Speaker 1: Welcome to Stuff to Blow Your Mind production of iHeartRadio.
Speaker 2: Hey, welcome to Stuff to Blow Your Mind.
Speaker 3: My name is Robert Lamb and I am Joe McCormick,
Speaker 3: and we are back for the third and final part
Speaker 3: in our series on the psychology and cultural significance of
Speaker 3: number parity pr it y paroity referring to whether a
Speaker 3: number is even or odd, and we are ending it
Speaker 3: with an odd number of episodes that just felt right now.
Speaker 3: If you haven't heard the other parts in this series,
Speaker 3: you might want to go back and listen to those first.
Speaker 3: But in part one we talked about the mathematical principle
Speaker 3: of number parity, as well as some evidence that people,
Speaker 3: if given the opportunity, will sometimes project associations and emotions
Speaker 3: onto even and odd numbers, for example by maybe feeling
Speaker 3: more positivity towards even numbers on average, or by having
Speaker 3: an esthetic preference for odd numbers in visual art, as
Speaker 3: reflected in the conventional rule of thirds and rule of
Speaker 3: odds in art theory, which we discussed in some detail
Speaker 3: in that episode. But then we also brought in some
Speaker 3: questions and counter evidence about the real world validity and
Speaker 3: alleged universality of these preferences for odds in art. In
Speaker 3: part two of the series, we talked about a research
Speaker 3: paper on the cognitive psychology of number parity, which advanced
Speaker 3: what I thought was a really interesting argument that despite
Speaker 3: the fact that all positive integers are mathematically defined as
Speaker 3: simply odd or even and nothing in between, our brains
Speaker 3: may in practice treat some numbers as more even or
Speaker 3: more odd than others, mentally transforming these definitionally discrete categories
Speaker 3: into a semi smooth gradient. And this could be due
Speaker 3: to multiple factors, involving mathematical properties like the ease of divisibility,
Speaker 3: and also linguistic properties how easily we process different words
Speaker 3: and their associated concepts. We also talk some more about
Speaker 3: even and odd groupings in visual art, specifically in religious
Speaker 3: images such as that of the ten headed demon king
Speaker 3: Ravna in Hindu mythology, and we also talked about preferences
Speaker 3: for even or odd groupings on food plates. I think
Speaker 3: the conventional wisdom favors odd numbers of food items, but
Speaker 3: the research maybe paints a slightly more complicated picture.
Speaker 2: Yeah, I think in either case, like what does a
Speaker 2: plate of food and the multi headed incarnation of a
Speaker 2: Hindu God, what do they have in common? It's that
Speaker 2: there are other things involved in and how you're ultimately
Speaker 2: going to perceive this image. Either religious iconography is going
Speaker 2: to be trying to relate other concepts to you the viewer,
Speaker 2: the intended audience viewer, and the food imagery is of
Speaker 2: course showing you something that on some level at least
Speaker 2: you want to eat.
Speaker 3: Yeah, exactly. So we're here today to finish off this
Speaker 3: series with a few more things about odd and even topics.
Speaker 3: So I just wanted to mention at the top of
Speaker 3: the episode here a few more interesting ideas I came
Speaker 3: across while reading about evens and odds. Previously, we talked
Speaker 3: about some evidence that, at least in certain contexts, people
Speaker 3: like some numbers more than others. For example, they may
Speaker 3: have more positive emotional feelings about even numbers, or at
Speaker 3: least about numbers that are easily divisible, because one of
Speaker 3: the studies we talked about in part one apparently found
Speaker 3: that people had more positive feelings toward even numbers and
Speaker 3: numbers divisible by five. Coming back to the question of
Speaker 3: certain numbers feeling more even or less odd than they
Speaker 3: really are. So a great example is that twenty five
Speaker 3: is an odd number, but why does it feel like
Speaker 3: an even number to me? I would say the ease
Speaker 3: of divisibility by the sub base of five is a
Speaker 3: pretty good guess. And this sort of brings me back
Speaker 3: to idea I first encountered in a couple of the
Speaker 3: articles that we were talking about in part one by
Speaker 3: a British author named Alex Bellows who writes newspaper columns
Speaker 3: about mathematics and puzzles sometimes, but it also written a
Speaker 3: book addressing some of these topics. And in these articles
Speaker 3: he talked about people's feelings about odd and even numbers,
Speaker 3: and the idea he raises that if it's true that
Speaker 3: people sometimes feel better about even numbers than odd ones,
Speaker 3: what if that sense of liking for even numbers is
Speaker 3: related to the concept of processing fluency. Now, this is
Speaker 3: a psychological concept that has come up on the show before.
