Dark visions, ancient fears
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- Published 17.07.06
Those dreams about being chased by wild animals may not be meaningless after all. And the bottomless pits, the running but not moving, and those rooms with no doors and windows, they also may have a real purpose.
According to new research from Canada and Finland, which is backed by a Boston University study presented at a recent international conference, dreams are not meaningless but are part of an evolutionary survival strategy that developed in early man to help him to learn how to recognise and deal with threats in a hostile world. And Canadian research indicates that almost seven dreams out of 10 do involve threats and the practising of defensive and evasive tactics, and that almost a third include chases. The Finnish hypothesis is that the biological function of dreaming is to simulate threatening events and to rehearse threat perception and threat avoidance. “In the ancestral environment, human life was short and full of threats,” says Dr Antti Revonsuo, of the University of Turku in Finland, a pioneer of the evolutionary idea, who analysed 592 dreams.
He adds: “A dream-production mechanism that tends to select threatening events and to simulate them over and over again in various combinations would have been valuable for the development and maintenance of threat-avoiding skills.” Dreams have long fascinated scientists and a huge range of theories about their purpose have been generated over the years, from the idea that the mind has a complete world of its own during sleep, to Freud’s suggestion that dreaming is a safety valve for unconscious desires.
What is known is that we dream for more than two hours a night, although little of it is remembered, and that most activity is in the rapid eye movement (REM) period of sleep. REM sleep begins with signals travelling from one area of the brain to another, arriving at the cerebral cortex, the part involved in learning, thinking and organising.
Dr Revonsuo and other theorists who say that dreams evolved as a way of learning about threats, believes it is no coincidence that the cerebral cortex is involved in dreams because of its pivotal role in the overall learning system.
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Why kids are sacred of monsters
This evolutionary theory is increasingly finding support from other researchers. Another key piece of supporting evidence is the discovery that children dream about animals more than adults; 60 per cent of the dreams of four-year-olds involve animals, compared with 10 per cent of older teenagers. This is important because other research shows that in most animals the young share more traits with evolutionary ancestors.
And at the just-completed International Conference of the Association for the Study of Dreams, Boston University anthropologists said that hormonal changes at the age of six may be responsible for a sudden increase in childhood dreams about monsters. This could be part of the evolutionary mechanism.
“Children’s dreams show a strong bias towards simulating a world that contains animals, especially wild animals, aggression, conflicts, animal aggressors and victimisation to a greater degree than their own waking world or the dream world of adults,” says Dr Revonsuo. Another piece of the evidential jigsaw supporting the theory comes from research showing that many elements of modern life, such as reading and writing, are rarely found in dreams, while primitive fights and chases are universal.
Probing sleep disorder
Support for the evolutionists also comes from academics in Italy who have been investigating a sleep disorder called REM sleep behaviour disorder (RBD), sufferers of which ? about one person in 200 ? act out their dreams, often injuring themselves or their bed partners. People with the condition have been reported as jumping out of windows, firing guns and choking spouses.
An RBD case reported in the medical journal Sleep Medicine last year described how a 35-year-old woman waved her arms and shouted so much in her dreams that it resulted in marital problems because of the disruption to her husband’s sleep. The researchers, from Salute San Raffaele University in Milan, who investigated 100 people with the disorder, found that sufferers have violent dreams four times as often as normal adults.
They also have five times as many dreams about wild animals. Intriguingly, the prevalence of violence and animals was at the same level as those of young children. One theory is that RBD may be the result of an overreaction by the brain's threat-simulation system, leading to simulations that are much more intense and realistic, and which cause them to respond physically.
The basis of recurrent dreams
Threats are common in dreams. Psychologists at the University of Montreal analysed 212 recurrent dreams and found that the 65.6 per cent had a threatening event. Nearly one in three involved chases, and in 94 per cent of the dreams it was the dreamer who was being pursued. The dreamer was threatened with death or serious injury 65 per cent of the time.
The results show that in eight cases out of 10, almost half the threats were rooted in fantasy or fiction, including fairy tales, comics and science fiction, while a third were unlikely events, including falling into a deep ravine.
“Throughout their evolution, humans learnt to react to various dangers with practical solutions, and this might account for why most dreamers’ reactions in such situations are generally centred on running and fighting,” says Dr Antonio Zadra, who led the Canadian study. “But in our modern society, the threats people are most likely to face on a daily basis are primarily emotional.”
New problems, newer nightmares
He says that in the course of our evolution, language and an increase in emotional rather than physical threats may have altered dream content.
It’s argued that threats in modern life involve conflicts at work, peer pressure, relationship issues and financial worries. Faced with different types of threats, the brain’s threat simulation system is still triggered during sleep, but often misses the mark, dealing in metaphors and similes rather than practical advice.
That’s perhaps why some of the Montreal dreamers were more likely to be chased by supernatural characters, outlaws and other human beings rather than animals.
Research at California University, which has its own dream bank where people log their nightly experiences, points to dreams of bridges as being symbolic of problems to be solved, and bottomless pits as symbols of losing control.
Research there shows, too, that some modern problems are increasingly finding their way into dreams. Their log shows that women dream more about weddings than men, and experience more mistakes and mishaps, including the wrong groom, wrong church and wrong dress.
Little did he know it but, as he dreamed about hoofing it across the savannah pursued by wild animals, early man was laying the foundations for a sophisticated brain that would one day be fine-tuned to handle wedding anxiety.