Why do we get goose pimples?

Goose pimples help in regulating the body temperature. When we are exposed to cold temperature or get scared, our body hairs stand up so that the air between them can form an insulating layer. Each hair is permanently anchored to the skin with its root. Small muscles are present at these roots, which contract in case of cold or fear. This is visible on the skin as small bumps. The contraction of the muscles also produces heat in the body. This was an excellent warm-up device for our thickly haired curly ancestors who did not wear clothes.