Peter Zhang

Why We Dream


Alice Robb’s Why We Dream is a well-researched introduction to sleep, dreams, and lucidity. A great mix of personal stories, anecdotes, and research, the book is both entertaining and informative.

Here’s the paperback and audiobook.

Utility: ★★★★✰ (4/5)

Writing: ★★★★✰ (4/5)

I took away the following key ideas:

  • The study of dreams is tainted by historical connections to spirituality and psychoanalysis. Recently, the field has rebounded as scientists have connected dreaming to health and performance.
  • Dreams unlock creative ideas, solidify learned knowledge, and diagnose illness. In contrast, nightmares can deepen trauma and cause health problems.
  • Journaling boosts dream recall. Dream groups assist in interpretation. Reality tests and intentionality are key to lucidity.

The book was an overall great read. It occasionally delves too deep into unrelated backstory, but the bulk of the book is attention grabbing and well researched. I was even convinced to begin keeping a dream journal. The first week of entries are below.

  • 1/10/21: I get a haircut. The barber attempts to trim my mustache stubs with scissors, which puzzles me. In a later dream, I recall seeing my friends from Voyager Consulting.
  • 1/11/21: I am doing programming assignments (maybe for Data 100). I don’t think it’s going well. Earlier in the night, I went on some sort of adventure with my friends from high school.
  • 1/12/21: I’m helping to create a course. For some reason, my notes say “strip clubs are not allowed” (repressed, even in my dreams?). In my next dream, I am urging someone to fix climate change by banning all fossil fuels. Finally, I have the bright idea that Steam community marketplace prices correlate with real world gaming interest (e.g. when it’s cold and people are indoors, greater gaming activity may drive prices up).
  • 1/13/21: I compete in some sort of Hunger Games event. I narrowly avoid death several times. I wake up at 5AM and go back to bed. This time, I’m in the gym with a friend and we meet someone who claims to follow my friend on social media.
  • 1/14/21: I am making some kind of difficult decision. Later, I am writing an essay about free speech and discussing ideas with a friend.
  • 1/15/21: I trade stocks. I guess.
  • 1/16/21: For three nights in a row, Professor Rao breaks into my home with knives and chases me around. I attempt to arm myself and find hiding spots. On the third night he catches me and—just as I resign myself to a bloody execution—he reveals that all of it was never meant to hurt me, but instead to help me grow. Then, I meet up with friends for a vacation.
  • 1/17/21: I dreamt that I was competing at a debate tournament and kept missing all of my rounds. I would run around the massive tournament hotel, occasionally falling asleep, occasionally getting distracted. The anxiety was gut-wrenching.

My dream recall definitely improved, but the progress wasn’t very steady (imagine how I felt waking up on the 15th). Some observations:

  • The subjects of dreams seem to reflect significant events from the day before.
  • Dreams can provide concrete lessons (e.g. the horrifying Rao parable) and ideas (e.g. the Steam marketplace insight).
  • A lot of my dreams feature friends. Freud might say that I don’t get enough friendship in the daytime.
  • Dreams are weird.


As I mentioned earlier, the book is full of great personal anecdotes. I omitted them here for brevity and clarity. The full book is much more captivating and detailed.

How We Forgot About Dreams

Across the world, dreams have historically been associated with spirituality. Some researchers even suggest that religion emerged from dreams. Supernatural accounts of dreams persisted well into the twentieth century despite advances in scientific thinking, permeating both popular culture and the ideas of famous historical figures.

In the early twentieth century, Sigmund Freud brought dreams to academia when he proposed a connection between dreams and subconscious desires. During the daytime, Freud posited, people repress their innate sexual desires. At night, these desires manifest in dreams as a litany of sexual symbols.

Freud mentored a fellow psychoanalyst named Carl Jung, who also studied dreams. They later split, as Jung thought that dreams reflected more than just sexual desires, and instead involved a “collective unconscious” compromised of societal myths.

