Gooseflesh is the bumpy texture your skin gets when you're cold, scared, or deeply moved by something. Those tiny bumps appear because muscles at the base of each hair follicle contract, making the hairs stand up. It's also called goosebumps or goose pimples because your skin resembles the bumpy skin of a plucked goose.

You might get gooseflesh when you step out of a warm shower into a chilly bathroom, or when a character in a scary story creeps toward a dark basement. Sometimes gooseflesh appears during powerful moments, like hearing a beautiful piece of music or watching an athlete achieve something extraordinary.

This reaction is left over from our evolutionary past. When our ancestors had more body hair, making it stand on end created better insulation against cold and made them look bigger and more threatening to predators. We've lost most of that body hair, but our bodies still respond the same way. Now gooseflesh is mostly just a signal that something has triggered a strong physical or emotional response, whether it's a cold breeze, a thrilling moment, or a genuinely spooky experience.