Threat Simulation Theory

Why Humans Were Designed to Have Nightmares

Dreams often carry unpleasant emotion, and that is an awkward feature to account for if dreaming is only about sorting memories or granting wishes. The threat simulation theory, put forward in 2000 by the Finnish cognitive neuroscientist Antti Revonsuo in the journal Behavioral and Brain Sciences, answers with evolution. In ancestral environments, escaping a predator, running into a hostile stranger, and coping with disaster all bore directly on survival. Rehearse those threats often enough in a dream, the argument goes, and your response in the waking encounter comes faster and lands better. On this reading a nightmare is not a broken function; it is a function.

Why Chase Dreams Keep Getting Studied - Comparisons Across Cultures

Being chased is a theme that dream researchers have returned to again and again. There is the 2003 survey of typical dreams among Canadian university students by Nielsen and colleagues, and the 2013 comparison of Tibetan and Han Chinese dreamers, to name two studies built on quite different samples. Threat simulation theory reads the prominence of this theme as a shared evolutionary inheritance. You may live with no realistic chance of being chased by a predator, yet deadlines, other people's judgment, and money worries persist as threats in another shape. If the theory is right, the brain loads them onto the old template of pursuit and processes them there.

Does Being Exposed to Threat Change Your Dreams?

The theory yields a prediction you can test: people who have actually been exposed to threat should dream of threat more. In 2005 Revonsuo and colleagues published a study in Consciousness and Cognition on the dreams of children growing up amid war, and reported it as evidence in favor of that prediction. The implication is that the threat simulation machinery learns from experience and starts producing more elaborate simulations. A recurring nightmare, on this line of argument, can be read as that machinery running too hot.

None of which means you can work through a wound by interpreting dreams. If nightmares are costing you sleep, or the scene keeps returning during the day, and this has gone on for weeks, the reliable move is to talk to a sleep or mental health professional before you work on what the dream means.

Theory Limitations - Not All Dreams Are Threat Simulations

Threat simulation theory explains one side of dreaming and no more. Pleasant dreams, sexual dreams, creative dreams, and dreams that make no sense at all sit outside the frame. Even its starting premise, how much threat dreams actually contain, has been contested: Malcolm-Smith and Solms published a response in the journal Dreaming in 2004. Revonsuo himself went on in 2015 to propose a social simulation theory, widening the argument toward dreaming as practice for social skills and bonds. The settled position across this whole discussion is not to pin dreaming to a single function, but to see emotional processing, memory consolidation, and creative problem-solving overlapping in it.

That boundary is useful when you read your own nightmares. Threat simulation dissolves the worry that there is something wrong with a person who dreams frightening things, but it will not tell you what a particular dream is pointing at. To learn which threat your dream borrowed, you have to look at your life rather than at the theory.