Stuff You Should Know - Does Kin Selection Explain Altruism?

Episode Date: April 21, 2016

There's a curious puzzle unanswered by the theory of evolution: why do some animals give up their chance to reproduce to help others reproduce instead? For decades biologists have suggested family was the reason, but that has recently been challenged. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

On the podcast, Hey Dude, the 90s called, David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're gonna use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s.

We lived it, and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, Frosted Tips with Lance Bass. Do you ever think to yourself, what advice would Lance Bass

and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. And a different hot, sexy teen crush boy bander each week to guide you through life. Tell everybody, ya everybody, about my new podcast and make sure to listen so we'll never, ever have to say. Bye, bye, bye.

Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple Podcasts, or wherever you listen to podcasts. Welcome to Stuff You Should Know, from HowStuffWorks.com. Hey, and welcome to the podcast. I'm Josh Clark, this is Charles W. Chuck Bryant, this is Jerry, puzzling us as always.

This is her jibber jabber. Right, Jerry? That was funny. Should we say what happened? No. No? I think we should leave it mysterious. All right.

Like whether Jerry exists or not. Oh, she exists. You know, a lot of people out there are not convinced. Yeah, still, even though she's, we've shown pictures of her with her face blurred. Could be a work a day actress. She's appeared at scores of live events and met people in person.

Same actress, but with like a gig, a regular gig. And she even spoke on our Guatemala episodes. That was Stanley Kubrick's doing. How are you, sir? Good. Good, I'm excited about this one. This is Nito. Are you a kin selection float your boat?

I thought it was, you know me, like any, you bring up the name Charles Darwin and you just see my face light up. Yes. So you know that HowStuffWorks trivia event that you and I longer hosted. You guys had some hard questions, but one that my team got 100% right.

Yeah. It was a six part question. Yes. And there was a couple of tough ones in there, but it was Charles Darwin or Chuck D from Public Enemy. Yeah, Charles D or Chuck D. Right. And then we named off five or six things.

I think it was six. And it was basically, who was it? Charles D or Chuck D. Yeah, like who's the pescatarian? You don't know. Oh, we did. It was Chuck D. Who married his first cousin.

Charles Darwin. That one I definitely knew, because I remember Darwin was kind of anxious as he was learning about evolution and natural selection and genetics. Right. That he had married his first cousin. He started to get kind of worried about his kid.

Yeah. He said, should I marry her? And then he said, it was Jennifer Connolly. She's beautiful. Where did you pull that one from? Well, she played Darwin's wife in the Darwin movie. Oh, well, that makes a lot more sense. Had I known that, I would have been like great reference.

Sorry, man. He's like, I gotta marry her. Did you see her and... Who played Darwin, Paul Bettany? Yeah. Well, he was her husband already. Oh, were they married? I don't know if they are not anymore,

but they were for a while. Oh, okay. Whatever became of him. He was great. He's around. Good. I bet he's treading the bolds. Oh yeah, I'll bet he is too.

Sounds like something he'd do. Yeah. I didn't even get to say that Jennifer Connolly in the movie I was gonna say. Proof. No, let's just move on. What was it? I can't think of the name of it, the Darren Aronofsky...

Oh, Requiem for a Dream? Yeah, yeah. So I gotta marry her. Did you see her in Requiem for a Dream? Man, that was a crazy movie. Great movie, but not for the faint of heart. No, no. So Chuck, we've got a whole evolution suite going on here.

And this contributes to it. Evolution, natural selection. We've covered Charles Darwin, the man himself. That's right. We've done Evolve and Isolation. All sorts of stuff. All to put together. Extinction?

Yes. Bam. That's probably all of them. But this one's kind of like a nuanced version of the evolution suite of the idea of evolution, but it actually is a fulcrum or lever, something on which... A buttress?

The whole idea of evolution and natural selection and what drives it, or if it's even real, kind of swings. It's easy to overlook, but there's a real problem. Like Darwin had all this great stuff laid out with his theory of evolution by natural selection. And it basically goes, as everybody knows. A little something like this.

