How Population Works

get chunks punkins. Yeah, okay again Science Channel. The Road to punkin Chunkin starts at eight pm Eastern Time. Punkin chunk In Itself starts at nine Thanksgiving night. Yes, Science Channel on with the show. Yeah, chuck, Um, have you ever belonged to a population? No, man, I'm like, I'm totally independent. Screw population. You're like that guy who lives in the commune, right right, Yeah, Well the joke's on him,

because a commune constitutes a population. Um, this sounds kind of boring, and you would think it is how population works. It actually started to pick up. Actually didn't know what it was even gonna be. When I saw how population works, I was like, what you know, it's awesome. This was my idea, this article was. I pinched it. Why didn't they let you write it? I don't know, jerks, I know, but the grabst did a good job with it. Oh yeah,

the grabs is always good. Yeah, class, that's ed grab Ainowsky. By the way, right, So, UM, human beings marriage, human beings tend to um congregate. Yes, we segregate. Interestingly, that is an excellent You just blew my mind. Good lord chuck. Um. Well, let's get back to what I was saying. Unless you want to go on a segregation we'll get on that later. Um, humans congregate and segregate. But let's talk about congregation and that.

UM most of the time, I would say, our early early ancestors, uh, and probably even other species congregate because there's safety and numbers and it helps like with farming, collecting water and food power numbers. But even before farming, um h hunter gatherers lived in bands. I think thirty was about tops. They figured out somewhere along the way that groups of thirty or groups of more than thirty, they're tending to be a lot more hostility and UM

in a group problems. Have you ever tried to kill a mass it on by yourself? That's another good point too. There's cooperation masted on. Um. There's um. If if let's say, if you are farming and your crop fails, well you're not standing there like, well I'm in trouble. You can say, hey, neighbor, um, I'll totally give you favors of some variety if you will let me have some of your grain. Right, I'll give you a chicken. Let's say, sure, you can trade. Yeah,

there's a lot of reasons people live together. So it's my theory that pepe will aggregate together naturally. Yes, And then there are people out there who get their jollies by studying these groups of people. They're called demographer demographers. So we have populations natural or otherwise. And let's say a natural population, uh today are people who live in

a certain state Georgians. That's where we are, So that you have natural populations, and demographers study um right um, and they look at things like say, how many people in this natural population are Republicans or Democrat, or how many are Caucasian, or how many have um, how many live below the poverty line. All kinds of things you can study right by looking at a population and are are is this? Are these groups segregated like you brought up?

You know, like if you study, uh, where different races are living? Are they living mingling? If so, then that's probably a fairly harmonious place hopefully. If not, why are they living apart? How do we fix this? Because it's probably a problem. Who knows, but yes, so demographers study populations natural or otherwise. Right. The problem is is you very few people have the ability to hover over the earth and use super binocular vision to study populations by side.

Very few people. Yeah, like three or four I think tops. Uh so does that count as a statistic I think so? Okay, Richard, um so measuring populations after you can talk about how do we actually determine this kind of thing? Yeah, that was my sec That was that was a good segue. There's a kind of way, josh one is um by counting them literally counting them like it's counting every single person, right,

and that is called complete enumeration. Yeah. Remember we talked about that poor guy who was killed or possibly kill himself in Kentucky. The census taker. Right, Oh, I didn't know that suicide was a possibility. There. I got a cryptic email from somebody never followed up on that said that he identified himself as a doctor and I think said that he was part of the group that was the medical examination team and said that they suspected, strongly

suspected suicide. My problem with it is is how do you bind yourself in duct tape? How do you bind your own risks and duct tape? Okay, um, So my point is, wow, he threw me off of that one. My point is that he was called an enumerator, yes, literally counter, and that's the people who worked for the census whenever they had their their drive and they count and that's one way to determine it. Well, let's talk

about the census. It's gone on every ten years since, right, And the reason they do it every ten years because it's a real pain in the asked to count every person in America. Yeah, the real reason they do it so they can Well there's a lot of reasons, but that is the reason why anyone's ever conducted a sense. Yeah. Well, plus they they determine the number of House representatives for your state based on population. Stuff like that. Oh yeah,

there's that too. But you know, come on, Texas, did you know that um that that the census information is kept is kept secret for seventy two years? Yeah, aside from the numbers, I believe the public cannot see that information for seventy two years. Right, what do I seventy two? That's odd? It is odd. I wonder if that was the average lifespan at the time or something. Dude, that's

got to be it. I'll bet you're right. Okay. The other way, Josh, is to uh do something called sampling, and that is when um statticians use a mathematical formula to determine the minimum number of people that must be counted, and then they multiply that out and basically end up getting a full population. And sometimes I did, I don't know this. That's even more accurate than an actual head count.

