How Zero Population Growth Works

definitely that kind of weather for sure. Yeah, it's hard to not sit on the deck and have a citrusy, delightful drink. Nice going. So I'm just a little sleepy, but I'm feeling good. I feel like this topic is is all about being sort of down in the dumps a little bill. It depends, it depends on where you land, and you just place yourself pretty squarely in the gloom and doom camp. My friend. No, I'm actually not in

the doom and gloom camp. I was about to say, which, if I remember correctly, in our episode, was Malthus right about carrying capacity? You overtly said that you are a an optimist. That's right, not Mauthusian uh naysayer. You know, yeah, I forgot about that one. We've touched on this a few times. We talked about we did a whole profile and Norman Borlog alone on our very short lived and reasonably so UM live webcast. Do you remember we did

basically a book report on Norman Borlog. Yeah, he was, um, well, I think he's even controversial. He is very much So you know, you win a Nobel Prize but for saving a billion lives. Yeah, but still people are gonna put you. You get interesting stuff. So um, if you don't know what we're talking about, should probably press pause, go listen to the Malthus episode, Go to stuff you should know dot com slash podcast, I think it's plural slash archive.

Make that your homepage and all seven hundred and change episodes are there, and then do control f is everybody doing this so far? And then type of mouths m A L th h U S. It's gonna highlight that link, click that and press play and then come back to us. That's right, we'll wait boom. So so we're back an hour.

We we're talking about is carrying capacity in part, but carrying capacity checkers is just kind of a it's a reflection of a larger issue, and that larger issues population specifically overpopulation, and is that a thing or not is a big question, because I mean, at any given point in time, you know, they have, like the the CIA World back book has you know, a pretty good assessment of how many people are alive. It's a total guess.

It's a total estimate. We could be at ten billion right now, we could be at a hundred million, and everybody just is really terrible accounting. The point is we don't specifically know. It's it's probably pretty accurate, but it's still a guess. The point isn't to shoot holes in the estimates of how many people are alive on the planet. It's to point out that, like, there's so many people we don't know and we can't possibly know at any given point in time. And that has led a lot

of people to say, well, wait a minute. There's this thing called carrying capacity, which is the Earth's ability to support and sustain us humans and really any any creatures. But really we're just kind of concerned with us humans at this moment um and right and sustainably those two factors have to be met or else you're putting a tremendous amount of stress on Earth, and you're eventually bringing

about your own demise. So a lot of people are saying like, uh, we're probably past carrying capacity and we just don't know it yet. Or other people are saying, there's really no such thing as carrying capacity city. Thanks to human ingenuity, anytime we come up against it, we'll figure out a way around it. And Norman Borlog was a way to go. But before Borlog really became famous, there was a lot of people who were legitimately concerned

that we were all going to die. Yeah Borlog, Um, I don't if you haven't listened to that one, if you didn't follow Josh's instructions like a good little podcast listener. Uh. He was the um, one of the leaders of the Green Revolution in the sixties and seventies, in which we made great advances in agricultural Uh than agriculture in yields. Yeah, new new types of wheat in Mexico, new types of rice in India that um yielded much much more than

they ever had. And and plus they were drought resistant, flood resistant. They could stand up and and hold more grain. They could stand up and say Hello. They basically they could pick the day daily double at high Laia. So, uh, Borlog was, you know, by all standards, a very smart guy. He cared very much about the people. He wasn't doing it for fame or riches or anything like that. Like this guy felt like he was working against the clock. And if he didn't and he wasn't the only one

doing this, yeah he's the most famous. Um, but if he didn't do it, then yeah, a lot of people were going to starve. Yeah. And I think, um, I proposed to you before this that we do just one on the Green Revolution. Uh and I think that would be a one to three podcast, sweet one. I love this stuff. Psychology population That was another one we did too, was how population works. And it sounds so like eye bleedingly boring, but it turned out to be really interesting stuff.

So go go read that too. Well we'll wait, go ahead, and we're back and it's yeah, and everybody's a little nervous. Everyone is nervous. And uh Stanford biology professor Paul airlic Um, there's another famous Paul air Like this is Paul are airlic I believe, Oh it's a different one. Well, there's two dudes, I did not realize that. What do you mean, I mean, I'm familiar with the other Airic. Then I guess, well, who was the other one? Again? He wrote, um, some

other famous books. He's a biologist. I think it's it's not the same guy. Yeah, the other guy was a German physician, uh who worked in chemotherapy immunology. Oh yeah, that's not thinking of different guy. So this guy he wrote other things besides the Population Bomb. Yeah. So in nineteen six eight he writes, the population bomb goes on the Tonight Show, it explodes, is huge hit. Apparently he was on more than once. Yeah, and everyone got super

nervous because his book started with these words. The battle that he had all the humanity is over in the nineteen seventies, the world where under will undergo famines. Hundreds of millions of people are going to starve to death in spite of any crash programs embarked upon. Now that's not so good. That's how he starts his book. He basically says there's gonna be a Malthusian collapse. Um. At one point in the book, he said, if I was a betting man, I would wager by the year two thousand,

