September 20, 2025 • 38 mins
In this classic episode of Stuff to Blow Your Mind, Robert and Joe explore the world of odd and even numbers. How does it factor into our psychology, our art and our culture? Find out…(originally published 9/12/2024)
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Speaker 1 (00:06):
Hey, you welcome to Stuff to Blow your Mind. My
name is Robert Lamb, and today is Saturday. Once more,
so we have an episode from the vault. This is
going to be Odds and Evens, Part three, and it
originally published nine to twelve, twenty twenty four. Enjoy Welcome
to Stuff to Blow Your Mind, production of iHeartRadio. Hey,
(00:34):
welcome to Stuff to Blow your Mind.
Speaker 2 (00:35):
My name is Robert Lamb and I am Joe McCormick,
and we are back for the third and final part
in our series on the psychology and cultural significance of
number paroity pr it y parody referring to whether a
number is even or odd, and we are ending it
with an odd number of episodes that just felt right now.
(00:57):
If you haven't heard the other parts in this series,
you might want to go back in list into those first.
But in part one we talked about the mathematical principle
of number parity, as well as some evidence that people,
if given the opportunity, will sometimes project associations and emotions
onto even and odd numbers, for example, by maybe feeling
(01:18):
more positivity toward even numbers on average, or by having
an esthetic preference for odd numbers in visual art, as
reflected in the conventional rule of thirds and rule of
odds in art theory, which we discussed in some detail
in that episode. But then we also brought in some
questions and counter evidence about the real world validity and
(01:38):
alleged universality of these preferences for odds in art. In
part two of the series, we talked about a research
paper on the cognitive psychology of number parity, which advanced
what I thought was a really interesting argument that despite
the fact that all positive integers are mathematically defined as
simply odd or even and nothing in between, our brains
(02:01):
may in practice treat some numbers as more even or
more odd than others, mentally transforming these definitionally discrete categories
into a semi smooth gradient. And this could be due
to multiple factors, involving mathematical properties like the ease of divisibility,
and also linguistic properties about how easily we process different
(02:23):
words and their associated concepts. We also talk some more
about even and odd groupings in visual art, specifically in
religious images such as that of the ten headed demon
king Ravina in Hindu mythology, and we also talked about
preferences for even or odd groupings on food plates. I
think the conventional wisdom favors odd numbers of food items,
(02:44):
but the research maybe paints a slightly more complicated picture.
Speaker 1 (02:48):
Yeah, I think in either case, what does what does
a plate of food and the multi headed incarnation of
a Hindu god? What do they have in common? It's
that there are other things involved and how you're ultimately
going to perceive this image. Either religious iconography is going
to be trying to relate other concepts to you the viewer,
(03:10):
the intended audience viewer, and the food imagery is of
course showing you something that on some level at least
you want to eat.
Speaker 2 (03:17):
Yeah, exactly. So we're here today to finish off this
series with a few more things about odd and even topics.
So I just wanted to mention at the top of
the episode here a few more interesting ideas I came
across while reading about events and odds. Previously, we talked
about some evidence that at least in certain contexts, people
(03:39):
like some numbers more than others. For example, they may
have more positive emotional feelings about even numbers, or at
least about numbers that are easily divisible because one of
the studies we talked about in Part one apparently found
that people had more positive feelings toward even numbers and
numbers to visible five. Coming back to the question of
(04:03):
certain numbers feeling more even or less odd than they
really are. So a great example is that twenty five
is an odd number, but why does it feel like
an even number? To me? I would say the ease
of divisibility by the sub base of five is a
pretty good guess. And this sort of brings me back
to an idea I first encountered in a couple of
(04:24):
the articles that we were talking about in Part one
by a British author named Alex Bellows who writes newspaper
columns about mathematics and puzzles sometimes, but it also written
a book addressing some of these topics. And in these
articles he talked about people's feelings about odd and even numbers,
and the idea he raises that if it's true that
(04:44):
people sometimes feel better about even numbers than odd ones,
what if that sense of liking for even numbers is
related to the concept of processing fluency. Now, this is
a psychological concept that has come up the show before.
The gist of the idea is that a lot of
the judgments that humans make, from whether we like something
(05:08):
to whether we trust a piece of information or believe
something is true, a lot of these judgments are influenced
by our subconscious reaction to how easy it is for
us to mentally process the stimulus in question. There are
a lot of studies looking at this. I remember this
came up when we were discussing the illusory truth effect,
(05:31):
the idea that if a claim a claim may have
no real evidence for it, or you may have no
particular reason for believing a claim is true, but if
you hear it repeated a bunch of times, it starts
to feel more and more true to you. And one
of the popular explanations for this effect is the idea
(05:52):
that hearing a hearing a claim on subsequent exposures increases
its process in fluency because it's more a miliar to you.
