They’ll make the experience better. Okay, here we go.

All of these clips, or at least the audio from them, have been used in scientific studies

where researchers have tried to make people’s hair stand on end; and cause what we commonly

know as goose bumps, goose flesh, chilly bumps, or goose pimples.

The scientific term for this is the pilomotor reflex or “piloerection”… I probably

won’t use that word again.

Really, all sorts of things can give you goosebumps. And I want you to think of the last time you

remember experiencing them. Was it at the beginning of this video? And if not, was it

from cold? Or music? A movie? Were you just having an intense emotional response to something?

The most obvious time we experience goosebumps is when we’re cold. In this case, your hair

standing on end creates a buffer between your skin and the cold air, helping you thermoregulate.

This makes sense, but why do we also get goosebumps from listening to music or watching a movie?

Let’s take a closer look.

There’s a tiny muscle at the base of every individual hair on your body, the arrector

pili. When these muscles contract, they pull on your hairs, making them stand upright.

And when they relax, the hair lies flat again.

These are involuntary muscles and they’re part of our sympathetic nervous system, which

is responsible for most fight or flight responses. The reaction is closely tied to our emotional

state.

And apart from being cold, this is why movies may be the best trigger for goosebumps. Movies

tend to simulate social interactions, and the combination of both audio and visual stimuli

can trigger intense flight or fight responses, resulting in adrenaline release, and that

tiny arrector pili muscle contraction.

But listening to music also causes goosebumps in a vast majority of adults – though the

reasons are a little more nuanced.

One theory suggests that just the structure and nature of music itself are sufficient

to cause goosebumps, because it creates anticipation in the brain. Often, our minds automatically

try to predict what fits next within a song, and the internal stakes build while we listen.

If our predictions are correct, we receive a dopamine release and eventually this can

be enough to cause a chilling sensation.

One study found that Samuel Barber’s Adagio for Strings, what’s what’s playing in

the background right now, was extremely effective in causing goosebumps in a majority of people.

Another theory suggests that sad songs are more likely to cause chills than happy songs,

and depending on who you ask, this could be because sad or nostalgic music recreates the

chilling feeling of social loss. Feeling separate from your family or social group is known

to give rise to goosebumps, but the reason why isn’t well understood.

We do know that getting shivers down the spine from music activates the same brain structures

as other things that make us feel euphoric – like food and some drugs.

Brain imaging studies have found that goosebumps activates structures like the amygdala and

parts of the prefrontal cortex, and they’re commonly involved in pleasure and reward.

Getting the chills can make us feel good, but when you think about it, if we didn’t

get them, lots of other things would make us feel good too. Like our friends, or cake.

Goosebumps… are pretty useless.

But chills are more useful to cats, dogs and many other animals– their hair stands on

end when they’re especially worked up or afraid. The same pilomotor reflex that we

get makes them look bigger, scarier and may deter predators.

Imagine you’re an echidna. Similar bundles of muscles at the base of their quills allows

them to move their quills independently, for protection.

And for us, goosebumps are a remnant of evolution. Our hair standing on end kept us warm before

clothing and it may have deterred predators as well. These chills are a weird and wonderful

quirk of our biology that you can, quite literally, see on the skin of a goose.

Goosebumps have many different names in different countries – Goose skin, skin of the hen,

chicken skin, duck skin and bird skin. Let me know what you call it, and if there’s

any movies or songs that specifically cause it, down in the comments.