Why Are Our Dreams So Weird?

From The Lecture Series: Understanding the Mysteries of Human Behavior

By Mark Leary, PhD, Duke University

Studies have been conducted in which people’s dreams are compared to the things that happen in their everyday lives. These studies show that there is continuity between the content of people’s dreams and their waking lives.

Woman dreaming of flying
(Image: Yuganov Konstantin/Shutterstock)
This is a continuation of Why Do We Dream? Three Modern Theories

Manifestations of Everyday Life in Our Dreams

Researchers who analyze people’s dream journals, without knowing anything about the people who wrote the journals, find that they can develop an accurate sense of what the people’s lives are like and what their pressing concerns are from the content of their dreams. The content of people’s dreams is related to their thoughts and preoccupations in everyday life.

Studies show that, contrary to the belief that dreams are mostly bizarre and unrealistic, most dreams involve realistic life situations. It doesn’t mean that people necessarily dream about real things that have happened, but the situations and activities are mostly realistic. In only about 10% of dreams is the setting of the dream truly bizarre or distorted. It might not be a place the person has ever been, but otherwise, there’s nothing unusual about it.

This is a transcript from the video series Understanding the Mysteries of Human Behavior. Watch it now, on The Great Courses Plus.

The things that people do in dreams also tend to be realistic. In about 80% of dreams, people do as they would in everyday life. Even when dreams involve fictional scenarios, such as fighting in the Civil War or being an astronaut, people engage in normal human behaviors. Less than 10% of dreams are truly bizarre, unrealistic, or fantastic.

Most events of what happens in our dreams are rather ordinary. But sometimes dreams do contain pretty weird material. We might fly under our own power, find ourselves interacting with beings from another planet, or see another person in our dream suddenly turn into an animal.

Often, we aren’t surprised by these kinds of bizarre events. Only after we wake up do we think, “Wow, that was really weird.”

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Verbal Metaphors Can Become Visual in Dreams

Some researchers suggest that much of the strangeness that we experience in dreams is due to the use of metaphors. Much of our thought in everyday life is metaphorical, as when we say that we feel “down in the dumps” or that we were so happy that we were “walking on air.” We use metaphors regularly in normal thought and language, and it seems that these metaphors creep into our dreams as well.

But, when these verbal metaphors are expressed in dreams, they can generate bizarre images because, while dreaming, we interpret them literally. In a dream, the thought of being “down in the dumps” might involve an image of being stuck under a pile of garbage.

There’s probably nothing symbolic about these kinds of images. They’re just visual images for metaphors that are interpreted literally when parts of the brain that normally distinguish literal from figurative language shut down during sleep.

That might seem implausible, but even in everyday life, metaphors can evoke visual images. If someone says they were “held up at the bank last week,” many people will get an image of the person being robbed at gunpoint, when in fact they were held up by a long line of cars at the drive-through teller. Children sometimes get the wrong image from metaphors, as when a child is frightened when his mother says that she is “dying to meet someone.”

Some of the oddities of dreams may be a manifestation of what happens when the brain makes metaphorical connections as we sleep. In waking life, we think in metaphors, knowing how to interpret them as metaphors. But when we think in metaphors during REM sleep, the brain can interpret those metaphors literally.

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How Brain Activity During REM Sleep Impacts Dreaming

Another reason that parts of dreams are nonsensical—and that we don’t even notice how strange they are at the time—is that certain areas of the brain are deactivated during REM sleep.

In particular, many researchers believe that decreased activity in the dorsolateral prefrontal cortex may be responsible for the lack of reality testing and critical judgment that occur in dreams. The dorsolateral prefrontal cortex is located roughly at the sides of the forehead, and it’s involved in reasoning, abstract thinking, behavior regulation, and reality-testing, among other things.

An illustration of brain's prefrontal region
The dorsolateral prefrontal cortex is located roughly at the sides of the forehead, and it’s involved in reasoning, abstract thinking, behavior regulation, and reality-testing, among other things. (Image: By Pancrat – Own work/Public Domain)

…researchers believe that decreased activity in the dorsolateral prefrontal cortex may be responsible for the lack of reality testing and critical judgment that occur in dreams.

One hypothesis is that, during dreaming, deactivation of this area leads to illogical and unrealistic thinking, and to our failure to recognize the strangeness of things that happen in a dream.

Perhaps it’s no coincidence that problems in the dorsolateral prefrontal cortex are also associated with delusions among schizophrenics and with disordered thinking in patients with Alzheimer’s.

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Still No Definitive Answers on Why We Dream

Dreams are often a combination of normal and commonplace events, paired with occasional nonsense, and are linked loosely to the people, places, and things that we know while also containing many fictional elements with a little bit of fantasy.

Most people assume that dreams do something. After all, if dreaming wasn’t important somehow, why would we all do it?

But decades of research have failed to offer a definitive answer to the question of why people dream. We’ve hit such a dead end that some experts suggest that dreaming must not do anything. They point out that many structures and processes in the body exist that don’t have a purpose, and it’s possible that dreaming is one of them—just a side-effect of important brain activities that occur in the REM stage of sleep.

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But given that most of us can’t shake the idea that our dreams must do something, it is likely the scientific search for the function of dreaming will continue for many years to come.

Common Questions About Why Our Dreams Are So Weird

Q: What makes dreams happen?

Dreams are not fully understood, but they appear to be a way for the brain to organize a person’s life events with their goals or as a mechanism for cleaning up the brain’s neural pathways.

Q: Do disturbing dreams mean anything?

Disturbing dreams mean different things to different people depending on their culture. Dreams of anxiety are thought by clinicians to potentially be a way for the ego to reset itself.

Q: What can chronic sleep deprivation cause?

Chronic sleep deprivation can result in weight gain, clumsiness, and general lack of alertness, leading to depression and other mental illnesses.

Q: What does awake sleep mean?

Awake sleep is another term for hypnagogia, which is the state one is in as they begin to fall asleep but have not quite made the transition from wakefulness to sleep.

This article was updated on December 18, 2020

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