Overview
This lecture explains why humans get goose bumps, the biological mechanisms behind the response, and the evolutionary and emotional reasons for their occurrence.
Biological Mechanism of Goose Bumps
- Goose bumps occur due to a reaction called horripilation, triggered by adrenaline.
- Adrenaline is released by glands above the kidneys during fear or stress.
- Adrenaline prepares the body for "fight or flight" by raising heart rate, dilating pupils, and widening airways.
- In the skin, adrenaline causes tiny muscles to contract, making hairs stand up and forming bumps.
Evolutionary Purpose
- Goose bumps likely helped ancestors appear larger or more threatening to predators by fluffing up body hair.
- In animals like hedgehogs or porcupines, raised hair or quills serve as defense.
- Goose bumps help mammals trap warm air by making fur stand up, aiding warmth in cold conditions.
- Modern humans have less body hair, so the function is mostly redundant now.
Cultural and Global Perspectives
- The term "goose bumps" comes from the resemblance to a plucked goose's skin ("cutis anserina" in medical terms).
- Various cultures noticed this similarity; for example, in Vietnam, they are called "snail bumps."
Emotional and Non-Survival Triggers
- Goose bumps can occur during pleasurable or intense emotional experiences, like music or massages.
- They can also be caused by sudden sensations, like hearing fingernails on a chalkboard.
- Scientists believe intense emotions may momentarily trigger a survival response before the brain realizes there is no real threat.
Key Terms & Definitions
- Horripilation â the technical term for goose bumps.
- Adrenaline â a hormone released during stress or fear, causing physical readiness for action.
- Cutis anserina â medical term for goose bumps (literally "goose skin").
- Fight or flight â the body's response to perceived danger, preparing for action or escape.
Action Items / Next Steps
- Review the causes and evolutionary purposes of goose bumps.
- Reflect on personal experiences with goose bumps and what emotions triggered them.