England won't be around boom. He drops the mic um and we should probably mention who mouth says Thomas. Malthus was a very forward thinking, smart, mathematically inclined minister, I believe in the early nineteenth century, late eighteenth century, an economist, and he was the one who said, we have a problem here everyone. I've just done the math. And population grows exponentially, but our food supply grows linearly, and so we are destined to outgrow our food supply. And that's

where the idea of carrying capacity came from. So Malthis and Malthusians um are the people who think like we're going to exceed the food supply eventually and die from famines. And Erlic was one of the most vocal and alarmist neo Malthusians around. Yes, absolutely, and he scared the pants off of people back then. Uh in night, there were about three and a half billion people. And the birth rate. We're gonna talk a lot about birth rates and such,

has a lot to do with this buckle up. Um. The American women had three and a half babies on average, and the global birth rate was five babies for a woman. It seems like a lot to me. It was a lot kids. Supposedly, in the fifties we were at six the global average fertility it was six babies per woman. And that's not just per woman. That's you want to

talk about fertility rates. So fertility rate basically is the number of live births that a population has assigned to the population of women thought to reasonably be a reproductive age. So fifteen to forty four times a thousand, So you take all of those, figure out the the how many women there are, and then you multiply it by a thousand, so you have something like, um, fifty births per one thousand women aged fifteen to forty four, and that's your

fertility right. Yeah, okay, that's you can figure out how many actual births are taking place. Yeah, with reasonable detail. Um. So like Mauthis Airlic did the math in the sixties and said, you know what, our food production isn't keeping up. Just like Mautha said, we're in big, big trouble, wrote the population bomb and co founded Zero Population Growth, which is an organization that is now called uh what are they called now? Population Connection? Population Connection? A very uh,

a little sunnier sounds Electric company. It does, and you should check out their website. It's good. They have a lot of good information on it, just to help you, you know, figure out what you might want to believe. UM. So people are scared the zero population growth group. Their aim is to uh, They're big thing is is contraception and giving women um control of their reproduction basically in their fertility right. That's that you decide how many kids

you want exactly they have that many. They've identified that that there's an issue that could easily address overpopulation, and that is cutting out unwanted pregnancies or pregnancies or having unwanted kids. They've identified that, you know, plenty of people.

There are two different fertility rates. There's the wanted fertility rate and then there's the unwanted fertility rate, and pretty much across the board in any country in the world, the unwanted fertility rate is higher, whether slightly or largely,

than the wanted fertility rate. So they're saying, like, if the unwanted fertility rates like three point eight babies per woman in a given country and the wanted fertility rate is like two point five, well, if we can just figure out a way to only have the wanted pregnancies, then you are doing a lot to control of a population. And the way that they figured out how to address this is to just basically spread awareness and access to contraception. Right,

the two pronged approach. UM what their goal is is they aren't saying that people should not have babies like you said, They're saying people should only have the babies that they want to have, and their their ultimate goal is to um to have a sustainable global birth rate below the replacement level, which means there's a lot of different factors, but it basically means that the world is not growing. When it's like, uh, working a club at at a door, being a doorman, one person goes out,

one person comes in. Yeah, you got a little quicker. That's basically what that means is, you know, someone dies, someone can be born, and of course it's not that one to one, but you know, well, if you're a big picture away, if you're a bouncer and you're tasked with keeping it in even ratio, you just have to remember that you can't keep people inside until a new person comes along, because that's called kidnapping. You still they still have to leave and you have to deal with

an imbalance for a little while. Right now, the replacement level of fertility rate in the US is two point one babies for a woman and three point zero and other developing countries because they have higher death rates and shorter lifespans, which makes sense. So we were onto the replacement rate basically, right. The replacement rate is the number of kids a woman of reproductive age would have to have to replace herself. And she's not just replacing herself,

she's replacing herself and her male mate who she's reproducing with. Yes, and it's kind of gross to think that a woman is giving birth to a boy and a girl who can mate and reproduce her. That's not the point he want them to go mingle with other people's babies. But the replacement rate, you would think then is to right for every woman, two point zero kids is what you need to have to have an even replacement rate. That means that people die, new people are born, and the

population never grows or declines, it stays the same. The replacement rate is never actually two point oh though most two point one right now, and the reason why is because we humans um tend to have more male offspring than female. Apparently, for every one hundred girls that are born, one hundred and seven boys are born. So the actual replacement rate is two point zero seven and then they round up to two point one plus there's I mean,

there's a lot of other factors too, for sure. So those other factors include things like you said, like, um, infomortality rates, lifespan, immigration into a certain area, And the thing is of birth rates or fertility rates and replacement rates. The replacement rate tends to be a little more stable. Um.

