Dream meanings: what science and culture actually say

Before you look for a meaning

Dream interpretation is not prediction and not diagnosis. This article separates what sleep research observes from what popular interpretation associates with the theme.

Looking for the meaning of a dream is an old habit, present in almost every culture. What changed is that we now have research on what happens in the brain while we dream, and it does not support the idea of dreams as warnings about the future.

That does not make dreams pointless. They usually say a lot about what you lived and felt in the past few days.

What research has shown

Researchers woke volunteers several times a night while recording brain activity, and identified a region at the back of the brain whose activity indicated whether the person was dreaming, both inside and outside REM sleep. The pattern was clear enough to predict, from the signal alone, whether someone would report a dream.

Source: Siclari et al., The neural correlates of dreaming, Nature Neuroscience, 2017.

A second key finding is the continuity hypothesis: dream content follows waking life. In a diary study, everyday activities and worries reappeared in dreams, though in different proportions.

Source: Schredl and Hofmann, Continuity between waking activities and dream activities, Consciousness and Cognition, 2003.

Freud, Jung and faith on this dream

In Freud's psychoanalysis. Of the two popular methods Freud described, the symbolic one appears in the Bible, when Joseph reads Pharaoh's seven fat cows and seven lean ones as seven years of plenty and seven of famine (Genesis 41). The decoding method, typical of dream books, uses a fixed code: "letter" means "trouble" and "funeral" means "engagement." Freud found both lacking and chose free association, which breaks the dream into parts and asks what comes to mind about each one. Juliana David Jorge's master's thesis (PUC Minas, 2007) shows how it became the "fundamental rule" of his method.

In Jung's psychology. Jung was even harsher. In Man and His Symbols, he calls it foolish to trust ready-made guides, as if you could buy a reference book and look up a symbol: no dream symbol can be separated from the person who dreamed it. He told his students to learn all they could about symbolism and then forget it all when analyzing a dream.

In faith traditions. In Spiritism, The Spirits' Book (Allan Kardec, 1857, questions 400 to 418) teaches that in sleep the ties between spirit and body loosen and the spirit can interact with other spirits; a dream would be partly a memory of that, often confused and mixed with worries. In Umbanda, an Afro-Brazilian religion, Pai Rodrigo Queiroz's Diário dos Sonhos (Dream Diary) asks for a daily entry, since a dream sometimes makes sense only days later, and proposes the CEC scale, scoring Clarity, Emotion and Confirmation to separate an ordinary dream from a possible spiritual message.

Bringing both views together. The dream journal in the workbook for Lori Gottlieb's Maybe You Should Talk to Someone asks for a title, date, description, characters, themes and, only at the end, an interpretation. The order teaches the method: write it down first, look for meaning later, in therapy or in faith.

Sources: Freud, Die Traumdeutung, 1900; Jorge, PUC Minas, 2007; Jung (ed.), Man and His Symbols; L. P. Baçan, O Livro dos Sonhos, 2014; Kardec, The Spirits' Book; Pai Rodrigo Queiroz, Diário dos Sonhos; Gottlieb, Maybe You Should Talk to Someone journal.

Why danger shows up so often

Finnish psychologist Antti Revonsuo proposed that dreaming works as a threat simulator: the brain rehearses risky situations in safety. That would help explain why being chased, falling and dangerous animals appear so often in dream reports worldwide.

It is an influential hypothesis, debated by other researchers, not a settled fact.

Source: Revonsuo, The reinterpretation of dreams, Behavioral and Brain Sciences, 2000.

See also: Night terrors and Lucid dreaming.

The most common dreams

A survey measured which dream themes appear most often over a lifetime. Among the most reported: being chased, falling, arriving late, flying, being naked in public, being attacked, losing teeth and dreaming of someone who has died.

So if you dreamed one of those, it says more about how human minds work than about a message aimed at you.

Source: Nielsen et al., The Typical Dreams of Canadian University Students, Dreaming, 2003.

A better way to look at a dream

Instead of reaching for a dictionary, three questions help more:

1. What was the emotion? Fear, relief, shame, longing. The emotion is usually the most faithful part of a dream.
2. What happened in the last few days? An argument, an exam, a move, an unpaid bill, a series you binged.
3. Does it repeat? A single dream is noise. A recurring theme usually points to something taking up space in your head.

Writing it down right after waking, before touching your phone, is what most improves recall.

What dream books say

The search for meaning in dreams is as old as writing. In the second century, Artemidorus of Daldis wrote the Oneirocritica, the oldest complete Greek dream book that has survived, and already argued that the same dream changes meaning depending on the dreamer's life. Centuries later, popular "dream books", such as Brazil's Livro do Sonho, organized symbols as a dictionary, with one meaning for each image. Freud, in The Interpretation of Dreams in 1900, described these two paths, the symbolic and the "decoding" method, and proposed a third: understanding the dream through each person's associations and history. On this blog, every article brings what science observes and what the books say. The Brazilian dream book O Livro dos Sonhos, by L. P. Baçan (2014), follows that dictionary format and even has an entry for the dream itself: in life, success in your activities; in love, happiness.

Freud described dream books as a kind of dictionary that translates each image into another with a fixed meaning. Artemidorus of Daldis, author of the oldest complete Greek dream book that has survived, advised looking at the dreamer's life before interpreting. If you see the dream as a message, both paths suggest the same thing: ask what this image brings to mind in your life right now.

Source: Livro do Sonho, Brazilian dream dictionary; Freud, Die Traumdeutung, 1900; L. P. Baçan, O Livro dos Sonhos, 2014.

And popular interpretation?

In folklore each element gets a symbol: snakes are linked to betrayal, water to emotions, money to worth, teeth to loss. These associations come from cultural and religious traditions, change from country to country and have no scientific backing.

They can be an interesting starting point for thinking about your own life, as long as nobody makes an important decision based on them.

See also dreaming about snakes and dreams about teeth falling out.

When a dream deserves professional attention

Frequent nightmares that disrupt sleep, dreams tied to a traumatic event, or fear of falling asleep are worth discussing with a health professional. There are treatments with good evidence for recurring nightmares.

Read also: why nightmares happen and how to have fewer; why the same dream keeps coming back.