A one and a two. I so wish we had a natural selection song we could play. Well, it goes like this. Animals need to reproduce for the species to survive. And it's hard sometimes for little eggs to survive, harsh environments and seeds and things. So they make lots and lots of them.

That's right. That's part one. And they make lots and lots of them because a lot of them don't survive, like you said. But a lot of these things that try to reproduce don't have the good genes, right? So they fail to reproduce. They've got tough skins, not levis.

So the tough skins tend to die out, right? Like tough skins did. Instead, the levis continue on because they've got the good genes. So therefore they are more apt to survive and reproduce and be successful than they are the tough skin counterparts. So what we have there is called survival of the fittest. You are reproductively fit

if you are likely to go on and bear fruit as it were. Yeah. Little baby fruit. Darwin realized early on too that variation was a big key to all this. You take two sets of pigs and they have baby pigs. They're not all going to be identical. Some of those pigs will have little seemingly insignificant

details about themselves. Like brown spots. Maybe. But it turns out that brown spots drive the lady pigs wild. It might be that easy. So this guy is mating left and right and has a bunch of kids.

So his brown spots make him reproductively fit. That's right. What looks, or not even looks like, what could be a random variation could really lead to the survival of that pig and maybe an entire species. Yeah. I read this really interesting article

on Nautilus I think recently. And it was basically the idea that the human body is just a hackathon of, well, we need to fix this problem. So let's come up with this. Right. The human started standing up on two legs so we need to fix it with this. I love that.

And, but if you stem back and look at it, the human body is just this really kluge thing held together with like duct tape and bubble gum, right? Yeah. Like a VW book. Uh-huh. And the author interviewed like I think

10 different biologists and said, you know, what's something you would change about the human body to improve it? That was basically the hack. It was pretty interesting. That's awesome. See if I can find it. Is that gonna be in your best things I've read this week?

Posts, blog posts? I think so. Maybe? It should be. And you read it while you were working out on your Nautilus machine? No, I read it on Nautilus website. Gotcha.

And they have a clever website. It's n-a-u-t-i-l dot u-s. Oh. Let's see what they did there. Yeah. So it's nautil-i dot u-s. Or nautil dot u-s? Nautil-s.

Okay. So you talked about fitness. The more offspring you have, the more fit you are as a parent. Right. And as a mammal or animal or whatever. You've hit the Nautilus so often that you're just totally fit if you've had a bunch of kids.

That's right. Because as we all know, not all, not 100% of your genetic material goes into each one of your little babies because you, you know, you have sex with someone else. You gotta share. You gotta share. If you compromise.

So in order to increase the chances of one of your little babies having all of your genetic material, you just need to have more and more babies. It's amazing. That's weird. Because I always thought that the amount of genes that you pass on was set, like 50% or whatever, went into your kid, right?

Well, yeah, but you have sex and 50% of these genes goes in. You have sex again and another set of your genes might get picked. I've never heard it put like that. That makes sense though. Yeah. I always thought the more like the drive to keep having kids and reproduce was to,

because you were gonna have 50% of your genes out there in the world no matter what, but all those kids could like, you know, bite the dust. Sure. And so the more you have, the more insurance you have that those 50% go on. Never thought of it the way you just said. Well, it's both though, I think.

That's pretty interesting. Either or. But the upshot of all this and by extension, the upshot of Darwin's entire theory of evolution by natural selection driven by variation is that you, any trait that an organism has that improves its capability to reproduce or its likelihood of reproducing

is going to be selected for and that's going to lead to the evolution of the species, right? And that basically the whole point, this is the unspoken part, the whole point of everything is to reproduce to pass your genes along. That was Richard Dawkins contribution

with the selfish gene, right? Yeah. The problem is in Darwin saw this while he was coming up with his theory was that there is behavior found in nature that does the exact opposite of that where organisms choose it seems to live a life where they don't reproduce

and instead help others of their kind reproduce which is called biologically altruistic behavior and it makes zero sense whatsoever under Darwin's theory of evolution and it's just been a puzzle and a challenge to the theory ever since he first noticed it. Well, I think that's a great place for a break my friend and we'll talk about this weird thing after we get back.

