Mar 14, 2025
Transcript
LULU MILLER: Hey, Lulu here. So a few months back, our illustrator Jared Bartman got a difficult prompt. We asked him to design a cute tote bag based on our incredibly morbid episode "Cheating Death." And Jared was stumped. How do you create something plucky and cheerful and design forward about the inevitability of dying? And so he brooded and he doodled, and then one day it hit him. It is easily my favorite design ever, and because it's sort of this secret code about death, it has the effect that it's kind of like carrying around carpe diem around on your shoulder.
LULU: And you can get that tote bag right now if you become a member of The Lab. You knew it was coming. The Lab is the way we have designed to support the show. It's super easy—just a couple clicks, you can send a few bucks our way a month in exchange for, you know, public radio currency—tote bags—and other perks.
LULU: Whether you support us or not, we are so grateful for you, but if you've ever been on the fence, I would say that now is a really good time because not only does the tote bag have a very cool, surrealist design, it also has—a zipper! [laughs] So go take a peek at Radiolab.org/join. That's Radiolab.org/join. And that's all. Thank you. On with the show.
[RADIOLAB INTRO]
LATIF NASSER: Okay, so we're gonna begin with producer Matt Kielty.
MATT KIELTY: Okay, Latif. Let me take you to the land of the midnight sun.
LATIF: Whoa, is that Japan?
MATT: No.
LATIF: No, "rising sun" is Japan. Oh, the midnight sun's probably gotta be Antarctica or something? Alaska?
MATT: Alaska.
MATT: Whoa! Do you see the mountains all the way out there?
MIKE GLADNEY: Those are snowy.
MATT: That's beautiful.
MATT: Specifically ...
MATT: Jagged mountains kind of everywhere.
MATT: ... Palmer, Alaska, which is, like, an hour north of Anchorage.
LATIF: Never heard of it.
MATT: Yeah, it's a little town where they host, every summer, the Alaska State Fair.
MATT: Got a wallet.
MIKE GLADNEY: I have a phone.
MATT: Okay.
MATT: Which is where I went last August ...
LATIF: Fun!
MATT: ... with ...
MIKE GLADNEY: You know, I've never seen a corndog that I don't like.
MATT: ... my childhood best friend, Mike Gladney.
MIKE GLADNEY: So I'm pretty excited.
MATT: And Mike and I, we're from Minnesota, which has a really big state fair. Alaska's ...
MIKE GLADNEY: It's like a small county fair.
MATT: ... it's a little bit smaller. But ...
MIKE GLADNEY: Cheese curds!
MATT: ... it does have a lot of good food.
MIKE GLADNEY: Oh, right there!
MATT: A lot of classics, but also ...
MIKE GLADNEY: Whoo! Alaska crab cakes!
MATT: ... a lot of great seafood.
MIKE GLADNEY: Salmon quesadilla.
MATT: And then of course games, rides.
MIKE GLADNEY: Ahh!
MATT: But Latif ...
LATIF: Yeah?
MATT: ... this little fair does have something very, very, very, big.
[cheering]
MATT: Which is the annual great pumpkin weigh-off.
LATIF: Ooh, so this is a competition? Like, a state fair competition?
MATT: That's right. A competition to see who can grow the biggest, heaviest pumpkin in the state, but also maybe in the world.
LATIF: [laughs] Okay.
MATT: Because in Alaska ...
WOMAN: We grow the best pumpkins in Alaska.
MAN: We grow the biggest pumpkins around.
MATT: Yeah, I know. Why is that?
MAN: I think they put milk in them.
MATT: [laughs] They just water them with milk the whole time?
MAN: That's what I heard.
MATT: Mike and I talked to one of the workers, Kathy Liska.
KATHY LISKA: This is my 31st year working in the crops department, and I've seen maybe, I think about 25 Guinness world records.
LATIF: Wait, pumpkins specifically?
MATT: No, no, no. All sorts of stuff: carrots, beets, cabbages.
KATHY LISKA: What's Alaska—you know, what's the fair known for? It's the giant vegetables.
MATT: Because in Alaska, the land of the midnight sun, plants can get a ton of sunlight, and so essentially, you can grow these plants to, like, really, really big sizes.
KATHY LISKA: There's a lot of growers all around the world that'll be keeping their eye out around here to see what's going on.
MATT: So ...
MATT: Okay, wait. We should describe what we got. We got ...
MATT: ... Mike, Kathy, me ...
MATT: ... it might be called a barn? Farm?
KATHY LISKA: It's an open air arena, yeah. This is our ag building.
MATT: We're standing in the ag building.
MIKE GLADNEY: It smells like—not good in here.
MATT: And we are standing inside this, like, cattle pen, this little fenced in area. We are surrounded by bleachers.
KATHY LISKA: So here we are, center ring.
MATT: When out comes ...
MIKE GLADNEY: Where is it? Oh my God!
MATT: Oh my God!
MATT: ... this huge ...
MIKE GLADNEY: Wow!
MATT: It's enormous!
MIKE GLADNEY: It's gigantic.
MATT: ... orange pumpkin.
MIKE GLADNEY: It's intimidating to look at.
MATT: Kathy, is it okay if I touch the pumpkin?
MATT: And this pumpkin ...
KATHY LISKA: Can you feel the magic?
MATT: You're touching it, too.
MATT: ... it's about the size of a Volkswagen beetle.
LATIF: Wow!
KATHY LISKA: It's got, like, a heartbeat.
MATT: What does it actually weigh?
KATHY LISKA: It's alive.
MATT: It's just so big!
MATT: Except it's, like, lumpy and, like, kind of blobby.
LATIF: Like Jabba the Hut, kind of?
MATT: Yeah.
LATIF: Could you and Mike have fit in the pumpkin?
MATT: We could've crawled inside the pumpkin and held each other.
LATIF: Weird!
DALE MARSHALL: That's 98 days old right there, that pumpkin.
MATT: So the pumpkin belongs to this guy, Dale Marshall of Anchorage.
DALE MARSHALL: Hey, I'm about sick of that thing, to tell you the truth, you know?
MATT: He's a seasoned grower.
MATT: Are you pleased with your pumpkin this year?
DALE MARSHALL: Oh, yeah. Just getting one here is half the battle, you know?
MATT: Like, when I see something this big, I'm like, "This is frightening."
DALE MARSHALL: I like it. I like the color. Do you know how long it took me to paint all those little spots on there?
MATT: [laughs]
MATT: And while we're talking ...
DALE MARSHALL: Okay. Oh. Oh, they're putting the thing ...
MATT: ... Dale rushes over to his pumpkin.
MATT: Something's happening!
MIKE GLADNEY: Here we go.
MATT: Yeah, here we go.
MATT: And basically ...
DALE MARSHALL: Michael! Get over here, Mike.
MATT: ... Mike and I get in position. And then we watch them as they push this pumpkin underneath this crane.
MATT: Everybody looks like they're excited, they're anticipating.
MATT: And dangling from the crane ...
MATT: Bated breath.
MATT: ... are these straps.
MIKE GLADNEY: Everyone's circling.
MATT: Okay, Dale's getting the straps ready.
MATT: Dale takes the straps from the crane, wraps them down around the pumpkin.
MATT: Pumpkin appears to be strapped in there. Securing the rope.
MATT: Ties it all together with a rope.
MIKE GLADNEY: Kind of nerve wracking.
MATT: And then ...
MIKE GLADNEY: You could hear a pin drop in here.
MATT: The crane begins ...
MATT: The straps are tightening.
MATT: ... to lift the pumpkin ...
MATT: Here we go. It's up. It's up off the pallet. It's off the pallet.
MATT: ... up into the air, so it's dangling, like, two feet off the ground. And then ...
DALE MARSHALL: Jody. Careful, Jody.
