Why Do We Dream?

The question of why we dream has fascinated philosophers and scientists for thousands of years. Despite scientific inquiry into the function of dreams, we still don't have a solid answer for why we do it. But, while much remains uncertain about dreaming, many experts have developed theories on the purpose of dreams and new empirical research is providing greater clarity.

Some of the more prominent dream theories contend that the function of dreaming is to consolidate memories, process emotions, express our deepest desires, and gain practice confronting potential dangers.

Many suggest that we dream due to a combination of these and other reasons rather than adhering to a singular theory. Additionally, while many researchers believe that dreaming is essential to mental, emotional, and physical well-being, some scientists suggest that dreams serve no real purpose at all.

The bottom line is, while many theories have been proposed, no single consensus has emerged on why we dream.


7 Theories on Why We Dream

What Is a Dream?

A dream includes the images, thoughts, and emotions that are experienced during sleep. Dreams can range from extraordinarily intense or emotional to very vague, fleeting, confusing, or even boring. Some dreams are joyful, while others are frightening or sad. Sometimes dreams seem to have a clear narrative, while many others appear to make no sense at all.

There are many unknowns about dreaming and sleep, but what scientists do know is that just about everyone dreams every time they sleep, for a total of around two hours per night, whether they remember it upon waking or not.

The most vivid dreams happen during rapid eye movement (REM) sleep, and these are the dreams that we're most likely to recall. We also dream during non-rapid eye movement (non-REM) sleep but those dreams are known to be remembered less often and have more mundane content.

Studying dreams is especially tricky as they happen hidden inside people's heads.

Traditionally, dream content is measured by the subjective recollections of the dreamer upon waking. However, increasingly, observation is also accomplished through objective evaluation in a lab.

In one study, researchers even created a rudimentary dream content map that was able to track what people dreamed about in real-time using magnetic resonance imaging (MRI) patterns, which was backed up by the dreamers' reports upon waking.

But beyond what's in a particular dream, there is the question of why we dream at all. Below, we detail the most prominent theories on the purpose of dreaming and how these explanations can be applied to specific dreams.

Dreams Provide Unconscious Expression

Consistent with the psychoanalytic perspective, Sigmund Freud’s theory of dreams suggests that dreams represent unconscious desires, thoughts, wish fulfillment, and motivations. According to Freud’s view of personality, people are driven by repressed longings and primitive thoughts, such as aggressive and sexual instincts, that are subverted from conscious awareness.

While many of Freud's assertions have been debunked, some experts believe that there is validity behind the idea that repressed thoughts often appear in dreams. In fact, research suggests there is a dream rebound effect, also known as dream rebound theory, in which suppression of something tends to result in dreaming about it.

Your Truest Wishes

Freud believed that repressed longings find their way into our awareness via our dreams. Freud also divined symbolic meaning from the seemingly random images and emotional content that make up dreams, creating a method of dream interpretation.

The purpose of dreams under this ideology is to bring these repressed wishes and deepest desires to the surface so that the dreamer can confront and reconcile these repressed feelings. In his famous book "The Interpretation of Dreams," Freud wrote that dreams are "disguised fulfillments of repressed wishes."

He also described two different components of dreams: manifest content and latent content. The manifest content is made up of the actual images, thoughts, and content contained within the dream while the latent content represents the hidden psychological meaning of the dream.

Freud’s theory contributed to the rise of dream interpretation, which remains popular today. While research has failed to demonstrate that the manifest content disguises the real psychological significance of a dream, many experts do believe that dreams play an important role in processing emotion and stressful experiences.

Dreams Are a Byproduct of Mental Processing

According to the activation-synthesis model of dreaming, which was first proposed by J. Allan Hobson and Robert McCarley in 1977, circuits in the brain become activated during REM sleep. This process causes areas of the limbic system involved in emotions, sensations, and memories, including the amygdala and hippocampus, to create an array of electrical brain impulses.

According to this theory, the brain synthesizes and interprets this internal activity and attempts to find meaning in these signals, which we experience as dreams. 

This model suggests that dreams are a subjective interpretation of these signals generated by the brain during sleep. When we wake, our active minds pull together the various images and memory fragments of the dream to create a cohesive narrative.

The Random Becomes Meaningful

While this theory contends that dreams do not serve a purposeful function on their own, Hobson's theory does not hold that dreams are completely meaningless. Instead, he suggested that dreaming is "our most creative conscious state, one in which the chaotic, spontaneous recombination of cognitive elements produces novel configurations of information: new ideas.

While many or even most of these ideas may be nonsensical, if even a few of its fanciful products are truly useful, our dream time will not have been wasted." In the activation-synthesis hypothesis, dreams are nothing more than a compilation of random thoughts, images, and memories that appear to the sleeping mind.

