Stop it, you’re giving me goosebumps.
Sometimes a compliment, sometimes a warning signal. Always a mystery.
Well, until now.
Science has had its day, and finally uncovered just why it is we get goosebumps.
Sure, we know when they appear – when we’re cold, we’re in a heightened emotional state and for some people, when they’re on the toilet.
It’s known that goosebumps are a throwback to our hairier days, when cold temperatures would signal our body to bristle our human-coats to keep us warm.
In scientific terms, the sympathetic nerve in our skin contracts in the cold, pulling a wee muscle that’s connected to the bottom of a hair follicle.
This makes the hair stand up on end, while simultaneously bringing the skin around its base inwards, creating a little bump.
A team of researchers from Harvard wanted to find out more about ‘piloerection’ and why it’s stuck around.
“The skin is a fascinating system: It has multiple stem cells surrounded by diverse cell types, and is located at the interface between our body and the outside world,” said Ya-Chieh Hsu, the Alvin and Esta Star Associate Professor of Stem Cell and Regenerative Biology, who led the study in collaboration with Professor Sung-Jan Lin of National Taiwan University.
“Therefore, its stem cells could potentially respond to a diverse array of stimuli – from the niche, the whole body, or even the outside environment.”
So they set about uncovering the tale of the goosebump.
They used electron microscopy to examine the skin, focusing on the sympathetic nerve.
They found that nerve also connect to the stem cells of the hair follicle – so when it does its cold contract-dance, the stem cells are pushing into gear to grow a new hair.
What does that mean? It means goosebumps act to not only spring into action the hair that we do have (or had) to keep us warm, but tell our body to grow more hair, to keep us even warmer.
“This particular reaction is helpful for coupling tissue regeneration with changes in the outside world, such as temperature,” study first co-author Yulia Shwartz explained.
“It’s a two-layer response: Goosebumps are a quick way to provide some sort of relief in the short term. But when the cold lasts, this becomes a nice mechanism for the stem cells to know it’s maybe time to regenerate new hair coat.”
Oh and why are they called goosebumps?
Because they look like the feather-less skin of a goose, or similar poultry.