MATT: ... a volunteer named Jody gets on her back, climbs underneath this pumpkin, so it's just dangling above her. And she inspects the pumpkin for, like, any holes, any tampering.
JODY: All right. Good!
MATT: She gives the thumbs-up.
DALE MARSHALL: Oh, Jody is a wild woman.
MATT: And then ...
MATT: Okay. All right, they're transporting it over to the scale.
MATT: ... the crane begins to lower the pumpkin onto this huge metal scale.
MATT: Okay. All right, they're taking the straps off, and—and the rope. All of it's coming off.
MIKE GLADNEY: Wow!
MATT: Okay.
MIKE GLADNEY: That's fully on the scale.
MATT: Dale steps back from his pumpkin.
MATT: It's on the scale. It's being weighed.
MIKE GLADNEY: Okay.
MATT: And then ...
MIKE GLADNEY: The moment of truth.
MATT: All right, here we are.
MIKE GLADNEY: Oh my God, 2,000 pounds!
MATT: Oh my God! Oh my God!
MATT: First place, grand prize-winning 2,035 pound pumpkin.
LATIF: Oh my God. Oh my God. Wow!
MATT: To put that into perspective ...
LATIF: Yeah?
MATT: ... that is about eight to ten panda bears.
LATIF: [laughs] Okay.
MATT: Just to give you a sense of the weight.
LATIF: All right.
MATT: A lot of pandas. Anyways ...
MATT: High fives all around for Dale. Dale is psyched!
MATT: Dale's got his arms in the air. He's running around his pumpkin.
MATT: Dale, how are you feeling?
DALE MARSHALL: Well, I'm ecstatic. That's about 150 pounds more than I thought I was gonna get.
MATT: And then pretty quickly ...
DALE MARSHALL: We're moving it, we're moving it, we're moving it. I'm out of here. I'm out of here.
MATT: ... the local news crew surrounded Dale. He gets a ribbon, $1,000. And then that's—that's pretty much it.
LATIF: Okay.
MATT: Yeah, that's kinda everything.
LATIF: Huh. And was this a record-setting pumpkin, then?
MATT: No. Actually, it didn't even beat Dale's previous pumpkin record in the state. So—but it was a good—it was a good pumpkin, first-place pumpkin.
LATIF: Then, like, what happens to the pumpkin afterwards?
MATT: Well, Dale typically takes his home. He says his grandkids like to play on it. And—or if you don't do that, you can donate it to the Alaska Zoo or the wildlife conservation center, where they will feed it to bears.
LATIF: Bears?
MATT: Yeah, grizzly bears.
LATIF: That feels like an Alaska punchline joke that you would make up, right? No, it can't be bears.
MATT: It is bears.
LATIF: Because it's not fit for human consumption? Or is—like, could you eat these?
MATT: Yeah, yeah. You can eat them. I don't think they taste very good the bigger they get. They're not being grown for flavor.
LATIF: So what's the point of this? It's just so hard to imagine the point of this.
MATT: What do you mean?
LATIF: Like, what are we—what ...?
MATT: What are we doing?
LATIF: What are we doing here?
MATT: Well, I mean, for the growers, I think it's just like—it's, like, pushing the limits. Like, you're just trying to grow something really ...
LATIF: Stronger, faster, bigger, better, da da da da da?
MATT: Yeah, exactly. But I think for us to be there, like, if you average it out, Dale's pumpkin grew 20 pounds a day. And to just come and look upon that ...
CHILD: I think it's cray-cray.
MATT: To see something that's just so incomprehensibly big ...
CHILD: I think it's crazy how big it is.
MATT: It just stirs up …
WOMAN: Look how big that thing is.
MATT: ... this real sense ...
WOMAN: It's gorgeous. I think it's beautiful.
MATT: Really?
MATT: ... of awe.
WOMAN: I do. Because it's so big. I mean, where else will you see something like that?
MATT: Because seeing something like that just sort of makes you think about the fact that everything has this blueprint for growth, for how it's supposed to grow, for what it's supposed to grow into. And yet, here you are confronted by something that seemingly doesn't fit that blueprint at all. And that is what we're doing there, Latif. Coming together to feel a little bit of joy, a little bit of terror, brought on by an enormous pumpkin.
LATIF: [laughs] Yeah. All right. Sure.
LULU: All right. This is Radiolab. I'm Lulu Miller.
LATIF: I'm Latif Nasser.
LULU: And today we are looking at ...
LATIF: Growth! Which is actually an episode we started working on when you were off growing a person.
LULU: [laughs] Yeah. Actually, my belly was just like that pumpkin. It was, like, bigger and bigger.
LATIF: Two thousand pounds.
LULU: I couldn't touch my toes or tie my shoes. And then the baby came out, and she has already doubled in just a few months. She's already doubled in size.
LATIF: Wow! But we have—we have more. This is not an hour about pumpkins, as much as I know you would have wanted that. We have three different stories about growth—growth that happens in places you'd never expect, growth that follows a pattern that seems woven into the universe itself, and even a growth that has taken over the whole planet and, for better or worse, the surprising thing that might stop it.
LULU: All right! Let's do this thing.
LATIF: Yeah. First up, we have a story from Becca Bressler.
BECCA BRESSLER: Hello.
LATIF: Hey.
BECCA: Okay, so I'm gonna take you from pumpkins to carrot.
LATIF: Okay.
LULU: Okay.
LATIF: Huge leap. Huge leap. Orange vegetable to orange vegetable.
BECCA: Stick with me. This story starts in a kitchen.
LATIF: Okay.
LULU: Uh-huh?
KATHERINE RAE MONDO: So this was a few years ago. November 30, 2021.
BECCA: With this woman named Rae Mondo.
KATHERINE RAE MONDO: All of my housemates were away for the evening, and I was making dinner. I had vegetables out. There's broccoli, there's carrots.
BECCA: Music is playing.
KATHERINE RAE MONDO: Vibes are good.
BECCA: Pretty normal evening.
KATHERINE RAE MONDO: And as I'm chopping—chop, chop, chop, chop, chop, chop—all of a sudden ...
BECCA: She looked down and was like ...
KATHERINE RAE MONDO: I just cut off my fingertip!
LATIF: Oh!
BECCA: The end of her left middle finger from halfway down the nail was just gone.
KATHERINE RAE MONDO: The wound was just white for a moment, and then I saw just, like, the river of blood, like, rise.
BECCA: So she grabs a paper towel, presses it up against her finger that's gushing blood.
LATIF: Oh!
BECCA: And she immediately calls her friend Amy.
KATHERINE RAE MONDO: My best friend Amy.
BECCA: Used to be a trauma nurse.
LATIF: Person to call. Right person to call.
KATHERINE RAE MONDO: So Amy picks up.
BECCA: They tell Rae to bandage it.
KATHERINE RAE MONDO: Keep pressure on it, go on the couch, elevate it and just, like, dissociate for a while.
LATIF: Wait, but she didn't go to the ER or something?
BECCA: So actually, that was the question that consumed her.
KATHERINE RAE MONDO: I'm like, how much is having a fingertip worth to me? Like, can I put a dollar amount on it?
BECCA: Her deductible was super high.
KATHERINE RAE MONDO: If the emergency room bill were gonna be $5,000, naw, I'm good. Like, I can live life without a fingertip. If it's $1,000, I'm, like, tempted. But, like, geez.
BECCA: Mm-hmm. Yeah.
KATHERINE RAE MONDO: I do really like having, like, all my fingertips. Like ...
BECCA: But eventually she decides it's not worth it.
KATHERINE RAE MONDO: No. And at that point, I was like, "I'm done. I have a short middle finger now."
BECCA: "This is just my life."
KATHERINE RAE MONDO: Yeah.