The the birth rate. The fertility rate has a lot more to do with social attitudes, access to healthcare, education, and it's a it can change, uh dramatically from place to place, whereas say, anywhere in the western world, the developed world, the replacement rates about two point one exactly. That's in the yeah, the three point oh for the developing countries. All the monographers just stood up and we're clapping. So clearly Aerlic was not correct in his dire predictions.

Here we are in and um, there are problems, but England is still around four billion people haven't starved to death. Um. But does that mean that he was wrong altogether? Not necessarily because right now, uh, and This was a pretty startling stat to me. Over the past hundred and ten years, we have grown from one point six billion people to

seven point to billion people in a hundred and ten years. Well, we're expected to get up to nine point two and another uh thirty five years by twenty and so one of the reasons we have this many people, uh, most of the reasons are positive because of like advances in healthcare. The lifespan in nineteen hundred was thirty one years old and now it's seventy or maybe even little bit higher because that was two thousand, twelve UM, so imagine it's

a little bit higher. And the infant mortality rate globally in nineteen hundred was a hundred and sixty five deaths per one thousand live births was down to thirty four. So that's why there's more people, because we're doing better

at taking care of ourselves. Yeah, and that those are two huge factors when it comes to um demographics and population because though the longer you live, the more old people you have, so therefore the less babies you need to replace those people, and the fewer babies that die or that survive infancy UM will be adults one day exactly. But these are the really if you're a demographer, the

sweet spot is that working age. So when you're a demographer, especially one that's um economics minded, chuck that sweet spot the reproductive working age people. That's a good sizeable population you want to have. If you have a lot of babies, well then you have a lot of people who are raising those babies, so those babies are dependent on So say you have a lot fewer women in the workforce,

so your workforce is depleted. If you have a lot of like an aging population, you have a lot of older people who have already aged out of the workforce and are now dependent on the taxes paid by that workforce. So a large population of either babies or old people, and god forbid both at the same time. It puts a lot of strain on the middle you know what

I'm saying. Sure, So when you have a longer life expectancy and a lower infant mortality rate like we have now in the developed world, you want to have something closer to the replacement rate, you know, which makes sense. Um, I got some more stats that would uh seem to back up air likes. Predictions are not predictions. But at least his gloomy outlook currently. You know, I couldn't find much on what he felt today. Yeah, I'm curious that

he's still around. I'm curious about there's some good interviews. I'm gonna check that out. You know what, We'll post it on uh the website because now we're posting links, yeah, to like the research that we do stuff. You should know, great links on that on the podcast page for this episode. Guys. So currently, as of last year and estimated eight hundred and five million people go to bed Hungary every night,

more than half of which are in Asia. One in four people in Sub Saharan Africa was chronically malnourished UM seven hundred fifty million people worldwide like access to clean water UM, contributing to about eight hundred and fifty thousand deaths per year. And UM, here's the thing, though, is we're living in cities out more than ever. UM. People are moving into cities, which is a good thing and one way because it provides a lot of opportunity, economic

economic opportunity for people, especially in developing countries. But when you look at these cities, a lot of them are full of slums and sweatshops. In these developing nations, something like um half of the population and a lot of cities live in slum conditions in Africa, that's right. So you think sub Saharan Africa, I think rural in a lot of ways. So yes, I'm aware that they they lack access to clean drinking water, and that's an issue

that Sub Saharan Africa faces. You don't think about that being an issue in a city. But the problem with slums is they very rarely have access to clean drinking water in the exact same way that places like rural Africa have the same problem. Yeah, and and we're not even I mean that's that's clean drinking water and like sanitation and shelter. We're not even talking about education and healthcare and like all the things that people need to live a fruitful life. You know. So cities are a problem.

