Why do we dream? Some researchers believe that dreams helped the earliest human beings and their ancestors by teaching them how to survive in harsh conditions. Dreaming enabled them to live long enough to reproduce. Thus, evolution selected us to be dreamers.
Dreams Help Us Learn
Scientists know that we can become better at performing tasks by imaging them before we perform them. Athletes often use techniques of mental imagery to improve their performance.
When you imagine performing an activity, your brain responds as if you actually are performing the activity. If you imagine seeing something, the part of your brain that is involved in vision becomes active. If you imagine moving a part of your body, the part of your brain that you would use to move that part of your body becomes active.
If it can be helpful to imagine a situation before it happens, it could be even more helpful if your brain actually treats the situation as though it is happening. This is what happens when we dream.
Our Dream Worlds are Full of Danger
According to a research paper written by Antti Revonsuo in 2000, human beings inherited the capacity to dream in order to learn how to cope with dangerous situations. Dreams are a form of threat rehearsal. Revsonsuo’s theory is known as the “threat simulation” theory.
Revonsuo looked at the widely accepted Activation Synthesis theory of dreams that was developed by J. Allan Hobson and Robert W. McCarley. This theory says that dreams are created when the brain tries to ascribe meaning to random stimuli that are produced by the brain stem.
According to Revonsuo, there was a problem with this theory. If the Activation Synthesis theory were true, dreams would be extremely disorganized and incoherent.
However, our dreams take place in complex, well-organized models of the world. In our dream worlds, we have dream selves that are almost exactly like our real selves. We are surrounded by people and objects that exist in the waking world, and our dream selves interact with them just as we would in the waking world. Many studies have shown that people usually think that their dreams are realistic, with well-constructed plotlines.
Revonsuo also noticed that while our dream worlds are very similar to the waking world, they are not exactly the same. Some types of situations occur much more in our dream worlds than in the waking world. Some types of events take place much more often in the waking world than in our dream worlds.
Studies show that bad things tend to happen much more often in our dreams than in our waking lives.
In 1966, a study was made of the dreams of 1000 college students. The study showed that four fifths of the emotions addressed in these dreams were negative, while only one fifth were positive. In 411 of these dreams, characters had negative experiences that were out of their control, while there were only 58 dreams in which characters had good luck. About 45% of these dreams had at least one aggressive interaction. The dreamer was much more likely to be the victim of aggression than the aggressor was.
In 1970, the dreams of 635 students were studied. Over two thirds of the emotions in these dreams were negative. A 1996 study of 44 subjects found that dreamers reported negative emotions twice as much as positive ones.
In a 1983 study of 123 university students, three fifths said that they had recurring dreams. The only type of recurring dream that occurred with any frequency was one were the dreamer was being chased or threatened. The most common dreams of people who suffer from frequent nightmares are dreams of being chased or attacked.
Just as there are events that happen more often in our dreams than in our waking lives, there are events that happen frequently in our waking lives but rarely occur in our dreams. For example, two studies have found that people who spend several hours a day reading, writing, typing or calculating hardly ever dream about these activities.
Dreams Helped Our Prehistoric Ancestors to Survive
Various studies have found that in dreams:
• Attackers are most often animals and strange men.
• If an animal initiates an interaction with a dreamer, the interaction is aggressive 96% of the time.
• Dreams about animals usually take place outdoors.
This reflects the situation of the ancient human beings and their ancestors who lived as hunter-gatherers in the Pleistocene era for hundreds of thousands of years. Men frequently competed violently with each other over territories and resources. Predators and poisonous animals often threatened people’s lives.
In order to survive and reproduce in these dangerous conditions, people would have to develop skills for recognizing dangerous situations, avoiding them when possible, and dealing with them when they could not be avoided.
People who had dreams that simulated realistic threats, such as strange male attackers and dangerous animals, became better at avoiding or coping with danger. These people would be more likely to live long enough to reproduce. Thus, we evolved to have dreams as they exist today.