But when we wake up, we pull the images together into a story to make sense of the experience. In this way, dreams that seem to have no factual basis or significant meaning may ultimately provoke the dreamer to make new connections, inspire useful ideas, or generate epiphanies in their waking lives.

Dreams Sort and Consolidate Memories

According to the information-processing theory, one of the main explanations for why we sleep is that slumber allows us to consolidate and process all of the information and memories that we have collected during the previous day. Some dream experts suggest that dreaming is a byproduct or even an active part of this experience processing. 

This model is also known as the self-organization theory of dreaming, which explains dreaming as a side effect of brain neural activity as memories are consolidated during sleep. During this process of unconscious information redistribution, it is suggested that memories are either strengthened or weakened.

According to the self-organization theory of dreaming, while we dream, helpful memories are made stronger, while less useful ones fade away.

Research supports this theory, finding improvement in complex tasks when a person dreams about doing them. Studies also show that during REM sleep, low-frequency theta waves were more active in the frontal lobe, just like they are when people are learning, storing, and remembering information when awake.

The Memory Filter

During our conscious hours, we accumulate a multitude of data and memories—too much to remember each one vividly. According to this theory, when we dream, our brains sort, condense, and file away all that information. This process shows up in our sleeping minds as images, impressions, and narratives (as in dreams) that echo all of the activity and thoughts going on in our lives.

In fact, researchers have shown that as memories move from short-term to long-term memory storage, fragments of memory are created which appear in dreams. So, under this theory, your odd or nonsensical dream may be a flash of memories as they are erased or mixed with others that are destined for long-term storage.

Dreams Spur Creativity

Another theory about dreams says that their purpose is to help us solve problems. In this creativity theory of dreaming, the unconstrained, unconscious mind is free to wander its limitless potential while unburdened by the often stifling realities of the conscious world. In fact, research has shown dreaming to be an effective promoter of creative thinking.

A Nightly Think Tank

Relishing in the absurdity or nonconventional content of your dreams may inspire epiphanies if you are receptive to the messages. Scientific research and anecdotal evidence back up the fact that many people do successfully mine their dreams for inspiration and credit their dreams for their big "aha" moments.

Specifically, the ability to make unexpected connections between memories and ideas (as occurs in many dreams) often proves to be an especially fertile ground for creativity.

Dreams Are Your Life in Pictures

Under the continuity hypothesis, dreams function as a reflection of a person's real life, incorporating conscious experiences into their dreams. But rather than a straightforward replay of waking life, dreams show up as a patchwork of memory fragments.

However, this theory doesn't explain why some parts of waking life, such as the more embarrassing, scary, or emotionally heightened components, are often replayed in dreams while other moments are not.

Still, studies show that non-REM sleep may be more involved with declarative memory (the more boring, routine stuff), while REM dreams include more emotional and instructive memories. So, as research shows we don't remember as much of the non-REM dreams, we may just not recall all the basic, day-to-day content we may have dreamed about the night before.

Nightly Reruns

Under the continuity hypothesis, dreams replay waking life experiences, but only selective experiences from real life are included. Memories may be fragmented purposefully in our dreams as part of incorporating new learning and experiences into long-term memory. Still, there are many unanswered questions on why some aspects of memories are featured more or less prominently in our dreams.

Dreams Prepare and Protect

The primitive instinct rehearsal and adaptive strategy theories of dreaming propose that we dream to better prepare ourselves and to confront dangers in the real world. The dream as a social simulation function or threat simulation provides the dreamer a safe environment in which to practice important skills, especially potentially dangerous ones, such as evading a wild animal.

So, while dreaming, we hone our fight or flight instincts to give us an increased potential for survival and build mental capability for handling such scenarios, from the frightening to the embarrassing, if they happen for real.

Virtual Reality Fight or Flight Practice

Under the threat simulation theory, our sleeping brains utilize our ancient defense mechanism of fight or flight to prep us for life-threatening scenarios, like running from a pursuer or falling over a cliff. The theory suggests that practicing or rehearsing these skills in our dreams gives us an evolutionary advantage and helps to explain why so many dreams contain scary, dramatic, or intense content.

Additionally, this simulation model works to make sense of the often embarrassing, stressful, emotionally-fraught, or awkward dream narratives many of us experience, such as showing up somewhere naked, going to the bathroom in public, or forgetting to study for a final exam. This theory contends that these dreams are intended to help us avoid, cope with, or endure these experiences in the real world.

Dreams Help Process Emotions

The emotional regulation dream theory says that the function of dreams is to help us process and cope with our emotions or trauma in the safe space of slumber.

Research shows that the amygdala, which is involved in processing emotions, and the hippocampus, which plays a vital role in condensing information and moving it from short-term to long-term memory storage, are active during vivid, intense dreaming, showing a strong link between dreaming, memory storage, and emotional processing.

