SE-Ed: Why Do We Get Goosebumps?

Have you ever stepped outside on a freezing morning? Suddenly, your arms are covered in tiny bumps! The same thing can happen during a sad film, or when your favourite song starts to play. We call them goosebumps. But what are they, exactly? Every hair on your body grows out of a tiny tube. At the bottom of each one, there's a very small muscle. When you get cold, this muscle suddenly tightens. It pulls the hair straight up, and it pushes up the skin around it too. Thousands of tiny bumps appear at the same time! In English, we say our skin looks like a goose's. In French, Spanish and Vietnamese, it's chicken skin! Either way, a bird's skin has the very same bumps. So why do our bodies do this at all? Scientists think the answer is millions of years old. Our early ancestors had much thicker hair than we do. When their fur stood up, it trapped a layer of warm air. It worked like a free winter coat! Sadly, we've lost most of that hair, so goosebumps don't keep us very warm today. Fear can give you goosebumps too. Look at a frightened cat, and you'll see why. Its fur stands up, so it looks bigger and scarier. A porcupine does the same thing with its sharp quills! Our hair is far too short for this trick, but our bodies still try it when we're scared. But why do we get them from music? Strong emotions send the body the same signal as cold. That's why a beautiful song can give you chills. A few people can even make goosebumps on purpose! And in 2020, scientists at Harvard found something new! In mice, the nerve behind goosebumps also helps new hair grow! So these tiny bumps may still be useful after all. Next time you shiver, say thank you to your ancestors!