Why do we get goose bumps? Sometimes it starts with fear The word horror actually comes from a Latin word that means "to bristle" And the technical term for goose bumps is horripilation. When you get scared little glands on top of your kidneys release a stress hormone: adrenaline It rushes through your bloodstream, preparing your body for fight ... or flight It widens your airways and raises your heart rate so your muscles will have plenty of oxygen It dilates your pupils so your eyes can take in more light and see enemies in the shadows And in your skin, adrenaline causes tiny muscles to contract, producing bumps and making your hair stand on end. The medical term is cutis anserina Cutis means skin And anserina means goose Goosebumps look like the skin of a plucked bird And apparently cultures all over the world noticed that similarity From Russia to Japan to Spain But in parts of Vietnam, they call it something like snail bumps Which also makes a lot of sense. Unlike most human fight or flight responses, goose bumps don't seem like they'd help you out in a crisis But imagine you were a cat. Fluffing up your hair would make you look bigger - less of an easy target If you were a hedgehog or a porcupine, goose bumps would raise your quills Goosebumps can also help mammals survive when its cold out. Fluffed up fur traps an insulating layer of air and helps them stay warm. Our ancestors were hairy - and so for them goosebumps were useful. We moderns humans don't have much hair. But we still get goosebumps when we're cold or scared. Aaand... lots of other times too Scientists have studied chills brought on by getting a head massage drinking lemon juice looking at a picture of a kid Hearing fingernails on a chalkboard - let's not do that one And even listening to music. Scientists have discovered that different people get goosebumps listening to different songs. But why? None of these things are that critical to our survival in fact many of these experiences bring us pleasure. These goose bumps might have something to do with feeling intense emotion We're so surprised or moved that for a moment our brain's think there's an emergency and then when we figure out there's no threat we feel good. That's probably why people are strangely drawn to horror.