Déjà vu refers to the feeling that you get when you think that something is happening again. Like maybe you're talking to someone and you get this weird feeling that you've had the same conversation before? Or if you're walking down a path and you think that you've walked the exact same path before.
The term itself translate to "already seen" from French to English. A French scientist named Emile Boirac first studied this phenomenon in 1876. She also named it.
Many of the early scientists thought that déjà vu had something to do with our memories. Like the past of our brain that strores memories springs up to remind us that we've seen/experiences/smelled/ felt the same thing before. There are hundred of theories about what déjà vu could really be.
Déjà vus aren't very common thought, so if you've ever felt one you might be lucky!
According to the Scientific American blog déjà vu also depends on age. Most people don't experience déjà vu till they're at least 6 years old. The blog also mentions that most people experience most déjà vus between the ago of 15 and 25. Not many older people experience it. Which might be a little crazy, because if it has anything to do with memory then older people should experience it more, right??
Have you ever felt déjà vu then eliminated the possibility because you figured out that it wasn't really happening again?
I sure hope so, because that means that you have a healthy mind. It means that your brain effectively dismisses false theories. Perhaps, as you get older your brain doesn't efficiently erase theories and you start to believe that something is really happening all over again.
This would explain why older people experience less déjà vu. They don't believe that it's déjà vu, rather that history really is repeating itself.
As science develops further and further, scientists are trying to better understand the concept of déjà vu. It is not very easy to conduct experiments about déjà vu. There are several reason for it:
1) - There are many definitions for it. Therefore, the question of which is right and which one to research.
2)- Many people do not take the experiments seriously, rather answer to please the researcher.
For example: If the teacher of your math class asks you "how many students got this question right?" Some kids will proudly raise their hand. Some will slowly raise their hands afraid that the teacher might ask them to demonstrate. Some kids will admit that they didn't quite understand the problem. The remaining kids might choose to raise their hands, just because the others did. Because they want to just like the others. They're afraid to stand out. This is what some people do during experiments. Preventing scientists from gathering accurate evidence.
Finally.....What causes déjà vu?
Most of our answers are still without proven evidence. Some theories are dismissed immediately, others are debated for years. Some scientists tried to find the answers by studying the group of people that experience the most déjà vu.
Most people in that group have a condition called "Temporal Lobe Epilepsy" This condition causes the brain to send out-of-control signals in the brain. The cells bump against each, causing the brain to go haywire to a few moments. This same phenomenon also occurs when someone has a seizure. Seizures also originate in the temporal lobe of the brain. This part of the brain is also responsible for making and remembering memories.
It all finally came together, didn't it?
Tell us about a theory of your own, maybe a question, or some feedback in the comment section. I look forward to reading them all.
Stay Curious ;)