What is Déjà vu?

Déjà vu, pronounced day-zhaa voo, is French for “already seen.” It describes the fascinating and strange experience where you feel that something is very familiar but you also know that this feeling of familiarity should not be as strong as it is. For example, you might be walking to school when you suddenly feel like you have been in exactly this situation before. Of course, you have been in the situation before – you have walked to school many times – but the feeling is so strong and so connected to right now, that you know it should not feel as overwhelming as it does (see Figure 1 for more explanation of what déjà vu is). Déjà vu experiences are often described in movies and books, because they can make people feel like they have somehow seen into the future. They are unusual but cool experiences that can actually tell us a lot about how our minds, particularly our memories, work. Déjà vu describes the strange experience of a situation feeling much more familiar than it should. Young people experience déjà vu the most. Many of us report our first experiences between the ages of 6 and 10. In this article, we review recent research on déjà vu including what it is, how common it is, and why scientists think it happens.