Déjà vu is the feeling that one has lived through the present situation before.
This is a French phrase that translates literally as “already seen”. The phrase was coined by a French psychic researcher, Émile Boirac in his book, L’Avenir des sciences psychiques (The Future of Psychic Sciences) (1907).
We associate the feeling of déjà vu with mystery and even the paranormal because it is fleeting and usually unexpected.
However, mainstream scientific approaches reject the explanation of déjà vu as “precognition” or “prophecy”. It is an anomaly of memory whereby, despite the strong sense of recollection, the time, place, and practical context of the “previous” experience are uncertain or believed to be impossible.
The curious sense of extreme familiarity may be limited to a single sensory system, such as the sense of hearing, but as a rule it is generalized, affecting all aspects of experience including the subject’s own actions. As a rule, it passes off within a few seconds or minutes, though its repercussions may persist for some time.
The experience of déjà vu seems to be quite common among adults and children alike – in formal studies 70 percent of people report having experienced it at least once.
Many of us report our first experiences between the ages of 6 and 10.
By the time you reach an age between 15 and 25, you will probably be having déjà vu experiences more often than you will ever have them after that. The number of déjà vu experiences people report steadily decreases after 25 years old.
The occurrence of déjà vu decreases with age.
On average, people who report experiencing déjà vu experience it about once per year.
Men and women seem to experience it at roughly the same frequency.
People who travel often or frequently watch movies are more likely to experience déjà vu than others. Furthermore, people also tend to experience déjà vu more in fragile conditions or under high pressure.
People who are more educated and of higher socioeconomic status are more likely to experience déjà vu.
While a little déjà vu now and then is very common, getting it a lot can be a signal that something’s awry. Déjà vu is commonly reported by patients with epilepsy.
Déjà vu can be produced by electrical stimulation of the cortex and deeper brain structures.
Certain drugs may increase the likelihood of a bout of déjà vu.
One theory suggests that deja vu is an experience you had in a parallel universe.
Déjà vu has also found its way into literature, having been well described by, among other creative writers, Shelley, Dickens, Hawthorne, Tolstoy, and Proust.
Déjà vécu is an intense, but false, feeling of having already lived through the present situation.
Déjà rêvé is the feeling of having already dreamed something that is currently being experienced.
Déjà entendu is the experience of feeling sure about having already heard something, even though the exact details are uncertain or were perhaps imagined.
Jamais vu is any familiar situation which is not recognized by the observer. Often described as the opposite of déjà vu, jamais vu involves a sense of eeriness and the observer’s impression of seeing the situation for the first time, despite rationally knowing that he or she has been in the situation before. Jamais vu is more commonly explained as when a person momentarily does not recognize a word, person, or place that they already know.
Presque vu, from French, meaning “almost seen” is the intense feeling of being on the very brink of a powerful epiphany, insight, or revelation, without actually achieving the revelation. The feeling is often therefore associated with a frustrating, tantalizing sense of incompleteness or near-completeness.
L’esprit de l’escalier meaning “staircase wit” is remembering something when it is too late. For example, a clever come-back to a remark, thought of after the conversation has ended.
Historically, the earliest account of déjà vu-like experience is referred to Saint Augustine in 400 AD, who named it as “falsae memoriae”. The term déjà vu was first used by Emile Boirac in 1876 in his Revue Philosophique, wherein he mentioned “le sensation du déjà vu” to recall this experience in his letter to the editor.
During a trip to Africa, Carl Jung described a feeling of déjà vu when he viewed a slim, black man leaning on a spear looking down at his train as it made a turn around a steep cliff on the way to Nairobi. He writes, “I had the feeling that I had already experienced this moment and had always known this world.” Although this world and this man were something alien to him, he saw the whole thing as perfectly natural. He called this a recognition of what was “immemorially known.”