Even if air look was wrong, there are clearly issues. Um. Some people will argue and we'll get to the critics and stuff later, but a lot of people argued that it's distribution of food and stuff like that, Like we have the resources, we're just not dividing it out properly. Right, And apparently if I read that if everyone lived like an American and consumed like an American does, the caring capacity would be something like two billion, So we would

have already far exceeded it. But if everybody lived with just the minimal amount that they need to live, the caring capacity would be something like forty billion. We've been able to sustain the caring capacity as it is right now because not everybody lives like an American. But if you're an American, that means that a lot of the other world, especially developing world, thinks that you are over

consuming by a lot. And that's really evident. And um there's a graph that went around recently that shows water use in agriculture by type of product, so everything from like soy to beef. It showed how much water? Did you see that? I didn't see that, but I've seen stuff like that. Beef is like a huge consumer water, right, A hundred and six point to eight gallons of water used to produce one ounce of beef. That's a lot. That's a lot of water. And so that's that's part

of the point. Whereas if everybody's and apparently in China and India and these ascending countries with ascending economies. Um. One of the one of the great benefits of being part of the developed worlds. You can get steak anytime you want, baby, and uh, I want a big one right now, put it in front of me. I'll give you some money here. Here, just take this and and put in your pocket. There's some money for you. Give me my steak, and you don't care how much water

it took. And they're these people who are saying they don't necessarily agree with their like, but they're saying, he was totally off here, he was alarmed. They're saying, this is one of the problems. You know, this is one of the problems with too many people. Yeah, and so getting back to to uh, contraception and zero population growth or now the population connection they're big goal. They say there are two two million women in the developing world

who have an unmet need for family planning. So they're not saying, you know, we want to put our ideals on you and you shouldn't be having kids. They're saying they're that many women that are like, I don't want these five kids. I would have wanted to and I either don't know about contraception, don't have contraception or I have literally no idea how conception works for a lot of them. Well, I shouldn't say a lot. The first idea that women just need access to contraception and they

will use it. Yeah, and they're they're they're working on that, right, But they found in studies it's something like ten percent or less of the women who are defined as having unmet contraceptive needs. Um site a lack of access as to why they're having unwanted kids. Instead, they're saying it's things like family pressure or societal pressure to have a bunch of kids. Um Like you're saying, like not understanding contraception or how conception works. Yeah, they say they don't

believe that they need contraception. If you have sex infrequently or after birth, after I've had one kid, we don't need to use contraception anymore. Like literally not knowing how conception works. So that's a big educational hurdle that Population Connection is trying to overcome. Right, So they're saying it's not just getting contraception to women, is educating them on how to use it and changing their social outlook. Yeah, changing the culture. Yeah, largely men, you know, saying you know,

like revolutionary road or something. You know. Alright, So, uh, we're gonna talk a little bit after the break about what the critics of zero population growth have to say. So we're back. We're talking about solutions to overpopulation. But not everybody thinks it's a problem. Some people say over population is a myth. They say that are like in and of it himself damaged his own argument. Yeah, he got a lot of personal heat. Yeah, still does because

of the language he used. It was so alarmed as starting his book off with, you know that we've already lost and no matter what we do, billions of people are going to die. Um and then it not panning out saying that England is going to be around in thirty years. I mean that was putting a lot on the line. And so a lot of people said, you're your specific landmarks or um or milestones were unmet. Therefore

your heart whole arguments out the window. And some people believe that other people are like, that's not necessarily true. That is alarmist as well, possibly your reactionary at least. But some people say, I still don't agree with Earli because humans are smart. We can figure our way out of any problem. That's right. Critics will say that humans

UM are not parasites to the earth. We are the saviors of Earth, and we are the ones that are coming up with these solutions like the Green Revolution and uh, longer lifespans and progressing medically to help people live longer. I don't know about saviors of Earth, you know, Like I think that's stretching it a little bit. I think we um extract a little too much to be called saviors of Earth. Well, I've guarantee you there's a lot of people that think humans are saying years of birth.

You know. I would see us more as like Homer with Pincy the lobster again and the salt water and fresh water, trying to strike the balance. I wouldn't call him a savior of either the goldfish or Pinchy at that moment. He's just keeping them both in stasis. How many times have you referenced pinch there's probably seven seven It's not bad. It's one for every one shows roughly. UM. Other critics will say that low birth rates are no good for the economy, UM, like you were talking about

earlier UM, older people and babies. Uh. Well, I guess low birth rates wouldn't affect that. But older people are more of a tax on society than they are spenders and investors, right, But in the same in the same way, if you have too many babies, that's a big text eventually that those babies will be a workforce like spend money exactly. So the baby boom and the post war boom economic boom in the United States, it's not coincidental

