Why do People have Hair?

Summary

Podcast Summary: "Why do People have Hair?"

Podcast: Who Smarted? (Educational Podcast for Kids)
Date: April 10, 2026
Host: Trusty Narrator, with Harry and Curious Kids

Overview

This lively episode of "Who Smarted?" takes curious young listeners on a humorous, science-packed adventure to answer: Why do people have hair? Using skits, trivia, and playful banter, the Trusty Narrator and the ultra-hairy Harry break down the evolutionary, biological, and cultural reasons humans (even the not-so-hairy ones) have hair in different places and patterns. Along the way, listeners learn about early human ancestors, adaptation, parasites, personal scent, and individual genetics, all while laughing at clever puns and memorable jokes.

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Key Discussion Points & Insights

1. How Hairy Are Humans?

• Evolutionary Origins:
  • Humans evolved from much hairier, ape-like ancestors.
    • "As you probably know, humans evolved from ape-like creatures millions of years ago. And these now extinct primate species were literally covered in hair." (03:31)
  • Despite appearances, humans still have about as many hair follicles as chimpanzees (around 5 million).
    • "Actually, you might be surprised to know that by the numbers, humans still have about as much hair as chimpanzees…[but] most of our hair is very wispy and short that appears almost invisible." (05:48–06:04)

2. Why Did Humans Lose Their Fur?

• Environmental Adaptation:

  • Climate changes 3 million years ago led ancestors to live on open savannas, making thick fur a disadvantage in the heat.
    • "All that heavy, insulating hair became very hot. So the leading theory is our early hominid ancestors evolved an ability to cool their skin by sweating. Body hair became thinner, shorter, and less prevalent." (06:54–07:17)
  • Our sweating ability helped early humans outlast predators during hunts.
    • "Hominids…are uniquely good at [thermoregulation]…hunting and sweating, while lions had to lie on a shady rock and pant to keep cool instead of eating us." (08:02–08:36)

• Parasite Control:

  • Less body hair meant it was easier to spot and avoid parasites, a big plus before soap and medicine.
    • "As luxurious as fur can be, it is a prime habitat for parasites…Without showers, soap or doctor visits…it was easier to spot someone who is parasite free if they weren't covered in thick fur." (08:44–09:15)

3. Why Do We Still Have Hair?

• Different Hair Types:

  • Modern humans have two main types of hair:
    • Terminal Hair: Thick hair on scalp, eyebrows, eyelashes, beards, armpits, and pubic region.
      • "Terminal hair, the thicker, coarser hair, which grows on your scalp, eyebrows and eyelashes." (12:12)
    • Vellus Hair: Fine, short "peach fuzz" covering the rest of the body.
      • "And vellus hair, the fine, often light and short hair you find all over your body…" (12:19–12:26)

• Protective Functions:

  • Head hair protects the scalp and brain from the sun.
  • Eyelashes and nose hairs filter dust, pollen, and spores.
    • "My lush, luxurious eyelashes protect my eyes. And my ridiculously dense nose hairs help keep all this spring pollen from going straight to my sinuses and lungs…" (12:45–13:05)

4. Culture & Hair

• Personal Style & Social Signals:
  • Hair became a means of expressing identity, status, and belonging across cultures.
    • "Hairstyling is an ages-old practice, common among cultures all across the world. Hair became a status symbol or a uniting symbol among specific communities." (09:49–10:12)
  • Bald heads and different styles are all part of human diversity.
    • Harry: "Is Bald a style? Cause that's what I'm rocking up top." (10:12)
    • Trusty Narrator: "It sure is. And that hair suits you. Get it?" (10:18)

5. Hair Growth, Loss, and Genetics

• Growth Cycles & Patterns:
  • Hair follicles cycle through growth and rest. Growth length is controlled by genetics and hormones.
    • "You see, hair follicles cycle through periods of growth and dormancy…The length of the growth phase is controlled by hormones." (13:30–14:05)
  • Different hairs have different growth cycles (legs: ~2 months, armpits: ~6 months, head: many years).
    • "Leg hairs will grow for about two months, armpit hairs for six months, and your head hairs can grow for more than six years." (14:05–14:22)
  • Baldness is largely inherited.
    • "If people in your family tend to lose their hair, there's a good chance you'll lose yours, too." (14:26–14:44)

