The Reflex Behind Goosebumps

Written by Studio AM.

When you feel a sudden chill or a wave of strong emotion, small bumps may rise on your skin. Each bump appears where a tiny muscle at the base of a hair tightens and pulls the hair upright. We call the effect goosebumps, though the muscles do the real work.

In furry animals, this reflex is useful. Raised fur traps a layer of air close to the skin, which helps hold in warmth on a cold day. A frightened animal with its fur standing on end also looks larger and more dangerous to a rival. The same reflex that warms can also serve as a threat.

Humans retained this reflex despite having much less dense body hair than many furry mammals. Raising our hairs provides much less insulation. A feature reduced from an ancestral role is described as vestigial; this does not necessarily mean it has no remaining function. Goosebumps are a small reminder that our bodies still carry machinery built for an older, hairier way of life.

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  1. Question 1 of 4

    The passage mainly explains

  2. Question 2 of 4

    What actually makes a goosebump rise?

  3. Question 3 of 4

    Why does raising body hair provide less insulation for humans?

  4. Question 4 of 4

    In this passage, a 'vestigial' feature is one that

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