that they went hand in hand. There are a bunch of people having babies and eventually they grew into the workforce and they made a bunch of money in the eighties for the United States. Yeah, and there's it's also supported in developing countries. Uh. More than seventy countries are categorized now as low fertility with two babies or less per woman, And those areas are expected to make a big economic gains in the coming decades because they're going to be people to spend money, right and be in

the workforce. And there's kind of a few ways that the workforce and wealth in the economy and birthrates are all kind of tied together too. It turns out that if you give a woman rights to her own contraceptive decisions, um the birth rate tends to inevitably fall as a result. Uh. And then when that happens, it happens because some women have more babies than they want to when they don't

have right to their own count receptive decisions. UM. Another reason is when they have those kind of rights, they usually also have the right to an education. When they enter um school, they will tend to put off having kids because once they graduate from school, they'll usually enter the workforce, and so just by nature of getting to the whole thing later on in life, they're having fewer kids as well. Uh. And when you have more educated

women in the workforce, your economy is stronger too. So directly and by proxy, um, lower birth rates are associated with the stronger economy. But again, you don't want to get too low, because if you get too low, then all of a sudden, the generation before it started to taper off is going to be bigger than the generation

that's working. And if it costs fifty dollars in tax money to keep the average retiree afloat, say in the United States, well that divided by a thousand people is a lot easier to bear than divided by a hundred people. A hundred working people, you know what I mean. Yeah, we gotta keep up the old folks and uh keep

them in stake and ovaltine right. You know. So if you're if you're an economist, demographer, whatever, everybody's kind of saying like, you want to get a country developed, and you want to get them at the two point one replacement rate and everything will be hunky dory from there. Yeah. And the other thing a critic might say too is um, and this is what we were talking about earlier about the environment, Uh, the impact on the environment, Like we're

just going to destroy our world with so many people. Um. It turns out that impact carbon emissions aren't really tied to population growth rates. It's tied to per capita income levels. By evidence that China in the US have some of the lowest UH fertility rates right now, and we are the worst polluters. So it's not because we have all

these people. It's because we're consuming too much as Americans exactly, and I guess in China as well, which actually makes it seem kind of nerve racking that India and China with these enormous populations, are starting to become wealthier and wealthier, because that's just going to make it even worse as far as the environment goes. Did you check out the Population Connection site? No? I didn't. They have a pretty interesting f a q um that if you don't know

where you stand. I mean, it's helpful to read uh like they say things like, instead of we want to focus on quality of life, not quantity, and instead of saying how many people can the earth support, maybe how many people can't be or support because right now all these people are dying from lack of you know, clean water and sanitation and food. Um. And there's the counter argument that you hear from critics a lot. I've seen this stat thrown around that the entire world's population could

live in Texas. It's still mind boggling. I have trouble like believing it. Well, I think somebody forget to carry a one or something. No, it's true. Population Connection says, sure they can. Uh, you could fit everyone in Texas. You could also fit forty people in a phone booth. But um, Texas, they said, in no way has the carrying capacity to take care of those people. So it's a little bit of a hollow. You know the fact that you throw out when you say that, right, like,

sure you can jam everyone in there. Um. Texas would be like what do you guys doing here? Everyone? Um? But it's pretty interesting stuff. I recommend people read their f a Q U. It seems like they definitely have the right um mindset because that what they want to do is, you know, make sure people have a good quality of life all over the world. Well, I will go read the f a Q because I suddenly feel underprepared.

But I will tell you that the impression that I have from researching them without going on their website was, um, I didn't find anything like where population connection or the

population connection myth or anything like that. There's definitely debate on the other side saying overpopulation is a myth, but no one seems to be attacking population connection is like a nefarious organization because they're not saying don't have babies, right, And that's a really sticky situation to be in because a lot of people are like, well, God wants us to have as many babies as we possibly can. Who are you to be meddling in that kind of thing.

It's a it's a fine line that a group like that has to walk, and they seem to be walking at fine, there's just saying like, here's some contraception. Maybe let's not have unwanted babies. Let this little angels stay in heaven, and uh, we'll just go from there. I think that's their on their homepage, all right, the Behavioral Sink. What um, where did you find this? I don't remember where I ran across it, but um, I'd read it

a while back. But I have to give a shout out to Josh from Jersey, the original Jersey, not New Jersey, who recently wrote in to suggest we we do an episode on that and a perfect timing, because he wrote in after you'd selected this one, and I was like, these two would go great together, hand in hand. Yeah, So thanks Josh for reminding us. Well, thank you Josh for thanking Josh, which Josh, I'm thinking all the Josh is so. In nineteen seventy two, this dude named John B. Calhoun. Um,