BECCA: But over the next few days, as Rae gets into a routine of changing out the bloody bandage, she starts to notice a couple things happening.
KATHERINE RAE MONDO: Uh-huh.
BECCA: One ...
KATHERINE RAE MONDO: What I noticed was my fingernail continued to grow outward in the same shape that it grew before.
BECCA: And two ...
KATHERINE RAE MONDO: The finger started to fill in underneath the fingernail that was growing outward.
BECCA: And after a few weeks ...
KATHERINE RAE MONDO: I was like, wait a minute. Like, is my fingertip growing back? And slowly but surely, it was just sort of like—whoop!—my finger was back.
LATIF: What? Like, her whole fingertip grew back?
BECCA: Yeah.
LATIF: Like, you couldn't even tell if anything happened to it?
BECCA: No.
KATHERINE RAE MONDO: Now it's, like, I would say, 99.5 percent back to normal.
LATIF: Man, this feels so—like, I mean, I've heard of human—like, you can regrow skin. I get that.
BECCA: Yeah.
LATIF: Like, I feel like I've vaguely heard of someone regrowing part of a liver back, maybe.
BECCA: Yeah. Yeah.
LATIF: Yeah. But, like, this is—this is different. This is—like, there's a whole—there's a bone in there. There's, like—there's so much going on.
BECCA: Yeah. It does feel more complicated.
LATIF: There's layers. It's a—it's flesh lasagna that you're growing back.
LULU: Oh! [laughs]
BECCA: Actually, totally. I had never heard of this before, and obviously this was very surprising to Rae.
KATHERINE RAE MONDO: Oh, totally.
BECCA: And so actually, she emailed us to tell us about this.
LATIF: To be like, "What? I mean, how? Am I a mutant with superpowers?"
BECCA: Kind of, yeah. She wanted us to find out how did this happen? Like, how did my fingertip grow back?
LATIF: Right.
BECCA: So Rae and I together called up ...
KEN MUNEOKA: It's nice to meet you, Rae.
KATHERINE RAE MONDO: Oh, it's so nice to meet you, too!
BECCA: ... this guy.
KEN MUNEOKA: Can I—can I see your finger?
KATHERINE RAE MONDO: Oh, yeah.
KEN MUNEOKA: Before you ...
BECCA: So this is Ken Muneoka. He actually studies fingertip regeneration.
KEN MUNEOKA: Currently at Texas A&M University.
BECCA: And Ken wasn't that surprised to hear about Rae's fingertip.
KEN MUNEOKA: I felt bad for you, but I suspected it all came back.
BECCA: He says that people have been writing about this for nearly a hundred years.
KEN MUNEOKA: Yeah. That story begins back in the 1930s. A physician in Canada had a severely infected finger, and he basically removed the bone out of his finger.
BECCA: Just the tip of it.
KEN MUNEOKA: And he—he—but he X-rayed it, and he sort of followed it with time, and he found out that his whole finger regenerated.
BECCA: Whoa!
BECCA: Ken also told us that back in the '70s, doctors in the UK saw a bunch of kids with chopped off fingertips.
KEN MUNEOKA: There was a reasonable number of them coming into the clinic.
BECCA: No idea what was going on over there, but ...
KEN MUNEOKA: They documented hundreds of children regenerating their fingertips.
BECCA: So Ken studies this stuff at a microscopic level.
KEN MUNEOKA: In fact, I spend most of my time working with mice.
BECCA: Unfortunately—or fortunately—there aren't a lot of controlled studies around chopping off human fingertips and seeing how they grow back.
LULU: [laughs]
BECCA: But thanks to our good friends, the mice ...
KEN MUNEOKA: We're able to follow the regeneration process using this machine called a micro-CT.
BECCA: What's that?
KEN MUNEOKA: So it's like a CT scanner but it's, like, for tiny little things.
BECCA: And Ken says that when you cut off your fingertip, a few things happen.
KEN MUNEOKA: You know, the initial response to a trauma like that is an inflammatory response that cleans up the wound.
BECCA: Pretty standard stuff.
KEN MUNEOKA: But then some time after that ...
BECCA: Something very unusual happens.
CHRIS ARNOLD: Stem cells that are in the nailbed that are normally required for having your nails grow continuously throughout your life.
BECCA: They sort of kick off this rebuilding process.
CHRIS ARNOLD: Forming this sort of organizing response to make the other parts of the tissue in that lost fingertip.
BECCA: So this is Chris Arnold. He's a professor at West Virginia University.
CHRIS ARNOLD: In the biology department.
BECCA: And he says that these stem cells under the nail call up a bunch of other stem cells in the body.
KEN MUNEOKA: You know, cells that can make bone.
CHRIS ARNOLD: Skin tissue.
KEN MUNEOKA: Nerves.
CHRIS ARNOLD: Muscle tissue.
BECCA: And so these different types of cells basically start regrowing what was lost, and eventually you have a whole brand new fingertip.
LATIF: Huh! Like, we plumped back out to what it was.
BECCA: Yeah.
BECCA: How does it know when to stop, right? Like, if your fingertip grows back, it doesn't become bigger than it was before.
KEN MUNEOKA: There's apparently—there are signals to stop regeneration, but we don't know exactly where it's happening, when it's happening.
BECCA: Got it.
LATIF: Weird! Also, can I just say what a weird use of stem cells. It's like you have these miracle cells in your body that can do whatever, regrow whatever, and then it's like, "Okay, you know what we need you for? Just keep regrowing nails that we're gonna have to cut anyway." [laughs] Seems like so futile, right?
BECCA: That's—yeah, so that's exactly what I said to Chris.
CHRIS ARNOLD: Yeah, so it doesn't make a lot of sense for us, right? As, like, why is it our nails, like, just keep growing and growing? But if you think a little earlier, for earlier mammalian ancestors, maybe that's where you actually get more of the answer of why this is happening. Because I mean, from our earlier sort of, kind of rodent-like ancestors, known for the ability to dig, burrow into new environments where you're getting this constant damage. And so that maybe came along with it, this ability to constantly regrow from that damaged kind of part.
BECCA: Wow! It's kind of crazy to just, like, look down at them and be like, "I have these because of rodents."
CHRIS ARNOLD: Exactly. Yeah. I mean ...
BECCA: Like, should I go use them and burrow? I don't know.
CHRIS ARNOLD: Yeah. Are you burrowing with them? Like—what are you—what are you using your nails for?
BECCA: I know!
CHRIS ARNOLD: Really?
LULU: I'm never going to look at my fingernails the same. It's like the former us hunched over, trying to dig away.
BECCA: Yeah. But when Chris started telling me about other animals ...
CHRIS ARNOLD: There's animals that regenerate even better than that.
BECCA: ... I realized that we're not that impressive at all.
CHRIS ARNOLD: Yeah, so if I could regenerate like a salamander, if I cut off my hand, a new hand would grow back in its place.
BECCA: And as he told me about more and more of these creatures, it just kept getting weirder.
CHRIS ARNOLD: Like our friend the planaria.
BECCA: Mm-hmm?
BECCA: So there's this tiny little flatworm called a planaria.
CHRIS ARNOLD: If you cut it into small pieces ...
BECCA: Even hundreds of them.
CHRIS ARNOLD: ... those pieces can regenerate the entire animal over again.
BECCA: Wow!
CHRIS ARNOLD: So the whole body can grow from any part.
LATIF: Hmm.
BECCA: Some starfish can also do this.
CHRIS ARNOLD: Mm-hmm.
BECCA: You can cut off one of their arms and that can become a whole new starfish.
CHRIS ARNOLD: There was a famous story where scuba divers were trying to get rid of a starfish population in their area by going down and cutting them into little pieces, only to find to their dismay, that the next day there were—well, the next few weeks there were even more starfish than they started with.
