What are "Goose Bumps" and why do we get them?

What are "Goose Bumps" and why do we get them?

Goose Bumps are caused by a contraction of a tiny muscle that is attached to each hair. The muscle contraction causes the surrounding area to become raised and the hair to stand up. People get goose bumps for two reasons, extreme cold and sudden intense emotions.

When animals with a thick coat of fur get goose bumps, the rising of hair expands the layer of air that serves as insulation; the thicker the layer, the more heat is retained, the more heat retained, the warmer the animal feels. In people this reaction is useless because we do not have a coat of fur, but goosebumps persist nevertheless.

Goose bumps caused by intense emotions also derive from old animal instincts. The raised hair acts as a defense mechanism. For instance, when a cat is threatened by a dog, the elevated hair, together with the arched back and the sideward position makes the cat appear bigger in an effort to get the dog to think twice about attacking it. Again, this is a useless trait for modern humans as we do not need to intimidate others with our raised arm hair.

Both of these reactions are caused by the subconscious release of the hormone adrenaline. Humans release adrenaline not only when they are scared, but also in times of intense anxiety or otherwise emotional events. Goose bumps are one of the many side effects of adrenaline, which is why we get goose bumps when watch an emotional movie, or during weddings, or right before a job interview... it's the adrenaline!