6. Hair and Personal Scent

• Sweat and Scent:
  • The hairiest parts of the body wick sweat and amplify the body's natural scent—partially why humans have body odor.
    • "It turns out all people have a natural scent, and this scent is also related to individual genetics and hormones. … It's not because of your sweat. It's because of your hair." (15:18–15:47)
  • Androgen hormones control much of hair growth, leading to differences between males and females.
    • "As far as the growth and placement of your body hair, that's mostly controlled by hormones known as androgens." (16:04)

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Notable Quotes & Memorable Moments

• Harry’s Introduction:

  • "I'm Harry. No, my name is Harry, but as you can see, I'm hairy. My friends call me Harry Harry." (02:01–02:11)

• Discussing Ancestors:

  • Trusty Narrator: "Humans still have about as much hair as chimpanzees. About 5 million follicles." (05:48)

• Evolution’s Big Joke:

  • "Wouldn't all that thick, messy hair on his head make hunting tougher? …But while long head hair could be a hindrance in most ways, this new hair arrangement worked in our favor." (07:42–08:02)

• On Parasites:

  • Harry: "Ick."
  • Trusty Narrator: "Ick is right. Without showers, soap or doctor visits available, it was easier to spot someone who is parasite free if they weren't covered in thick fur." (09:02–09:15)

• The Scent Segment:

  • "Have you ever sniffed a T shirt before putting it on…turns out all people have a natural scent, and this scent is also related to individual genetics and hormones." (15:08–15:38)

• A Hairy Family Tree:

  • Harry: "I have some hairies and some not so hairy. Which might explain why I'm bald from my forehead up and look like a Bigfoot from my eyebrows down." (14:44–14:59)

• Ending with a Whiff of Humor:

  • Trusty Narrator: "Nope. I just realized I'm late for my haircut." (16:35)

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Timestamps for Important Segments

• Introduction & Harry’s Hairiness – 01:22–03:11
• The Evolution of Human Hair – 03:31–07:17
• Sweating, Climate, and Hair Loss – 06:19–07:17
• Parasite Avoidance – 08:44–09:33
• Cultural Meaning of Hair – 09:33–10:18
• Different Hair Types & Functions – 12:12–13:05
• How Hair Grows, Why You Might Go Bald – 13:30–14:44
• Why Hair Affects Scent – 15:05–15:47
• Hormones & Family Hair Traits – 16:04–16:35

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Conclusion

"Why do People have Hair?" is packed with science, storytelling, and laughs, helping kids—and adults—understand the evolutionary, practical, and cultural reasons humans have hair in some places (and not others). Through memorable skits and clear explanations, it highlights how our hair (or lack thereof) is part of our unique human story.

Memorable sign-off:
Trusty Narrator: "Nope. I just realized I'm late for my haircut." (16:35)

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Transcript

[Jane Lindholm]

Kids, you have a lot of questions.

[Harry]

Is a crocodile a dinosaur?

[Curious Kid 1]

Why do people vote?

[Trusty Narrator]

How does your food turn into your poop?

[Jane Lindholm]

But why? A podcast for curious kids has answers. I'm Jane Lindholm. Join me as we dig deep into everything from science to history, nature, emotions, and sometimes even the weird.

[Trusty Narrator]

Why are jellyfishes made of jelly? Or are they made out of jelly? Find.

[Jane Lindholm]

But why? Wherever you get your podcasts.

[Trusty Narrator]

Psst. Hey, smarty pants. I'm walking through the woods, way off the beaten path, headed to a secret, natural watering hole nobody else knows about. I can't wait to go swimming all by myself in the tranquility of nature. Did I mention nobody else knows about this secret watering hole? It's my own private oasis. Ah, there it is. And here I go. Ah. So relaxing. So peaceful.

[Harry]

So, hey, buddy, how's the water?

[Trusty Narrator]

Huh?

[Harry]

Oh, sorry. Didn't mean to startle you.

[Trusty Narrator]

That's okay. I thought I was the only one who knew about this watering hole. Obviously not.

[Harry]

Mind if I join you in a quick dip?

[Trusty Narrator]

Sure. The water's nice.