On the podcast, Hey Dude the 90s called David Lasher and Christine Taylor stars of the cult classic show, Hey Dude bring you back to the days of slip dresses and choker necklaces. We're gonna use Hey Dude as our jumping off point but we are going to unpack and dive back into the decade of the 90s.

We lived it and now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co-stars, friends and nonstop references to the best decade ever. Do you remember going to blockbuster? Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal?

No, it was hair. Do you remember AOL instant messenger and the dial-up sound like poltergeist? So leave a code on your best friend's beeper because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy,

blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude the 90s called on the iHeart radio app, Apple podcasts or wherever you get your podcasts. Hey, I'm Lance Bass host of the new iHeart podcast Frosted Tips with Lance Bass. The hardest thing can be knowing who to turn to

when questions arise or times get tough or you're at the end of the road. Ah, okay, I see what you're doing. Do you ever think to yourself, what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help.

This I promise you. Oh God. Seriously, I swear. And you won't have to send an SOS because I'll be there for you. Oh man. And so my husband, Michael. Um, hey, that's me.

Yep, we know that, Michael. And a different hot sexy teen crush boy bander each week to guide you through life step by step. Not another one. Kids, relationships, life in general can get messy. You may be thinking, this is the story of my life. Just stop now. If so, tell everybody, ya everybody

about my new podcast and make sure to listen so we'll never ever have to say bye, bye, bye. Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple podcast or wherever you listen to podcasts. No, that we should know, that we should know. So Darwin talked a lot about competition. That was one of the big keys to his theory working

is unfortunately in nature. It can't be like elementary school field day where everyone gets a participant ribbon. There's gonna be winners and losers and the winners will go on to survive and the losers might not. But where this wrinkle comes in is what you mentioned before the break, biological altruism.

It's remarkable that there are, and we'll talk about some of them, that there are species that don't even try to reproduce. So yeah, well there's members of certain species. So a really good example is the bee, right? A drone is a female. And a female that I think in some bee species are totally sterile.

So they can't reproduce anyway. But even if some of them could, they don't. Instead, they go out and collect honey or they collect the nectar, they make honey, they chew the pollen and spit it back up and then do that a bunch of times and all of a sudden you have honey, which as everybody knows is nothing but bee vomit.

Yeah, listen to our bee podcast, that was a good one. It was great. They tend to the offspring, the young, they bring food to the queen who is the only one to reproduce. Doesn't make any sense whatsoever, right? Yeah, they serve the queen. Because not only does that,

so there's two things at play here that make the whole thing weird. One, if an individual organism is basically here to pass along its genes, then why would any individual organism not attempt to do that, right? Yeah. And then secondly, and this is the real mystery,

how could these traits that the organism is driven by to be helpful and altruistic rather than be reproductive? How could that possibly be passed on from one generation to the next if that organism isn't passing that trait along? It's a big question mark, man. Well, it was and it's not proven,

but in the 1960s, there was a kid in school who would later go on to be a very famous evolutionary biologist, but he was a graduate student in the 60s named William Hamilton. Yeah. He said, you know what, I got this idea. It's called inclusive fitness or kin selection.

K-I-N, Jerry, selection. Not like a kindol. But kin selection, inclusive fitness. Basically, here's what's going on here. It's not random. When you see in nature this altruistic behavior of a part of a species, of a member of a family, helping, most times, they're helping their family.

Yeah, this is actually supported by some studies. Very famously, it was supported by a study of, well, a number of studies of Florida scrub jays, which are pretty little bluebirds. And some members of the Florida scrub jays species don't mate when it comes time to mate during mating season, right? Instead, they help gather food.

They help defend nests and protect the eggs. They help build, they're like, here, let me build you a little sex room, brother. Right, and, you know, here, I'm gonna put a tie on the nest. I'll bring some food later if you're tired. But you just go in there and do your business. Hugs, hugs brother deeply.

It's like the whole family's proud of you. Yeah, get in there. But I'm gonna go out here and not have sex. I'm just gonna stand guard and maybe listen. That's what the scrub jays do. Exactly, it's remarkable. So it doesn't make any sense, right? No.