This theory suggests that REM sleep plays a vital role in emotional brain regulation. It also helps explain why so many dreams are emotionally vivid and the fact that emotional or traumatic experiences tend to show up on repeat. In fact, research has shown a connection between the ability to process emotions and the amount of REM sleep a person gets.

Interestingly, research also points to heightened empathy among people who share their dreams with others, pointing to another way dreams can help us cope by promoting community and interpersonal support.

Psychotherapy While We Sleep

The emotional regulation model proposes that dreams function as a form of psychotherapy, allowing the dreamer to make connections between different thoughts and emotions, process challenges, and cope with troubling experiences in a safe environment.

This dream-to-heal viewpoint is backed up by the often emotionally-charged content many people report in their dreams. The many content similarities and common dreams shared among dreamers may also help promote empathy, understanding, and shared identity, which may be another evolutionary advantage of dreaming.

Plus, research has shown that stress transmitters are less active during dreams, which may aid in processing troubling events and promote psychological healing as people are in a more relaxed state while asleep. Many people with mood disorders and PTSD have difficulty sleeping, and some researchers speculate that lack of dreaming may contribute to their illnesses.

Other Theories on Why We Dream

Many other theories have been suggested to account for why we dream. One such theory contends that dreams are the result of our brains trying to interpret external stimuli (such as a dog's bark, music, or a baby's cry) during sleep.

Another theory uses a computer metaphor to account for dreams. According to this model, dreams serve to "clean up" clutter from the mind, refreshing the brain for the next day. The reverse learning theory suggests that we dream to forget. Our brains have thousands of neural connections between memories—too many to remember them all.

So, this view contends that the purpose of dreaming is to review and cull these connections. In the continual activation theory, we dream simply to keep the brain active while we sleep, in order to keep it functioning properly.

Lucid Dreaming

Lucid dreams are dreams in which the dreamer has awareness of being in a dream and often has some control to direct dream content. These dreams are relatively rare. Research indicates that around 50% of people recall having had at least one lucid dream in their lifetime and just over 10% report having them regularly (two or more times per month).

It is unknown why certain people experience lucid dreams more frequently than others. While experts are unclear on exactly why or how lucid dreaming occurs, preliminary research signals that the prefrontal and parietal regions of the brain play a significant role in this type of dream experience.

Researchers have found that many people covet lucid dreaming and seek to experience it more often. In fact, lucid dreaming has been compared to the popularity of virtual reality headsets and hyper-realistic video games, giving lucid dreamers the ultimate, completely safe, immersive, self-directed dreamscape experience, unlimited by the constraints of the real world.

Potential training methods for inducing lucid dreaming include cognitive training, external stimulation during sleep, and medications. While these methods may show some promise, none have been rigorously tested or shown to be effective.

What is clear is that a strong link has been found between lucid dreaming and highly imaginative thinking and creative output. In fact, while lucid dreaming may be analogous to lucid imagination, research has shown that lucid dreamers perform better on creative tasks than those who do not experience lucid dreaming.

Stress Dreams

Another mystery of dreaming is that stressful experiences tend to show up with great frequency in our dreams. Stress dreams may be described in many ways, from sad to scary, the most intense of which are often called nightmares.

Experts do not fully understand how or why specific stressful dream content ends up in our dreams but many point to a variety of theories, including the continuity hypothesis, adaptive strategy, and emotional regulation dream theories, to explain why we have stress dreams.

Stress in daily life and past traumas often show up during sleep as stressful dreams. In fact, research has shown that those who experience greater levels of worry in their waking lives, and people with post-traumatic stress disorder (PTSD) report a higher frequency and intensity of nightmares.

Many studies have shown that those with mental health disorders, such as anxiety and depression, tend to have more distressful dreams, as well as more difficulty sleeping in general.

Additionally, a 2018 study published in Scientific Reports, found a strong link between anxiety and stressful dream content, as well as a similarly strong relationship between waking "peace of mind" and general well-being with more positive dreams. Researchers speculate that stress dreams may be the brain's attempt to help us cope with and make sense of these stressful experiences.

A Word From Verywell

Clearly, much more research is needed to fully tease out the true function of dreams. What has become increasingly evident, however, is that many of the theories on dreaming have merit. In fact, rather than assuming only one hypothesis is correct, many researchers believe the purpose of dreaming is likely a patchwork of the factors proposed in a variety of dream theories.

Knowing that so much is left uncertain about why we dream, we can feel free to view our own dreams in the light that resonates best with us—whether that is as a fruitful idea generator, an emotional processing space, a replay of our greatest hits (or secret desires), or a meaningless menagerie of imagery.