BECCA: Okay, now this is my favorite thing. So you know the classic one, lizards, right?
LATIF: Right.
BECCA: How they can break off their tails and grow them back?
LATIF: Yeah.
BECCA: What's amazing, though, is that they have this tearaway site on their tail.
CHRIS ARNOLD: Kind of like—I think of, like, the perforated part of, like, a ketchup packet or something.
LATIF: It's like a coupon.
BECCA: Exactly. But they're not the only animal that has one of these.
CHRIS ARNOLD: The sea slug.
BECCA: Oh!
CHRIS ARNOLD: But it's not the tail they're losing. They actually lose all of their body from the neck down.
BECCA: It turns out that when they're sick, they can just shed their entire body.
CHRIS ARNOLD: And at the end, it's just a head that's swimming around, that will then go on to regenerate all the rest.
BECCA: Oh my God!
LATIF: Wow! I've been sick over the last few weeks, and that is just so relatable. Like, I have thought about doing that so many times.
BECCA: [laughs] Now I'm coughing.
LULU: It is wild that you can just dispense of a body, and be a head and then grow a new body. I mean, when it goes to that level, it feels like—it does feel like a superpower.
BECCA: No, totally. And I know these things feel like superpowers to us.
CHRIS ARNOLD: Yeah. We generally think of animals more like a planaria. Something that can regenerate its whole body is just something sort of weird and alien.
BECCA: But Chris told me that this thing that seems just like a strange little quirk of nature is really not that strange at all.
CHRIS ARNOLD: When we look at the tree of life, the ability of an organism to regenerate itself from a small piece—whole body regeneration, the most extreme form of regeneration—that is actually very widely distributed throughout the tree of life.
BECCA: Wow!
CHRIS ARNOLD: And it's only been lost in a couple of branches. Ours is one of them, and so it's not really weird that an animal can regenerate its whole body. It actually might be more weird that we can't.
BECCA: Hmm.
LATIF: Why can't we do this, though? Like, why are we the ones left out?
LULU: [laughs]
BECCA: Yeah. I mean, scientists think that it's because we're complex, right? Like, they typically see these regenerative properties in simpler organisms.
CHRIS ARNOLD: The more complex, the more many parts there are to a structure, the more interdependent those parts are, it makes sense that if you lose a part of that, it's really hard to recreate it.
LULU: Huh! It's like a devil's bargain thing?
LATIF: Right.
LULU: Like, this is the price you pay for complexity?
BECCA: Yeah, it's the price we pay for, like, having our big old brains and ...
LATIF: It's like it costs way more to fix a fancy car, you know what I mean, than an off-the-shelf thing?
BECCA: Yeah.
LATIF: Totally.
LULU: You know, I am curious. What does—what does Rae think about all this? You know, how does this reporting change her? Because she wrote to you feeling like she had a superpower.
BECCA: Yeah.
LULU: And now you've told her that not only doesn't she, we are—we pale in comparison to what most animals can do. That we are the outliers. We're the odd men out of being unempowered. Does it—did it change her sense of specialness?
KATHERINE RAE MONDO: I mean, I don't think I feel less special. I think I feel way more connected to the tree of life.
BECCA: Hmm.
KATHERINE RAE MONDO: Like, oh, I got to experience this thing that, like, all the other, like—or, like, so many of the other—maybe the majority of the other, like, branches of the tree get to experience. And, like, how cool that, you know, it was just a fingertip but, like, I'm out there with all those other guys.
BECCA: Yeah. Yeah, you're in good company.
KATHERINE RAE MONDO: Yeah. You know, before this story, I would not have associated my fingertips with sea slugs in the slightest, but I hope that going forward that is what I continue to think of when I look at my—I don't even know what sea slugs look like. I'm gonna have to go home, look at a picture of them and then just, like, hold my fingertip up next to it and be like, "That's me!"
BECCA: [laughs] Yeah.
LATIF: Producer Becca Bressler. We're gonna take a quick break, and if you don't know what a sea slug looks like, or even you think you do, just look it up during the break because they're—I mean, it's like a Martian fashion show down there. So beautiful, so strange. We'll be right back with two more stories of growth.
LATIF: Hey, I'm Latif Nasser.
LULU: I'm Lulu Miller.
LATIF: This is Radiolab. Today's episode is about growth.
LULU: Pumpkins that can grow 20 pounds a day.
LATIF: Fingertips that miraculously grow back after they've been chopped off.
LULU: Slugs that can chop off their own body and then grow the whole thing back.
LATIF: This growth I have at the bottom of my toenail.
LULU: [laughs]
PAT WALTERS: Yeah, so there are obviously all different kinds of growth, but it seems like they must be, like, tied together by some underlying rules of nature.
LULU: Oh, hello Pat!
PAT: Hi. I am here. I've invaded. I've invaded your host intro.
LATIF: Okay, great. This is Pat Walters. He's our managing editor
PAT: Yeah. And whenever we get curious about the rules governing nature and the universe, we tend to call this one particular guy.
STEVE STROGATZ: Hey old man.
PAT: Hey! How are you?
STEVE STROGATZ: This—this is actually very comfortable here. Let's talk all day.
PAT: His name is Steve Strogatz.
STEVE STROGATZ: I'm a mathematician and math professor at Cornell University.
PAT: Also has a great podcast called The Joy of Why. And I asked him just, like, what are the different ways things can grow?
STEVE STROGATZ: Okay, here we go. There's linear growth.
PAT: A simple kind of growth—basically adding.
STEVE STROGATZ: Like one, two, three, four.
PAT: This, if you're like me, is how that stack of the magazines grows on your desk each month.
STEVE STROGATZ: And then there's exponential: growth that feeds on itself.
PAT: The kind of growth that multiples.
STEVE STROGATZ: Like one, two, four, eight.
PAT: Picture each magazine on the stack giving birth to another issue of the magazine each month.
LULU: No!
STEVE STROGATZ: The more of something there is, the faster it grows.
PAT: This, of course, is how diseases spread and pandemics happen.
STEVE STROGATZ: Now there are kinds of growth that are faster than exponential.
PAT: What's that?
STEVE STROGATZ: There's something called blow-up. [laughs]
PAT: What's blow-up?
STEVE STROGATZ: Which sounds like what it is.
PAT: Something goes from nothing ...
STEVE STROGATZ: Boom.
PAT: ... to infinity ...
STEVE STROGATZ: In a finite amount of time.
PAT: But Steve says this doesn't actually happen in the real world.
STEVE STROGATZ: Because we don't believe there are infinite anythings in our existence.
LATIF: Oh, thank God.
PAT: And then there are these other kinds of growth that are a little more, I don't know, peculiar. And Steve told me about this one that completely took me by surprise and showed me how these patterns, these invisible blueprints of growth, can sometimes stretch out and connect parts of the world that I didn't think had anything to do with each other.
LULU: Hmm!
LATIF: Hmm.
STEVE STROGATZ: So you've heard the name Fibonacci. There's the famous Fibonacci sequence, which is where I take a number like one and two and then I add them to make three. And then I always take the two most recent numbers and add them to make the next number. So two plus three is five, five plus three is eight. Where am I? Eight plus five is thirteen. These are all Fibonacci numbers, and you can keep going like that and you can see they're getting big.
PAT: So the sequence goes one, two, three, five, eight. And each number in the sequence is the sum of the two that came before it.
LULU: So it keeps getting bigger in this strange and yet oddly, like, predictable way.
PAT: Yeah.
LULU: Okay.
PAT: And I think when I started talking to Steve about it, I had the vague sense that what was interesting about it is that it sort of shows up in nature ...
LULU: Okay.
PAT: ... maybe in plants.