You've heard it before, so it's easier to take in
the second, third, fourth, fifth time you hear it, and
thus it because it has increased processing fluency, it just
feels more right, It feels more true. One of the
(06:13):
key findings that already came up in some of the
papers we talked about in Part two is that it
seems even numbers are on average more easily processed than
odd numbers are. You know, when it's easier to think
about even numbers, we can more quickly classify them mathematically
as even numbers, it's easier to think about doing mathematical
operations with them. Odd numbers are just they're introducing friction
(06:37):
to your brain when you have to consider them. And
if this is the case, it could be a major
contributor to these particular situations where people seem to like
even numbers better than odd numbers. But of course we
don't always like even numbers better than odd numbers. And
this comes back to the issues of these additional bits
of context and cultural associations happen to pin onto these numbers,
(07:02):
and whether at the time of us having a feeling
about a number or making a judgment about it, these
other associations become salient. So anyway, that brings me to
another line of research that I stumbled across when looking
into this, that I thought was curious and sort of
funny also, which is the apparent association between number parity
(07:24):
and the social concept of gender. Now in much the
same way, it seems absurd that without any context, in
other words, without quantifying anything in particular, specific numbers whatever
feel good or bad to people. It also seems kind
of absurd that anyone would think of standard Arabic numerals
as masculine or feminine. But there are some experiments in
(07:48):
which researchers claim to have found that in some contexts
there is a pattern of gendered associations between odd and
even numbers that emerge.
Speaker 1 (07:58):
This is interesting because I I was thinking about gender
numbers earlier in the research process for this series, because
I ran across an interesting skit about the number one
on Sesame Street.
Speaker 2 (08:10):
Oh care to elaborate?
Speaker 1 (08:11):
Oh sure, sure, So in this sketch, this is from
nineteen ninety seven, so this is not one that I
was originally exposed to as a kid. But we have
number one, which is of course a muppet. It is
the numeral one, and it is a she. So the
number one she is feeling really down about herself because
she is such a low value number, like you know,
(08:34):
it's just she's it's one and then zero, like all
the other numbers are more potent than her, more important
than her, and she feels she's really feeling down in
the dumps about it. Well, who comes up to cheer
her up? But the Count? Oh, And the Count proceeds
to sing an entire song for her about how important
(08:54):
she is numerically, and then afterwards he's like, do you
feel better? And she's like, well a little bit, and
he says, well, I'm going to sing it for you
one more time. But it got me think. It's like, well,
you know, I didn't think about one being male female,
what have you? I didn't think about the gender of
the number one. I just considered it like a number.
(09:17):
But now I'm thinking of it. I just can't help
but picture it with like the big full lips and
the beauty mark here from this nineteen ninety seven Sesame
Street sketch.
Speaker 2 (09:25):
Well, that is adorable. I like the Count. I hope
that the Count can help any number feel better about itself.
All numbers are important, but one is really special.
Speaker 1 (09:34):
Yeah. I think the Count is going to be the
biggest fan, the biggest supporter of any number. He's not
going to pull a Harry Neilson and talk about how
crappy the number one is and how number two is
also no good. He's a big fan of all of them.
Speaker 2 (09:48):
I like knowing you can count on the count for
emotional support, so anyway to mention A couple of these
studies apparently finding this association between gender and number parody.
A couple of the ones I came across were by
a pair of researchers named Wilkie and Bodenhausen. One of
these papers was from twenty twelve in the Journal of
(10:09):
Experimental Psychology, another one by the same authors from twenty
fifteen in Frontiers in Psychology, and these papers published the
results of a number of different experiments about the gender
associations of odd and even numbers. Now, some of these
experiments involved explicit judgments, just asking people straight up whether
(10:30):
they felt like specific numbers were more masculine or feminine,
and other experiments looked for indirect associations, like people's tendency
to interpret the faces of babies or unfamiliar foreign names
with different genders when they were labeled with different numbers.
And to note that this indirect measure here does rely
(10:52):
on implicit association tests, which have been subjected to various
methodological critiques over the years. They've undergone some refinements over
time to try to improve reliability. But there's still sort
of debates about how they can be depended on and
in what context. So anyway, caution on relying too much
on the implicit parts of these findings. But the authors
(11:13):
say from the totality of their experiments that on average,
for some reason, people from sample groups within the United
States are more likely to say that odd numbers are
masculine and even numbers are feminine. And while that's the
general trend, there are some exceptions and caveats. While they
say that this pattern was on average true for everyone,
(11:36):
the association was stronger among women, So on average, women
were more likely to view odd numbers as more masculine
and less feminine than even numbers. Weirdly, this is where
it starts getting funny. I thought the numbers in when
the numbers involved were two digit instead of one digit,
men started to drift away from this parody association and
(12:00):
started to say that all numbers were masculine, regardless of parody.