In the 20s, interest in dreams was propelled by rising interest in indigenous groups, who revered the prophesizing power of dreams and incorporated dreaming into rituals.

By the 40s, two scientists named Calven Hall and Robert van de Castle undertook the first empirical study of the subject. They gathered the dreams of university students can found that, against Freud’s theory, the majority of them involved negative emotions like fear—not unabashed sexual pleasure. The study did, however, confirm that dreams were linked to internal conflicts: aggressive people fought imaginary foes, powerless people were persecuted by fantastic governments, confident people had a great time.

In the 60s, a psychologist named David Foules stumbled upon a strange finding while studying children’s dreams. Young children seemed to be incapable of remembering complicated dreams; as they aged, the complexity and recallability grew as well. Foules’ finding further shed doubt onto Freud’s ideas.

In the 70s, a neuroscientist named Allan Hobson found further proof against Freud. When cats slept, they brains replaced serotonin and norepinephrine (which assist decision-making and focus, respectively) with acetylcholine) which is associated with emotions and visual imagery). Hobson and his colleague proposed that dreams were simply reaction to these neurochemical changes.

By the 80s, Freud’s ideas had been discarded as pseudoscience. Feminist criticized his penis-focus and mistreatment of women, while scientists distanced themselves from dreams, which by now was tightly associated with parapsychology.

Parapsychologists believed that dreams mediated supernatural events, such as communication or prediction. Riding on popular interest in eastern ideas, Americans in the 60s and 70s embraced these ideas, opening labs at many prestigious universities. Bogus studies were conducted, where vague similarities between dreams and future, real events were taken as evidence of supernatural behavior. Even public intellectuals got swept up.

These ideas had a grain of truth. Not all information from dreams is useless. During the rise of Hitler, a journalist named Charlotte Beradt interviewed three hundred Germans. Their dreams repeatedly foretold mass surveillance and persecution—an ominous forewarning.

Most paranormal claims are explained by simple statistics. Given how often we dream (tens of thousands of dreams in a lifetime), occasional connections to past dreams are inevitable. Premonitions have been thoroughly discredited, and previous research institutes dedicated parapsychology now work to discredit the idea.

The Vanguard

Eugene Aerinsky was a smart but unreliable student who, by chance, ended up studying dreams at Stanford under Nathaniel Kleitman. During his first assignment, he noticed that the pupils of babies would dart around for brief periods of time. Instructed to investigate further, Aerinsky hooked his son to a polygraph and found that his eyes oscillated in jittery waves. Moreover, he found that these rapid eye movements were associated with dreams. He presented these results, naming the phenomena “REM sleep.”

There are countless accounts of lucid dreaming throughout history, and Stephen LaBerge experienced his first lucid dream at a young age. As an adult, he worked under William Dement to gather evidence for lucid dreaming. He started by training himself, eventually being able to trace a line with his eyes while sleeping. For the next months, he made several fascinating discoveries. LaBerge trained himself to communicate with clenched fists in Morse Code. He showed that during lucid dreams, areas of the brain were activated in a similar pattern to waking people. He even showed that lucid dreaming subjects could achieve orgasm.

Dreams Enter the Lab

Matt Wilson had just finished another experiment involving a rat, a maze, and a device that measured brain activity. When he let the rat go to sleep, he noticed that its brain waves were similar to those that it had while passing through the maze. These brain regions weren’t just associated with visual cortex, so Wilson concluded that the rats were actually experiencing the maze.

Around the same time, Robert Stickgold theorized that stressful events tended to show up in dreams. He gathered a group of Tetris experts and ammeters and found that, after an intense gaming session, both groups reported seeing Tetris-related imagery in their dreams. Intriguingly, even the participants with amnesia—who couldn’t even remember the rules of Tetris—nevertheless reported Tetris-themed dreams.

Joseph de Konnick connected these findings to the process of learning. He found that students in an intensive crash course on French had more REM sleep and began dreaming in French. Moreover, subjects who had the most REM sleep also tended to perform the best. He repeated this experiment, instructing students to wear glasses that flipped the world upside-down. Sure enough, the subjects had much more REM sleep, and many dreamed upside-down.