It doesn't until you investigate it through the lens of kin selection. And so this one study in particular that followed scrub jays as they didn't mate and instead carried out this altruistic helping behavior, they found that of the 74 relationships that were observed, 48 assisted their parents. To family.

Gross, 16 helped their father. Again, Groty, seven assisted a brother, two assisted their mother, and then one, one out of all 74 helped a stranger. And you can imagine that bird was probably just a little dimwitted. Well, I was about to say, I bet it was confused maybe. Right.

And they thought like, you're my brother, right? Or the researchers were confused and didn't realize that this was their close kin. But the point is, is this altruistic behavior, this study supports the idea that the organism, the animal, the person, whoever is helping somebody related to them. And therefore it does make sense in evolution

because the person is helping ensure that some of their genes, not necessarily their specific genes that they are passing down through reproduction, but some of their genes through their direct blood relative, they're helping make sure that those get passed long and then altruism starts to make sense. It's amazing.

You wanna hear an evolutionary biologist joke about this? Yeah. I would gladly die for two brothers, or four cousins, or eight second cousins. Get it? It's pretty good. Yeah. That makes sense.

I read that and I thought, that kind of describes it perfectly. Well. And it's not very funny, because it's an evolutionary biology joke. That's right. But it does describe it. So this happened in the 1960s,

and like I said, Hamilton went on to write books and he actually came up with math that he says proves this to be the case. Yeah. Because he used letters instead of numbers so you know it's legit. It's actually a pretty smart little equation. It's called Hamilton's Rule.

I like it. You like it? Yeah. I mean, it makes sense. It's succinct. I can understand it. You can dance to it? I'm right.

It's got a good beat. I'm not threatened by it. So I like it. All right, well, should we talk about it? I know it's a little esoteric to talk about a math formula that is easier looked at. Well, just to close your eyes, everybody, and imagine this.

Okay. Well, in math terms, what we're talking about, it's an individual's relative genetic representation in the gene pool in the following generation. So if you literally look at it, it's B, the letter B greater than the letter C over R. Right. So in this case, the B is greater than,

so that's the benefit, which I guess would be the likelihood that their genes were passed down. Yeah. Okay, that would be the benefit. So the benefit is greater than the cost incurred by the person or the organism not reproducing divided by the relationship, right?

Yeah. So the closer you are, the likelier it is that you're going to enjoy a benefit over the cost. Yeah, there's a PhD online named Bjorn Bms, who is much smarter than me, because I had a little trouble wrapping my brain around, around how this math proves it.

And we'll get into the alternative theory here in a minute. Proves it over the alternative theory of group success. And he basically said the altruistic, the altruist act must be at least double the receiver's fitness in order for that altruist to gain representation in the next generation. Yeah, and it makes sense. So here's how it makes sense.

If you are going to have two kids. Yes. If you did reproduce and you were going to have two kids, but instead of having those two kids, you helped your brother and he was able to have three, there you go. Yeah. I saw Hamilton's rule expressed differently somewhere else and it made it easier for me to understand.

All right, let's hear your version. RB minus C is greater than zero. So if the relationship coefficient times the benefit minus the cost is greater than zero, then go for it says nature. Then it makes sense altruistically. All right, well, let's, my math brain hurts. So let's take a break and.

We even bragged about how we got that. I sort of get it. We'll take a break and talk more about some more animals who do this and the idea of group selection. On the podcast, Hey Dude the 90s called David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses

and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s. We lived it and now we're calling on all of our friends to come back and relive it. It's a podcast packed with interviews, co-stars, friends and nonstop references to the best decade ever.