Speaker 3: The gist of the idea is that a lot of
Speaker 3: the judgments that humans make, from whether we like something
Speaker 3: to whether we trust a piece of information or believe
Speaker 3: something is true, a lot of these judgments are influenced
Speaker 3: by our subconscious reaction to how easy it is for
Speaker 3: us to mint process the stimulus in question. There are
Speaker 3: a lot of studies looking at this. I remember this
Speaker 3: came up when we were discussing the illusory truth effect,
Speaker 3: the idea that if a claim a claim may have
Speaker 3: no real evidence for it, or you may have no
Speaker 3: particular reason for believing a claim is true, but if
Speaker 3: you hear it repeated a bunch of times, it starts
Speaker 3: to feel more and more true to you. And one
Speaker 3: of the popular explanations for this effect is the idea
Speaker 3: that hearing a hearing a claim on subsequent exposures increases
Speaker 3: its processing fluency because it's more familiar to you. You've
Speaker 3: heard it before, so it's easier to take in the second, third, fourth,
Speaker 3: fifth time you hear it, and thus it because it
Speaker 3: has increased processing fluency, it just feels more right. It
Speaker 3: feels more true. One of the key findings that already
Speaker 3: came up in some of the papers we talked about
Speaker 3: in Part two is that it seems even numbers are
Speaker 3: on average more easily processed than odd numbers are. You know,
Speaker 3: when it's easier to think about even numbers, we can
Speaker 3: more quickly classify them mathematically as even numbers. It's easier
Speaker 3: to think about doing mathematical operations with them. Odd numbers
Speaker 3: are just they're introducing friction to your brain when you
Speaker 3: have to consider them. And if this is the case,
Speaker 3: it could be a major contributor to these particular situations
Speaker 3: where people seem to like even numbers better than odd numbers.
Speaker 3: But of course we don't always like even numbers better
Speaker 3: than odd numbers. And this comes back to the issues
Speaker 3: of these additional bits of context and cultural associations we
Speaker 3: happen to pin onto these numbers, and whether at the
Speaker 3: time of us having a feeling about a number or
Speaker 3: making a judgment about it, these other associations become salient.
Speaker 3: So anyway, that brings me to another line of research
Speaker 3: that I stumbled across when looking into this, that I
Speaker 3: thought was curious and sort of funny also, which is
Speaker 3: the apparent asociation between number parity and the social concept
Speaker 3: of gender. Now, in much the same way, it seems
Speaker 3: absurd that without any context, in other words, without quantifying
Speaker 3: anything in particular, specific numbers whatever feel good or bad
Speaker 3: to people. It also seems kind of absurd that anyone
Speaker 3: would think of standard Arabic numerals as masculine or feminine.
Speaker 3: But there are some experiments in which researchers claim to
Speaker 3: have found that in some contexts, there is a pattern
Speaker 3: of gendered associations between odd and even numbers that emerge.
Speaker 2: This is interesting because I was thinking about gendered numbers
Speaker 2: earlier in the research process for this series, because I
Speaker 2: ran across an interesting skit about the number one on
Speaker 2: Sesame Street.
Speaker 3: Oh care to elaborate?
Speaker 2: Oh sure, sure, So in this sketch this is from
Speaker 2: nineteen ninety seven, so this is not one that I
Speaker 2: was originally exposed to as a kid. But we have
Speaker 2: number one, which is of course or some muppet. It
Speaker 2: is the numeral one, and it is a she. So
Speaker 2: then the number one. She is feeling really down about
Speaker 2: herself because she is such a low value number, like
Speaker 2: you know, it's just she's it's one and then zero,
Speaker 2: like all the other numbers are are are more potent
Speaker 2: than her, more important than her, and she feels she's
Speaker 2: really feeling down in the dumps about it. Well, who
Speaker 2: comes up to cheer her up? But the count? Oh,
Speaker 2: and the count proceeds to sing an entire song for
Speaker 2: her about how important she is numerically, and then afterwards
Speaker 2: he's like, do you feel better? And she's like well
Speaker 2: a little bit, and he says, well, I'm going to
Speaker 2: sing it for you one more time. But it made
Speaker 2: got me thinking. It's like, well, you know, I didn't
Speaker 2: think about one being male female, what have you. I
Speaker 2: didn't think about the ginger of the number one. I
Speaker 2: just considered it like a number. But now I'm thinking
Speaker 2: of it. I just can't help but picture it with
Speaker 2: like the big full lip and the beauty mark here
Speaker 2: from this nineteen ninety seven Sesame Street sketch.
Speaker 3: Well, that is adorable. I like the Count. I hope
Speaker 3: that the Count can help any number feel better about itself.
Speaker 3: All numbers are important, but one is really special.
Speaker 2: Yeah. I think the Count is going to be the
Speaker 2: biggest fan, the biggest supporter of any number. He's not
Speaker 2: going to pull a Harry Neilson and talk about how
Speaker 2: crappy the number one is and how number two is
Speaker 2: also no good. He's a big fan of all of them.