LULU: Yeah.
PAT: But according to Steve ...
STEVE STROGATZ: The Fibonacci sequence was originally posed as a problem about rabbits growing, where there was some made-up population biology rule about how many rabbits give birth to how many other rabbits, that led to the Fibonacci sequence. That's from 1200 AD, and it's not even ...
PAT: They—they observed something in rabbits?
STEVE STROGATZ: No, it's a made-up—it's a textbook problem. It's fake. Rabbits don't really grow according to the Fibonacci sequence.
PAT: Wait a minute, so they came up with the—where did the—where did the sequence come from?
STEVE STROGATZ: Well, it's got a good backstory.
PAT: Okay. What's that story?
STEVE STROGATZ: So Fibonacci—Fibonacci, whose real name was Leonardo, but of Pisa, not of Vinci.
PAT: Weirdly, Steve says, a historian sort of randomly stuck him with the name "Fibonacci" in the 1800s, but all this happened about 600 years before that when he was still just Leonardo of Pisa.
STEVE STROGATZ: So Leonardo of Pisa ...
PAT: AKA Fibonacci.
STEVE STROGATZ: ... is an Italian mathematician whose dad was working in North Africa. It's a really interesting, vibrant place. He's getting to meet people from Egypt and all over the Middle East, as well as Sicily. And there's a lot of trading going on. It's 1200, a very vibrant time in the Middle Ages. And this Leonardo learns about a fantastic new kind of math that has come from a different part of the world, from the traders coming from the Middle East, from Arabic world, including—who themselves learned math developed in India. And so when we talk about Hindu-Arabic numerals, the ones that we all use today to write with—0-1-2-3 up to 9—those digits are from India, by way—through Baghdad, and finally into Europe, through—dun dun dun—Leonardo of Pisa. Fibonacci brought Hindu-Arabic numerals to Europe.
PAT: Hmm!
STEVE STROGATZ: So it's a really ironic thing that Fibonacci gave us the numbers that we all use today, and nobody really remembers that that's what he did. He wrote this book called Liber Abaci, basically "The Book of Counting," "The Book of Reckoning." How to work with numbers in a really practical way that merchants of the type that he was encountering in all these trading spots in the Middle East. Everybody had to work with money, and Roman numerals were terrible. So everybody wanted a better way, and these Hindu-Arabic numerals were fantastic. You could do really good calculations in your head.
STEVE STROGATZ: So anyway, he introduced this fantastic system of Indian numerals to Europe around 1200, and he just, as a little footnote in his book—not really a footnote, but the book is filled with practice problems about taxes, about interest, about all kinds of money problems. But he made up this problem about growth, that the rabbits take one month to mature, and then when they mature they give birth to another set of rabbits, a pair or rabbits. And then that pair can mate—blah, blah, blah. Anyway, he made up this story about rabbits, where the Fibonacci sequence comes out.
PAT: Where did this—but this sequence, even though he—he applied it to a made-up story about rabbits, but don't we see the Fibonacci sequence ...
STEVE STROGATZ: Yes.
PAT: ... represented in nature?
STEVE STROGATZ: Yeah, yeah, yeah. We totally do. Sure. Plants really do have it. I mean, there's a million places we could go. We could—if you look at a pine cone, if you start following the straightest line that you can, you can make a certain number of windy spirals. So if you count them up, the number will end up being a Fibonacci number of—of these spirals. And no matter how you do it, you'll always get a Fibnonacci number.
PAT: So did he just get—did he just wing it and throw it on some rabbits, and then it turned out magically to be true? Or ...
STEVE STROGATZ: Yes. I think so.
PAT: Did it come from India? Or ...
STEVE STROGATZ: Well okay, that's another good story. [laughs] It's nice of you to keep asking me these kind of questions.
PAT: [laughs]
STEVE STROGATZ: Okay, so it turns out that Fibonacci was not the first to think of the Fibonacci sequence.
PAT: Oh!
STEVE STROGATZ: It's a—it's a misnomer, and we're only gradually starting to appreciate how much of European math is really Indian math or Arabic math. I mean, a lot of it is European. I don't want to pretend it's not. But the Fibonacci sequence was known 400 years before Fibonacci, if not longer, in India. And in a really surprising place. It's in connection with poetry. [laughs]
PAT: With poetry?
STEVE STROGATZ: Yeah, let me—can I try to explain it to you?
PAT: Yeah. Please.
STEVE STROGATZ: This will take a minute.
PAT: Okay, yeah. Do it.
STEVE STROGATZ: We can try it.
PAT: Take us there.
STEVE STROGATZ: Yeah. Okay. So going way back, a few hundred years before the birth of Christ, there are scholars in ancient India who are really interested in—let's call it meter—you know, like, rhythm, patterns of rhythm in poetry. The poems have certain rules to them, because the rules make it easier to remember. And in a time before people had books—because remember the printing press is in the future.
PAT: Oh right. Of course.
STEVE STROGATZ: Right? So, like, if you want to remember the Odyssey in ancient Greece, or memorize the Qur'an, you're gonna sing it.
PAT: Hmm. So it's not just because it sounds nice or pretty, it's because it's a tool for remembering.
STEVE STROGATZ: It's the way human psychology works.
PAT: Right.
STEVE STROGATZ: So these ancient scholars in India were trying to just think what exactly are the possible patterns if we obey—if our poetry obeys a certain rule, which is that you can build it out of two types of syllables. You can have something that lasts one beat, or something that lasts two beats.
PAT: Mm-hmm?
STEVE STROGATZ: And so, like, one question that—that people interested in the sort of the science of poetry were concerned with was: Suppose I want to make a line that is, for example, four beats long, how many different ways can I make something that's four beats? Basically, I have two things I can play with, something that's one beat long or two beats long. Right? There's these two kinds of syllables. So I could do one-plus-one-plus-one-plus-one. That adds up to four. Or I could do a rhythm that was two-one-one. That would also add up to four. Or I could do one-two-one. That would be four. Or I could do two-two. Or I could do one-one-two. I've said five possibilities. Now what's interesting about that is that five is the fourth Fibonacci number.
PAT: Oh!
STEVE STROGATZ: And in general, if I want to make something that's N beats long, there is the Nth Fibonacci number ways of doing it.
PAT: Whoa, wait. Okay, so—so to make a five-beat line, there would be eight ways of doing that, and to make a six-beat line, there would be thirteen ways of doing that?
STEVE STROGATZ: Yes.
PAT: And a seven-beat line, there would be twenty-one ways of doing that?
STEVE STROGATZ: Yeah. It's a growth problem, right? It's the growth of possibilities. It's the growth of creative possibilities in Sanskrit poetry. This was figured out in India by a person named Virahanka four centuries before Fibonacci was born.
PAT: What?
STEVE STROGATZ: Yeah.
PAT: So—so they noticed this phenomenon present in poetry, studying the possibilities in Sanskrit poetry. And then, like, when I google the Fibonacci sequence, and Wikipedia tells me it's, like, really all over nature, not just in pine cones but pineapples and sunflower seeds. Apparently lots of flowers have a Fibonacci number of petals?
STEVE STROGATZ: Yes.
PAT: I'm just now trying to, like, wrap my head around, like, is that because there's something in the universe that, like, made its way into the Sanskrit poetry by way of humans, that also made its way into the trees and the pineapples? And, like, what's the—that's wild, because I think about poetry as being so separate from ...
STEVE STROGATZ: Yeah.
PAT: ... a pineapple or—or the leaves on a tree.
STEVE STROGATZ: Yes. Well, okay.
PAT: That's not a question. That's just ...