So I don't whenever we look at studies like this,
By the way, I always like raise caution because I
just know from experience a lot of people get real
excited about like gender differences in responses to psychological experiments
and then start overinterpreting, thinking it explains everything about men
(12:21):
and women. Oh, you know why my husband or my
wife acts a certain way, et cetera. And so I
will raise the same caution here. You know, it's just
a few experiments. We're not sure if this is a
super robust finding, and even if it is robust, it's
easy to get carried away just reading too much into
little psychological quirks like this. However, I could not resist
finding it hilarious to imagine a guy looking at numbers
(12:44):
higher than nine and being like, thirty four. Huh, that's
a big number. That's a macho man.
Speaker 1 (12:50):
In between thoughts about ancient real right.
Speaker 2 (12:53):
Yeah, so in reality it's probably not that simple, but
I was laughing for several minutes after I read this. Anyway,
the authors of these studies, so they're making an argument
not that there actually is something objectively or universally gendered
about even and odd numbers, and instead they're sort of
making a case about what they call, quote, the pervasiveness
(13:15):
of gender as a social scaffolding for generating understandings of
abstract concepts. So the way I take that is they're
sort of saying gender is such an important concept to
people that we subconsciously apply it to categories of objects
that have nothing to do with the primary understanding of
masculinity or femininity. It's just like a major way of
(13:39):
making category distinctions that the brain kind of defaults to,
even in situations that don't have anything to do with
biological sex or with the social roles of gender.
Speaker 1 (13:50):
Right right, So yeah, it wouldn't be like the hypothetical
male in question is making a conscious effort to think
about all higher numbers as men. It's a little more
new as a little more subconscious than that.
Speaker 2 (14:05):
Now I mentioned that those studies were done on us
test subjects. I came across an interesting variation with respect
to culture. So there was a twenty twenty one study
in Frontiers and Psychology by Jordan Yakani and Sheen which
found some consistency and some variation across cultures regarding the
perceived gender of numbers. These researchers tested whether the same
(14:30):
patterns of association between number parity and gender would show
up among Arabic speaking people native to the UAE, and
their top level findings were that there were patterns of
gender association with number parity, but on the implicit association
of numbers with faces, the subjects in the UAE were
more likely to associate even numbers with their own gender,
(14:54):
whichever that was so, men seeing even numbers as more masculine,
women seeing even numbers as more feminine. And these findings
indicate that it may be cross culturally common to associate
even in odd numbers with gender, at least in some
weekly held way, to make some kind of weak association
of that kind, but that the association can vary from
(15:18):
culture to culture, which actually makes a lot of sense
to me that I think the idea would sort of
be that gender is a category lens that we're very
quick to apply to all kinds of phenomena outside of
its primary cultural meaning, but exactly how we apply it
probably depends on a lot of subtle influences that can
(15:38):
easily vary person to person and culture to culture, though
apparently within a given language culture, one way of making
the association is probably more common than another. So anyway,
all the warnings I gave up top about not reading
too much into these kinds of findings, but I do
think if this is basically on the right track, it's
an interesting example of the way that we we just
(16:00):
kind of recklessly apply category distinctions across every domain of life,
whether it really makes direct sense or not. You know,
I think we if we ever talked about the idea
on the show before, some people seem to think like
dogs or boys, cats or girls.
Speaker 1 (16:16):
Yeah. I have caught myself falling into that trap as well,
Like I kind of on a default level assume cats
are girls and dogs are boys until I know differently
concerning individual cats and dogs, and I don't know. One
reason for that is probably that I've only ever had cats,
and those cats have always been girls. I don't know, yeah,
female cats. Sorry, some of them have been very old ladies.
Speaker 2 (16:39):
Then again, at least cats and dogs are like animals.
You know. It's I guess it's even funnier thinking about
the way that we we just wantonly apply these categories,
possibly even to things like abstract numbers and symbols that
that don't even have like you know, bodies or minds
or anything. Yeah.
Speaker 1 (17:00):
The only the other prime example that comes to mind
is when especially a ship but sometimes other vehicles or
gendered as female.
Speaker 2 (17:07):
Yeah, that always seemed funny to me.
Speaker 1 (17:20):
All right, Now for this next little bit, I wanted
to talk briefly about the word odd. I was looking
at other angles on odd and even, and I came
across this excellent write up on Websters, and it points
out that the word in English comes from the Old
Norse word audie odd i, meaning point of land in
(17:41):
the geographical sense. So it's like the point of a triangle,
and so it eventually came to mean triangle, and it
also came to mean odd, as the point of a
triangle triangle must always oppose the two other corners, so
it's like the two other corners are an even pair,
and if they were to leave, then the audi is alone.
Speaker 2 (18:02):
Wow, that's almost poetic. That's like a beautiful etymology.