You see that margin of error, it's like plus or minus for sent Yeah, you gotta have a margin of error there whenever you're sampling, right, because you're not actually going around asking every single person in America are you left handed? To determine how many people are left handed? But let's say you have a population of a thousand, and some statisticians been like, you need a hundred do it, but do your egghead voice. Yeah, you need a hundred

and fifty people. The hundred and fifty people and that are left handed, and you can just multiply that out to determine that there are, in fact how many people, let's say, ten percent of the population of the population. Right, but your sample as perfect. Your sample has to be a random sample to be an effective sample. Yeah, and you know how they used to do that, Uh huh. Used to just pick it out of the phone book. Oh, I know and call people I know. And that makes

sense to a certain extent. No, well, back then it made a little more sense. I would think it made it made less sense, especially if you're talking like nineteen fifty years. Well, it depends on what year. I'd say, in the night, teen eighties, it was probably a good way. But now there are cell phones. People in college probably don't have a phone. Poor people who don't have phones at all, people who don't have phone. Sure, so that's not a very good way. Because what about freight train

writers of America? What's that they don't have phones? Yeah, good point. Yeah, they're not allowed. I don't think they want them. So sampling is a little harder than it seems. Yeah, right, especially coming up with a random population SANDOM sample of the population. Um. But okay, so so far we've talked about people and where they live. There's other ways to define a population. There's other attributes that people have that

we use to lump into population. It's not just a geography when people think, um, populations, it's not just a city population or state. Yes, what an age? You have a population of age or continent, a demographic? What else? Location? Of course, socio economic Well population, let's talk about age. Why would you even want to know age? Who cares?

People are old, people are young? Whatever? Right, Well, there's a lot of factors like, um, take the baby boom for instance, after World War Two, all these babies were born, so there was a bulge in the population, and I'd just like saying the word bulge. You got to do the air quote a quote. So, um, what that will show them then is wow, we got a bulge here. So that means probably in to sixty years, there's gonna be some serious buying power. Let's start borrowing as much

money as we can right now. But it also means in seventy plus years that they they may be a medical burden and a burden on social security. So let's start borrowing as much money as we can right now, same same result there. I like that, and we'll get to bulges again in a little bit. But let's move on. Like you said, socioeconomic data, right, yeah, what what? Why would they want to do this job? This one I found.

I find this the most interesting of all data. You can look at a bunch of people who are maybe related geographically, right, um, but other than that, aren't related in any other way. Uh, and all of them suddenly have this horrible cancer and they're just so happens to be some manufacturer or thereby what did you say, high tension wires, which has been proven I think to not actually have any effect on people, not in my buddy.

Um so uh, Now, all of a sudden, you have this information thanks to your demographer friend who went and collected it, and um, you can say, okay, paint factory, you guys better start giving away some free paint, yeah, or we're gonna sue you. Race. That's a little little more hinky because technically there is no such thing as any difference in different races. I remember watching MTV years and years and years ago, and um, the VJ was interviewing the Beastie Boys and he was like, Mike D,

