Frequently Asked Questions

1. What is déjà vu?

Déjà vu (French for “already seen”) is an experience that many people have: roughly 67% of the adult population say they have had one. It is the startling impression of reliving an event or revisiting a place while at the same time knowing that this is not possible. It seems that a number of different experiences are all called “déjà vu” (they even occur in people who have been blind from birth), so it would be better to use terms that describe more accurately what people say has happened. We can speak of “déjà experiences” as the general term, as proposed by Prof. Vernon N. Neppe, and use déjà vécu (“already lived through”), déjà visité (“already visited”) and other such terms that better reflect the actual experiences.

2. Why do déjà experiences occur?

At this point there is no good answer. Many explanations have been put forward (see the chapters in Prof. Alan Brown’s 2004 book the déjà vu experience), but none has been proven true or false. Attempts to reproduce déjà experiences reliably in the laboratory have not met with great success. They tend to be sporadic and, like dreams, are very subjective. As when studying dreams, we have to take people’s word for what they say they have experienced and proceed from there. There is the further problem that many different experiences are all called “déjà vu”, and each may well have its own cause. Actually, we know far too little about what people are experiencing, and until we know a lot more we cannot classify these experiences clearly. That has to be done before we can speculate intelligently about the various causes.

3. What effects do déjà experiences have on one’s mind?

Most people are baffled and confused by the paradox of living through something again, or visiting a place once more, while knowing with certainty that this cannot be true. Some are frightened and fear that they are going crazy. Others are intrigued, full of awe and wonder that such things are possible. Some feel reassured, convinced that they are on the right path. The reactions are very varied.

4. Why do déjà experiences affect people in different ways?

Because people are unique individuals, each with her or his own background, education, culture, personality and so on.

5. Who is most likely to experience déjà experiences?

They tend to happen more often, and to be more intense, among young people, say between the ages of 15 and 25. According to surveys, the incidence among college students (ca. 79%) is higher than among the general population (ca. 65%). Why this is so, no one knows. There does not seem to be any dependence on gender or nationality.

6. Why do some people get déjà experiences more often than others?

At our present state of knowledge, this is not known. There seems to be some connection with stressful life situations, and the experiences may also result from experimenting with recreational or prescription drugs.

7. Is there any way to stimulate a déjà experience?

There have been several attempts, using hypnosis and psychological strategies, but it seems that none has produced the specific déjà experience in which one is confused and baffled by the contradiction between what one is experiencing and the utter certainty that it is impossible.

8. Why do people with temporal lobe epilepsy (TLE) sometimes recall having a déjà experience before having a seizure?

The temporal lobe and the limbic system in the brain seem to be vital in the formation, storage and recall of memories, so it is not very surprising that people with TLE sometimes have déjà feelings before or during a seizure. It should be noted that the incidence of déjà vu among TLE patients is lower than in the general population (see Surveys). There is also a problem: people can have déjà experiences (65% do) and also have TLE, but it is not clear whether the TLE actually causes the déjà experiences.

9. Is there any correlation between stress/anxiety and déjà experiences?

There seems to be, judging from questions asked in e-mails and on Quora. This needs to be investigated.

10. Is there a possibility that déjà experiences could cause harm or have long-term effects?

Some sensitive souls might become so frightened by such experiences that they become morbid about them, believing they are crazy. Some are reluctant to speak about what they are experiencing, for fear that others will judge them to be unbalanced. Fortunately, thanks to the Internet, younger people today appear to be less inhibited and able to speak more readily and openly about their experiences.

11. Why do people decide to study déjà experiences?

Because they are intrigued by such amazing but poorly understood happenings. Having had such experiences makes the mystery even stronger and begs for study. This is especially true when precognition occurs in parapsychological forms of déjà experience.

12. Any additional comments?

It is important to distinguish between true déjà experiences and what may be termed “anomalous familiarity”. A true déjà experience is accompanied by the strong sense of bafflement, surprise and confusion mentioned above.
Many people are convinced that their déjà experiences arise from precognitive dreams that are not remembered until the situation or place seen in the dream comes true. This is not the explanation for all déjà experiences, but it does seem to explain some of them.
Déjà experiences tend to be connected with very banal events or places. People never, or very rarely, say that their déjà experiences happened in connection with some important or momentous event in their lives. Why this is so is not known.