Speaker 3: I like knowing you can count on the Count for
Speaker 3: emotional support. So anyway to mention a couple of these
Speaker 3: studies apparently finding this association between gender and number parody,
Speaker 3: A couple of the ones I came across were by
Speaker 3: a pair of researchers named Wilkie and Bodenhausen. One of
Speaker 3: these papers was from twenty twelve in the Journal of
Speaker 3: Experimental Psychology, another one by the same authors from twenty
Speaker 3: fifteen in Frontiers in Psychology, and these papers publish the
Speaker 3: results of a number of different experiments about the gender
Speaker 3: associations of odd and even numbers. Now, some of these
Speaker 3: experiments involved explicit judgments, just asking people straight up whether
Speaker 3: they felt like specific numbers were more masculine or feminine,
Speaker 3: and other experiments looked for indirect associations, like people's tendency
Speaker 3: to interpret the faces of babies or unfamiliar foreign names
Speaker 3: with different genders when they were labeled with different numbers.
Speaker 3: And to note that this indirect measure here does rely
Speaker 3: on implicit association tests, which have been subjected to various
Speaker 3: methodological critiques over the years. They've undergone some refinements over
Speaker 3: time to try to improve reliability, but there's still sort
Speaker 3: of debates about how they can be depended on and
Speaker 3: in what context. So anyway, caution on relying too much
Speaker 3: on the implicit parts of these findings, But the authors
Speaker 3: say from the totality of their experiments that on average,
Speaker 3: for some reason, people from sample groups within the United
Speaker 3: States are more likely to say that odd numbers are
Speaker 3: masculine and even numbers are feminine. And while that's the
Speaker 3: general trend, there are some exceptions and caveats. While they
Speaker 3: say that this pattern was on average true for everyone,
Speaker 3: the association was stronger among women, So on average, women
Speaker 3: were more likely to view odd numbers as more masculine
Speaker 3: and less feminine than even numbers. Weirdly, this is where
Speaker 3: it starts getting funny. I thought the numbers in when
Speaker 3: the numbers involved were two digit instead of one digit,
Speaker 3: men started to drift away from this parody association and
Speaker 3: started to say that all numbers were masculine, regardless of parity.
Speaker 3: So I don't whenever we look at studies like this.
Speaker 3: By the way, I always like raise caution because I
Speaker 3: just know from experience a lot of people get real
Speaker 3: excited about like gender differences in responses to psychological experiments
Speaker 3: and then start overinterpreting, thinking it explains everything about men
Speaker 3: and women. You know why my husband or my wife
Speaker 3: acts a certain way, et cetera. And so I will
Speaker 3: raise the same caution here. You know, it's just a
Speaker 3: few experiments we're not sure if this is a super
Speaker 3: robust finding, and even if it is robust, it's easy
Speaker 3: to get carried away just reading too much into little
Speaker 3: psychological quirks like this. However, I could not resist finding
Speaker 3: it hilarious to imagine a guy looking at numbers higher
Speaker 3: than nine and being like, thirty four. Huh, that's a
Speaker 3: big number. That's a macho man.
Speaker 2: In between thoughts about ancient real right.
Speaker 3: Yeah, so in reality it's probably not that simple, but
Speaker 3: I was laughing for several minutes after I read this. Anyway,
Speaker 3: the authors of these studies, so they're making an argument
Speaker 3: not that there actually is something objectively or universally gendered
Speaker 3: about even and odd numbers, and instead they're sort of
Speaker 3: making a case about what they call quote the pervasiveness
Speaker 3: of gender as a social scaffolding for generating understandings of
Speaker 3: abstract concept. So the way I take that is they're
Speaker 3: sort of saying gender is such an important concept to
Speaker 3: people that we subconsciously apply it to categories of objects
Speaker 3: that have nothing to do with the primary understanding of
Speaker 3: masculinity or femininity. It's just like a major way of
Speaker 3: making category distinctions that the brain kind of defaults to
Speaker 3: even in situations that don't have anything to do with
Speaker 3: biological sex or with the social roles of gender.
Speaker 2: Right right, So yeah, it wouldn't be like the hypothetical
Speaker 2: male in question is making a conscious effort to think
Speaker 2: about all higher numbers as men. It's a little more nuance,
Speaker 2: a little more subconscious than that.
