Welcome to Stuff to Blow Your Mind from how Stuff Works dot com. Hey, welcome to Stuff to Blow your Mind. My name is Robert Lamb and my name is Julie Douglas. And uh, you know, guys, we have to have sponsors, and this episode is sponsored in part by the numbers seven. Big sponsors were really happy to have landed, uh, this particular number as a sponsor because it's, uh, it's pretty magical. It's a magical, mystical number that we see in nature,
we see in culture, it's everywhere. Um. In fact, you could say that the number seven is just one of the underpinnings that we use to piece together reality for us. Yeah, it's easy to think of numbers as completely arbitrary, especially as we take in the world around us and apply these different values to things. But in this episode, we're going to stop for a second and think, huh, maybe there maybe there is something to off this seven. Uh magic.
It's true because when you start to consider the number seven and it's relevance in society and again the way that we organized life, you begin to see a pattern. And so the question becomes it's just just our brain's pattern recognition sinery or is seven somehow just branded into our brains, and so we're gonna try to tease that out a little bit without starting any sort of seven
conspiracy theories. No. Yeah, we're not going to get into into numerology, and particularly in this sub podcast, or at least I'm not going to advocate it, but we will discuss a number of the things that do occur in sevens in nature, in culture, in history, and pop culture. Um where it's not gonna be a comprehensive list by any stretch of the imagination, but um, I think we're gonna fit a lot of stuff on there. Yeah, okay, well,
let's let's begin with nature. We've got those seven seas, the seven continents, the seven colors in a rainbow, that's right, Roy g. BIV. Seven colors. Most mammals have next with seven bones in them. If you look at the periodic table, what do you find? Number of rows is seven? True? The neutral pH value that lies between acidity and alkalinity is seven. And should we bet on seven? Seven? Seven? A good gambling number? It is? Yes, it turns out, you know it's a nine right to die? Nine, you know,
a bit too high, five, a bit too low. But seven just right, So it's kind of like the Goldilocks of numbers. Yes, you often here too, that by age seven, the blueprint for adulthood is in place, that a child personality is set in stone. In fact, there's a whole documentary series based on this idea, and the first episode in the series is called Seven Up. I don't know if you've seen this before, but it's a it's a series in the UK that follows these children at age
seven and then every seven years. Yeah I think, I I'm I'm not quite sure what age they go up to, but um, well into to the middle ages of these kids, and it's fascinating to see really how very little these kids have changed that truly by age seven there's something that is set with a personality. Not to be confused though, with the Seven Ups, the Roy Schneider follow up to the French Connection, different film entirely, or the Drink or
the Drink. Yes, um. Now, of course, when we start getting into culture, this is where the list really gets pretty expansive. So um, you'll have to stop me once I get going on this, but just to go back and forth a little bit there, of course, seven Holy Virtues and seven Deadly Sins. We talked about both of those in our Seven Deadly Sins, a series that we
did on the science behind each one. And of course there are seven virtues, and of course if you look back at religious texts, you will see that seven shows up quite a bit. It's a it's quite a fortuitous number. And if you look at of course the Bible, there is that God created the earth in seven days, right um. And then of course that has to do with their the way we arrange our week seven days a week, right, seven chakras, the yoga, which we also did a podcast
about a couple of podcasts. Actually, in the Islamic tradition there are seven heavens and seven earths, and the number of fires in Hell, and the numbers of doors to both the heaven and the hell is also seven. Yeah. Yeah. Various uh maps of hell include seven levels, some a little more, some a little less. Um. Among the Babylonians, Egyptians and other ancient people's there were thought to be seven planets. The Hebrew verb for swear means literally to
come under the influence of seven or beersheba um. Again, you said there's seven days in creation. Likewise, there are seven divisions of the Lord's prayer. The seventh son of a seventh son will often turn out to be what magical or Catholic or your boss? Right right? Is our boss the seventh son of a seventh son. I don't. I'm still thinking about the spare words, and now I'm beginning to think about George Carlin and his seven sware words that you cannot say on TV. There were seven
meals for Sister Sarah. If you want to go into uh, into movies, um, seven notes in the musical scale. In the Apocalypse, the Christian Apocalypse alone, we have seven chronicles of Asia, seven candlesticks, seven stars, seven trumpets, seven spirits before the throne of God's seven horns, seven vials, seven plagues, a seven headed nonster, a lamb was seven eyes because the Book of Revelation is is essentially one big death metal album cover. UM. In the Spanish myth and fable,
you have the island of seven Cities. So where seven bishops fled the moors in Spain to found these seven cities that supposedly existed, I mean not really, it's smith uh. Seven gifts of the spirit. In Japanese folklore, there are seven gods of luck uh, seven Hills of Rome, seven
Joys of Mary, seven sacraments uh. Seven senses is interesting an ancient notion that the soul of man is comprised of seven properties under the influence of again those seven planets that we mentioned, and likewise, the dark lord Voldemort divided his soul into seven hore cruxes. You might remember that part um. There are seven Abdal, the Sumerian guardian water spirits who were kind of like Merman. Seven Naga