Speaker 1 (18:06):
Yeah. And eventually from here the term transfers over into English,
and by the fourteenth century it was written down, so
you know, it may have made the journey. It probably
it definitely made the journey earlier than that, but that's
when we have written evidence of it. And initially the
word odd meant without a corresponding mate, so it was
still like tied up with this idea of like to
(18:29):
leave and leave one. But then it comes to mean
irregular or non conformist, and Webster's notes that during the
fifteenth and sixteenth centuries, this usage of odd in English
language was a good thing. It meant you stood out,
you know. It's like, oh, look at that odd character there,
We've got to go chat him up. He has lots
of interesting things to say as he drinketh from his
skull and walketh is bear. But then by the seventeenth
(18:52):
century it comes to lean more toward the eccentric and
even dare we say, the weird, in the sense that
you might be like, let's stay away from the guy
with the bear and the skull. Lord knows what he's
going to talk about. Let's keep a distance. Wow.
Speaker 2 (19:09):
It almost invokes like a story in the sense that
if you imagine there were three people and two of
them left, and now one is odd. Why did the
other two leave? Were they driven away by the behavior
of the first one? Or could they just not handle
the genius?
Speaker 1 (19:25):
Yes, and my apologies to Lord Byron Fans, since he's
barely covered in the centuries reference there. But Webster's also
points out that the use of the noun odd for
a point of land seems to have crossed over a
second time into English during the nineteenth century, though more
exclusively to northern England and Scotland. Oh and one more
(19:47):
little bit here that I ran across. Audi is also
the name of a town in Iceland. And well, I'm
not as sure about the direct linguistic connection here between
what we're talking about and the name of the town
I did run across. The picture of a statue of
Salmon the Wise hitting the Devil, and the devil may
(20:08):
or may not be in the form of a seal
here with a bible. This was I found this a
photograph of this on a blog post by eric O
Scott on the website The Wild Hunt. And this ties
into a past episode because in our series on Shadows
from last October that is going to re air this October,
we talked a little bit about the shadow wizard and
(20:30):
priest semond or Semonder, the Wise, who has various encounters
with the Devil. I don't think we talked about him
hitting the devil with a Bible, but there is an
episode where he ends up having his shadow stolen by
the devil.
Speaker 2 (20:45):
Right doesn't he go to like the Devil's College or
the Devil's School to learn the learn the magical arts.
But then the devil is supposed to grab one of
the students at the end of the semester and keep them.
But semen, they're various tellings, but semen find some way
to kind of trick the devil and escape.
Speaker 1 (21:02):
Yeah. Yeah, and he like goes to snatch his soul
and gets his shadow instead and so forth. So I
don't know, I'm drifting drifting off topic here, but we're
still somewhere in the neighborhood of a lot and even now. Next,
I would like to turn to evens and odds and biology.
This is an area that, uh where you can you know,
(21:24):
I guess with any of this you have to, especially
when you're playing in to biology, you have to think
about like the relationship between numbers and reality, and you
can get, you know, kind of go do a fair
amount of navel gazing on that in and of itself.
But you know, just as we see a tendency for
external symmetry and biological organisms, we at least to some extent,
see a tendency toward even numbers. Again, huge caveat here.
(21:48):
It kind of it can also depend on exactly how
you want to cut it, because you know, you can
take a quick survey of your own body, and chances
are you're going to find some even numbers in play.
You know, two arms, to let, four limbs total, ten fingers,
ten toes, two eyes, two nostrils, and so forth. On
the other hand, I mean, yes, you do have one
(22:09):
mouth and so forth. But you know, the still of
course lines up with the basic idea of bilateral symmetry.
Divide a creature down the middle and you have two
equal sides, though of course we also have to throw
in the other caveat that the average human being is
not perfectly symmetrical, and artificially symmetrical faces tend to read
as uncanny to us.
Speaker 2 (22:28):
For this reason, we actually did a series on biological
symmetry and asymmetry a couple of years back. I don't
recall it was that the series called The Lesser of
Two crab Claws, where.
Speaker 1 (22:40):
I think the fiddler crabs mm hm, yes, Because you know,
there are plenty of examples too in the biological world
which we get into in that series, where there is
a glaring asymmetry. So anyway, it would be a gross mistake. Though,
coming back to odds and evens, if you were to
say that you only see even numbers and organisms. That
is absolutely not true, and they're ultimately far more common
place and satisfying ways to apply numbers more universally to nature,
(23:04):
such as say the Fibonacci sequence so forth. But it's
still interesting to see cases where there is that there
seems to be a tendency toward even numbers, and still
looking at the exceptions to those possible rules and possible tendencies.
One place that start is with chromosomes. So a chromosome
is a DNA package that contains all the genetic material
(23:25):
of an organism, and the chromosome count for individual species
varies greatly, and it has nothing to do with it
doesn't correlate with the apparent complexity of an organism. So
you know, for example, a jack jumper and has a
single pair of chromosomes, while turkey has eighty. A human
of course has forty six, and then you have a
(23:46):
case like and to be clear, you can also get
odd numbers via genetic disorders. But one of the biggest
examples it's often brought up of an odd number of
chromosomes in an organism is the mule. This is a
cross between donkey and a horse of course, and it,
you know, tends out for having sixty three and they're
usually infertile because of this. And there's some other interesting
(24:09):
outliers as well, like the Indian Mutjak, in which males
tend to have seven to the female six. In the
swamp Wallaby you see eleven for males and ten for females,
and there are various other examples of this nature. But
of course this is all hidden to the naked eye.