Speaker 3: Now I mentioned that those studies were done on us
Speaker 3: test subjects. I came across an interesting variation with respect
Speaker 3: to culture. So there was a twenty twenty one study
Speaker 3: in Frontiers and Psychology by Jordan Yakani and Sheen which
Speaker 3: found some consistency and some variation across cultures regarding the
Speaker 3: perceived gender of numbers. These researchers tested whether the same
Speaker 3: patterns of association between number parity and gender would show
Speaker 3: up among Arabic speaking people native to the UAE, and
Speaker 3: their top level findings were that there were patterns of
Speaker 3: gender association with number parity, but on the implicit association
Speaker 3: of numbers with faces. The subjects in the UAE were
Speaker 3: more likely to associate even numbers with their own gender,
Speaker 3: whichever that was so, men seeing even numbers as more masculine,
Speaker 3: women seeing even numbers as more feminine, and these findings
Speaker 3: indicate that it may be cross culturally common to associate
Speaker 3: even in odd numbers with gender, at least in some
Speaker 3: weekly held way, to make some kind of weak association
Speaker 3: of that kind, but that the association can vary from
Speaker 3: culture to culture, which actually makes a lot of sense
Speaker 3: to me that I think the idea would sort of
Speaker 3: be that gender is a category lens that we're very
Speaker 3: quick to apply to all kinds of phenomena outside of
Speaker 3: its primary cultural meaning. But exactly how we apply it
Speaker 3: probably depends on a lot of subtle influences that can
Speaker 3: easily vary person to person and culture to culture, though
Speaker 3: apparently within a given language culture, one way of making
Speaker 3: the association is probably more common than another. So anyway,
Speaker 3: all the warnings I gave up top about not reading
Speaker 3: too much into these kinds of findings, but I do
Speaker 3: think if this is basically on the right track, it's
Speaker 3: an interesting example of the way that we just kind
Speaker 3: of recklessly apply category distinctions across every domain of life,
Speaker 3: whether it really makes direct sense or not. You know,
Speaker 3: I think we if we ever talked about the idea
Speaker 3: on the show before. Some people seem to think like
Speaker 3: dogs or boys, cats or girls.
Speaker 2: Yeah, I have caught myself following into that trap as well,
Speaker 2: Like I kind of on a default lene assume cats
Speaker 2: or girls and dogs are boys until I know differently
Speaker 2: concerning individual cats and dogs, And I don't know. One
Speaker 2: reason for that is probably that I've only ever had cats,
Speaker 2: and those cats have always been girls. I don't know, yeah,
Speaker 2: female cats. Sorry, some of them have been very old ladies.
Speaker 3: Then again, at least cats and dogs are like animals,
Speaker 3: you know. It's I guess it's even funnier thinking about
Speaker 3: the way that we we just wantonly apply these categories,
Speaker 3: possibly even to things like abstract numbers and uh, symbols
Speaker 3: that that don't even have like, you know, bodies or
Speaker 3: minds or anything.
Speaker 2: Yeah. The only the other prime example that comes to
Speaker 2: mind is when especially a ship, but sometimes other vehicles
Speaker 2: or gendered as female.
Speaker 3: Yeah, that's that always seemed funny to me.
Speaker 2: All right. Now, for this next little bit, I wanted
Speaker 2: to talk briefly about the word odd. I was looking
Speaker 2: at other angles on odd and even, and I came
Speaker 2: across this excellent write up on Webster's and it points
Speaker 2: out that the word in English comes from the Old
Speaker 2: Norse word audie odd i meaning point of land in
Speaker 2: the geographical sense, so it's like the point of a triangle,
Speaker 2: and so it eventually came to mean triangle, and it
Speaker 2: also came to mean odd, as the point of a
Speaker 2: triangle triangle must always oppose the two other corners, so
Speaker 2: it's like the two other corners are an even pair,
Speaker 2: and if they were to leave, then the audi is alone.
Speaker 3: Wow, that's almost poetic. That's like a beautiful etymology.
Speaker 2: Yeah. And eventually from here the term transfers over into English,
Speaker 2: and by the fourteenth century it was written down, so
Speaker 2: you know, it may have made the journey. It probably
Speaker 2: it definitely made the journey earlier than that, but that's
Speaker 2: when we have written evidence of it. And initially the
Speaker 2: word odd meant without a corresponding mate, so it was
Speaker 2: still like tied up with this idea of like two
Speaker 2: leave and leave one. But then it comes to mean
Speaker 2: irregular or non conformist. And Webster's notes that during the
Speaker 2: fifteenth and sixteenth centuries, this usage of odd in English
Speaker 2: language was a good thing. It meant you stood out,
Speaker 2: you know, it's like, oh, look at that odd character there,
Speaker 2: We've got to go chat him up. He has lots
Speaker 2: of interesting things to say as he drinketh from his
Speaker 2: skull and walketh his bear. But then by the seventeenth
Speaker 2: century it comes to lean more toward the eccentric and
Speaker 2: even dare we say the weird, in the sense that
Speaker 2: you might be like, let's stay away from the guy
Speaker 2: with the bear and the skull. Lord knows what he's
Speaker 2: going to talk about. Let's keep a distance. Wow.
Speaker 3: It almost invokes like a story in the sense that
Speaker 3: if you imagine there were three people and two of
Speaker 3: them left, and now one is odd. Why did the
Speaker 3: other two leave? Were they driven away by the behavior
Speaker 3: of the first one? Or could they just not handle
Speaker 3: the genius?
