10 Facts Researchers Have Discovered About Dreams

Dreams can be fascinating, exciting, terrifying, or just plain weird. While there is no clear consensus on why we dream, researchers have learned quite a bit about what happens while we are dreaming. Here are 10 things you should know about dreams.

Everybody Dreams

Woman in dream holding colorful balloons and standing on water
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Men do it. Women do it. Even babies do it. We all dream for around two hours per night, even those of us who claim not to. In fact, researchers have found that people usually have several dreams each night, each one typically lasting for between 5 to 20 minutes. During a typical lifetime, people spend an average of six years dreaming!

But You Forget Most of Your Dreams

Most dreams are quickly forgotten
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As much as 95 percent of all dreams are quickly forgotten shortly after waking. Why are our dreams so difficult to remember? According to one theory, the changes in the brain that occur during sleep do not support the information processing and storage needed for memory formation to take place. Brain scans of sleeping individuals have shown that the frontal lobes, the area that plays a key role in memory formation, are inactive during rapid eye movement (REM) sleep, the stage in which dreaming occurs.

Not All Dreams Are in Color

Some dream in black and white
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While most people report dreaming in color, there is a small percentage of people who claim to only dream in black and white. In studies where dreamers have been awakened and asked to select colors from a chart that match those in their dreams, soft pastel colors are those most frequently chosen.

Men and Women Dream Differently

Men and women dream about different things
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Researchers have found some differences between men and women when it comes to content the content of their dreams. In several studies, men reported dreaming about weapons significantly more often than women did, while women dreamed about references to clothing more often than men.

Another study showed that men's dreams tend to have more aggressive content and physical activity, while women's dreams contain more rejection and exclusion, as well as more conversation than physical activity.

Women tend to have slightly longer dreams that feature more characters. When it comes to the characters that typically appear in dreams, men dream about other men twice as often as they do about women, while women tend to dream about both sexes equally.

Animals Probably Dream

Animals probably dream
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Have you ever watched a sleeping dog wag its tail or move its legs while asleep? While it's hard to say for sure whether the animal is truly dreaming, researchers believe that it's likely that animals do indeed dream. Just like humans, animals go through sleep stages that include cycles of REM and non-REM sleep.

It's Possible to Control Your Dreams

Man having a lucid dream
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A lucid dream is one in which you are aware that you are dreaming even though you're still asleep. During this type of dream, you can often direct or control the dream content. Approximately half of all people can remember experiencing at least one instance of lucid dreaming, and some individuals are able to have lucid dreams quite frequently.

Negative Emotions Are More Common in Dreams

Having a bad dream
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Over a period of more than 40 years, researcher Calvin S. Hall collected more than 50,000 dream accounts from college students. These reports were made available to the public during the 1990s by Hall's student William Domhoff. The dream accounts revealed that many emotions are experienced during dreams including joy, happiness, and fear. The most common emotion experienced in dreams was anxiety, and negative emotions, in general, were much more common than positive ones.

Blind People May Dream Visually

Blind man sitting on bench
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In one study of people who have been blind since birth, researchers found that they still seemed to experience visual imagery in their dreams, and they also had eye movements that correlated to visual dream recall. Although their eye movements were fewer during REM than the sighted participants, the blind participants reported the same dream sensations, including visual content.

You Are Paralyzed During Your Dreams

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REM sleep, the stage of sleep during which dreaming occurs, is characterized by paralysis of the voluntary muscles. Why? The phenomenon is known as REM atonia and prevents you from acting out your dreams while you're asleep. Basically, because motor neurons are not stimulated, your body does not move.

In some cases, this paralysis can even carry over into the waking state for as long as ten minutes, a condition known as sleep paralysis. Have you ever woken up from a terrifying dream only to find yourself unable to move? While the experience can be frightening, experts advise that it is perfectly normal and should last only a few minutes before normal muscle control returns.

Many Dreams Are Universal

Little girl dreaming
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While dreams are often heavily influenced by our personal experiences, researchers have found that certain themes are very common across different cultures. For example, people from all over the world frequently dream about being chased, being attacked, or falling. Other common dream experiences include school events, feeling frozen and unable to move, arriving late, flying, and being naked in public.


Bértolo H, Mestre T, Barrio A, Antona B. Rapid Eye Movements (REMs) and Visual Dream Recall in Both Congenitally Blind and Sighted Subjects. Third International Conference on Applications of Optics and Photonics. SPIE Proceedings. August 22, 2017;104532C doi:10.1117/12.2276048.

Domhoff GW, Schneider A. Similarities and Differences in Dream Content at the Cross-Cultural, Gender, and Individual Levels. Consciousness and Cognition. December 2008;17(4):1257-1265. doi:10.1016/j.concog.2008.08.005.

Hobson JA. REM Sleep and Dreaming: Towards a Theory of Protoconsciousness. Nature Reviews. Neuroscience. 2009;10:803-813. doi:10.1038/nrn2716.

Hockenbury SE, Hockenbury D. Discovering Psychology. 5th ed. New York, NY: Worth Publishers; 2011.

Mathes J, Schredl M. Gender Differences in Dream Content: Are They Related to Personality? International Journal of Dream Research. 2013;6(2):104-109.

Voss U, Holzmann R, Tuin I, Hobson JA. Lucid Dreaming: A State of Consciousness With Features of Both Waking and Non-Lucid DreamingSleep. 2009;32(9):1191-1200.