I hear you're dating a black girl. You know, what's it like dating somebody from a different race? Which is just an asinine question to begin with, But I remember Mike D going there's only one race, the human race, And I was like, huh so that that was clearly before he was down with the Ione or no, that was ad Rock. Sorry, yeah, ad Rocks down with the IONI Yeah they're divorced though, so he's not down with

her anymore, poor Ione. Uh So, Yeah, race is a little hinky, but you can't actually determine some um useful things when you study populations of race because of like, you know, it's important for people to be involved in their culture. Yeah, and and to hang onto that for sure. I guess racial profiling again. I don't know if I should say again or not, but it's such a hot button issue that yeah, I don't know. We need to talk about it collectively. That's my answer for everything. Everybody

needs to get together and decide what we want to do. Okay, well, the other thing with race so is if there's a medical problem that's specific to that race, that can help out that exactly. Josh alright, So, Chuck, We've got all these different factors, attributes, variables. We've used the word demographer several times. Um, so we know that people study populations. One of the reasons why we study populations is to

see how big it's getting. And I gotta tell you, buddy, the human population is kind of exploded on this planet in the last several thousand years. Yeah, but you know what they were reading these stats. There were a lot more people here way back when than I thought. Yeah. Again,

favorite book of all time, Um, Charles C. Man. Yes, he basically points out that there is probably a hundred million people on the North American or on the in the America's uh in that's awesome, Yeah, which is a fifth of the world population is way more than anyone thought. And the reason why is because Columbus shows up. Smallpox just ravages both continents, and by the time the European settlers start coming for real, Uh, the places decimated. It

seems like there's nobody there. Right. Well, he had the whole genocide. Two things you ever know about that Columbus I hear um his men used to like sharpen their knives on like the skulls of live um live natives. Well, there's the because genocide we talked about later on Um in the article. But there's uh speculation that Columbus may have been responsible for like the worst mass genocide in human history by completely wiping out the Tano Taino Indian people.

And that was in Hispanielo, which is modern day I think Haiti and Dominican Republic. And they some people say there were only like five thousand of them, and some people say there as many as fifteen million at the time that were decimated to about two thousand. Decimated through

violence or through disease. Yeah, well through violence, because Columbus came over, set up a camp in Hispaniola for about forty people, and then left, came back on trip number two and found that the Indian tribe there had killed all those people. So he went on to kill crazy rampage basically and completely wiped out the population. And they're saying it may have been like double the size of

the Holocaust. So Happy Columbus Day, everybody, seriously, but we do mention that because genocide is is a way that a population can change rapidly. Well, let's talk about population growth. Yes, all right, so I guess about ten thousand BC, they estimate that there's between one and ten million humans. So we're starting to slowly grow because by one thousand BC there's fifty million, and then by six hundred CE UM we're at two mill And see that's a lot more

than I thought. Yeah there would be at the time. Yeah, I think there was about five hundred million in the mid fifteenth century, so um, let's go. But let's say there's a five million in the mid fifteenth century. The twentieth century, the industrial revolutions happened, there's been great leaps in science and UM medicine. That's when populations really grow is during those big booms. Yeah, because it lends itself to fertility, higher and fertility and UM longer lifespans, good

times breed kids. So the twentieth century hits were at one point five billion people and then this century the population of the world has quadruple. Yeah, and with like six billions. I know that that's it sounded like there should have been a drum roll there, but there was by that Jerry mnd have put one in there, our producer, Jerry, we'll find out later. Uh, And Josh, you are projecting. The U. S CSUS Bureau projects that by there will be ten billion people. Right. So the reason for this

is what we call the malthusisant growth model. Mouth. This was a eighteenth century clergyman, Thomas huh he uh he actually, I guess inadvertently became one of the great economic theorists, and he figured out that population grows exponentially. Right, So if you have one million people and they have enough kids, double the population. But the next generation you have four million people. So in one full generation you've gone from

one million to four million people. Right. Yeah, that's that's big, especially when the planet is finite in size and we don't have the ability to go colonize other planets yet. Right. But it's not necessarily that incremental and steady because of what we talked about, which are bulges or spikes and bottlenecks like genocide. Right. Yeah, so it doesn't always grow steadily.