[Harry]

Cool. I've got my bathing suit on underneath my pants. I just need to take off my shoes and shirt and.

[Trusty Narrator]

Whoa. Sorry. I couldn't help noticing.

[Harry]

What? My furry feet?

[Trusty Narrator]

Yes.

[Harry]

And your stubbly shins, Pilious patellae, tufted thighs.

[Trusty Narrator]

That too.

[Harry]

And also my bearded belly, puliferous pecs, fleecy forearms, earsuit hands, and flocculent face.

[Curious Kid 2]

Wow.

[Trusty Narrator]

Yeah.

[Harry]

Yep. I'm Harry.

[Trusty Narrator]

Oh, hi, Harry. I'm the trusty narrator.

[Harry]

No, my name is Harry, but as you can see, I'm Harry. My friends call me Harry. Harry.

[Trusty Narrator]

Ah, yeah. Yes. And in case some of these words sound strange to you, smarty pants like pileus polyphorus, hirsute, or flocculant. They all mean the same thing. Hairy.

[Harry]

Like me.

[Trusty Narrator]

But guess what? Hairy. You're not the only human that's hairy. Pretty much all humans are hairy. Even if you are hairier than most.

[Harry]

You should see my bushy back.

[Trusty Narrator]

I can't wait.

[Harry]

Of course, if I take off my hat, you'll notice I've lost most of my hair up here. How can I be so shaggy from nose to toes, but the top of my head is bald as an eagle?

[Trusty Narrator]

Great question. Why are humans hairy? Why does their hair grow in some places and not others? And why do some people lose their head hair as they get older?

[Harry]

I'm all ears, which are also quite hairy.

[Trusty Narrator]

It's time for another whiff of science on who Smarted?

[Curious Kid 1]

Who's smarted

[Curious Kid 2]

who's smart?

[Harry]

Is it you?

[Curious Kid 2]

Is it me? Is it science or history? Listen up everyone. We make smarting lots of fun. Who's smarted?

[Trusty Narrator]

As you probably know, humans evolved from ape like creatures millions of years ago. And these now extinct primate species were literally covered in hair.

[Harry]

Hairier than me?

[Trusty Narrator]

Much hairier. Hairy. Hairy. Same goes for our ancestors, like the hugely hairy Homo habilis. So how and why did humans shed our super shagginess? What do you think, smarty pants? Are humans less hairy today because of A sweat, B, natural selection, C, climate change, or D scent? Well, whichever one you picked, you're right, all four of those played a part.

[Harry]

Really? Care to explain how?

[Trusty Narrator]

Sure thing. But first, do you know what an evolutionary biologist is?

[Harry]

A scientist who studies evolution.

[Trusty Narrator]

Bingo. Charles Darwin, a naturalist who is credited with the theory of evolution, started or at the very least popularized this whole field of study. He stated that all species of organisms arise and develop through natural selection of small inherited variations that increase the individual's ability to compete, survive and reproduce. Um, in other words, species biologically evolve from other species, passing along traits that help them to adapt and survive.

[Harry]

Only the strong and hairy survive.

[Trusty Narrator]

Sort of. According to evolutionary biologists, around 5 to 7 million years ago, our shared lineage with early primates diverged or split, and our evolutionary family tree branched off in different directions. One line resulted in a species that would eventually look like you, me and the smarty pants who smarted. The other line would go on to include gorillas, orangutans, bonobos and chimpanzees.

[Harry]

Ah, so the gorilla chimp line stayed hairy, but the human line didn't.

[Trusty Narrator]

Actually, you might be surprised to know that by the numbers, humans still have about as much hair as chimpanzees. About 5 million follicles.

[Harry]

What? But we don't look that fuzzy. Well, most of you don't.

[Trusty Narrator]

That's because most of our hair is very wispy and short that appears almost invisible.

[Harry]

Speak for yourself.

[Trusty Narrator]

And while your hairs may differ in coarseness, curliness and color from the average human, you're definitely not as fluffy as a monkey.

[Harry]

So what does this have to do with sweat and climate change?

[Trusty Narrator]

As our genetic line branched off our great great, great, great, great, great, great, great, great, great great grandparents foraged for food in the cool shade of trees in Central Africa. But about 3 million years ago, a global cooling dried out these forested areas and the region became grassland or savanna without a lot of shade.