STEVE STROGATZ: No, it's—it's an expression of wonder, which is appropriate. Why are Fibonacci numbers in botany? Why are they in so many plant structures? There are various theories out there. Some people will say that it has to do with, like, when a branch shoots out of a tree, it doesn't want to shoot out in a direction where it's covered over by another branch. It needs to get its own sunlight. So if the branches have to grow—I mean, natural selection. Evolution will have disfavored the trees that don't follow this principle. That may have something to do with it. I'm not giving you a clear explanation because I don't honestly know.
PAT: No, no. This is—this is helpful. And, like, maybe the same thing holds true for the poetry, where people are trying to create new—newness. You're trying to make—I don't know, create space in a sense.
STEVE STROGATZ: Yes. You're trying to create novelty subject to constraints.
PAT: Right.
STEVE STROGATZ: Right? And you could say novelty subject to constraints is art.
PAT: Hmm.
STEVE STROGATZ: Like, growth in creativity subject to constraints, that's—that's what art is, right?
PAT: Hmm! Yeah.
STEVE STROGATZ: Anyway ...
LATIF: Huh. So what do you make of all that?
PAT: I guess I don't know. It sort of makes me see the plants as a little bit more artistic than I did before. And the poetry as, like, a little bit more from nature.
LULU: Hmm. That gives me goosebumps. That's really cool. [laughs]
LATIF: You're also missing the other takeaway here, which is that Fibonacci didn't discover the Fibonacci sequence, and that's not even his real name.
LULU: He wasn't even named Fibonacci.
PAT: That is the point. Let's bring it back down to Earth and focus on what really matters ...
LATIF: What really matters is he's a fraud.
PAT: ... is that Fibonacci ...
LATIF: He's a fraud. Let's just call him out.
PAT: He's not who we thought he was.
LULU: Well, thank you Pat. That was beautiful. And we will be back in just a moment with one last growth story.
LATIF: Of planetary scale and import.
LULU: And the little humans trying to control it. Stick with us.
LULU: Lulu.
LATIF: Latif.
LULU: We are back.
ANNIE: Okay, so ...
LATIF: With one more story of growth from producers Annie McEwen ...
SIMON: I've just detangled my headphones.
LULU: And Simon Adler.
SIMON: But go on. Go on!
ANNIE: All right, let us begin.
LULU: All right!
ANNIE: So I think like—I think like most people, I thought for the longest time that human population was growing really fast.
[ARCHIVE CLIP: We already have between three and seven times more people than we can permanently support.]
ANNIE: Maybe exponentially.
[ARCHIVE CLIP: The growth rate is just incredible.]
ANNIE: You know, people were popping kids out and ...
[ARCHIVE CLIP: We are destroying our fossil fuels. We are dispersing our mineral resources.]
ANNIE: And that this was, like, a really big problem. We're frigged.
PHILIP COHEN: Yeah, a ball of flesh expanding at the speed of light, I think.
SIMON: A ball of flesh expanding at the speed of light? Oh God!
PHILIP COHEN: [laughs]
ANNIE: This is Philip Cohen.
PHILIP COHEN: I'm a professor of sociology at the University of Maryland.
ANNIE: And I called him up to talk about this fear. It's one that I really took deep into my soul at some point in my life. And he told me that, like, yes, this was a real concern, starting around the 1950s.
PHILIP COHEN: Population did start increasing exponentially. You know, two billion, four billion, eight billion.
LATIF: Population bomb kind of thing.
ANNIE: Yes. Yeah, yeah, yeah. But by the time I had even started worrying about it ...
PHILIP COHEN: By the '90s, really.
ANNIE: ... it was no longer a problem.
PHILIP COHEN: Right. You know, it's obviously a long, complicated story, and it's different around the world. But with better healthcare, better contraception and access to education, a lot of women started having fewer children.
ANNIE: Fewer kids meant slower growth. And as growth slowed, demographers predicted that population would just plateau.
PHILIP COHEN: Yes. The idea was that the average woman was going to have two children, and that world population would hit a peak around 10 billion, around 2060 or so. And after that, it'd be stable.
ANNIE: And we would all live happily ever after.
ANNIE: Oh, thank God!
PHILIP COHEN: Yeah, it's great.
SIMON: Big ol' exhale for Annie McEwen on the population front.
LULU: Okay.
ANNIE: That's right. But then, like, 10 seconds after I learned about this plateau and felt great about it, I learned that that is not what's happening.
LULU: Hmm!
PHILIP COHEN: Well, it would be in Europe that panic first started.
ANNIE: Because instead of watching things come to settle at a peaceful plateau, demographers noticed that especially in Europe, but also in other parts of the world ...
PHILIP COHEN: You know, South Korea, China, Japan ...
ANNIE: ... that this drop in birth rates ...
PHILIP COHEN: It accelerates.
ANNIE: The fall accelerates?
PHILIP COHEN: Exactly.
ANNIE: Oh!
ANNIE: Birth rates in a bunch of places were now dipping too low. Okay, so I've got the latest fertility rate information here in front of me so, like ask me—ask me a country and I'll tell you.
LULU: Okay. Okay, France. France. France.
ANNIE: Okay, so remember for us to keep replacing ourselves, the number to hit is 2.1. France is 1.8.
LULU: France is 1.8.
LATIF: 1.8. That's low.
LULU: Okay. Au revoir.
LATIF: Poland.
ANNIE: Poland is 1.5.
LATIF: 1.5? Wow!
ANNIE: Yeah.
LULU: Mexico?
ANNIE: Mexico, 1.8.
LATIF: Cameroon.
ANNIE: Uh, 4.29. So they're above replacement.
LATIF: Oh they're high!
ANNIE: Yeah, they're high. They're high.
LATIF: Yeah.
ANNIE: But they're falling. Like, in the '80s, I think it was 6.7.
LATIF: Whoa!
LULU: What about Ghana?
ANNIE: 3.5, but they also fell from over 6.
LULU: Oh, wow!
LATIF: Italy?
ANNIE: Italy is 1.3. Italy is low.
LULU: Whoa!
LATIF: Italy is 1.3? Wow!
ANNIE: Yeah.
LULU: What are we? What's the US?
ANNIE: 1.7.
LULU: 1.7?
ANNIE: Yeah.
LULU: Wow! And where is it the lowest?
SIMON: The lowest are, like, Korea and Japan, which I think Korea's at, like, 0.6.
LULU: Wow!
LATIF: No!
ANNIE: 0.6, 0.7.
LATIF: Wow, that's so low. Wait, and Earth as a whole is what right now?
ANNIE: Is 2.3, so we're just above total.
LULU: Wow!
ANNIE: Yeah. And Philip says that this downward trend is going to continue.
PHILIP COHEN: The world population is going to hit a peak around 10 billion, around 2060 or so, and after that it will almost certainly start to taper downward.
ANNIE: So we are on the verge of beginning to shrink.
LATIF: Really?
LULU: That makes me so happy! Yes!
ANNIE: In a couple of hundred years, it's projected that the Earth's population will be actually about six billion.
LULU: Wow!
LATIF: Wow, that far down?
ANNIE: Yeah.
LATIF: So less than now?
ANNIE: Oh, yeah.
LULU: We're, like, on a rollercoaster and we're like—we're coming at that—we're like, "Whoa!"
LATIF: It's like the tak-a-tak-a-tak on the rollercoaster before the drop.
ANNIE: Exactly.
LULU: I am really pumped to hear that. Whoa!
LATIF: I don't know. I think I kind of like the plateau. The plateau sounds so nice because the stability. It's like you can—you know what to plan for. Like, you know what to ...
LULU: But it's a stability of, like—of a hurting Earth that—and, like, strapped resources. How about a little less of us ...
LATIF: Oh, that's fair.
LULU: ... to drive cars and share wheat?
LATIF: That's fair, but I don't know, there's something that sounds sad about less people. It's like the party's ended.