And actually, Chuck, if you heard of the replacement right now, the replacement rate is it's how many kids a woman has to have to have a high uh statistical probability of having a daughter, so that she in essence replaces herself. And right now it's two point three three is the replacement rate worldwide, And the point of it is to trend towards zero population growth. Right, So for every woman who dies, she has a daughter that can reproduce and

and continue on and continue on and continue on. So you have overall as many people dying as they're being born. So there's no strain, right, and there's also no um dearth. Well, it's equilibrium that remot. Reading this reminded me of when we did our Big Econ audio book. It's kind of population kind of wants to seek equilibrium. I think, like, uh, just like economics does and now, and it doesn't always

happen uh organically, I should say, it probably rarely happens organically. Well, let's think about um, like you said, the baby boom, post war success in in Europe and um, the US and Canada, I guess led to um a huge boom in the population. Nobody went to war to grow the population. It was just an indirect effect. So all of a sudden we had a population spike that created a bulge bulge if you will, things can go the other way

to which is a bottleneck. Right. Yeah, and that's well we and I've got If I see genocide one more time, we should do a podcast in genocide. I wonder if there's a drinking game where every time I say genocide, genocide, drink um. Famine, disease. Uh, something called the plague I think wiped out like half the world population at one point, or half the population of Europe. They suspect that UM in uh the fifth century. That would be a c e. The plague of Justinian may have killed as many as

half the world's population, a hundred million people. Unbelievable. Can you imagine walking around on at that time, like, holy crap, the entire half the world is dead, just died in the last couple of years. It's crazy. On the Black Death killed twenty to thirty million Europeans. So so plagues can happen. There's also UM. I was talking to an evolutionary geneticist this is my way UM recently, and he was talking about study he authored where they found two

evolutionary bottlenecks, one coming out of Africa. Uh. They suggested a fifty thousand years ago, and another one that happened along the bearing Land Bridge, right, And he wasn't saying like all of a sudden a bunch of people died, but um, these bottlenecks turned up because big groups of people separating in smaller groups of people, which is which accounts for a loss of genetic diversity. So you have

the founders effect. Because, as he put it, if you take um, if you go into a town and grabbed the first fifteen people you meet and say, let's go found a new town, that new town isn't to have a representative sample of all the surnames in that town. If you do that enough times, some surnames are going to be lost because people didn't reproduce or whatever. The same thing happens with jeans in genetic diversity. Look at you,

good stuff? Thanks? Uh. Can I mention this place in Hong Kong, Yeah, we're talking about well we should mention. Population density is the number of humans per unit area whatever unit you you know, you choose to call it, And the highest ever is believed to have been a place called Kowloon Walled City in Hong Kong, and at one point evidently there were fifty thousand people in a mega block, which is five hundred by six fifty feet. Fifty thousand people stuffed in there, and apparently it was

a lawless district. The grabster. She kidding me. People could conceivably get along. Yeah, hands across America style. Did you know that um in Athens when Widespread Panic played that free show, there was an estimated hundred some people. They're not one fight really, Yeah, that's because they were all on dope. The dope. I wasn't there. Were you there? Yeah? I never got into them, although I did hang out with that guy, the bass player day schools. Yeah, I

hung out with him a couple of times, just through friends. Anyway. Uh, that that park is no, I'm sorry. It is now a park where the walled city used to be. Yeah, which is the opposite of the highest population. Ironically, it's just the park maybe the highest population of grass. But that's it. So what do we got here, Josh? We got um population control. It's something that we've referenced before with our China One Child policy. Yeah, and we talked

about why you would want to control the population. A huge group of people put a strain on resources. When resources go away, you have resource conflicts like in darfour again genocide. Right. Um. There's all sorts of problems that come from too many people coming or living in one place because of the strain that puts on resources and resource allocation. Right. Um. And yet you can control the population e g. You know, state mandated reproduction um, China, right,

and that actually works as as China shows. Um, although much to the detriment of some people, thank you Chuck for that look and not everyone thinks um, some people think we should add more people though, well, yeah, there's Japan.

In other countries, there's a problem of population declients. So we talked about the strain um people put on an area that's in capacity, which we've talked about before, and that's also from Malthus, right that eventually human population is going to outstrip advances in technology or our resources and

we're screwed. Right Um. On the other side is shrinking, population shrinking, And what's the problem with that, Well, you don't want the population to shrink too much because you, uh, you need those hands to go to work and to to contribute to the economy and to grow the grain and sow the flower and all that good stuff. And apparently in Russia, Japan and Australia they all have like little incentive programs to make little babies. Sure, how about that?