this is one of his experiments. This guy, what he liked to do was build um rat and mouse utopias. He've been doing it since the forties and basically with the aim to see what would happen to a population, in this case mice or rats if you gave them a perfect mouse world. And he called these world Universes. And the one in nineteen seventy two, the one that really like made all the headlines I guess, was called Universe, and it was pretty good size. It was a hundred

over a hundred inches square. Um. The walls were fifty four inches high. It had space for um, let's see, what's two hundred fifty six times fifteen chuck. Um, I'm gonna go with about in my head. I'm gonna say like close to thirty. It is exactly hundred. Yeah, that's what I meant. I meant three thousand, hundred forty okay okay um. So there was enough room comfortably for thirty

eight hundred and forty mice, yes, um. And long before that he introduced four breeding pairs, so eight mice he first introduced to Universe, and it was well stocked by the way. They had everything. They wood, water that was cleaned out. They were all disease free. No predators, yeah, no yah. He threw a cat in there one right, just to keep him on their toes or something. Yeah, I mean it was. It was mouse Heaven is what they called it. Yes, And he actually did in papers

about these universes. He would refer to them as heaven or utopia, and he would use words like that. Um. So he introduces these for breeding pairs of mice to UM to verse twenty five and um. After a hundred and four days, it took them to finally settle down and be like, Okay, this place is actually pretty great. It's not too good to be true, um, despite the fact that it seems to be built by human hand, which is weird, and the temperature never changes. But we're

just gonna say it's probably fine and start breeding. And they started breeding pretty quickly. Yes, they started doubling in population every fifty five days after that, right, Yeah, like you said, because it was so great there, they were just like, hey, let's eat and uh do it and make a little baby mice. Like you know, there is no end in sight, so you're doubling every fifty five days. Uh. This is all a big study to study what overpopulation,

what would happen. And what he found time after time was that things went bad. Yeah, which is really something because remember Paul Airic released the population bomb in but for decades before that, John Calhoun saw firsthand what the real problem was. The real problem wasn't over population leading to scarcity of food and conflicts, conflict and resource wars

and famine and starvation. What he found was that the real problem was over population itself, but just too many, too many mice, and not enough valuable roles for mice to play exactly, so there comes to be a point in any mouse population. As far as Calhoun was concerned. And again, this is the universe twenty five and he wasn't making like one a week or something. These were detailed or smart studies. He was hired by the National Institutes of Health. He spent like twenty or thirty years

working there. He was like a bona fide legitimate researcher um, and he would find that at some point the abundance would lead to overpopulation rather than scarcely. Like he he never ran out of food. They always had enough food and water and everything. What came to be an issue with space and social interactions. There were just too many people. There are too many mice, I should say to the mice. There people, sure, um, And they're rubbing shoulders up against

one another, constantly moving past one another. There's not enough room. And like you said, there wasn't enough. Um, there were too many mice to fulfill the number of social roles needed. Right. Yeah, it says by day three fifteen, so this is close to a year. Um. A lot of mice are living in there. And they said there were more peers to defend against. So males were stressed out and stopped defending their territory. They abandoned it. Uh said normal social discourse,

UM broke down completely. Social bonds broke down. UM. There was like randomized violence for no reason. It seemed like. Um. The female mice, the mothers saw this and would attack our own babies. And it was procreation slumped, infant abandonment, increase mortality sword um. Then he talked about the beautiful ones, which I thought was hysterical. There were these male mice that just they never fought, They never sought to reproduce or have sex. All they did was eat, sleep and

groom and just sort of loaf around. So all these social barriers are completely being destroyed, these social norms, I should say. Yeah, and these the the females that could reproduce one off by themselves to quester themselves away from society. And the males that were capable of reproducing became those beautiful ones and didn't seek sex either. So over time they lost their ability to carry out these complex social interactions that lead to reproduction, and they just stopped reproducing

it in general. Yeah, by day five sixty and this is um, I guess that's the close to two year mark. Um, well, I guess eighteen months they had mice and then growth ceased. Yeah, which is even close to the thirty that this place could could conceivably hang on to. Yeah, So it was how many was they stopped reproducing? Um? Very few My survive pass weaning at that point. The beautiful ones were still secluded, the females that they basically called this the

first death of two deaths. He did specifically social death essentially exactly like the death of the spirit, the death of the society, and then eventually the physical death the second death. Yeah, the one leads to the second, like there is a point that you pass, and he came up with a great name for it, called the behavioral sink um where they think they refer to it as

the event horizon. Once you pass that, it's all over, right, there's no coming back from that, and once there's no coming back from that, not only has your society collapsed, or does your society collapse? Um, you your population becomes extinct because reproduction becomes impossible even he found, which is