LULU: No. Absolutely not sad.
LATIF: The party is—it's, like ...
LULU: That's great. The parties are still—so many people. The club is popping.
ANNIE: Yes, the club is popping.
LULU: Yeah.
ANNIE: I think when I heard this, I was like, "Okay, great. I feel relieved, the skin ball's not gonna happen." But I guess the thing that I was most struck by is just while I was freaking out about humans exploding off the planet, eating everything, there was a whole other group of people freaking out about the exact opposite.
LATIF: Really?
LULU: Why would they be worried?
ANNIE: Well, you know,some of them are the gabillionaires.
[ARCHIVE CLIP, Elon Musk: Yeah, if we aren't making enough people to at least sustain our numbers, perhaps increase a little bit, then civilization's gonna crumble.]
ANNIE: Who are just like, "Let's grow, grow, grow so we can all make more money.
[ARCHIVE CLIP, Elon Musk: I'd rather civilization went out with a bang than a whimper in adult diapers.]
ANNIE: But then there are, like, also regular economists, especially in, like, the Western capitalist economies, who say that the shrinking is a problem because our economy needs workers to just, you know, keep things chugging[00:45:00.07] along.
LULU: I mean, what about immigration? Forget all the other reasons, just looking at it from this economic viewpoint, I mean, people in the United States might not be having that many kids, but there are lots of people who would love to come and live here, and there will be workers in the economy.
ANNIE: Yes.
PHILIP COHEN: Anybody who says there's a population shortage or problem in any rich country has to at least answer the question of what about immigration?
SIMON: Like, were it not for immigration, the US population would be falling right now.
LULU: Really?
ANNIE: Yes. Or it would be falling very soon.
LATIF: Which is so crazy that the administration in power right now, the whole thing is, like, "Get people out, get people out," and it's like yeah, we kinda need people right now.
ANNIE: Yeah. And actually, when I spoke with another demographer on the phone, James Raymo, he told me that, like, all these countries that are, you know, really not immigrant friendly, in 50 years' time they are gonna be fighting to attract immigrants.
LATIF: Oh, I bet. I bet.
ANNIE: But, like, even with all these wealthy countries holding their doors wide open, that's only a temporary fix.
PHILIP COHEN: That works for, you know, maybe a hundred years. Or 50 years.
ANNIE: Because by the year 2100, 97 percent of the world's countries will be below replacement level. So this sort of decline in fertility is happening everywhere, and it's happening more slowly in some countries than others, but it is happening.
LULU: So basically in 70 years or so, most of the planet will be dipping?
ANNIE: Yes.
LATIF: Hmm.
ANNIE: And, like, I think talking about the economy, especially the economy in the future, it feels just very abstract. But for me, like, the whole thing started to get kind of unsettling when I called up another demographer.
ANNIE: Hello?
LESLIE ROOT: Oh, I hear them. Hello!
ANNIE: This one, named Leslie Root.
LESLIE ROOT: I'm assistant professor of research at the University of Colorado-Boulder.
ANNIE: Who told me that, like, fundamentally, this whole thing is a question of how will we care for each other?
LESLIE ROOT: So this is like any human society, right? That you have people who need to be supported, and you have people who are capable of supporting. And people who need to be supported are the very young, right? Like, human children are pretty helpless and—like, compared to other primates.
ANNIE: Right.
LESLIE ROOT: They can't do anything.
ANNIE: Kind of useless, yeah.
LESLIE ROOT: Yeah, exactly. And—and the elderly. And then sort of the prime working years is when we are supposed to be able to produce more than we consume so that we can share it with other people. And so a big concern is that when you have lower fertility, and imagine your population with, like, people flowing into and out of it. Fewer people are flowing in, and the people who are already in it are getting older and older, so you have what's called an aging population.
ANNIE: So, like, in 200 years, when the population is down to six billion, that's gonna be a very different six billion than the one we just experienced in the year 2000. And because a lot of those people are going to be very old, and the worry is that, like, as society becomes more and more top-heavy ...
LESLIE ROOT: What does that mean for our ability to support each other?
ANNIE: Like, just super practically, you know, like, who are all the doctors gonna be to take care of these old people?
LATIF: Hmm.
ANNIE: And who is gonna staff the nursing homes? And who will grow the food to feed these old people? Like, you can sort of see that, like, as the proportion of young to old people shifts more and more out of whack, you have on the backs of these few young people, kind of the burden of everything. Unless ...
[ARCHIVE CLIP: Pope speaking Italian]
ANNIE: ... a whole bunch of us right now ...
[NEWS CLIP: The Pope told Italians to have more babies.]
ANNIE: ... start to breed like rabbits. Which is what a bunch of governments around the world are trying to get their citizens to do.
[NEWS CLIP: Putin has urged Russian women to have eight or more babies.]
ANNIE: Here's a bunch of stuff that countries have tried.
LATIF: Okay.
ANNIE: Japan tried government-sponsored speed dating nights.
LATIF: Funny.
ANNIE: Russia, they're like, "Hey, if you have more than two kids, we'll give you $7,000."
LATIF: Right.
[NEWS CLIP: About 10 times the average monthly wage.]
ANNIE: Taiwan, there was a presidential candidate in 2023 who was like, "Hey!"
[NEWS CLIP: The gift of yet another furry child.]
ANNIE: "Everyone who has a baby should get a free pet as well."
LULU: [laughs]
LATIF: A free pet? That's like more—more work.
LULU: It is.
ANNIE: There's also things like Sweden has this, like, amazing parental leave policies.
[NEWS CLIP: For 480 days.]
ANNIE: Germany has got free daycare.
LATIF: That's—that's money.
LULU: Big.
ANNIE: And, of course, there have also been some darker attempts to control, like in the US or in North Korea, where abortion has been banned.
LULU: Mm-hmm.
ANNIE: But the crazy thing is that, like, carrot or stick, none of this has worked.
LATIF: None of it's worked?
ANNIE: Yeah.
SIMON: And, like, one thing I'll add to that is, like, with—with few exceptions, and the exceptions are sort of explainable away, no country that has dipped below replacement rate has ever ...
LATIF: Come back?
SIMON: ... gone back above.
LATIF: Wow! Interesting.
PHILIP COHEN: Right. There really is no success story out there. Nobody has shown how you can turn this around.
LULU: Huh! That's wild! I mean, do people have any idea of why not?
ANNIE: I don't know. I think it's because it's just really hard to answer the question: Why does someone choose to have a kid or not?
LESLIE ROOT: Yeah, there's a lot of, like, casting about for explanations of what exactly drives lower fertility.
ANNIE: There are gonna be a hundred reasons, big and small, why someone becomes a parent or not.
LESLIE ROOT: You know, we—we meet a partner or we don't, and our partner has the same preferences that we do or they don't.
ANNIE: We can find affordable housing or we can't. We have access to great healthcare or we don't.
LESLIE ROOT: We get a—a good job with flexible hours or we don't. We live near family who can babysit the kids or we don't.
ANNIE: You know, for every one person, the decision is going to be this, like, really complicated mess of reasons and circumstances. And if you zoom out from there to the national or, like, global level, looking down and trying to understand this is just total chaos.
LULU: Hmm.
LATIF: Right.
GIDEON LEWIS-KRAUS: You're not going to solve the mystery of why, and basically there's nothing you can do about it. So what does this look like? You know, like, what does it look like when a society stops having children?
ANNIE: This is Gideon Lewis-Kraus.
GIDEON LEWIS-KRAUS: I'm a staff writer at the New Yorker.
ANNIE: He recently wrote an essay about declining population called, "The End of Children." And as he was starting to report the piece, he noticed that, like, there were all these articles in Western media about South Korea.