are often seen behind Buddha or the same with Shisha. Uh. Do you see this in very like Hindu and time is the serpent like creature? Yeah, especially entire They're crazy cool because it's like a serpent, and then it's kind of a serpent coming out of its head and out of its head, really beautiful, often golden in appearance. Seven dwarves uh. Seven Samurai, seven brides for seven brothers. There was a seven year itch. There are seven Narnia books House of the Seven Gables. Uh. There were a seven
headed demonic giant in Armenian folklore. Um. Oh what else do I have on this list? I think there was? Oh, well, I had to eventually just stop because it just it just kept kept going and going. Yeah, but that's all all I'm gonna get into right now. Well, of course, and that makes me think about why we put so much importance on the number seven, because it pops up everywhere and you begin to ascribe luck to it, fortitude
to it, and uh. In fact, I was thinking about when you're in Las Vegas, or really any casino for that matter, the winning number, of course is seven, triple seven. That is what is going to make the coins ring into your po But here's the thing. Before you start brushing your teeth seven times, are stirring your coffee seven times in a ritual way to to invoke the gods of luck, just consider that this is cultural and it doesn't necessarily mean in every culture that it is a
good sign of things to come. Yeah, A lot of it comes down to how we are this with these natural number crunchers. We're always trying to define meaning in the world around and when we've talked about this a lot in the past and about how this can bleed over into various supernatural beliefs and supernatural understandings of the world as we try to use our pattern recognizing minds just chew up all the data, and so we have all of the sense data around us, and then we
we put all this culture over everything. We apply various numbers to everything, and so it follows that we're going to end up attaching varying degrees of meaning to different things that occur in different numbers. Well in seven too. It's just something that I think shows up UM in different types of media too, because linguistically, it is the only single digit with two syllables, right, so it just
kind of falls off the tongue more smoothly. So you have uh snow white, and the seven dwarves snow white, and the five dwarves snow in the six doors it doesn't work as well, or the five samurai, the eight samurai, it doesn't really well. The seven summari. There's a pleasure in saying it's You get into that a lot too. With we're talking about this yesterday, particularly in China, there's a lot of influence um. Particularly in China. There's a
lot of emphasis on what a number sounds like. So like the number four, its like the word for death, and uh and therefore is to be avoided. Right, So there is a good measure of magical thinking going on here when we talk about in number, and maybe in the English language, seven sounds like the word happened heaven. There was even a show about the seventh Heaven, which
was I think, just all about numerology. All right, okay, all right, we are going to take a quick break, but when we get back, we're going to see if this whole idea of the number seven is being this mystical, magical number is somehow a lot into our brains. There's some sort of secret there about why we heard it
so much. So we're back, we're talking about the number seven, what it means to us, and we've mostly just rattled through various um cultural, historical, geographic, a little science, a little what have you there, all the different things that we attached seven to and why we think it's a pretty cool number. But is there more to that? Is there something? Is there something going on inside the human
mind that's deeper than that. Well, so there's this idea that when it comes to remembering numbers rattling them back out again, we basically have a seven limit on that, give or take it to and certainly there are individuals without standing limits to that who can rattle off, you know, pie to the ode of the ridiculous degree um sixty seven thousand, nine digit if you're chow Lou, who holds
again as world record for a citing pie. But for the most part we're hitting significantly lower than that um. And you know, if you think of anything like your social Security number or your phone number, it is worth noting that you will remember you maybe remembering a digit, a number longer than seven, but you're remembering it generally
like three different numbers. Yeah. I was gonna point out a little interesting anecdote here, and uh, this is our video producer and editor Tyler Or was telling me that when he memorized pie in school, that he did it in chunks of seven. Interesting. So again it places this idea of anything you you can memorize, but these chunks of seven sort of like when we talked about um the rooms, the memory recall rooms that we create in
our mind. It's that same sort of idea where if you can just make this definitive chunk, then you can recall it a lot better. And this is an idea that George Miller had. Yes, he wrote this excellent, at times very confusing paper. I find it's not it's not necessarily you know, it's not like straight up something you know, something you would find on a Twitter feed and go and just you know, consume it over lunch. And he
gets a little heady and a little mathematical. I mean, it's awesome, but it's a you can get lost in it a bit or I can. Uh. The title of the article is the magical number seven plus or minus two colon some limits on our capacity for processing information. And in this uh, he starts off by pointing out that there is a clear and definite limit to the accuracy with which we can identify absolutely the magnitude of you need dimensional stimulus variable. Uh. There's a span of