Limbs stand out far more in human consideration when we're
talking about evens and odds, and so this raises the
(24:31):
question what if anything naturally has an odd number of arms?
And basically the answer is nothing except blank. And I'll
come back to the blank in just a second. But
there's one potential possibility that often comes up if you're
just scanning the names of the popular names of organisms,
and it's one. There's one that came up on a
(24:53):
Monster Fact episode several weeks back. There is a species
of octopus known as the seven armed octopus.
Speaker 2 (25:02):
Now that is an oxymoron, isn't it right?
Speaker 1 (25:05):
Right? Because if you know anything about octopi, it is that,
as the name implies, they have eight arms. So if
you had a seven armed octopus that that would be interesting.
Why does it have why does it seem to have
seven arms? So this octopus is also known as the
septipus or the blob octopus, and it is Halofron atlanticus.
(25:30):
And here's the thing, it actually does have eight arms.
It like, do not believe the popular name. Uh, it's
just that the males specialized fertilization arm. It's hectocoidalus remains
coiled away in a sack beneath the right the right eye.
So this is a specialized arm. In various sephalopods have
(25:53):
these and there it's the kind of arm that will
be used to slip in genetic material or sometimes it
is like left detached and left with the mate. So
this species has a specialized arm for mating, and it
keeps it stored away out of sight behind the right eye.
And so if you're just checking out the specimen and
(26:15):
you don't know what to look for, you might see
only seven arms and assume, well, here we are, it's
a seven armed octopus. But like I said, there are
some examples of animals with an odd number of limbs.
But to find one we have to look to the
marine invertebrates known as c stars, which tend to boast
five arms, though they can't have more depending on the species.
(26:39):
Five arms in a radial presentation. I mean, everyone knows
what a starfish looks like. You've seen SpongeBob. You get
the general idea.
Speaker 2 (26:47):
Oh okay, and here's where we get into the different
types of symmetry that are found in animal body plans. Right.
Because while most animals, and especially most animals we're familiar with,
have a bi ladder really symmetrical body plan it can
be divided down the middle and folded in half, there
are some animals that live, especially in the ocean, that
(27:08):
have a radially symmetrical body plan, meaning it can be
it is symmetrical in that it has copied segments, but
they are copied by going around in a circle instead
of folding in half down the middle.
Speaker 1 (27:20):
Yeah. Yeah, And this is a This is especially interesting
concerning the sea star because this comes back to something
we talked about perhaps last October as well, that, according
to some analysis, particularly a twenty twenty three study publishing
the journal Nature by Formery at All, the c star
(27:41):
is really more of the head with five or more extensions.
They're not really arms. They're more like head projections, which
is an interesting way of looking at it. But another
thing that they point out in this article is that
sea stars evolved from an ancestor that add two fold
or bilateral symmetry, and it develops from larvae that also
(28:05):
have twofold or bilateral symmetry, but they have a typically
you know, fivefold radial adult body plan. So yeah, another
fascinating example. Now, another place to look for even numbers
(28:29):
in a mammal is, of course, look to the nipples.
Humans typically have two of these, though to be clear,
you do have situations where people have, like say, a
third nipple, but generally speaking you're dealing with a two
nipple scenario. If you have a cat, you can. I
don't recommend feeling around because unless you're a professional, because
you will often get clawed for this. But cats have
(28:52):
six to eight nipples, and indeed most mammals have an
even number of nipples. But if you turn to the marsupial,
the American opossum, you will find a famous outlier here
with an array of thirteen nipples.
Speaker 2 (29:10):
Now, don't start putting your cultural associations on the opossum.
No one of its nipples is the unlucky one.
Speaker 1 (29:17):
Now, because when you look at the number of young
they have like it's it's it's the like the ghost
nipples past thirteen that were the unlucky ones, because they
generally have and this is environmentally dependent, they generally have
like twenty young. So not everybody's gonna get a nipple
and survive. But but yeah, you can. You can look
up I don't strongly recommend the opossum nipple google image search,
(29:41):
but you can. You can find some illustrations that I
think are ultimately more helpful and better for you, know,
your sanity, than looking up the actual images of opossom
nipple arrangements. But the illustrations give you the general idea.
So I've seen this described as two arches of six nipples,
(30:03):
with one nipple located centrally. I've also seen it talked
about in terms of being like a U shape or
circular shape inside of the female opossum's pouch. Now, there
are various other classifications of the un and odds we
might get into there. Of course, odd toed and even
toed ungulates. Tapers, for example, have four hoofed toes in
(30:24):
the front and three hoofed toes in the back. Most
rhino species have three digits on each foot and in general, though,
and we've gotten into this a bit in the past,
especially when we talked about horse hoofs, evolution has resulted
in digit numbers greater and less than the human five
that we take for granted, you know, because you can
(30:45):
look at the horse's hoof and see it as a
single toe, a single great toe foot. And we see
the opposite as well in some other organisms, with the
development of a sixth pseudothumb. This is you can find
these in the giant panda, for example, where this has evolved.