Regardless, don't miss out. If you have questions about your dreams or are experiencing any sleep or dream concerns, consider consulting a sleep specialist. They are your dreams, so you might as well make the most of them.

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  1. Ruby PM. Experimental research on dreaming: state of the art and neuropsychoanalytic perspectives. Front Psychol. 2011;2:286. doi:10.3389/fpsyg.2011.00286

  2. National Institute of Neurological Disorders and Stroke. Brain Basics: Understanding Sleep. Updated August 13, 2019.

  3. De Gennaro L, Cipolli C, Cherubini A, et al. Amygdala and hippocampus volumetry and diffusivity in relation to dreaming. Hum Brain Mapp. 2011;32(9):1458-70. doi:10.1002/hbm.21120

  4. Horikawa T, Tamaki M, Miyawaki Y, Kamitani Y. Neural decoding of visual imagery during sleep. Science. 2013;340(6132):639-42. doi:10.1126/science.1234330

  5. Zhang W, Guo B. Freud's dream interpretation: a different perspective based on the self-organization theory of dreaming. Front Psychol. 2018;9:1553. doi:10.3389/fpsyg.2018.01553

  6. Wegner DM, Wenzlaff RM, Kozak M. Dream rebound: the return of suppressed thoughts in dreams. Psychol Sci. 2004;15(4):232-6. doi:10.1111/j.0963-7214.2004.00657.x

  7. Hobson JA, McCarley RW. The brain as a dream state generator: an activation-synthesis hypothesis of the dream process. Am J Psychiatry. 1977;134(12):1335-48. doi:10.1176/ajp.134.12.1335

  8. Eichenlaub JB, Van Rijn E, Gaskell MG, et al. Incorporation of recent waking-life experiences in dreams correlates with frontal theta activity in REM sleep. Soc Cogn Affect Neurosci. 2018;13(6):637-647. doi:10.1093/scan/nsy041

  9. Zhang W. A supplement to self-organization theory of dreamingFront Psychol. 2016;7. doi:10.3389/fpsyg.2016.00332

  10. Rasch B, Born J. About sleep's role in memory. Physiol Rev. 2013;93(2):681-766. doi:10.1152/physrev.00032.2012

  11. Marzano C, Ferrara M, Mauro F, et al. Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall. J Neurosci. 2011;31(18):6674-83. doi:10.1523/JNEUROSCI.0412-11.2011

  12. Stickgold R, Walker MP. Sleep-dependent memory triage: evolving generalization through selective processing. Nat Neurosci. 2013;16(2):139-45. doi:10.1038/nn.3303

  13. Llewellyn S, Desseilles M. Editorial: Do both psychopathology and creativity result from a labile wake-sleep-dream cycle?. Front Psychol. 2017;8:1824. doi:10.3389/fpsyg.2017.01824

  14. Gujar N, McDonald SA, Nishida M, Walker MP. A role for REM sleep in recalibrating the sensitivity of the human brain to specific emotions. Cereb Cortex. 2011;21(1):115-23. doi:10.1093/cercor/bhq064

  15. Blagrove M, Hale S, Lockheart J, Carr M, Jones A, Valli K. Testing the empathy theory of dreaming: the relationships between dream sharing and trait and state empathy. Front Psychol. 2019;10:1351. doi:10.3389/fpsyg.2019.01351

  16. Kets de Vries MFR. Dream journeys: a new territory for executive coaching. Consulting Psychology Journal: Practice and Research. 2014;66(2):77–92. doi:10.1037/cpb0000004

  17. Baird B, Castelnovo A, Gosseries O, Tononi G. Frequent lucid dreaming associated with increased functional connectivity between frontopolar cortex and temporoparietal association areas. Sci Rep. 2018;8(1):17798. doi:10.1038/s41598-018-36190-w

  18. Vallat R, Ruby PM. Is it a good idea to cultivate lucid dreaming?. Front Psychol. 2019;10:2585. doi:10.3389/fpsyg.2019.02585

  19. Baird B, Mota-Rolim SA, Dresler M. The cognitive neuroscience of lucid dreaming. Neurosci Biobehav Rev. 2019;100:305-323. doi:10.1016/j.neubiorev.2019.03.008

  20. Stumbrys T, Daunytė V. Visiting the land of dream muses: The relationship between lucid dreaming and creativity. 2018;11(2). doi:10.11588/ijodr.2018.2.48667

  21. Rek S, Sheaves B, Freeman D. Nightmares in the general population: Identifying potential causal factors. Soc Psychiatry Psychiatr Epidemiol. 2017;52(9):1123-1133. doi:10.1007/s00127-017-1408-7

  22. Sikka P, Pesonen H, Revonsuo A. Peace of mind and anxiety in the waking state are related to the affective content of dreams. Sci Rep. 2018;8(1):12762. doi:10.1038/s41598-018-30721-1