absolute judgment. And part of that is that there is a uh, that there is a finite s fan of immediate memory, and that for a lot of different kinds of test materials, this span is about seven items in length. All right, so we've already hit this seven items I can remember. I mean I have trouble remembering like three things if I need to pick them up at the grocery store, but ideally I should be able to remember seven. Right,
if you had to really sit there and concentrate. You could do it, and we'll get into why you can
concentrate for such a limited amount of time. But before we do that, I just wanted to mention that if you look at memory as this kind of house of memory, you see that on one side you have, you know, long term memory, which is like a library, which a bunch of with a bunch of books of your memories that you can recall whenever you want, right, just slip them off, Michelle, look up what you want, right, Yeah,
change them and then put them back right. Long term memory, but a short term memory is more like a white board where you kind of have a cheat sheet to keep up with the conversation or to remember directions, and so it's just kind of there to help you create
some sort of association with what the present topic is. Right, So if you look at someone like Mikhail Rabinovich and his uh research into neural pathways, you begin to see this idea that seven bears out just in the way that we have um our neural pathways paved for us and the limits really of our processing when we're working
with that white board, that working memory. Yes, he was one of the others on this paper that presented a mathematical picture of how neurons fire when we recall a sequence of steps, and one of the examples used here is is that it's like running across a tight rope walker not even a walker, because a walker can take his time and go back and forth between the World Trade Center buildings. But but this is the idea that that you you do not have that ability, you don't
have the big poll. What can you do? You just have to sort of speed up and go with it. How long can you go across that trip wire without falling off? Yeah? And that trip wire is that neural pathway, right, And what Rabinovitch discovered is that when a person recites a sentence or a list, you can actually see an excited cluster of neurons fire for each word. And then these excited clusters create a pathway okay, that that tight rope pathway, and at the same time they tamp down
any other competing neurons. Okay, So the competing neurons are really like any other memories or any other thoughts that you might be having at the same time. Okay, which is really important. When I was saying earlier that you could really do it if you're concentrated, you can recall a certain things. That's what we're talking about. This, these
excited clusters telling everybody to step off, right. So the longer the sentence or the string of numbers you try to recall, the harder it is for those excited cluster of neurons to suppress the others from firing. And then the weaker the pathway, and then the lousier your your memory. So really, what you're seeing here again as a mathematical model, as you say, a picture of the seven idea at
play in your brain. Yeah, this is really interesting and it ties right back into what I was talking about, remembering three things to pick up at the grocery versions remembering seven and uh. As they point out in this article, recalling seven items requires about fifteen times the suppression needed to recall three. And suppression again, like you say, forcing all the other thoughts and competing thoughts out of your
head so that you can remember things. Ten more items requires fifty times to strength, and twenty or more items requires uh, hundreds of times to strength. So even in the jump from three items to seven items, you see this this pretty big jump in the the the amount of memory. You're gonna have to throw it at the amount there the cognitive load and the cognitive ramifications of trying to remember things well, and it's interesting to put
a number on that cognitive load. We've talked about that a lot of times when we're talking about free will or well. One of the studies we looked at actually involved individuals having to remember a number and then they were introduced to the temptation of chocolate cake. And the individuals who had to hold the longer number in their in their head, which as I recall, was somewhere in the in the neighborhood of seven or eight digits, they had a harder time remembering it if they were introduced
with this to this cake temptation. What I think it's so interesting is I wonder if those neurons that are firing those competing ones are like chocolate cake, chocolate cake, chocolate cake, like the literally thing that to the excited
cluster that's trying to recall the actual string of numbers. Yeah, every time this is probably horrible, But every time I think about this about like our limits on remembering numbers, I think of the movie Running Man, because there was the you know, the old Arnold source because there was a scene in that where the good guys had to remember some sort of code and then input it, and
it was a pretty long code. But they had one character that's supposed to be a math whiz or something I guess, and it was able to hold all these numbers in his head. But I always found that that part kind of terrifying because I'm like, oh, my goodness, numbers so long, how can anybody remember it? Now, if certain certain types of autism will actually allow for people to have stronger pathways and recall a greater number of numbers, and then just some people in general can can sort