The Renaissance of Sleep Research

Scientific research in dreams was revived as we learned of the importance of sleep in our lives. Studies have linked sleep to a variety of physical and mental problems. Sleep-deprived people were more likely to be in car accidents and make mistakes on the job. Sleep is important for cellular repair and mental growth. Sleep is even important for mental health, s sleep helps us process painful memories.

When DJ Peter Tripp held a stunt where he stayed up for eight days, his body deterriorated and he began to go insane. An inspired high schooler, Randy Gardner, went into a zombie-like state after staying awake for eleven days.

Sleep is improves learning and is linked to better grades and standardized test scores. REM sleep is so important that if we don’t get enough one night, our bodies will make us dream more the next night. Studies like these have propelled movements for later high-school start times and noise blockers for sleep-deprived, impoverished people in loud communities.


Dreams assist problem solving and creative thinking. In a study of undergraduate students who tracked their dreams for a week, a quarter of them found solutions to real-world problems. In other studies, dreaming or being woken up from a dream helped subjects solve brain teasers, especially ones that required loose associations.

Psychologist associated sleep with the brain’s “default-mode network,” which whenever the mind wanders. Dreaming is like extreme fantasizing: unlocking spontaneous ideas and novel juxtapositions.

To use these dream-inspired solutions, you first to need to remember them. Being older or close-minded tends to make it harder to recall dreams. Fortunately, most people can easily and quickly improve dream recall. The best strategy is to keep a dream journal—it can be a physical notepad or a digital app—and notate. Dream logging has been associated with the ability to recall more detailed and vivid dreams.

To journal successfully, write down your dreams the moment you wake up. Checking your phone or performing other tasks could cause your dream to disappear. If you find this hard, putting yourself in sleeping poses can boost recall. Waking up naturally (with no alarm) can also help.

Artists have long exploited the creative power of dreams. Musicians, painters, filmmakers, and writers alike draw on dreams for inspiration. Conversely, the rare people who don’t dream at all tend to lack creative endeavors. Novelist Graham Greene logged his dreams for decades, and they became an endless source of inspiration for his novels; Maya Angelou, Kathryn Davis, and Steven King achieved artistic breakthroughs in their nocturnal adventures.

Even scientists can benefit from dreams. Otto Leowi identified the first neurotransmitter, thereby founding the field of neuroscience, in an experiment that he dreamt up. Mathematician Donald Newman credited John Nash in a paper for a conversation that they shared—in one of his dreams.

Preparation for Life

Psychologist Antti Revonsuo proposed that scary dreams are prepare us for threats. In lab experiments, rats deprived of REM sleep behaved more recklessly in tasks during daytime. Humans do the same: aspiring doctors with nightmares about the MCAT tended to do better on test day.

Some dreams are strange. One usually common nightmare involves losing your teeth. Opaque on face, but studies have linked these teeth-related dreams with anxiety, suggesting that losing teeth portends death.

Dreams serve a pedagogical purpose. In studies involving video game Doom, a skiing simulator, and a three-D maze, subjects that dreamed of these tasks performed better the next day.

If dreams have this practical purpose, then why are they so strange? They aren’t actually that bizarre. The majority of dreams occur in actual or familiar places. While dreams have strange plots, dreamers retain their personality and emotions.

Dreams improve mental health. A 2015 study by Matthew Walker found that sleepy participants struggled to differentiate emotions and tended to interpret facial expressions as hostile. Among those with depression, the rate of dream recall can drop from a normal rate of 80-90 percent to as low as 50 percent. Depression patients can begin losing the ability to dream. Moreover, their REM states start earlier, the first one lasts longer, and throughout the night, their dreams get increasingly negative.

Dreams can also assist people through stressful events. Rosalind Cartwright found that recent divorcees who dreamed about their exes were better off a year later. In particular, ex-wives who were assertive in their night-time encounters recovered the most. The same goes for mourners. Even though most of them had negative dreams, they were nonetheless associated with acceptance and greater well-being. Dreaming of a lost loved helps people grief.