[Harry]

And beach umbrellas hadn't even been invented yet.

[Trusty Narrator]

All that heavy insulating hair became Very hot. So the leading theory is our early hominid ancestors evolved an ability to cool their skin by sweating. Body hair became thinner, shorter, and less prevalent. Our head hair, however, became thicker to protect our scalps and and brains from the sun.

[Curious Kid 1]

Say, ugh. You're looking awfully handsome with your smooth arms and mop top head.

[Curious Kid 2]

Thanks. I do wish I had hat though. It's hard to hunt with all this hair in my face.

[Curious Kid 1]

What's a hat?

[Trusty Narrator]

According to genetic evidence, hominids became mostly furless about 1.7 million years ago.

[Harry]

But the first hat wouldn't be invented for another 1,695,000 years. But wait a second. Oog was right. Wouldn't all that thick, messy hair on his head make hunting tougher? After all, this is way before haircuts, hairbrushes and combs.

[Trusty Narrator]

Good point. But while long head hair could be a hindrance in most ways, this new hair arrangement worked in our favor. Hominids are not the only species who can thermoregulate, meaning balance our body temperature through sweating. But we are uniquely good at it. For early humans, life on the hot African savanna meant running around during the day, hunting and sweating, while lions and other predators had to lie on a shady rock and pant to keep cool

[Harry]

instead of eating us.

[Trusty Narrator]

Exactly.

[Harry]

In what other ways is having less body hair evolutionarily beneficial?

[Trusty Narrator]

Well, in order for any species to survive, it's important to have healthy offspring. And one way to ensure healthy offspring is to start with healthy parents. As luxurious as fur can be, it is a prime habitat for parasites.

[Harry]

Ick.

[Trusty Narrator]

Ick is right. Without showers, soap or doctor visits available, it was easier to spot someone who is parasite free if they weren't covered in thick fur.

[Curious Kid 1]

I see you have no parasite zug. Wanna be my boyfriend?

[Curious Kid 2]

Sure. And I've always liked the way you style your long, luscious locks.

[Curious Kid 1]

Thanks. I wish I had a scrunchie though.

[Curious Kid 2]

What's a scrunchie?

[Trusty Narrator]

In the beginning, people didn't care much about the hair on their head. But it wasn't too long before people developed personal style as they figured out what to do with their long hair. Have you ever heard of an anthropologist?

[Harry]

Yes. Don't they study human behavior?

[Trusty Narrator]

Exactly. Anthropologists studying history. So hairstyling as an ages old practice, common among cultures all across the world, hair became a status symbol or a uniting symbol among specific communities. Or a way to show off personal style. Smartypants, think of all the different hairstyles you've seen in history books versus today.

[Harry]

Is Bald a style? Cause that's what I'm rocking up top.

[Trusty Narrator]

It sure is. And that hair suits you. Get it?

[Harry]

Yeah. So besides hot looks, why do we still have any hair at all? And why do people have as much hair as chimpanzees?

[Trusty Narrator]

Good question. And we'll get into all the hairy details right after this quick break. Spring is here, and if you're a homeschool family trying to finish the year strong, I want to tell you about ixl. It's the award winning online learning platform that fits seamlessly into your homeschool routine covering math, language arts, science and social studies from Pre K through 12th grade. What I love most about IXL is how it adapts to each child's pace. Whether your kid needs to reinforce foundational skills before an assessment or push ahead into new material, IXL meets them exactly where they are. With no pressure and real encouragement built right in. Kids earn rewards, see their own progress, and actually feel good about learning. And for parents, the real time progress tracking is a game changer. You always know exactly where your child stands. Plus, it makes learning fun. And you know, I love that. Over 15 million students use IXL and it's proven to improve achievement in all 50 states. So make an impact on on your child's learning. Who smarted? Listeners get an exclusive 20% [e-mail] smarted that's ixl.com smarted for your 20% off. And now back to who's smarted? Modern people like you and me and me have two types of hair. There's terminal hair, the thicker, coarser hair, which grows on your scalp, eyebrows and eyelashes.

[Harry]

Also my beard, armpits and, ahem, private parts.

