Why Do We Dream? (6 Theories and Psychological Reasons)

Psychologists, scientists, and even spiritual leaders have built theories around why we dream. While not all these theories are accepted anymore, the true nature of why we dream is a mystery. What we do know is that dreams can benefit us in many ways!

Theories about why we have dreams include:

  • Ancient theories
  • Freud’s Wish-Fulfillment Theory
  • Activation-Synthesis Theory
  • Threat- and Social-Simulation Theory
  • Information-Processing Theory (Self-Organization Model)
  • Physiological-Functioning Theory

Ancient and Freudian Theories of Dreaming

“Why do we dream?” is a question that people have been asking since the dawn of time. In the earliest days of the study or contemplation of dreams, dreams had serious meaning. Humans are meaning-making creatures, so it’s natural for us to have a dream and ask “what does this mean?”

In the Bible, for example, dreams are often portrayed as messages from God. Mesopotamian kings took advice from their dreams. Ancient Egyptians wrote dream interpretations and what specific dreams meant for the dreamer. Medieval Europeans also wrote down how to interpret certain dreams.

Ancient cultures laid the foundation of this work, but one name is synonymous with dream interpretation: Sigmund Freud.


Sigmund Freud, like many people, asked himself, “Why do we dream?” He believed he discovered the answer after, you guessed it, a dream. After dreaming about a patient whom he felt he had failed,  Freud created the wish-fulfillment theory.

Freud’s wish-fulfillment theory suggests that we dream to fulfill repressed wishes. Often, these wishes are embarrassing. We wish to kill our father or have sex with our mother, for example. (Freud has some interesting theories.) That’s why, Freud believed, our dreams were so bizarre. We added unique elements so we could still fulfill our wish, but in a more palatable way. In Freud’s The Interpretation of Dreams, he interprets these unique elements. For example, he suggests interactions with sticks, trees, and other phallic-shaped items suggest…you can probably guess.

Freud’s theories of dream interpretation and wish-fulfillment are not accepted anymore. They have since been replaced by a variety of other theories about why we dream and how it benefits the dreamer.

When Do We Dream?

Before diving into more modern theories about why we dream, you should know when we dream. Dreaming takes place in the REM stage of sleep, or “rapid eye movement” stage. This name suggests exactly what happens during this stage. Although the rest of the body is close to paralyzation, our eyes rapidly move back and forth. The heart rate and breathing increases.

Brain activity is also especially high during REM sleep. REM sleep is crucial for the mind to recuperate, while other stages of sleep are vital for the body to do the same.

Knowing this, let’s dive into why modern psychologists think we dream.

Activation-Synthesis Theory

Remember when I said that humans are “meaning-making creatures?” Well, J. Allan Hobson and Robert McCarley took that into consideration. In 1977, they created the Activation-Synthesis Theory.

The Activation-Synthesis Theory suggests that dreams are the result of our brains attempting to make meaning from the brain activity that takes place during sleep. These dreams aren’t meaningless, necessarily, but they do not come from unconscious wishes or messages from the beyond. Just as we daydream to make sense of our social interactions, we dream to make sense of all the neurons firing in our brains during sleep.

Information-Processing Theory and the Self-Organization Model

Similarly, information-processing theory suggests dreams are just a part of our cognitive development. Cognitive psychology looks at how the brain makes decisions, solves problems, and stores memories. Memory storage is key to this study and why we dream.

Dreaming could just be a key part to how we convert our short-term memories into our long-term memory. And our minds don’t  shove all long-term memories into one big storage container. Information-processing theory suggests that we organize our memories as we sleep. Our dreams, which often contain elements from what we experienced that day, are a byproduct of that process.

To illustrate this, psychologists developed the Self-Organization Model. While this model does not address the content of dreams itself, it looks at how dreams are formed.

Threat-Simulation and Social-Simulation Theory

A lot of dream theories explain why we might have nonsensical, yet  pleasant, dreams. But what about nightmares? Why do we dream that we’re fired from our job, dumped by our partner, or taking a test without any pants on? Threat-simulation theory has a guess.

Finnish neuroscientist Antti Revonsuo suggested that nightmares are actually a biological defense mechanism. We simulate threats in our dreams so that we may be more prepared for them if we actually face them. Revonsuo theorized that the ancient humans that did “practice” facing these threats could fight them off and have children. Those children, too, simulated threats in their dreams and were more prepared to fight them.

The threats we face today are very different than what early humans faced. (We discuss this often when discussing fight-or-flight.) Whereas “threats” used to be carnivorous animals, now our bodies get just as stressed by pop quizzes and asking a cute girl out to the dance.

Social-Simulation Theory

Could it be that all dreams, nightmarish or not, are practice? Some say yes! The social-simulation theory of dreaming suggests that all dreams are a defense mechanism of sorts. When we practice social situations, we are more prepared for them.

How many times do you prepare for a conversation with a friend, partner, or boss? Dreams are just our unconscious way of doing the same thing!

Physiological-Functioning Theory

One last theory about why we dream is known as the physiological-functioning theory. This theory suggests that dreams are pretty much meaningless, and that we dream to preserve neural pathways. Have you ever been told to run your car for ten minutes once a week to keep it working properly? The physiological-funtioning theory suggests that dreaming works the same way. We spend a lot of time sleeping. Brain activity during this time keeps us functioning and ready to process information when we wake up the next morning!


Which Theory is Correct?

Physiological-functioning theory was supported in a 2009 paper written by J. Allan Hobson.

Yes, the same J. Allan Hobson who wrote about activation-synthesis theory. Hobson has been a sleep researcher at Harvard for many years now. While he continues to assert that dreams are not some divine message, he has shifted his thoughts on why we dream.

The answer to the question “why do we dream” is like the answer of many deep questions in psychology and biology. It’s always evolving. The theories on this page are just the more popular theories that exist in psychology today! There are other theories,  we dream to forget or to respond to what is happening in the outside world as we sleep. We cannot say for sure why we dream. With the help of modern theories and the creativity of ancient theories, we continue to get closer to the answer.

Theodore T.

Theodore is a professional psychology educator with over 10 years of experience creating educational content on the internet. PracticalPsychology started as a helpful collection of psychological articles to help other students, which has expanded to a Youtube channel with over 2,000,000 subscribers and an online website with 500+ posts.