It's not truly an additional digit on the hand, but
(31:06):
it is basically like doing the work of an extra
partially evolved digit to aid in the NonStop consumption of bamboo.
And then we also see a remarkable pseudo thumb emerge
on the hand of the II lemur. So the II
(31:27):
lemur may be a lemur that a number of view
familiar with from various nature documentaries, because it is a
very weird, goblin esque looking creature. It's it's it's wonderful,
I say it is. It is weird. In all of
the great ways that an animal can be weird. You know,
it is nocturnal. Uh, it again looks kind of like
a goblin, and it has these very specialized hands that
(31:49):
feature a super long middle finger, which it uses. Uh.
It uses it specialized hands to like cap on wood
and then uses that that super long middle finger to
reach in and dig out grubs and wood burrowing insects
to eat.
Speaker 2 (32:04):
Yeah, so it sort of has nose Feratu hands. But
I can't emphasize enough that the face in many photos
is going, oh dude, it's like very big wide eyes
and the mouth open like it is shouting at you
in excitement and surprise.
Speaker 1 (32:23):
Yeah. So it's the situation those seems to be pretty
fascinating here because they have this super specialized again long
middle finger. It basically has a single use. It's essentially
a unit tasker. But that means that they need a
little more help climbing. So it's like, you know, it's
like they had a callub evolution and say, look, I
need to put an order in for an extra digit.
(32:43):
Why you already have five digits. Well, yes, but I've
specialized one to the degree that it can no longer
help me in climbing. Trees, So do a search for
II hands II fingers to get a sense of what
I'm talking about here. And that's exactly what I was
doing when I found a mention of a study that
(33:05):
I had not run across before. I thought I knew,
like all the main cool things about the ei. But
as it turns out that elongated middle finger is proportioned
as such. First of all, that it would be like
us having a foot long middle finger. But not only
do they use this to fish out wood boring insects
and grubs, but according to Anne Claire Fabre and this
(33:30):
is an evolutionary biologist at the Natural History Museum of
burn as cited in a Cassidy Ward article for Sci
Fi in twenty twenty two, they also use this finger
to pick their own noses, and they get the whole
finger in there to the point that they're able to
reach all the way back through their sinuses to the
back of their throats and then back out again. The
(33:51):
most prodigious nose picking in nature. It has to be right,
certainly with fingers with digits. You know, there may be
other strong candidates. They're involving animals with very like prehinsile
tongues and so forth.
Speaker 2 (34:05):
But they zoologists right in with better nose picking in
the animal world.
Speaker 1 (34:10):
I mean, this has got to be one of the
top cases. So I mean, that's okay. So I'm getting
off off topic a little bit from the evens and
the odds here, but that study or and or that
sci fi article is definitely worth picking up, in part
because they include an illustration of just how far the
finger is thought to go into the skull, and you
(34:30):
get like a cutaway of the II's skull to show you,
like how deep it goes, all the way to the
back of the throat. Pretty fascinating.
Speaker 2 (34:38):
You really wouldn't want to, like trip and fall while
you're doing that.
Speaker 1 (34:41):
No, all right, I have one more biological tie in
here concerning odds and evens and animals, and this has
nothing to do with the actual biology of the species.
It's all about the way we categorize them. We have
what are called tautonyms. This is when you have a
speed sees alike Rattus rattus, in which both parts of
(35:04):
the name are identical. The genus is rattus and the
species is also rattus, So you have Rattus ratus or
are rattus.
Speaker 2 (35:13):
Yes, we've discussed a number of these before, But.
Speaker 1 (35:16):
Then there's a step beyond mere tautonyms. There are triple tautonyms.
This is where the scientific names end up, I think,
being rather hilarious at times, and resembling as well magical
spells of summoning, bringing to mind incantations of beetle juice
and bloody Mary, where you're saying something three times in
(35:39):
a row, and anything said three times in a row
will start sounding silly. For instance, there is a buffo
bufo buffo, the European toad, so it's genus buffo, and
then the species is Buffo bufo beautiful. We also have
the black rat that's Rattus ratus ratus, and then we
have the South African giraffe or giraffa Giraffa.
Speaker 2 (35:59):
Giraffe sounds the most like a spell.
Speaker 1 (36:01):
And there are other fun examples as well, like the
European eagle owl Boobo Boobo boobo, the Eurasian magpie or
Pika Pika Pika, and these are all again richly amusing,
because anything you say three times it's just gonna sound silly.
Speaker 2 (36:15):
Wait, isn't that what Pikachu says?
Speaker 1 (36:17):
Pikachu's definitely, says Pikapka. I don't know if there's a
third Peka in there or not for.
Speaker 2 (36:21):
When Pikachu really means it.
