arguments in The Origin of Species, but discussed them at length in later books, The Descent of Man, 1871, and The Expression of the Emotions in Man and Animals, 1872. Expression of the Emotions set out to demonstrate that different races, and even different species, show their emotions in a remarkably similar way, implying that emotions such as fear have been conserved throughout evolution:
That the chief expressive actions, exhibited by man and by the lower animals, are now innate or inherited – that is, have not been learnt by the individual – is admitted by every one. So little has learning or imitation to do with several of them that they are from the earliest days and throughout life quite beyond our control: for instance, the relaxation of the arteries of the skin in blushing, and the increased action of the heart in anger.
Fear is one of these chief emotions:
Fear was expressed from an extremely remote period, in almost the same manner as it now is by man; namely, by trembling, the erection of the hair, cold perspiration, pallor, widely opened eyes, the relaxation of most of the muscles, and by the whole body cowering downwards or held motionless.
Or, as he says elsewhere, quoting from Papinus Statius’ Thebaid: ‘Obstupui, steteruntque comae, et vox haesit’ (‘I was astounded, my hair stood on end, and my voice choked in my throat’).
Erection of the hair is singled out for special comment because it serves no purpose in humans and may simply be a leftover from evolution.
With respect to the involuntary bristling of the hair, we have good reason to believe that in the case of animals this action, however it may have originated, serves, together with certain voluntary movements, to make them appear terrible to their enemies; and as the same involuntary and voluntary actions are performed by animals nearly related to man, we are led to believe that man has retained through inheritance a relic of them, now become useless. It is certainly a remarkable fact, that the minute unstriped muscles, by which the hairs thinly scattered over man’s almost naked body are erected, should have been preserved to the present day; and that they should still contract under the same emotions, namely, terror and rage, which cause the hairs to stand on end in the lower members of the Order to which man belongs.
Darwin therefore argued that the similarity of our and animals’ response to danger is further proof of our common ancestry. But not all emotions are so ancient. Other emotions, such as blushing through shame, shyness or excessive attention, have developed more recently, he said. Different races of people across the world all blush, but animals never do.
It does not seem possible that any animal, until its mental powers had been developed to an equal or nearly equal degree with those of man, would have closely considered and been sensitive about its own personal appearance. Therefore we may conclude that blushing originated at a very late period in the long line of our descent.
Or as Mark Twain wrote, ‘Man is the only animal that blushes. Or needs to.’
Darwin referred to innate and inherited fears, but a key problem with his argument at the time was that he could not explain how physical or emotional traits were passed down. In fact, the Moravian monk Gregor Mendel was