pretty startling. He found that even after enough of the population dies off that it returns to those potable, ideal numbers of the early days in Universe twenty five or any of the universes, they still don't reproduction doesn't start up again because remember, social norms and bonds have broken down, so they can't even figure out how to reproduce once there's room for people enough again. It's it is so interesting,

he said that. Um. He wrote he wrote this really kind of blockbuster paper called Population Density and Social Pathology, and it was published in Scientific American in nineteen sixty two, and he said that the individuals that are born under these circumstances will be so out of touch with reality as to be incapable even of alienation, so like they can't even feel like they're not connected as society anymore, because there's no society for them to ever connect or

disconnect from. It's right, it really is. And a lot of people jumped on this and said, whoa, what's going on here, because if you look at his data, every time he ran this experiment, the results became the same. There was an abundance of resources, there was never scarcity. Population became overpopulation. Once they reached the point of the

behavioral sink, the population slid into extinction. And on the way there was violence, cannibalism um like uh and sexualism in fanticide um just like all the horrible things you can possibly think of, um, right, you know, on the way towards extinction. And so a lot of people said, you know, these mice kind of a reflective of our own society, don't you think and um, Calhoun was kind of like, yeah, I would say that's probably correct. Yeah.

And there was a big boom at the time because of this experiment in literature and movies with a lot

of doomsday uh areas uh. Tom Wolf, the Great writer wrote in The Pump House Gang in nine UH he actually referenced the behavioral sink um and uh in reference to New York City, and he said, I got to uh, it was easy to look at New Yorkers as animals, especially looking down from someplace like a balcony at Grand Central at the rush hour Friday afternoon and the floor was filled with poor white humans running around, dodging, blinking their eyes, making a sound like a pinfull of starlings

or rats or something. And there are all these movies that came out. There was one called ZPG with Oliver Reed and Geraldine Chapman Chaplain that was called Zero Population Growth. Yeah, like for a generation the government said no, one's allowed to have babies. Here's your robot baby, right, and they're like, no, we're gonna have a real baby. And they're like, no, you're not. Um, I think it. I didn't see, but I'm sure it ended very portly. I didn't see it either. Yeah.

I saw it on IMDb though. And of course, of course Soilent Green. Yeah, great, great movie from the novel Make Room, Make Room. And there's there's another novel called stand On Zanzibar, and um, there were people called muckers who ran them up and just suddenly went crazy and started killing a bunch of people. Oh no, what happens.

From time to time in the news, a lot of people would were saying, Yeah, the stuff that Calhoun's finding is clearly extrapolateable onto human society, and at the time too there was a lot of discussion about what to

do about um, inner city over population, crime, housing projects. UM. There's this really great documentary called The pruitt I go Myth and it's about there was this the pruitt I Go UM project in St. Louis became I think we've talked about it before, but it became like the the the poster child for how no matter what you do for poor inner city people, they're gonna screw it up and it's gonna become crime ridden. And it's them. It's not it's not the their their quality of life or

education or anything like that. It's them. And this this this documentary just totally demolishes that idea, but it's still a longstanding idea. And there were a group of policy policymakers who looked at Calhoun's research and said, clearly, we need to we need to do something. There's there's too many people, and there's a lot of people who don't have um valuable social roles and they're turning a crime

and everything. UM. It was very much open to interpretation because Calhoun, even though he was putting these things in terms like heaven and utopia and hell and behavioral sink and that kind of stuff. He was still just kind of putting data out there and it was up to society at large or interpreted, and it really said a lot about your attitudes towards your fellow human how you interpreted it. But Calhoun himself actually took something of an optimistic view of all of this data, which is kind

of mind boggling. Yeah, I was surprised to read this actually, he Um, it makes sense that if you think about it. Yeah. He found that there were outliers and that not all the mice descended into a hellish violence and looting and mouse looting. He found that some could actually handle this and what he called the ones that could had a high social velocity, UM, mice that fared well with a lot of high number of social interactions. And that is not me. And he said, I'm a type, A blood type,

blood personality type. Uh. He said that basically, these mice will thrive. Um. And he said, and even the ones who don't, what he termed the losers, um, found ways

to be more creative. And he sufficient, Yeah, he had a sunny your outlook, basically saying that man is essentially a positive animal and we will create and design our own solutions, right, and his solution was since and it makes sense because he own that it's not scarcity or famines or anything that leads to trouble, it's overpopulation itself.

