What Causes Goosebumps?
The quirky journey from prehistoric necessity to modern-day party trick and hair-loss therapy
Goosebumps are an evolutionary throwback that helped humans thousands of years ago, but today, not so much. In the 21st Century, they seem to serve a limited purpose other than as an entertaining party trick when some folks produce a cascade of the bumps on demand.
That pebbled surface reminiscent of the plucked skin of a dead goose (hence the name goosebumps) results from a process called piloerection. Tiny embedded skin muscles — piloerector muscles — are attached to individual hair follicles. When the piloerector contract, they cause a temporary rising of the hairs on the skin’s surfaces.
When humans were hairy, this call to attention of skin hair created another layer of insulation to keep us warm. The “fluffed up” appearance also made us look larger and more threatening to ward off predator attacks. Think porcupine. This explains why the sympathetic nervous system — an involuntary mechanism tied to the fight or flight response — controls goosebumps.
Though cold and fear are the two most common triggers for the goosebumps, many brain regions connect to the sympathetic nervous system, including areas linked to motivation, arousal, and emotion. So other stimuli…