[Trusty Narrator]

And vellus hair, the fine, often light and short hair you find all over your body, arms, legs, tummy, back and

[Harry]

neck, sometimes called peach fuzz.

[Trusty Narrator]

Now while hair that's too thick can hide parasites, a little hair can help protect you by filtering dust, spores, bacteria and other yucky stuff blowing around out there.

[Harry]

My lush, luxurious eyelashes protect my eyes. And my ridiculously dense nose hairs help keep all this spring pollen from going straight to my sinuses and lungs, even though it still makes me sneeze

[Trusty Narrator]

a little. Gross but true. Now, just between you, me and the smarty pants, humans probably don't need their velos hair anymore. It's more of a reminder of our evolution. Ah. What is particularly curious is how humans evolved to have such an unusual combination of hair types and your own personal hair patterns. And growth is determined by your own unique genetics.

[Harry]

Like a furry Body map.

[Trusty Narrator]

Yes. Like a furry body matter. You see, hair follicles cycle through periods of growth and dormancy arrest. Hair gets longer and thicker as it grows. But when your hair producing cells die, the growth stops. The hair will fall out, and the hair follicle will remain dormant. Usually about six months before new hair producing cells begin a new growth phase.

[Harry]

Um, it's been longer than six months, and my hair hasn't grown back.

[Trusty Narrator]

We're getting to that. Hairless head Hairy. The length of the growth phase is controlled by hormones. Leg hairs will grow for about two months, armpit hairs for six months, and your head hairs can grow for more than six years.

[Curious Kid 2]

Whoa.

[Harry]

Some people's head hairs, right.

[Trusty Narrator]

Genetics and hormones are also the root causes for hair to stop growing. We're not 100% sure why, but if people in your family tend to lose their hair, there's a good chance you'll lose yours, too. And if people in your family have long hair, you have a good chance of maintaining a thick head of hair.

[Harry]

Hmm. I have some hairies and some not so hairy. Which might explain why I'm bald from my forehead up and look like a Bigfoot from my eyebrows down.

[Trusty Narrator]

Oh, I almost forgot. Beyond personal style, your hair is also important to your personal scent.

[Harry]

Another whiff of science.

[Trusty Narrator]

You bet, smarty pants. Have you ever sniffed a T shirt before putting it on? Or maybe after running around outside, you get so sweaty that you can smell yourself.

[Harry]

Oh, yeah, that's me.

[Trusty Narrator]

It turns out all people have a natural scent, and this scent is also related to individual genetics and hormones. Usually, it's not so bad. Pretty neutral, really. In fact, most people are actually attracted to the natural scent of other people.

[Harry]

You sure about that? I can get pretty stinky.

[Trusty Narrator]

Well, if so, it's not because of your sweat. It's because of your hair.

[Curious Kid 2]

Huh?

[Trusty Narrator]

You see, the hairiest parts of your body pull sweaty moisture away from your skin to help you stay cool. And then these wet hairs hold onto whatever scent your body parts make and spread it all over pee.

[Harry]

Ew.

[Trusty Narrator]

As far as the growth and placement of your body hair, that's mostly controlled by hormones known as androgens. That includes hormones like testosterone, which is present in higher levels in males than in females.

[Harry]

That must be why I'm better at growing a mustache than my wife, Harriet. In fact, here she comes now with her entire knitting circle. Hey, trusty narrator. Where are you going? I hope you're not leaving on our account.

[Trusty Narrator]

Nope. I just realized I'm late for my haircut. A big shout out to super Smarty fan Grayson in Leander, Texas. My sources tell me that you think the trusty narrator is hilarious and love listening to who Smarted on the ride to school with your dad and little brother. Aw, thanks for that. And thanks for starting your day with lots of smarting. This episode Hairy Humans was written by Libby Ward and voiced by Taya Garland, Kim Davis, Adam Tex Davis and Jerry Colbert. Technical direction and sound design by Josh Han. Who Smarted is recorded and mixed at the Relic Room Studios. Our Associate producer is Max Kamasky. The theme song is by Brian Suarez with lyrics written and performed by Adam Tex Davis. Who Smarted was created and produced by Adam Tex Davis and Jerry Colbert. This has been an Atomic Entertainment production.

[Curious Kid 2]

Who smarted.