What causes déjà vu?
About two-thirds of people have felt it. Research suggests déjà vu is a memory glitch: a new scene feels familiar because it resembles one you can’t recall.
Quick Answer
Déjà vu, French for “already seen,” a term coined by French scientist Émile Boirac in 1876, is the unsettling sense that a new moment has happened before. About two-thirds of people report experiencing it, and it tends to become less frequent with age. A leading explanation is that it’s a memory glitch: your brain registers familiarity without retrieving the memory behind it. In a 2012 virtual-reality study, Colorado State University psychologist Anne Cleary found people reported more déjà vu in new scenes whose layout matched one they’d seen before but couldn’t recall. Déjà vu can also bring a feeling that you know what will happen next, but in a 2018 study that feeling didn’t help people predict anything better than chance.
By the Numbers
Key Facts
- How common
- About two-thirds of people report having it
- The name
- Coined by Émile Boirac in 1876; French for “already seen”
- Leading theory
- Familiarity from a forgotten, similar-looking scene
- A premonition?
- A 2018 study found no real predictive power
How a forgotten memory can trigger déjà vu
- You see a new place
You walk into a room or street you’ve never visited.
- Its layout echoes an old memory
The arrangement of things resembles a place you’ve seen before.
- The memory stays hidden
Your brain senses the match but can’t pull up the original memory.
- Familiarity without a source
You get a strong “I’ve been here” feeling with no explanation: déjà vu.
A common, puzzling experience
In a 2003 review of the research, psychologist Alan Brown found that about two-thirds of people report having had déjà vu. It becomes less frequent with age and is usually triggered by places rather than conversations.
Testing it in virtual reality
Anne Cleary’s team built virtual scenes, then showed people new scenes that matched earlier ones in layout but not in content. When people couldn’t recall the matching scene, they reported more familiarity and more déjà vu, support for the idea that déjà vu is familiarity without recollection.
The illusion of prediction
In a 2018 study in Psychological Science, Anne Cleary and Alexander Claxton found déjà vu came with a stronger feeling of knowing which way a path would turn next, but people guessed no better than chance.
Myth vs. Fact
MythDéjà vu is a glimpse of the future.
FactPeople often feel they know what’s coming during déjà vu, but in a 2018 study they couldn’t predict the next turn any better than chance.
MythDéjà vu means you’ve lived this moment before.
FactResearch points to memory instead: a new scene that resembles a forgotten one can trigger it.
The Bottom Line
Déjà vu seems to be a memory glitch: a new scene feels familiar because it echoes one you can’t consciously recall. The eerie sense of knowing what’s next is just a feeling.
Sources & Further Reading
- Psychological Bulletin — Brown, A Review of the Déjà Vu Experience (2003)
- Scientific American — Déjà Vu Found to Originate in Similar Scenes
- Consciousness and Cognition — Cleary et al., Familiarity from the configuration of objects in 3-dimensional space and its relation to déjà vu (2012)
- Psychological Science — Cleary & Claxton, Déjà Vu: An Illusion of Prediction (2018)
- Colorado State University — Déjà vu and feelings of prediction: They’re just feelings