of break that seven rule. Yeah, And certainly if you if you bust out the memory palace on it, then then you can really go far with it. Right Again, there's that idea of storing seven, you know, having a chunk of seven and storing maybe five chunks of seven so that you can really roll out an impressive amount of items. UM. Now, I wanted to also mention this really cool study about neurons and dendrites UM. And I do want to say that it doesn't mean that you know,
the brain is um. The brain especially loves the number seven. But it it does kind of give you pause for thought, because researchers Miliori, Novora and Togola published a two thousand and eight study on neuros and the hippocampus that, of course, this is the memory input unit of the brain. The study showed that neurons produced the best information when they're dendrites, the branches of a neuron that receives stimulation, when those
branches numbered seven. So again, here's this idea that this uh sort of recall fitness has a limit, has a limit within the neuron structure itself, within the pathway that these neurons create, and then within our own ability to recall information. And of course that brings up this crazy idea of well, if we keep ordering the world in sevens, you know, is it the tail wagging the dog? Is that because that's the way our brains are constructed? Do we end up falling into the trap of seven rather
than actually applying it logically? Yeah? Is it more to it than just you know, a linguistic lovely sound of seven? Ye, let's say, Oh, it's because our brains have a constraint on them. You know, I can't help but think that seven also appeals to us in numbering things because seven, being an odd number, you have that you have that room for one of the digits to be a leader,
you know, I guess you know. You have it in five as well, you have it in nine, but it seems most clear in seven because you have I can easily picture seven dudes. You have the one dude in the middle, and he's flanked by three on each side, but you have one that stands out. Or if it's a body of seven voting on something, then you have room for there to be a clear majority pretty easily. Well, there's a certain kind of natural symmetry to it. Yeah,
it's a very symmetrical number. You can just picture it there on a movie poster. And esthetically too, it's it's better to have seven objects displayed than yeah, six. Yeah, And and then the numeral is pretty, uh, pretty sexy too. You know. It looks kind of like a like a weapon, like we're like a hockey stick, you know. Yeah, I don't know. I feel a little bit weird about saying yeah, it's got a long neck. I mean, like, now I'm
getting into some weird territory here. Probably, So I like it because I can seven is an odd number, but eventually if I do another seven to it's even number. I don't know if anybody has this sort of particular numbers obsession. Wait wait, so break this down for us again, your number of obsession. How it works? Well I did. I like even numbers, and I like getting to even numbers.
So you know, I could be sitting there in a conversation counting letters, or in a sentence, or if there's a sign nearby, and if it ends in an odd number, it's uh disconcerting to me. Well, I'd say you have to keep counting. I'm not a big fan of one because one is the loneliest number to um, yeah, I'm I'm okay. To two is a good number. I guess three, three is three is nice because three is like a three is that? You know, you're a nice odd number.
It's a trinity. Uh. Four, you got the four Horsemen of the Apocalypse, So that's pretty good. I like that, yeah, for in in Chinese death right, Yeah, so that's kind of it's got, you know, some sort of death metal vibe to it, which is nice. Uh. Five, you know the five Wounds of Christ. So I kind of like that. It's nice and grizzly, exactly what I thought of. Yeah. Six unholy numbers, so you gotta love that. Um. Seven, as we've been discussing here, lots of great things going
for that. Eight you turn it on its side, it's infinity, so nice like that. Nine we have the nine Rings of Power from Lord of the Rings, the Nine Ring Ray. It's it's off the jokes store because it can flip upside down and be a six. That's right, and it's a it's also a trinity of trinities, so it's got that going for it. And ten, I don't know, I kind of lose interest at ten. Well, you know, now you've gone into double digits. Yeah. Um, I would really
love to hear from from you guys out there. Do you have a certain sort of number that you really liked? You have some number obsession going on? And seven? Do you if you have a particular feeling for it. Do you think there's something to this the way that our minds were constructed, in the way that we paint reality with it. Yeah, I think about it and think about it the next time you're walking, uh walking through your video store. If you still go to those and you
should because they won't be around for long. You should appreciate him while you have them. Check out the titles. Notice the ones that have seven in the number in the title. Those the ones that have six that have three? Like, how does it? How does it affect you? Like? What is the like instant cognitive impact of that title? Uh? You know? Likewise look at I think the same thing at a bookstore or library while those exist. Indeed, Yeah,
so we'd love to hear from you on that. Well, let's let's call over the robot and do it just a quick bit of listener mail, because I think he may have something that relates to this. All right, here's one that comes to us from Aaron Erin, writs In and says, Hi, Julian Robert, I'm a bit behind at times. I am commenting on episodes you did a year ago, but you'll have to forgive me. I've spent the last year as a Peace Corps volunteer in a rural village
in West Africa. I recently finished listening to your episodes on the seven Deadly Since and was especially intrigued by the episode on Gluttony. My fellow volunteers and I live mostly in in small rural villages without access to markets or food other than what has grown on the desert like village land or brought in from a large town.