Dreams can also help us grapple with our own mortality. Terminally ill patients often dream of religious figures or family members, which in turn ease their fear of death. In lonely nursing homes, the elderly use dreams to feel closer to their loved ones and their youth. For nonbelievers, pop icons like Madonna can substitute for spiritual figures, providing comfort through turmoil.

There’s a dark side too. Traumatic nightmares can be induced by a tragedy like 911, a natural diaster like a wildfire, or an episode of sexual abuse. Unlike PTSD, these horrifying dreams don’t exactly replay our real memories. Instead, they mix elements of the present and the past.

Although these patterns are strong, predicting dreams remains impossible. Stickgold believe that what you dream about on a given night depends on emotions, repetition, and recency. In the 80s, Tore Nielsen found events we witness tend show up in our dreams the day of, two days later, and a week later. In other words, it alternates. This cycle between related dreams and unrelated dreams can serve a practical purpose by helping victims of trauma cope. For example, Holocaust had more pleasant dreams while they were in the concentration camps—where so-called “freedom dreams” provided a crucial source of comfort”—than after they were released.

New research suggests that dreams can alter memories. An experiment by Gaetan de Lavilléon was able to control the way rats behaved during the day by stimulating the associated brain regions during sleep. A similar strategy is a potential therapy for PTSD patients.


Nightmares aren’t just “bad dreams.” They can be disorienting and panic-inducting. They can also start in children as young as two and continue to occasionally strike in adulthood.

Bad dreams matter. Among couples, people who dreamed that their partners wronged them had negative feelings towards their actual partners. In other cases, people with realistic nightmares can wake up believing that they had been in an affair, that a relative had died, or that a home intrusion was underway. Severe cases of dream-reality confusion can even trigger mania.

Reliving trauma events can be deepen the effect. When students were primed to dream about a gut-wrenching film, they felt even more stressed the next time they watched it. The same goes for PTSD patients, for whom nightmare-flashbacks can be crippling. Unsurprisingly, having more nightmares has been linked to greater rates of self-harm.

Nightmares can trigger stress responses, including episodes of migraines. Painful dreams among ill patients have been shown to interfere with recovery. Nightmares have even caused heart attacks.

A curious case study involves Hmong asylees who settled in the Midwest after the Vietnam war. In the 80s, men in these communities began dying in their sleep in the early morning, despite being otherwise healthy. An anthropologist later concluded that the Hmong has suffered intense nightmares featuring a spirit from their native culture, spiking their stress levels and triggering cardiac arrest.

Some treatments can mitigate nightmares. Drugs are unreliable and have side affects, while cognitive therapy tends to be unpleasant and time consuming. A new treatment by Patrick McNamara might change that. It uses virtual reality to simulate nightmares, which is faster and more pleasant. Another treatment aims to make people


Dreams assist diagnosis because patients are more willing to divulge dream then to admit to an embarrassing symptom. A growing body of empirical research confirms Freud’s basic thesis that subconscious daytime stresses emerge in our dreams.

One phenomena is the dream rebound effect. Daniel Wegner rounded up students and instructed them to “not think about a white bear.” They weren’t great at it, but the next day, when they were allowed to think about white bears, those students thought about white bears even more than a control group.

Neuropsychoanalysts now use brain science to study Freudian ideas. Contrary to previous research, people could dream even without a pontine brain stem. Dreams, under this theory, are driven by our reward system, which drives us to explore our surroundings and gives us various appetites. Since we can’t physically pursue these things while sleeping, dreams are manifestations of these desires.

Recurrent dreams can reflect stress triggers. Anorexic teenagers may have stressful dreams about grocery stores. Newly abstinent drug users often dream about their drug of choice. Dreams about drinking are used as an early warning for relapse.

Dreams can also preempt manic and depressive episodes. Depressed people at risk of suicide are more likely to dream about destruction, loneliness, and self-harm.