Do you remember going to blockbuster? Do you remember Nintendo 64? Do you remember getting frosted tips? Was that a cereal? No, it was hair. Do you remember AOL instant messenger and the dial up sound like poltergeist? So leave a code on your best friend's beeper

because you'll want to be there when the nostalgia starts flowing. Each episode will rival the feeling of taking out the cartridge from your Game Boy, blowing on it and popping it back in as we take you back to the 90s. Listen to Hey Dude the 90s called on the iHeart radio app, Apple podcasts,

or wherever you get your podcasts. Hey, I'm Lance Bass, host of the new iHeart podcast, frosted tips with Lance Bass. The hardest thing can be knowing who to turn to when questions arise or times get tough or you're at the end of the road. Ah, okay, I see what you're doing. Do you ever think to yourself,

what advice would Lance Bass and my favorite boy bands give me in this situation? If you do, you've come to the right place because I'm here to help. This, I promise you. Oh, God. Seriously, I swear. And you won't have to send an SOS

because I'll be there for you. Oh, man. And so my husband, Michael. Um, hey, that's me. Yep, we know that Michael. And a different hot, sexy teen crush boy bander each week to guide you through life step by step. Oh, not another one.

Kids, relationships, life in general can get messy. You may be thinking, this is the story of my life. Just stop now. If so, tell everybody, yeah, everybody about my new podcast and make sure to listen so we'll never ever have to say bye, bye, bye. Listen to frosted tips with Lance Bass on the iHeart radio app, Apple podcasts,

or wherever you listen to podcasts. No, self you should know, self you should know. All right. So we mentioned the scrub J, the scrubby little scrub J who likes to build sex dungeons or his family. We talked about bees. There are also ants and wasps and other insects who serve the queen.

These workers, it's sort of like insect socialism almost. Working side by side for the benefit of the group. For get my own, yeah, for get my own reproduction. I want the colony to survive and this is my job. And so I'm gonna do it well. Another example is some animals have a call. They will signal out, hey, there's an intruder coming family for the house and I might be giving it my own life

by drawing attention to myself, but I'm still gonna do that. No, I actually did see an explanation for that that doesn't have to do with actual altruism or selection among meerkats. They have sentinels. Anytime a gang of meerkats is out hunting, one of them is just standing up,

looking very cute in all directions. They're the best. And when they see danger, they call out a warning to the rest of the group. But this one study that included like 2000 hours of watching and observing these meerkats found that not one sentinel was killed during this time. So what's your trick?

And as a matter of fact, they were the ones that get away first because they're the ones watching. So they see first and then they call, but it's actually that call is not much of a cost to the individual. Well, that's a meerkat. They're super smart.

What about the dumb squirrel? I don't know. I mean, maybe. Although meerkats do very famously engage in altruistic behavior themselves. Like meerkat pups can't feed themselves, but apparently they can squeal and beg. And most of the time they will be fed,

but the meerkat feeding them is not necessarily and in most cases isn't their biological parents. It's somebody else. And meerkats definitely have that whole village charades of child thing going on for sure. And it makes a lot of sense through kin selection and not in other ways. Interesting.

It's hard not to think of politics when you're reading this stuff in the animal world. For sure. Yeah. That's a good model for it. Well, it depends on what you think. Well, I mean, it's a good model to understand it, I should say.

Yeah. I saw, I had a, it was funny. I was driving home from the grocery store the other day and there was a major intersection near my house where the traffic lights were out. Like four four-way intersection and each one had their own turn lane. And it was rush hour.

And I just laughed looking around. Like the American political system was entirely represented. Oh yeah. Oh yeah, man. Some people just barreled through. Didn't care. Boo. Some people just wouldn't go.

They were just like frozen in fear. Some people are like, no, you go. Well, no, you go. Well, you go. And then someone behind him went honking. I was like, all right, I'll go. And you could just really kind of see everything. Just like it really opened my eyes.

Yeah. And I think I don't know what you would call me because I'm the by the book guy. Oh yeah. I'm like blinking yellow doesn't mean stop. It means proceed slowly, cautiously. Yeah. But one is red and one is yellow.

Everybody was stopping because it was just so crowded. Exactly, yeah. And there's definitely people who do see it the way you do. And then go ahead and do that. But it does seem like humans have recently decided like, no, if it's red blinking red and blinking yellow, the people with the yellow are going to stop eventually and let the people with the red go.

