We've all had goose bumps before — they tend to pop up when we're cold or nervous, or even when we have a visceral response to music. But, why exactly does a good song equal instant goose bumps?
Here to explain goose bumps, or if we're getting all sciency, cutis anserina, is YouTube channel asapSCIENCE. We've already posted their videos on baldness, aging, and my personal favorite — the snooze button — so what's the deal with goose bumps, asapSCIENCE?
First, adrenaline causes the tiny muscles surrounding our hair follicles, known as arrector pili muscles, to contract. This causes the hairs to stand on end, but what triggers the adrenaline at the outset? For mammals with a lot of hair, this serves a very practical function: to insulate from cold weather. Adrenaline is also triggered when we're in fight or flight mode, which is an "involuntary evolutionary response" that makes us appear larger to potential predators.
But how does this explain why we sometimes get "the chills" when we're listening to music? There are several theories on this, but an especially interesting one explains that humans like predictability, so any abrupt changes in a song can actually stress us out or scare us on a subconscious level and trigger an alarm, which releases adrenaline. Eventually, our brains remind us that "it's just music," and the goose bumps go away.
Ultimately though, scientists don't know why this happens with music. The relationship between music, emotion and physiology is so complex that researchers are still studying this fascinating phenomenon. But, as far as being cold or feeling threatened, goose bumps are an evolutionary carryover from our ancestors and, according to asapSCIENCE, "are a fairly useless trait in humans."