GIDEON LEWIS-KRAUS: Obviously South Korea, with the lowest fertility rate in the world, comes up all the time in all of these columns. And I noticed that everybody invoked South Korea, but it didn't seem like anyone had gone there. And I thought, like, it would be interesting to hear from some South Koreans about this.
ANNIE: South Korea is a country that has more deaths than births every year, and it's not an easy country to immigrate to. So its population is getting older and smaller. And so it's sort of seen as almost like this bellwether for where the rest of us are headed.
GIDEON LEWIS-KRAUS: And so I got there and, you know, I got into the center of Seoul, and I went to the subway at rush hour. And you saw no children anywhere. But at first I thought, like, oh well, you know, in New York, like, would I take my kids on the rush hour subway? Like, probably not. But then pretty immediately, like, you really just don't—you know, you don't see playgrounds. Or, like, the handful of playgrounds that I saw were completely empty any time of day. And you just don't see a lot of children.
GIDEON LEWIS-KRAUS: And there were these no-kid zones everywhere. There were signs on restaurants and other establishments that said, "No kids here." And I mean, so much of it is about a rapid shift in cultural norms about kids. So in fact, I met with this young economics reporter who writes about this for a living, and she was in her late twenties or early thirties. And she said, "Like, I understand all of this stuff on a deep economic level, but when I write about it I think, like, well what would change my mind? And the answer is nothing. There is nothing that would make me want to have kids because it's the norm to not want to have kids."
ANNIE: Gideon eventually made his way out to some of the more rural areas of the country, where it's projected that about 2,000 schools are gonna be closing in the next 10 years.
GIDEON LEWIS-KRAUS: And so I wanted to go visit one of these schools. So I went to one in the far south, and this school I think at its max it had about 1,300 students. Now it has five. It had ...
SIMON: Wait, five students?
GIDEON LEWIS-KRAUS: Five students, yeah.
SIMON: What grades?
GIDEON LEWIS-KRAUS: It had three first-graders and two sixth-graders.
ANNIE: Hmm.
GIDEON LEWIS-KRAUS: And when I was talking to the sixth grade teacher, I said to him, like, "So you have two kids. Like, do they get along?" And he, like, looked at me like I was a complete idiot, and he was like, "What do you mean, like, do they get along? Like, they don't know anyone else. They've been in school together since they started school. Like, the other child is, like, the only other child they know."
ANNIE: Hmm. What was it like walking through this school? Like, what did it look like?
GIDEON LEWIS-KRAUS: Well, there—you know, there's a feeling of great dignity and resignation about this stuff. So this—you know, the outside of the school had been freshly painted, and the inside was bright and totally broom-swept and spotless. And everything was in perfect order, except it was empty.
GIDEON LEWIS-KRAUS: And, like, there was no heat on in the hallways, and almost all the classrooms were dark. And some of the classrooms had photos of the last group of kids that occupied that classroom. Like, the classroom was dark and just hadn't been open in a couple of years. And the cafeteria had, like, a little proscenium stage with a curtain, and clearly they had had, like, school plays there and stuff. And, like, you know, you probably could have seated 300 people in this cafeteria. So it just felt like everyone had—like, there was no sense of decay. It just felt like everyone had evaporated.
ANNIE: Right. It does feel like children are disappearing.
GIDEON LEWIS-KRAUS: Yeah. And something like 200 nursery schools have been converted into retirement homes, because there was, like, a radical dearth of retirement homes. And you can see that some of these nursery schools that have been turned into retirement homes, they've kept the same directors, and they had kept the same, like, rubberized playfloors for the old people. And they even had—actually my fact-checker Emily found this when she talked to them. She was like, "Not only do we have the same rubberized playfloors, we have the same crayons that, like, the kids used to use the crayons and now we just let the seniors use the crayons."
ANNIE: There's something really dark about that.
GIDEON LEWIS-KRAUS: Yeah.
SIMON: Yeah.
GIDEON LEWIS-KRAUS: Yeah.
SIMON: The bell curve of life.
LATIF: But this is our projection.
LULU: Yeah.
LATIF: We've already in this very story been wrong twice about projections. We thought, oh my God, it was gonna be a population bomb explosion—too many people. Then we were, like, oh, it's gonna level out so nicely, perfectly. That didn't happen. How do we know that these projections are worth anything?
LULU: Yeah. Yes.
ANNIE: That's a—that is a great question. I think that—that we just don't know. We just don't know what's gonna happen next.
LATIF: Right.
ANNIE: But what we're heading towards is, like, really unprecedented. And there is no way to, like, be like, "Oh, yeah, last time we—this happened, so we can project forward and imagine it."
LATIF: Right, right, right, right.
ANNIE: And I do think ...
LATIF: The last planet we were on—yeah.
ANNIE: And as fewer people have fewer kids, those fewer kids are gonna have fewer kids, and this is just—mathematically it seems tricky to get out of that spiral. However, we totally don't quite know, and I think that's very fair. What—what is very much agreed upon is that the population of the world is going to start declining, and that is a totally new thing for humanity. And that is set to happen pretty soon.
PHILIP COHEN: Yeah. Yeah, pretty soon. I hope to—I hope to live to see it.
ANNIE: It—it's just interesting to imagine being on the planet and sort of looking around and being like, "This is the most people there might even be alive at one time."
PHILIP COHEN: At that moment, yeah. It's big. It's like—yes, it's like going to the moon or, you know, our first nuclear bomb. I mean, it's—it's a big moment in human history, when we turn that around, and for the first time the global population is declining. You know, the feeling like you might never come back from it. Like it's—you've turned, you've changed direction.
ANNIE: Yeah, it's a shift from growth to something else, something new.
PHILIP COHEN: Right. Exactly.
LULU: Producers Annie McEwen and Simon Adler.
LATIF: So that's the end of the growth show, a story about shrinking.
LULU: [laughs] Yeah. Yeah, from a pumpkin that was kinda growing uncontrollably to a population that seems to be shrinking uncontrollably.
LATIF: Well, at least we're making room for more giant pumpkins
LULU: [laughs] There's always that, the silver lining, the orange lining. That, I guess, is our show.
LATIF: [laughs] This episode was reported and produced by Matt Kielty, Becca Bressler, Pat Walters, Sindhu Gnanasambandan, Annie McEwen and Simon Adler, with additional reporting by Rae Mondo. And it was edited by Pat Walters.
LULU: Mixing and sound design by Jeremy Bloom, fact-checking by Emily Krieger and Natalie Middleton. And special thanks to Elie Tanaka, Keith Devlin, Deven Patel, Chris Gole, James Raymo and Jessica Savage. I'm Lulu Miller.
LATIF: And I'm Latif Nasser. And thanks for listening.
LULU: Thanks for listening! We'll see you soon.
[LISTENER: Hi, I'm Paolo Mara-Biggs, and I'm calling from Amouli, American Samoa. And here are the staff credits. Radiolab was created by Jad Abumrad and is edited by Soren Wheeler. Lulu Miller and Latif Nasser are our co-hosts. Dylan Keefe is our director of sound design. Our staff includes: Simon Adler, Jeremy Bloom, Becca Bressler, W. Harry Fortuna, David Gebel, Maria Paz Gutiérrez, Sindhu Gnanasambandan, Matt Kielty, Annie McEwen, Alex Neason, Sarah Qari, Sarah Sandbach, Anisa Vietze, Arianne Wack, Pat Walters and Molly Webster. Our fact-checkers are Diane Kelly, Emily Krieger and Natalie Middleton.]
[LISTENER: Hey, I am Speth. I'm from Melbourne, Australia. Leadership support for Radiolab's science programming is provided by the Gordon and Betty Moore Foundation, Science Sandbox, a Simons Foundation initiative, and the John Templeton Foundation. Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation.]
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