According to research, around 30 percent of people experience sleep paralysis at least once during their sleep.

It’s somewhat astonishing when you consider what sleep paralysis looks like at different points in history and geography. The phenomenon itself hardly varies. People wake up in the middle of the night fully conscious they are awake, but they can’t move. They have a pressure on their chest as if something is lying on it. They feel a presence in the room. Sometimes they even hear or see things that are, to all appearances, completely real. You just turn on the part of the same whether you’re in Europe hundreds of years ago or living in a modern city today, and you’re fine. What differs is the way people describe it.

Conclusion

Centuries ago, someone would have called it a night hag, but the sensation is pretty much identical. This reveals something important about the human mind. The biological portion – how the brain skews consciousness and muscle control – is the same for everyone. But the interpretation of the experience is derived from culture, upbringing, and belief. People who believe in spirits tend to have more vivid and terrifying episodes.

Those who know the science are less frightened, and recall the experience differently. Sleep paralysis isn’t just a quirk of the brain. It expresses the fears, narratives, and social attitudes that we harbor. A momentary malfunction of the brain can snowball into a fully flesh-and-blood experience that feels entirely real and deeply personal.