Dreams Help Other Mammals to Survive
If we inherited the ability to dream so that we could be better able to survive, it’s likely that this ability came from a shared ancestor of humans and other animals. This means that other mammals would also use dreams to learn how to survive.
Scientists have studied the behavior of cats during REM (rapid eye movement) sleep, the stage of sleep in which human beings are most likely to dreams. When they eliminate the paralysis that naturally occurs during REM sleep, and allow cats to act out what are, presumably, their dreams, the sleeping cats act out the motions of searching for and attacking prey – skills that are crucial for their survival. Similar experiments performed on rabbits have shown that rabbits act out behavior that prey animals must perform in order to survive.
In a 2007 paper, Michael Franklin and Michael Zyphur expanded on Revonsuo’s theory by saying that we did not just inherit the ability to dream so we could learn how to handle threats. We also inherited the ability to dream so we could learn learn how to behave in social situations.
They noted that many of our dreams contain other people and provide situations where the dreamer has an opportunity to develop social skills and that during REM sleep (dream sleep) the part of our brain that is involved with conflict resolution and social judgments remains active.
Franklin and Zyphur argued that in prehistoric times, people with better social skills would have a better chance of survival. If someone were thrust into an environment full of strangers, knowing how to behave to fit in with the group would make it easier for them to survive. Those who were best able to avoid conflict would have easier access to food and to mates.
Children are even more likely than adults to have dreams that reflect the lives of our prehistoric ancestors. This makes sense according to the evolutionary theory of dreams, since children have had less time for the modern environments in which they live to influence them.
Animals are more likely to appear in children’s dreams than in adults’ dreams. Children tend to dream about wild animals much more than they dream about domestic animals, despite the fact that they are more likely to encounter domestic animals in their waking lives.
The dreams of children are also more likely to include instances of aggression and conflict. They are more likely to have an animal as the aggressor.
Children are more likely than adults to dream about family members and close friends. This might be because children need more practice interacting with people who are close to them.
What Happens When We Don’t Remember Our Dreams?
We don’t remember the majority of our dreams. Can we learn from dreams if we don’t remember them?
Yes, we can. A large amount of research shows that we can learn many skills without consciously realizing that we are learning them. Even people with amnesia can learn tasks without remembering that they have ever performed the task before
Why Dreams Seem Real
Most of the time, when people dream, they believe that their dreams are real. This means that when they dream, their abilities to access specific types of memories and to think critically are switched off.
Franklin and Zyphur have argued that this could be an evolutionary advantage. It could be dangerous to spend time considering if a threatening situation is real or not. Therefore, in dreams, we automatically perceive threats as real.
When someone dreams they become fully engrossed in the events of the dream, and their consciousness revolves around the here and now. It has been suggested that the ancestors of early humans had minds that, in waking life, existed only in the here and now. Thus, their waking minds resembled the dreaming minds of people who live today.
Sometimes, however, people will dream while remaining aware that their dreams are not real. This is called lucid dreaming. When people have lucid dreams, they retain the ability to think critically and to remember things outside of the scope of the dream. In lucid dreams, people notice when things don’t make sense logically (The clock can’t say 12:63 because there are only 60 minutes in an hour) or when events in the dream don’t make sense based on past events in waking life (I can’t be taking a high school biology exam because I graduated from high school years ago.)
Franklin and Zyphur think that people who frequently have lucid dreams might have brains that function differently than the brains of non-lucid dreamers during REM sleep.
Why Can Some, But Not All, People have Lucid Dreams?
There may be an evolutionary advantage for a small number of people in a group or tribe to be lucid dreamers. By practicing lucid dreaming, an individual could improve their critical thinking skills, their memories and their ability to learn from the past.
Within a group, the people who dreamed lucidly could be the most capable of dealing with long-term strategy. Non-lucid dreamers would become adept at skills involving reacting quickly to immediate situations, such as hunting and avoiding attacks by large predators. Lucid dreamers, on the other hand, would be experts at activities that involved thinking far ahead and looking at alternative scenarios, such as deciding where the group should settle in order to gain the best success at hunting and have the least chance of encountering danger over time.