Speaker 2: Yes, and my apologies to Lord Byron Fans since he's
Speaker 2: barely covered in the centuries reference there. But Webster's also
Speaker 2: points out that the use of the noun odd for
Speaker 2: a point of land seems to have crossed over a
Speaker 2: second time into English during the nineteenth century, though more
Speaker 2: exclusively to northern England and Scotland. Oh and one more
Speaker 2: little bit here, that I ran across Audi is also
Speaker 2: the name of a town in Iceland, and well, I'm
Speaker 2: not as sure about the direct linguistic connection here. Between
Speaker 2: what we're talking about and the name of this town,
Speaker 2: I did run across a picture of a statue of
Speaker 2: Samon the Wise hitting the Devil and the devil may
Speaker 2: or may not be in the form of a seal
Speaker 2: here with a bible. This was I found this a
Speaker 2: photograph of this on a blog post by eric O.
Speaker 2: Scott on the website The Wild Hunt. And this ties
Speaker 2: into a passed up episode because in our series on
Speaker 2: Shadows from last October that is going to re air
Speaker 2: this October, we talked a little bit about the shadow
Speaker 2: wizard and priest Semon Semond or Sevender the Wise, who
Speaker 2: has various encounters with the Devil. I don't think we
Speaker 2: talked about him hitting the devil with a bible, but
Speaker 2: there is an episode where he ends up having his
Speaker 2: shadow stolen by the devil.
Speaker 3: Right, doesn't he go to like the Devil's College or
Speaker 3: the Devil's School to learn the learn the magical arts.
Speaker 3: But then the devil is supposed to grab one of
Speaker 3: the students at the end of the semester and keep them.
Speaker 3: But Seemen. They're various tellings, but Seeman finds some way
Speaker 3: to kind of trick the devil and escape.
Speaker 2: Yeah. Yeah, and he like goes to snatch his soul
Speaker 2: and gets his shadow instead, and so forth. So I
Speaker 2: don't know, I'm drifting drifting off topic here, but we're
Speaker 2: still somewhere in the neighborhood of a lot and even now.
Speaker 2: Next I would like to turn to evens and odds
Speaker 2: in biology. This is an area that where you can,
Speaker 2: you know, I guess with any of this, you have to,
Speaker 2: especially when you're playing in a biology, you have to
Speaker 2: think about like the relationship between numbers in reality, and
Speaker 2: you can get you know, kind of go do a
Speaker 2: fair amount of navel gazing on that in and of itself.
Speaker 2: But you know, just as we see a tendency for
Speaker 2: external symmetry and biological organisms, we at least to some extent,
Speaker 2: see a tendency toward even numbers. Again, huge caveat here.
Speaker 2: It kind of it can also depend on exactly how
Speaker 2: you want to cut it, because you know, you can
Speaker 2: take a quick survey of your own body and chances
Speaker 2: are you're going to find some even numbers in play.
Speaker 2: You know, two arms, two legs, four limbs, total, ten fingers,
Speaker 2: ten toes, two eyes, two nostrils, and so forth. On
Speaker 2: the other hand, I mean, yes, you do have one
Speaker 2: mouth and so forth. But you know, the still of
Speaker 2: course lines up with the basic idea of bilateral symmetry.
Speaker 2: Divide a creature down the middle and you have two
Speaker 2: equal sides, though of course we also have to throw
Speaker 2: and the other caveat that the average human being is
Speaker 2: not perfectly symmetrical, and artificially symmetrical faces tend to read
Speaker 2: as uncanny to us.
Speaker 3: For this reason, we actually did a series on biological
Speaker 3: symmetry and asymmetry a couple of years back. I don't
Speaker 3: recall was that the series called the Lesser of two
Speaker 3: crab claws, where.
Speaker 2: I think the fiddler crabs mm hm, yes, because you know,
Speaker 2: there are plenty of examples too in the biological world
Speaker 2: which we get into in that series, where there is
Speaker 2: a glaring asymmetry. So anyway, it would be a gross mistake. Though,
Speaker 2: coming back to odds and evens, if you were to
Speaker 2: say that you only see even numbers and organisms, that
Speaker 2: is absolutely not true, and they're ultimately far more complex
Speaker 2: and satisfying ways to apply numbers more universally to nature,
Speaker 2: such as say the Fibonacci sequence so forth. But it's
Speaker 2: still interesting to see cases where there is a there
Speaker 2: seems to be a tendency toward even numbers, and still
Speaker 2: looking at the exceptions to those possible rules and possible tendencies.
Speaker 2: One place that start is with chromosomes. So a chromosome
Speaker 2: is a DNA package that contains all the genetic material
Speaker 2: of an organism, and the chromosome count for individual species
Speaker 2: varies greatly and it has nothing to do with it
Speaker 2: doesn't correlate with the apparent complexity of an organism. So
Speaker 2: you know, for example, a jack jumper ant has a
Speaker 2: single pair of chromosomes, while turkey has eighty. A human
Speaker 2: of course has forty six, and then you have a
Speaker 2: case like and to be clear, you can also get
Speaker 2: odd numbers via genetic disorders. But one of the biggest
Speaker 2: examples it's often brought up of an odd number of
Speaker 2: chromosomes in an organism is the mule. This is a
Speaker 2: cross between donkey and a horse, of course, and it
Speaker 2: sends out for having sixty three and they're usually infertile
Speaker 2: because of this. And there's some other interesting outliers as well,
Speaker 2: like the Indian mutjak, in which males tend to have
Speaker 2: seven to the female six in the swamp Wallaby you
Speaker 2: see eleven for males and ten for females. And there
Speaker 2: are various other examples of this nature. And but of
Speaker 2: course this is all hidden to the naked eye. Limbs
Speaker 2: stand out far more in human consideration when we're talking
Speaker 2: about evens and odds, and so this raises the question,
Speaker 2: what if anything naturally has an odd number of arms?
