Why Do We Get Goosebumps?

What You'll Learn

• Goosebumps happen when tiny muscles at the base of each hair pull the hair upright
• The scientific name for goosebumps is "piloerection"
• Goosebumps are a leftover from when our ancestors had more body hair
• Cold and fear both trigger goosebumps
• For furry animals, goosebumps make them look bigger and stay warmer

Words to Know

Goosebumps

Tiny bumps on your skin when you're cold or scared

"I got goosebumps in the cold wind!"

Piloerection

The fancy science word for goosebumps

"Piloerection means hair standing up."

Muscle

A part of your body that squeezes and pulls

"The tiny muscle pulled the hair upright."

Ancestor

A family member from long, long ago

"Our ancestors had more body hair."

Check What You Learned

Fun Facts

• Goosebumps are caused by tiny muscles called arrector pili at the base of each hair follicle contracting

  Source: American Academy of Dermatology

• The scientific term is "piloerection" — from Latin "pilus" (hair) + "erigere" (to stand up)

  Source: Oxford Dictionary of Biology

• In furry animals, piloerection traps a layer of insulating air next to the skin

  Source: National Geographic

• Cats puff up their fur when threatened to appear larger to predators

  Source: Smithsonian Magazine

• Porcupine quills are modified hairs that stand up via the same reflex

  Source: National Geographic

• Humans lost most body hair through evolution but retained the goosebump reflex

  Source: Journal of Human Evolution