Speaker 1 (36:23):
Yeah, another interesting thing about this is you'll only find
these in zoology because they are forbidden in botany under
the International Code of Botanical Nomenclature. So you're not going
to find anything like cannabis, cannabis, cannabis because it's just
forbidden that we don't do that in botany. Leave that
(36:44):
to the zoologists. They're the silly ones.
Speaker 2 (36:46):
Well, I like this. I think the botanists should do it.
Maybe they just don't have the guts.
Speaker 1 (36:51):
Yeah, I didn't get in deep enough to find out
like when this law was laid out and like how
for what reason? Like why did they really need to
take a stand on this. But maybe we'll have to
get into that another time.
Speaker 2 (37:03):
I'm just kidding with you botanists. I know you have
plenty of courage. All right, Does that do it for
this series? On even an odd.
Speaker 1 (37:11):
I believe so. Yeah, like you said, we've had our
third episode. We had a nice odd number of episodes
for it, so I think we're good to go.
Speaker 2 (37:19):
Obviously, there are even an odd instances of pretty much everything.
So we could keep going forever, but we got to
stop somewhere exactly.
Speaker 1 (37:27):
Yeah, yeah, So we'll go ahead and you call it here.
We want to remind everybody that's Stuff to Blow Your
Mind is primarily a science and culture podcast, with core episodes,
publishing and the Stuff to Blow Your Mind podcast feed
on Tuesdays and Thursdays, short form episodes on Wednesdays. On Fridays,
we set aside most series concerners to just talk about
a weird film on Weird House Cinema, and then we
(37:50):
have some bald episodes or reruns at air on Saturdays
and Mondays.
Speaker 2 (37:55):
Here's thanks, as always to our excellent audio producer JJ Posway.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at stuff to Blow
your Mind dot com. Stuff to Blow Your Mind is
(38:19):
production of iHeartRadio.
Speaker 1 (38:21):
For more podcasts from My Heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you're listening to your favorite shows.
Hey, you welcome to Stuff to Blow your Mind. My
name is Robert Lamb, and today is Saturday. Once more,
so we have an episode from the vault. This is
going to be Odds and Evens, Part three, and it
originally published nine to twelve, twenty twenty four. Enjoy Welcome
to Stuff to Blow Your Mind, production of iHeartRadio. Hey,
(00:34):
welcome to Stuff to Blow your Mind.
Speaker 2 (00:35):
My name is Robert Lamb and I am Joe McCormick,
and we are back for the third and final part
in our series on the psychology and cultural significance of
number paroity pr it y parody referring to whether a
number is even or odd, and we are ending it
with an odd number of episodes that just felt right now.
(00:57):
If you haven't heard the other parts in this series,
you might want to go back in list into those first.
But in part one we talked about the mathematical principle
of number parity, as well as some evidence that people,
if given the opportunity, will sometimes project associations and emotions
onto even and odd numbers, for example, by maybe feeling
(01:18):
more positivity toward even numbers on average, or by having
an esthetic preference for odd numbers in visual art, as
reflected in the conventional rule of thirds and rule of
odds in art theory, which we discussed in some detail
in that episode. But then we also brought in some
questions and counter evidence about the real world validity and
(01:38):
alleged universality of these preferences for odds in art. In
part two of the series, we talked about a research
paper on the cognitive psychology of number parity, which advanced
what I thought was a really interesting argument that despite
the fact that all positive integers are mathematically defined as
simply odd or even and nothing in between, our brains
(02:01):
may in practice treat some numbers as more even or
more odd than others, mentally transforming these definitionally discrete categories
into a semi smooth gradient. And this could be due
to multiple factors, involving mathematical properties like the ease of divisibility,
and also linguistic properties about how easily we process different
(02:23):
words and their associated concepts. We also talk some more
about even and odd groupings in visual art, specifically in
religious images such as that of the ten headed demon
king Ravina in Hindu mythology, and we also talked about
preferences for even or odd groupings on food plates. I
think the conventional wisdom favors odd numbers of food items,
(02:44):
but the research maybe paints a slightly more complicated picture.
Speaker 1 (02:48):
Yeah, I think in either case, what does what does
a plate of food and the multi headed incarnation of
a Hindu god? What do they have in common? It's
that there are other things involved and how you're ultimately
going to perceive this image. Either religious iconography is going
to be trying to relate other concepts to you the viewer,
(03:10):
the intended audience viewer, and the food imagery is of
course showing you something that on some level at least
you want to eat.
Speaker 2 (03:17):
Yeah, exactly. So we're here today to finish off this
series with a few more things about odd and even topics.