Speaker 2: And basically the answer is nothing except blank. And I'll
Speaker 2: come back to the blank in just a second. But
Speaker 2: there's one potential possibility that often comes up if you're
Speaker 2: just scanning the names of the popular names of organisms,
Speaker 2: and it's one. There's one that came up on a
Speaker 2: Monster Fact episode several weeks back. There is a species
Speaker 2: of octopus known as the seven armed octopus.
Speaker 3: Now that is an oxymoron, isn't it right?
Speaker 2: Right? Because if you know anything about oct octopi, it
Speaker 2: is that, as the name implies, they have eight arms. Yes,
Speaker 2: so if you had a seven armed octopus, that that
Speaker 2: would be interesting. Why does it have why does it
Speaker 2: seem to have seven arms? So this octo this is
Speaker 2: also known as the septupus or the blob octopus, and
Speaker 2: it is Halofron atlanticus and here's the thing. It actually
Speaker 2: does have eight arms. It like, do not believe the
Speaker 2: popular name. It's just that the males specialized fertilization arm.
Speaker 2: It's hectocoidalus remains coiled away in a sack beneath the
Speaker 2: rate of the right eye. So this is a specialized arm.
Speaker 2: And various sephalopods have these and there it's the kind
Speaker 2: of arm that will be used to slip in genetic
Speaker 2: material or sometimes it is like left detached and left
Speaker 2: with the mate. So this species has a specialized arm
Speaker 2: for mating, and it keeps it stored away out of
Speaker 2: sight behind the right eye. And so if you're just
Speaker 2: checking out the you know, a specimen, and you don't
Speaker 2: know what to look for, you might see only seven
Speaker 2: arms and assume, well, here we are, all right, it's
Speaker 2: a seven armed doctor. But like I said, there there
Speaker 2: are some examples of animals with an odd number of limbs.
Speaker 2: But to find one we have to look to the
Speaker 2: marine invertebrates known as c stars, which tend to boast
Speaker 2: five arms, though they can't have more depending on the species.
Speaker 2: Five arms in a radial presentation. I mean, everyone knows
Speaker 2: what a starfish looks like. You've seen SpongeBob. You give
Speaker 2: the general idea.
Speaker 3: Oh okay, and here's where we get into the different
Speaker 3: types of symmetry that are found in animal body plans. Right,
Speaker 3: Because while most animals, and especially most animals we're familiar with,
Speaker 3: have a bilaterally symmetrical body plant can be divided down
Speaker 3: the middle and folded in half, there are some animals
Speaker 3: that live, especially in the ocean, that have a radially
Speaker 3: symmetrical body plan, meaning it is symmetrical in that it
Speaker 3: has copied segments, but they are copied by going around
Speaker 3: in a circle instead of folding in half down the middle.
Speaker 2: Yeah. Yeah, uh. And this is a This is especially
Speaker 2: interesting concerning the C star because this comes back to
Speaker 2: something we talked about perhaps last October as well, that,
Speaker 2: according to some analysis, particularly a twenty twenty three study
Speaker 2: published in the journal Nature by Formery at All, the
Speaker 2: C star is really more of a head with five
Speaker 2: or more extensions. They're not really arms. They're more like
Speaker 2: head projections, which is an interesting way of looking at it.
Speaker 2: But another thing that they point out in this article
Speaker 2: is that C stars evolved from an ancestor that had
Speaker 2: twofold or bilateral symmetry, and it develops from larvae that
Speaker 2: also have twofold or bilateral symmetry, but they have a
Speaker 2: typically you know, fivefold radial adult body plan. So yeah,
Speaker 2: another fascinating example. Now, another place to look for even
Speaker 2: numbers in a mammal is, of course, look to the nipples.
Speaker 2: Humans typically have two of these, though to be clear,
Speaker 2: you do have situations where people have, like say, a
Speaker 2: third nipple, but generally speaking you're dealing with the two
Speaker 2: nipple scenario. If you have a cat, you can. I
Speaker 2: don't recommend feeling around because unless you're a professional, because
Speaker 2: you will often get clawed for this. But cats have
Speaker 2: six to eight nipples, and indeed most mammals have an
Speaker 2: even number of nipples. But if you turn to the marsupial,
Speaker 2: the American opossum, you will find a famous outlier here
Speaker 2: with an array of thirteen nipples.
