Why do we dream? Deeper answers to the dreaming question

Woman asleep

It's a question which has plagued scholars and scientists for hundreds of years: why do we dream?

Is it our brain's way of making sense of the events of the day? Is it part of a built-in creative process? Or something else entirely?

Here we get at least some of the answers to questions about what, when, how and why people dream...

What is a dream?

A dream is a state of consciousness in which a person has mental, sensory and emotional experiences during the hours when they are asleep.

These experiences may be extraordinarily vivid, yet the person who is dreaming tends to have very little control over what is being dreamed.

They may contain common themes, be linked to real-life concerns or seem very real and believable despite having no logic when viewed from the outside.

Dreams are ubiquitous – all humans experience them, even if they don't remember them.

When do you dream? (In what stage of sleep do you dream?)

Dreams only occur during Stage 5 sleep, otherwise known as REM (Rapid Eye Movement).

Around 20-25% of a person's sleep time consists of REM sleep. Some of the most commonly noticed effects of REM include:

  • Faster, irregular and shallower breathing
  • Eyes moving rapidly behind the eyelids
  • Temporary paralysis of limb muscles
  • Increased heart rate
  • Penile erections in males
  • Rises in blood pressure

It is thought that everyone experiences between three and six dreams every single night.

How long does a dream last?

Although a person who is dreaming may perceive that their dream has lasted for almost any given timeframe, each dream is thought to last somewhere between five and twenty minutes.

Some people argue that this could be as long as 45 minutes.

Unfortunately, how long a dream lasts is very hard to objectively measure!

Fantasy Dream Land

Why do people dream?

A great deal is known about why we need to sleep. It regulates our brain functions, blood pressure, metabolism and much more besides.

Much less is known about why people dream...

Here are some of the most common schools of thought and beliefs:

1) Mental balancing and processing

Many people suggest that dreams provide a sort of internal therapy for the brain.

By working through any strange, unsettling or difficult thoughts or experiences you might have had during the day while you are unconscious, your brain is attempting to “clean house”, so to speak.

Dreams may also assist in organizing memory storage, retaining things you consider important and discarding some of the rest.

The old adage to “sleep on it”, may be advice which actually has some basis in reality! Several studies have shown that people who sleep after being taught some new information will retain it better.

This is thought to at least partially happen through dreaming.

2) Internal stress training

Another theory says that when you dream, your brain is essentially training itself to be ready for forthcoming challenges.

The link here is that the amygdala (the part of your brain which helps you control emotions as well as in producing the stress response, a.k.a. the “fight or flight” response) is very active when you dream.

The theory goes – and there is some proof for this – that our brain is imagining possible future scenarios and preparing itself to deal with them as a kind of built-in biological defence mechanism.

This is called the Threat Simulation Theory of dreaming (TST).

3) Inspiration

Although this may not sound like a reason why we dream, the fact that many creative people – and indeed scientists, inventors and mathematicians trying to solve problems – say that inspiration has struck them in their dreams cannot be denied.

From an evolutionary standpoint, perhaps this has been part of humankind's development of the ability to use tools.

4) Simple science

Another theory which attempts to explain why people dream is based on straightforward science:

During sleep, you go through biochemical changes and generate electrical impulses. Dreams may simply be your brain's reaction to these.

5) A reflection of reality

Another theory is that dreams are simply a reflection of reality, a sort of poorly-tuned reception for the experiences of the day, serving no other purpose than to happen because the relevant parts of your brain – the same used in daydreaming – are active at this time.

So which is it? Why do we dream?

Based on current scientific research, the answer could be all of the above, none of the above – or some combination of them.

Dreaming appears to have links to the physical body, as well as a person's cognition and psychology.

The number of dreams a person has, as well as their content and intensity, certainly seem to be affected by physical, mental and psychological changes to the body.

Some of the many things which may affect when, how and why we dream include:

  • Medication: for example, SSRIs – Selective Serotonin Uptake Inhibitors sometimes used to treat depression – may decrease dream recall. Withdrawal from SSRIs may intensify dreams, increase their emotional content and turn them into nightmares.
  • Depression and anxiety: people with depression or anxiety are more likely to have stressful or scary dreams. The presence of nightmares and other stressful dreams in people suffering from severe depression is often said to be linked to suicidal thoughts.
  • Drugs and alcohol: taking drugs or alcohol can destroy a healthy sleep cycle – especially if taken in excess before sleeping. Possibly because alcohol is a depressant, people who are dependent on it often have very negative dreams. Withdrawal from regular cocaine or cannabis use has been shown to have some links with very unusual dreams.
  • Sleep disorders: insomnia, narcolepsy and sleep apnea can all have a major effect on dreams – again because they make achieving a regular sleep cycle very difficult or impossible.
  • Trauma and PTSD: Post-Traumatic Stress Disorder and other aftereffects of trauma may seriously affect dreams, turning them into nightmares and prompting other effects such as sleepwalking.
  • Environment: similarly, some research done into TST shows that children from backgrounds which included major trauma experienced far more dreams as well as being much more likely to have dreams with threatening content.
  • RBD: people with REM Behavior Disorder don't get the normal paralysis of limbs experienced by others during Stage 5 Sleep mentioned above. This means they can move about – move around wildly in bed, climb out of bed and more – while still asleep. There are many causes of RBD, including most of the rest of the entries on this list.
  • Degenerative neurological conditions: conditions such as dementia or Parkinson’s disease can be indicated by someone starting to suffer from RBD and can have many dream-related side effects.
Sleeping woman

What does it mean if you don't dream?

The question of why some people do not dream and others do tends to be moot:

There are many conditions which may affect your dreams. But there are many more reasons why you may simply not be able to remember them...

Because every human – and even some animals – dream. In fact – as mentioned above – it is commonly held that every human has between three and six dreams every night.

Yet most people can recall very little of what happens in their dreaming state. As much as 95% of all dreams are forgotten as little as ten minutes after waking. Sometimes they aren't retained when in a state of full consciousness at all.

This means that even if you think that you don't dream, you may not need to figure out how to dream more. You may simply need to work out how to remember the dreams you, in reality, already have.

If you want to try to remember more of your dreams, you might want to try:

  • 1. Getting deeper sleep: make sure you're reaching REM sleep properly by measuring your sleep. There are many devices on the market which help you do just that. You might also try other products to help you sleep – from eye masks to advanced technological gadgets!
  • 2. Waking up naturally: being jarred out of your sleep by your alarm clock will not help the memory process.
  • 3. Focus and make notes: immediately focus on and write down whatever small snippets of your dream you remember.

Making all of these a part of your routine may strengthen your memory and encourage your mind to start remembering your dreams.

Because, although nightmares do exist and questions like “why do we dream” and “what are dreams for” may never be answered, for many people dreams are an interesting and intriguing part of the human condition which they wouldn't want to be without.


Henry Warren I am a professional writer and health & wellness enthusiast.

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