Altruistic act. Very interesting. All right, so let's, we teased group multi-level selection or group selection. This is something Darwin talked a little bit about in The Descent of Man, but his main focus was on the individual. But he dabbled in it.

He dabbled in group play. But this is a theory where there are these altruistic traits. No one's denying that. We see it all over the animal kingdom, but it's not necessarily toward a family. It's just for the good of the whole group. Yeah, so the whole idea of kin selection apparently has been challenged, although not widely challenged,

by the idea that if you really look at some species, the species that are closely related, some of them don't do anything altruistically. And then others that do engage in altruism don't necessarily do it for close relations. So if that's the case, then the whole idea of kin selection is challenged because the basis of kin selection

is that these are organisms helping to pass on some of their related traits that their relatives are passing along through reproduction. And if that's not the case, then that's the question mark returns. Well, yeah, and then there's the whole thing that there are in groups of animals. Some are related, some aren't.

So it's hard to tell where group behavior stops and family behavior begins. So you have a lot of biologists saying, this is just sort of semantical. We shouldn't be arguing about this. It's sort of their equivalent basically, helping the family is helping the group. Right, but then a few years back,

very famous ant man, E.O. Wilson, who actually awesome guy. Like as far as scientists go, this guy should have statues erected to him. He's a very brave scientist. He's known as the father of socio-biology. Right, he also, when he was a teenager, was the first to observe and study fire ants

when they just happened to be transported to South America from South America to New Orleans as ballast in a ship. He happened to notice them for the first time, fire ants in the Southeast Red Ants. Wow. He was there when they came about. Oh, they didn't originate here?

No, they were brought in scoops of dirt from South America. Crazy. He just took over, but he was a teenager and he was studying them. So he's a really great scientist, but he has attracted the ire of his fellow scientists by saying, kin selections bunk. Yeah, he reversed his position though, right?

Yeah, he was an early and long time champion of kin selection and he apparently changed his way of thinking and now says it's group selection instead. Yeah, in Richard Dawkins, we mentioned him earlier, he fired back at E.O. Wilson and was basically like, you know what, dude, you're wrong. I know you wrote a book about it, but he said there are quote pervasive theoretical errors

in your books, sir. And Wilson, is he still alive? I think he is, Dawkins isn't. Wilson's old though, because he was 85 when in 2011, so he'd be 90 now, right? He may be 11, I'm not sure if he's not, or if he is. Well, Dawkins is very famous for his freeloader effect too.

Yeah, as part of the selfish gene. And that's the problem, I think that's one of the reasons why E.O. Wilson has attracted so much ire from the scientific community because a lot of scientists built their careers on things like kin selection and explaining it. And they were doing so following in the wake of E.O. Wilson, who was a huge proselytizer for it.

And then all of a sudden, this prophet turns around on him toward the end of his life and after his own career, you know? Yeah. And a lot of people were ticked off by it, but it makes sense, the group selection doesn't. Basically it's saying, like you said, a lot of people are like, this is just semantics, we shouldn't be arguing about it.

But group selection says it's not the relatives that these organisms are looking out for, it's their group, it's their species. They're making sure their species continues along. And that's enough for an altruistic act to exist. Yeah. And so like I said, with all these other scientists that were upset by this, Dawkins is included.

And one reason Dawkins would be upset about that is because he wrote the selfish gene, which helps explain kin selection and altruism. And yeah, he was taking shots at E.O. Wilson in the press over the whole thing. Yeah, and his freeloader effect, which I mentioned a few minutes ago, was basically he said, you know what?

You get a, you call it a mutant freeloader. One of these freeloaders can take it down, take down this altruistic society or species, because they're just lazy and about, and they have more time to have sex and reproduce, and they can reproduce faster. So everyone else is out there working for everybody, altruistically, this freeloader is just having sex

and having babies. So that's gonna be the gene that gets carried down the most. Which, yeah, I guess that supports kin selection. I don't know. Not sure either. I don't have to read the selfish gene and find out. Yeah, I just thought it was interesting. Yeah, I do too.