Speaker 3: Now, don't start putting your cultural associations on the opossum.
Speaker 3: No one of its nipples is the unlucky one.
Speaker 2: Because when you look at the number of young they
Speaker 2: have like it's it's it's the like the ghost nipples
Speaker 2: past thirteen that are the unlucky ones because they generally have,
Speaker 2: and this is environmentally dependent. They generally have like twenty
Speaker 2: young so not everybody's gonna get a nipple and survive.
Speaker 2: But but yeah, you can. You can look up I
Speaker 2: don't strongly recommend the opossum nipple google image search, but
Speaker 2: you can. You can find some illustrations that I think
Speaker 2: are ultimately more helpful and better for you, know, your sanity,
Speaker 2: than looking up the actual images of bossom nipple arrangements.
Speaker 2: But the illustrations give you the general idea. So I've
Speaker 2: seen this described as two arches of six nipples, with
Speaker 2: one nipple located centrally. I've also seen it talk talked
Speaker 2: about in terms of being like a U shape or
Speaker 2: circular shape inside of the female opossum's pouch. Now, there
Speaker 2: are various other classifications of even and odds we might
Speaker 2: get into there. Of course, odd toad and even toad ungulates. Tapers,
Speaker 2: for example, have four hoofed toes in the front and
Speaker 2: three hoofed toes in the back. Most rhino species have
Speaker 2: three digits on each foot. And in general, though, and
Speaker 2: we've gotten into this a bit in the past, especially
Speaker 2: when we talked about horse hoofs, evolution has resulted in
Speaker 2: digit numbers greater and less than the human five that
Speaker 2: we take for granted, you know, because you can look
Speaker 2: at the horse's hoof and see it as a single toe,
Speaker 2: a single great toe foot. And we see the opposite
Speaker 2: as well in some other organisms, with the development of
Speaker 2: a sixth pseudothomb. This is you can find these in
Speaker 2: the giant panda, for example, where this has evolved. It's
Speaker 2: not truly an additional digit on the hand, but it
Speaker 2: is basically like doing the work of an extra partially
Speaker 2: evolved digit to aid in the nonstock consumption of bamboo.
Speaker 2: And then we also see a remarkable pseudo thumb emerge
Speaker 2: on the hand of the II lemer, so the II
Speaker 2: lemur maybe a lemur that a number of view are
Speaker 2: familiar with various nature documentaries, because it is a very weird,
Speaker 2: goblin esque looking creature. It's it's it's wonderful, I say
Speaker 2: it is. It is weird in all of the great
Speaker 2: ways that an animal can be weird. You know. It
Speaker 2: is nocturnal. Uh. It again looks kind of like a goblin,
Speaker 2: and it has these very specialized hands that feature a
Speaker 2: super long middle finger which it uses. It uses it
Speaker 2: specialized hands to like cap on wood and then uses
Speaker 2: that that super long middle finger to reach in and
Speaker 2: dig out grubs and wood burrowing insects to eat.
Speaker 3: Yeah, so it sort of has nose faratu hands. But
Speaker 3: I can't emphasize enough that the face in many photos
Speaker 3: is going, oh dude, it's like very big wide eyes
Speaker 3: and the mouth open like it is shouting at you
Speaker 3: incitement and surprise.
Speaker 2: Yeah. So it's the situation, though, seems to be pretty
Speaker 2: fascinating here because they have this super specialized again long
Speaker 2: middle finger. It basically has a single use. It's essentially
Speaker 2: a unit tasker. But that means that they need a
Speaker 2: little more help climbing. So it's like, you know, it's
Speaker 2: like they had a callub evolution and say, look, I
Speaker 2: need to put an order in for an extra digit.
Speaker 2: Why you already have five digits. Well, yes, but I've
Speaker 2: specialized one to the degree that it can no longer
Speaker 2: help me in climbing trees. So do a search for
Speaker 2: II hands II fingers to get a sense of what
Speaker 2: I'm talking about here, And that's exactly what I was
Speaker 2: doing when I found a mention of a study that
Speaker 2: I had not run across before. I thought I knew,
Speaker 2: like all the main cool things about the II. But
Speaker 2: as it turns out that elongated middle finger is proportioned
Speaker 2: as such. First of all, that it would be like
Speaker 2: us having a foot long middle finger. But not only
Speaker 2: do they use this to fish out wood boring insects
Speaker 2: and grubs, but according to Anne Claire Fabre and this
Speaker 2: is an evolutionary biologist at the Natural History Museum of
Speaker 2: burn as cited in a Cassidy Ward article for sci
Speaker 2: Fi in twenty twenty two, they also use this finger
Speaker 2: to pick their own noses. And they get the whole
Speaker 2: finger in there to the point that they're able to
Speaker 2: reach all the way back through their sinuses to the
Speaker 2: back of their throats and then back out again. The
Speaker 2: most prodigious nose picking in nature. It has to be
Speaker 2: right certainly with fingers, with digits. You know, there may
Speaker 2: be some other strong candidates. They're involving animals with very
Speaker 2: like prehinsile tongues and so forth.
