Have you ever been in a situation you wholeheartedly felt like you’ve been in before, down to the dialogue, movements, and funny quips? Chances are, you were experiencing déjà vu. And no, I’m not talking about the hit song by Olivia Rodrigo. According to WebMD, around 60-70% of all people with good health have reported feeling déjà vu at least once in their lifetime.
Before we dive into the how and why of déjà vu, we need to lay down the groundwork. According to the Merriam-Webster Dictionary, déjà vu refers to the illusion of remembering scenes and events when experienced for the first time. Despite the event never taking place before then, you can almost predict what is going to happen as it happens and everything about the situation feels unnervingly familiar.
One of the earliest recorded writings about feeling déjà vu, and the term itself, comes from Émile Boirac, a French philosopher, who wrote an article in response to a question about the phenomena. This article was published in 1867 in a French philosophy magazine. I believe it is safe to say that déjà vu was experienced well before that, but because of tensions in the 1800s regarding psychological illness, it was never talked about.
So why does this happen? Depending on who you ask they may have a different explanation for this strange feeling. It is difficult for scientists to do testing or experimentation on déjà vu because it is such a random phenomenon. Because of this, there are no definitive and widely-accepted scientific explanations for déjà vu, but there are a handful of theories that people believe. These include the memory recall theory, minor brain circuit malfunctions, and other explanations relating to psychic experiences of past lives.
The memory recall theory suggests déjà vu happens when the brain remembers an incomplete memory of a certain object or situation. In simple words, the person doesn’t remember the original experience because it was minor at the time, but their brain recalls the past experience they forgot about. This results in them experiencing déjà vu.
A theory that is a little easier to digest is the minor brain circuit malfunction theory. This theory suggests that the brain “glitches” and falsely perceives what is currently happening as a memory of something that happened in the past. There is also another theory called delayed processing that falls under the same “brain-malfunction” umbrella but has a different explanation. Delayed processing is when a person observes something and the same information is brought to their brain using two different pathways. One signal reaches the brain before the other, which causes the person to think the event has happened before.
Others believe that déjà vu is more of a spiritual experience. A believer in this theory may think déjà vu indicates an experience from a past life or another dimension. Some may even believe that they are somewhat psychic.
Déjà vu is something many of us will experience, but there’s no real answer to what causes it. Maybe one day we will be able to definitively prove what causes it, but until then all we can do is speculate.