But then also Chuck, with the whole idea as well, of whether kin selection or group selection explains anything. If you are helping somebody, if an organism helps a related or just a group organism reproduce, and that organism who gave up reproducing was gonna have two kids, but only helps that other organism have one,

then isn't that a net loss for the species or the family? Well, yeah, but I think that's what that math formula was all about, is it has to be double, or else it's not gonna keep happening. I got to. So I wonder then if there's been study that shows, yes, it's typically double. I think that's what he said, the math proved.

Huh, crazy stuff, biologists going nuts on one another. Yeah. And we're just sitting on the sidelines eating popcorn, talking about it. If you wanna know more about sociobiology and other stuff like that, including kin selection or group selection,

you can type in kin, K-I-N, into the search bar at howstuffworks.com, and it will bring up a pretty interesting article. Since I said kin, it's time for Listener Man. Uh, I'm gonna call this companion to the previous Listener Male Finland rules, and I'm gonna call this Sweden rules. Uh-oh, starting some static on more crazy Scandinavians.

Hey guys, longtime listener, just finished with Dark Money and wanna give you some insight about our socialist paradise of Sweden. Yes, we do pay quite a bit of tax. A regular Joe pays about 30% of his or her income as tax. If you earn more, you pay more tax. There's also a VAT tax on everything between 6%

on food to 25% on everything else. So yes, we never stop paying the man. So what do we get? Well, we're guaranteed healthcare. There's a small fee about $10 for a medical situation, but after that, it's all free. X-rays, cancer treatments, it's all free. Also, you can, if you have enough visits to the hospital,

I guess you get a punch card. You get a free card, which means you don't even have to pay that $10 or pay for medicine, sweet deal, he says. School is naturally totally free. We actually even get a salary for attending university. About $300 a month is a stipend, all for free. We can also take out a student loan

with very affordable payment plans that don't kick in until after you've graduated. Makes it common, that makes it so it's common for all people of all ages to go to university. And lastly, we have kids. When you have kids, the parents can take out 480 days of paid paternity leave. Oh yeah, the US is so far behind

other industrialized nations. Yeah, they're like two weeks and then good luck. Right, get back to work. And we need you responding to emails the whole time too. If they, I must say our company had a more generous leave than that, so I wasn't talking about us. Even for dads. Yeah.

If they take an equal amount, they get a bonus payment. After that, there's a system of kindergartens that takes care of the kids until they reach school age. Again, free. We do have some problems, of course. A lot of the healthcare has been privatized in recent years, which hasn't been all great. Also, there's a movement of xenophobia sweeping the nation

fueled by the terrible refugee situation in Europe. The third largest political party has its roots in far right, anti-democratic, even Nazi movements, is what he says. That's really surprising because usually they point to the rise of things like that as the result of economic woes. Yeah.

It doesn't sound like Sweden has too many economic woes. So, I mean, what accounts for that? I don't know. We'll have to ask for one. We need a follow-up. He says, on the whole, it's a great place to live. Thanks for the show. Edutainment at its very finest.

And that is from Guren Bextrum. Great name, GB. He said, if I can pronounce his name, I get a prize. Oh yeah. Guren Bextrum. He's gonna send you his thumb because you got it right. That'd be great. Thanks, Guren.

I'd like your other thumb. If you want to get in touch with us, you can tweet to us at SYSK Podcast. You can join us on facebook.com slash stuffyoushouldknow. You can send us an email to stuffpodcast.howstuffworks.com and as always join us at our home on the web, stuffyoushouldknow.com. For more on this and thousands of other topics,

visit howstuffworks.com. On the podcast, Hey Dude, the 90s called David Lasher and Christine Taylor, stars of the cult classic show, Hey Dude, bring you back to the days of slip dresses and choker necklaces. We're going to use Hey Dude as our jumping off point, but we are going to unpack and dive back into the decade of the 90s.

We lived it and now we're calling on all of our friends to come back and relive it. Listen to Hey Dude, the 90s called on the iHeart radio app, Apple Podcasts, or wherever you get your podcasts. Bye bye bye. Listen to Frosted Tips with Lance Bass on the iHeart radio app, Apple Podcasts,

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