Self-diagnosis is also possible. Someone who has a nightmare about binge-eating lettuce may realize that their anorexic habits are abnormal. In fact, dream research William Denent quick smoking after dreaming of lung cancer.

Even physical illness can leave traces in dreams. “Fever dreams” are a reference to the increased delirium associated with inflammation. Ill-boding dreams can be precursors to migraines, Parkinson’s, sleep apnea, and even miscarrage.

Dream Groups

Dreams are sometimes derided as poor conversation topics. They’re unrealistic, long, and often incoherent. It’s also hard to get people to care—they didn’t even happen!

But talking about dreams with others can help generate insights and tighten social bonds. Studies have found that across a variety of domains, divulging personal hardships improves relief and mental health.

Montague Ullman founded Ullman dream groups, structured discussions dedicated to interpreting dreams. Research now confirms that they have both social and psychological benefits. By drawing on the entire groups’ insights, participants can find meaningful lessons in even mundane dreams. Dream groups also invite people to divulge personal struggles, helping them cope with breakups or troubled relationships.

Even the informal dream groups that emerged in Holocaust concentration camps were a bonding and rewarding experience. When dream groups were brought to modern prison, the conversations gave female prisoners a sense of community. They worked out repressed traumas and helped each other prepare for stressful events.

Nowadays, free apps enable users to share and discuss their dreams with fellow dreamers across the world.


Frequent reality tests can induce a lucid dream. Make a habit out of checking your environment and body for clues that seem off. A suitable reality test for you may depend on the nature of your dreams and your ability to perform these tests in everyday life.

Intentionally thinking about lucid dreaming can also help bring it about. Mediation in particular has been associated with improved dream recall.

The best time to become lucid is late at night. Wake yourself up from a dream, state and repeat your current dream, and go back to sleep an hour later, paying attention to cues that you are dreaming. Another method is to focus on hallucinatory images and slowly drift into sleep, with the goal of retaining your consciousness.

Staying lucid can also be a challenge. Too much excitement and you might wake up. Too little attention and it may revert to a regular dream. Paying close attention to the senses can help, but even practiced lucid dreamers can’t controlling everything—physical laws, independent characters, and emotions still come into play.

Young age, a strong locus of control, and creativity are all associated with more lucid dreaming. Gamers and athletes are also better since they regularly engage in imagination, whether in a video game world or in mentally practicing their sport.

The best studies estimate that 55% of people have experienced lucidity and a quarter have at least one lucid dream a month. But people who can become lucid on command are exceedingly rare. Moreover, it isn’t clear is everyone is able to lucid dream.

Studies have confirmed that reality testing and intention setting are the best methods. The ideal strategy is to regularly conduct reality testing, wake up after five hours of sleep, and set an intention to become lucid before going back to bed.

Informal experiments by Stephen LaBerge have also shown that galantmine—an Alzheimer’s treatment associated with earlier and longer REM cycles—is able to quadruple the likelihood of lucid dreaming. Galantmine-induced dreams were also longer, more vivid, and more stable. The drug, however, has side effects and could induce nightmares.

Recent studies have linked brain activity during lucid dreaming with logical reasoning and self reflection. Studies on blind subjects, the subjective passage of time, and muscle activation continue to shape what we know about lucid dreaming.

Lucidity has therapeutic potential for schizophrenia, anxiety, and other mental health problems. A study on lucid dreamers found that peacefully confronting an imaginary adversary decreased anxiety in daytime. Lucid dreaming seems to even boost performance in physical activity.


New technologies could accelerate the study of dreams. In 2013, a team led by Tomoyaso Horikawa built a dictionary of fMRI patterns that correspond to various real-world objects. The team was able to guess the content of dreams by comparing fMRI scans of the sleeping subjects to the dictionary.

Finally, studying dreams doesn’t take away from their magnificence. Even if you manage to find patterns in your dreams, your nighttime adventures will continue to shock you in their creativity and grandeur.

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