Which is the way to go? Remember John Fuller's famous quote, um, when he was pitching an article about that program in Russia, and he's talking about poutin giving away a TV. Oh, yeah, that's right, that's really funny. Yeah, um and the baby get a TV. I think you had to be there and check the reason why. Uh, some of these places are seeing a population shrink and or have to, I guess give incentives to reproduce. Uh. Started in about nineteen sixty birth control. That's so crazy that it had an

effect that much of an effect that pronounced of an effect. Yeah, well it would seem like it would though, I guess so because it's called birth control. Sure you know before that it was called have as many babies as you possibly can. It was called no control alright, So clearly there's a lot of reasons to study people. Yeah, it's

I thought it would be. There's a lot of stuff to study to h you can find out whether or not we're going to kill the planet or whether um, people need to stop using contraceptives, or whether you know what your chances are of putin giving you a free TV. Uh. It's all in there. It's all demographers know everything, all there for the taking. So when you're a frenzy friendly enumerator comes knocking on your door, don't chase them off your land with your dog or a gun. Let him in,

give him some lemonade, maybe some cookies. Yeah, we'll check their lambing at first, but oh yeah, before you let them in. Ceo Ah, Chuck could go in. And if you want to know more about population, you can read Grabanowski's great article on the site. Just type in population in the handy search bart how stuff works dot com, which of course leads us to listener mail. Josh, I'm just gonna call this your turn at listener mail because I think you have to know we'll talk about Yeah.

I just I don't necessarily have too much listener mail per se um. But I just wanted to give a shout out to a couple of fellow Toledo wins. One who's a longtime resident, one who's a recent transplant. Christopher is holding the fort down in Toledo for me, keeping it real, he has uh officially lobbied, um, the congresswoman from Toledo to get me the key to the city.

How awesome with it? Yeah, so Marcy kept her. If you're listening, I would like, if you get to the city, we gotta go for a ceremony and I at least want to get like a key chain to the city. Okay, and you can have the key. We'll see what we can do. Um. So yeah, Christopher has officially petitioner. He's he suggested that I'm the third most famous Toledo in of all time after Jamie Farr, Jamie Farr, Danny Thomas,

the Great Entertainer, and then me. And I was like, I think you're for getting Katie Holmes because she's from Toledo. And he's like, no, you got her bek Kate Cruz. You know, is it Kate Cruise now? So anyway, thanks a lot for the effort, Christopher, even if it doesn't come to fruition. If it does, you will get a firm handshake and a free Friendlies Sunday of your choosing for me. Friend. Yeah, we'll be going to Friendlies if

we go to Toledo. Sure. Uh. And then I also want to say hi to Colin, who is a recent transplant, as I said, Um from Colorado, I believe, who moves from Colorado to Toledo. He moved to Toledo to attend Bowling Green State University. Joe falcons my brother went there, and uh, Colin did so in an eight eight Dodge Colt. Right, that's having a couple of problems. One of the rear struts are completely detached and the axle is holding on

by a tread, he says, Um. And the mechanics didn't want him to leave when he took it in for service, so they're like, you're going to die in this thing, um. And the other problem is it has ants, he says. I've never heard of a car having ants. I had an incident car once. Really, you can't get rid of them when they well, that's probably when you were living in the car, which was probably always parked on the ant hill. This is actually prior to that, when I lived in the car. Um. But yeah, no, it's a

it's a it's a real problem. And Collin's basically just put the bullet and said, well, I have ants in my car now. He loves his ad eight Dutch Colt, he said he loves Salito. He's enjoying. He went to Tony Paco's as I suggested. I gotta try that one day. I also told him to go to Rusty's Jazz Cafe. So it's as authentic as it comes. Awesome. Um So, hey Christopher, Hey Colling, you guys enjoy yourselves, Be safe and toledown for the winner, Go mud Hens and h

Thanks for writing in. And if you want to say hi to me or Chuck or both of us Chuckers or Jerry, you're right, Chucker's Jerry chuck Er, I I mean Chucker me chuck in me. Um. You can put that in an email to stuff podcast at how stuff works dot com for more on this and thousands of other topics, does it how stuff works dot com. Want more how stuff works, check out our blogs on the house stuff works dot com home page