Each week, we eat with our host families out of out of communal bowls, and while we usually get just enough calories consumed, it's not the food that we are used to in the United States, and it's not high nutritional value. I think lots of porridge, white rice in oil. So when I go into the cities and meet up with my friends, we binge as a recovering health nut. My sister calls my diet reindeer food. I never out
I was capable of that kind of eating. For example, I had an entire jar of nutella in one setting, remarkably easy to do um, something I wouldn't even touch a year ago. My father recently referred to me as as a sumo wrestler during one of my of the many buffets we enjoyed. On implication, I began to call us opportunistic bingers. Here's a nice way of avoiding the word glutton us. Our circumstances that have definitely turned on some evolutionary need may be triggered by being denied what
we are used to eating. I think this is true not only of gluttony, but other sins as well. Lust, wrath, sloth, and pride have emerged in our lives far more than ever before because of living in a completely different culture or and living in a completely different lifestyle. This sounds blasphemous, and I mean no disrespect to any religion or to
me uh and other volunteers. But maybe we feel a need to be more gluttonous, lustful, wrathful, slothful, and prideful if we are going to maintain our sense of identity in this new and challenging place. Or maybe we're simply more aware of those tendencies here. Sometimes it feels like we haven't changed, We're just using more of the potential of our personalities, both for the worse and for the better.
So back to glightening. While most of us are not dieting, our minds and bodies are rebelling, subconsciously demanding the food we are not providing. Meanwhile, my host family and my village is not very interested in the foods I make, and they are perfectly satisfied and happy with the food they're used to. It makes me wonder if it was better to have loved than lost the variety and plethora of food in the US than to never have loved
it at all. Does the loss of what we once had make us more sinful in trying to fill the void? Two very big hips in a hurrah for opportunistic eaters everywhere. Thanks for the awesome science and stories you keep me entertained and sane during long, hot days in a foreign land. I make connections between the lives of people here in my village and the science you unveil every day, and I feel more informed and at peace because of it. You help me understand this crazy world within the world
erin Wow. So that's really interesting. I keep thinking about to one of the studies that talked about when you lose something like of your weight, that you really your body sort of rewires itself to crave fatty foods, to want to regain that weight because it thinks that there's something wrong, and it makes it incredibly hard to maintain
that weight. In fact, for someone who is a similar weight but has not lost it, um you have to expand many more calories exercising to maintain than that other person such as your your body trying to make up for this loss. Yeah, indeed, Yeah, I thought that was a great email. I really enjoyed a particularly by the way, you know, Aaron was sort of extrapolating this to the other um sins that that we discussed as well. Yeah. No,
I mean it's a very interesting perspective to take. I can't help the of course, thinking about how your body is sort of gaining the gaming, the gluttony part of it, yea. Um. But there's a lot to think about two in terms of maintaining identity. Yeah. Yeah, So Aaron, Uh, first of all, thanks for the great work you're doing out there, and thanks for writing in and sharing your thoughts with us. The rest of you can do the same. Uh. There are numerous ways to get in touch with us, uh
and find out what we're up to. The big one, of course, is go to Stuff to Blow your mind dot com. That's the mothership. That's where all of our stuff winds up in some form or another and links to everything else we're in. It's the center of the spider's web, and uh, I guess that makes us spiders, but you cannot. You can also find us on elsewhere in the web. On Facebook, we are Stuff to Blow your Mind. You can find us on Twitter where we
are blow the Mind. We have a tumbler account we are stuff to Blow your Mind on that as well, and if you head on over to YouTube you will find our account at mind stuff Show. That's right, you'll see puppets of us talking in video about science. Really now, it wouldn't be nice. I just got excited. Maybe soon we can that's that's on the table. We could do that. If you think we should do that, let us know. Yeah, do you want to see puppets of us interacting and
us doing some freaky voices? Can build those puppets also, that would be also, I would also be heppy. Please do drop us a line there and let us know about your thoughts on the number seven about puppets and everything else that you can think of. Um, you can do so at blow the Mind at discovery dot com for more on this and thousands of other topics. Does it how stuff works dot com