Speaker 3: But the zoologists right in with better nose picking in
Speaker 3: the animal world.
Speaker 2: I mean, this has got to be one of the
Speaker 2: top cases. So I mean, that's okay. So I'm getting
Speaker 2: off off topic a little bit from the evens and
Speaker 2: the odds here, But that study or and or that
Speaker 2: sci fi articles deaf worth picking up in part because
Speaker 2: they include an illustration of just how far the finger
Speaker 2: is thought to go into the skull. And you get
Speaker 2: like a cutaway of the II's skull to show you,
Speaker 2: like how deep it goes, all the way to the
Speaker 2: back of the throat. Pretty fascinating.
Speaker 3: You really wouldn't want to, like trip and fall while
Speaker 3: you're doing that.
Speaker 2: No, all right, I have one more biological tie in
Speaker 2: here concerning odds and evens and animals, and this has
Speaker 2: nothing to do with the actual biology of the species.
Speaker 2: It's all about the way we categorize them. We have
Speaker 2: what are called tutonyms. This is when you have a
Speaker 2: species like Rattus ratus, in which both parts of the
Speaker 2: name are identical. The genus is Rattus and the species
Speaker 2: is also rattus, So you have Rattus ratus or are rattus. Yes,
Speaker 2: we've discussed a number of these before. But then there's
Speaker 2: a step beyond mere toutonyms. There are triple tops, and
Speaker 2: this is where the scientific names end up. I think,
Speaker 2: being rather hilarious at times and resembling as well magical
Speaker 2: spells of summoning, bringing to mind incantations of beetle juice
Speaker 2: and bloody Mary, where you're saying something three times in
Speaker 2: a row, and anything said three times in a row
Speaker 2: will start sounding silly. For instance, there is a buffo
Speaker 2: bufo bufo, the European toad, so it's genus buffo, and
Speaker 2: then the species is buffo bufo beautiful. We also have
Speaker 2: the black rat that's Ratus ratus ratus, and then we
Speaker 2: have the South African giraffe or giraffa giraffa giraffe.
Speaker 3: That sounds the most like a spell.
Speaker 2: And there are other fun examples as well, like the
Speaker 2: European eagle owl Boobo Boobo Boobo, the Eurasian magpie or
Speaker 2: Pica Pika Pika, and these are all again richly amusing,
Speaker 2: because anything you say three times it's just gonna sound silly.
Speaker 3: Wait, isn't that what Pikachu says?
Speaker 2: Pikachu's definitely says Pika Pika. I don't know if there's
Speaker 2: a third Peka in there for when Pikachu really means it. Yeah.
Speaker 2: Another interesting thing about this is you'll only find these
Speaker 2: in zoology because they are forbidden in botany under the
Speaker 2: International Code of Botanical Nomenclature. So you're not gonna find
Speaker 2: anything like cannabis, cannabis, cannabis because it's just forbidden that
Speaker 2: we don't do that in botany. Leave that to the zoologists.
Speaker 2: They're the silly ones.
Speaker 3: Well, I like this. I think the botanists should do it.
Speaker 3: Maybe they just don't have the guts.
Speaker 2: Yeah, I didn't get in deep enough to find out
Speaker 2: like when this law was laid out and like how
Speaker 2: for what reason? Like why did they really need to
Speaker 2: take a stand on this? But maybe we'll have to
Speaker 2: get into that another time.
Speaker 3: I'm just kidding with you botanists. I know you have
Speaker 3: plenty of courage. All right, Does that do it for
Speaker 3: this series? On even an odd I believe?
Speaker 1: So.
Speaker 2: Yeah, Like you said, we've had our third episode. We
Speaker 2: had a nice odd number of episodes for it, so
Speaker 2: I think we're good to go.
Speaker 3: Obviously, there are even an odd instances of pretty much everything,
Speaker 3: so we could keep going forever, but we got to
Speaker 3: stop somewhere exactly.
Speaker 2: Yeah, yeah, so we'll go ahead and you call it here.
Speaker 2: We want to remind everybody that's stuff to blow your mind.
Speaker 2: Is primarily a science and culture podcast. With core episodes, publishing,
Speaker 2: and the Stuff to Blow Your Mind podcast feed on
Speaker 2: Tuesdays and Thursdays, short form episodes on Wednesdays. On Fridays,
Speaker 2: we set aside most series concerners to just talk about
Speaker 2: a weird film on Weird House Cinema, and then we
Speaker 2: have some bald episodes or reruns at air on Saturdays
Speaker 2: and Mondays.
Speaker 3: Here's thanks, as always to our excellent audio producer JJ Posway.
Speaker 3: If you would like to get in touch with us
Speaker 3: with feedback on this episode or any other, to suggest
Speaker 3: a topic for the future, or just to say hello,
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