His idea was, well, let's go find more space. And so he was a member of this group called the Space Cadets, which was a group of thinkers that we're trying to figure out how to establish colonies on like Mars or the Moon or wherever, which is exactly what Calhoun's point was, is that we just need more space. As long as we can sustain ourselves, that's fine. But even if we don't stress agriculture, the planet or whatever, we're still going to run into problems. So let's go

off to other worlds and terror form. Oh and did you see the thing about the rats of nim Oh? Was that taken it? It was based directly on his research, Mrs Brisbee and the Rats of nim Nice. Yes, So go see that again and also go read the Behavioral Sink, Super interesting, an article on Cabinet by Will Wiles that informed a lot of episode. Yeah, this stuff is fascinating to me because I see kind of both sides. Um clearly there are some issues going right now, and uh,

but I also think that there are solutions around the corner. Yeah. I ultimately don't have a strong opinion either way, and I think if I think about it, it's because I think humans will, yeah, become an ingenuitouve. You can have steak tonight, me too, grass fed only you know, it doesn't make it any better. I mean that's why beef is so it uses so much because it eats so much food that also requires water. Right, it requires water like two times over at least the dumb cows. Yeah,

does you feel bad about our steak consumption? Chuck, I don't need much steak. Good for you, buddy, It's because Emily doesn't eat beef. So oh yeah, you know, usually I just will cook chicken because it's not like I'll have a steak and I'll cook work chicken every now and then. But usually it's just easier because chicken comes in like a two or three pack, right, you know. Yah, Plus you cook it until it's dry as a bone,

so you can feel better about the water consumption, that's right. Uh. If you want to know more about population growth and specifically zero population growth type, those words into the search bar house to works dot com and don't forget to go to stuff you shaulow dot com and listen to this episode and check out the extra great links on there too. Uh. And since I said search bar in there somewhere, it's time for listener mail. I'm gonna call

this linguists sticks up for us, all right? Right? Hey, guys studied linguistics in college, so it always pickles me when you guys go on tangents about words and language. The main reason I'm writing is because I want to offer you a counterpoint to the language police that have been harshing your vibe. Grammar nuts are what we call in the biz. Uh, prescriptivists, um, who like to dictate

how people should speak. Linguists, on the other hand, are descriptivists who make their careers out of how people actually speak in real war old situations. Oh, I didn't realize. I thought linguists could be one or the other. I didn't realize that like linguists tend to be descriptive ists. That's what she says. What is um who wrote Infinite Jess David Foster Wallace. He was a big time prescriptivists, really he used to drive him crazy, like how people

should speak? Yeah, like that, there is a a specific way that humans are supposed to speak and right, right and communicate, and if you dedate from that, you're about as bad as human being and that would be like the downfall of society or pretty much on um. We don't use the terms good or bad grammar. Instead, we prefer standard and non standard Linguists recognize the social functions of non standard grammars and observe their uses and functions

rather than to try and micromanage them. A final point, I'm certain your listeners still know what you mean when you say things like there's a lot of something, even if it isn't standard grammar and the laws of linguistics, as long as you're interlocuature, which is a listener interlocutor interlocutor. Yeah, as long as they accurately understand what you mean, you have successfully communicated. And that's why humans had been in language,

isn't it. So go be free and know that I will always love your show no matter how you speak. And that is from Kristen. Thanks Kristen. The supportive linguists appreciate that that's funny that Kristen mentioned that as long as your interlocutor understands what you're saying, you're communicating correctly. Um, someone else, I don't remember who it was, they wrote in and suggested we do an episode on shorthand. Oh interested. I was just talking about that with Emily last night. Bam,

it's all over the place. I took speed writing in high school and she was, did you very surprised at that? So like speedwriting with hands? Speedwriting is like like stenography, No, right with your hand. Um, it's basically a version of shorthand, but not exact shorthand. Got you. It's a kind of shorthand. It sounds like shorthand, but like more aggressive. Yeah, like max power or something. The joke was my friend Shannon, I won't see her last name, but she would cheat

and class because she didn't learn the shorthand. So the test where they would just read a long passage quickly and you would have to do it and then transcribe that into longhand. She was just super good at writing really fast, so she would just write down everything in longhand super fast and then figure out how to transcribe it back to shorthand and then back to Longhand and she she got caught doing that. Yeah, and the teachers like that's cheating. Yeah. It sounds like she was like,

well name with fast. Nope, that's not speedwriting, that's just writing fast. Uh. If you want to get in touch with us, either to show us support, criticize us, and even something neutral is fine, you can tweet to us at s y s K podcast. You can join us on Facebook dot com, slash stuff you Should Know. You can send us an email to Stuff Podcast at how stuff Works dot com and has always joined us at our look Curious home on the web, Stuff you Should

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