So I just wanted to mention at the top of
the episode here a few more interesting ideas I came
across while reading about events and odds. Previously, we talked
about some evidence that at least in certain contexts, people
(03:39):
like some numbers more than others. For example, they may
have more positive emotional feelings about even numbers, or at
least about numbers that are easily divisible because one of
the studies we talked about in Part one apparently found
that people had more positive feelings toward even numbers and
numbers to visible five. Coming back to the question of
(04:03):
certain numbers feeling more even or less odd than they
really are. So a great example is that twenty five
is an odd number, but why does it feel like
an even number? To me? I would say the ease
of divisibility by the sub base of five is a
pretty good guess. And this sort of brings me back
to an idea I first encountered in a couple of
(04:24):
the articles that we were talking about in Part one
by a British author named Alex Bellows who writes newspaper
columns about mathematics and puzzles sometimes, but it also written
a book addressing some of these topics. And in these
articles he talked about people's feelings about odd and even numbers,
and the idea he raises that if it's true that
(04:44):
people sometimes feel better about even numbers than odd ones,
what if that sense of liking for even numbers is
related to the concept of processing fluency. Now, this is
a psychological concept that has come up the show before.
The gist of the idea is that a lot of
the judgments that humans make, from whether we like something
(05:08):
to whether we trust a piece of information or believe
something is true, a lot of these judgments are influenced
by our subconscious reaction to how easy it is for
us to mentally process the stimulus in question. There are
a lot of studies looking at this. I remember this
came up when we were discussing the illusory truth effect,
(05:31):
the idea that if a claim a claim may have
no real evidence for it, or you may have no
particular reason for believing a claim is true, but if
you hear it repeated a bunch of times, it starts
to feel more and more true to you. And one
of the popular explanations for this effect is the idea
(05:52):
that hearing a hearing a claim on subsequent exposures increases
its process in fluency because it's more a miliar to you.
You've heard it before, so it's easier to take in
the second, third, fourth, fifth time you hear it, and
thus it because it has increased processing fluency, it just
feels more right, It feels more true. One of the
(06:13):
key findings that already came up in some of the
papers we talked about in Part two is that it
seems even numbers are on average more easily processed than
odd numbers are. You know, when it's easier to think
about even numbers, we can more quickly classify them mathematically
as even numbers, it's easier to think about doing mathematical
operations with them. Odd numbers are just they're introducing friction
(06:37):
to your brain when you have to consider them. And
if this is the case, it could be a major
contributor to these particular situations where people seem to like
even numbers better than odd numbers. But of course we
don't always like even numbers better than odd numbers. And
this comes back to the issues of these additional bits
of context and cultural associations happen to pin onto these numbers,
(07:02):
and whether at the time of us having a feeling
about a number or making a judgment about it, these
other associations become salient. So anyway, that brings me to
another line of research that I stumbled across when looking
into this, that I thought was curious and sort of
funny also, which is the apparent association between number parity
(07:24):
and the social concept of gender. Now in much the
same way, it seems absurd that without any context, in
other words, without quantifying anything in particular, specific numbers whatever
feel good or bad to people. It also seems kind
of absurd that anyone would think of standard Arabic numerals
as masculine or feminine. But there are some experiments in
(07:48):
which researchers claim to have found that in some contexts
there is a pattern of gendered associations between odd and
even numbers that emerge.
Speaker 1 (07:58):
This is interesting because I I was thinking about gender
numbers earlier in the research process for this series, because
I ran across an interesting skit about the number one
on Sesame Street.
Speaker 2 (08:10):
Oh care to elaborate?
Speaker 1 (08:11):
Oh sure, sure, So in this sketch, this is from
nineteen ninety seven, so this is not one that I
was originally exposed to as a kid. But we have
number one, which is of course a muppet. It is
the numeral one, and it is a she. So the
number one she is feeling really down about herself because
she is such a low value number, like you know,
(08:34):
it's just she's it's one and then zero, like all
the other numbers are more potent than her, more important
than her, and she feels she's really feeling down in
the dumps about it. Well, who comes up to cheer
her up? But the Count? Oh, And the Count proceeds
to sing an entire song for her about how important
(08:54):
she is numerically, and then afterwards he's like, do you
feel better? And she's like, well a little bit, and
he says, well, I'm going to sing it for you
one more time. But it got me think. It's like, well,
you know, I didn't think about one being male female,
what have you? I didn't think about the gender of
the number one. I just considered it like a number.
(09:17):
But now I'm thinking of it. I just can't help
but picture it with like the big full lips and
the beauty mark here from this nineteen ninety seven Sesame
Street sketch.
Speaker 2 (09:25):
Well, that is adorable. I like the Count. I hope
that the Count can help any number feel better about itself.
All numbers are important, but one is really special.
Speaker 1 (09:34):
Yeah. I think the Count is going to be the
biggest fan, the biggest supporter of any number. He's not
going to pull a Harry Neilson and talk about how
crappy the number one is and how number two is
also no good. He's a big fan of all of them.
Speaker 2 (09:48):
I like knowing you can count on the count for
emotional support, so anyway to mention A couple of these
studies apparently finding this association between gender and number parody.
A couple of the ones I came across were by
a pair of researchers named Wilkie and Bodenhausen. One of
these papers was from twenty twelve in the Journal of
(10:09):
Experimental Psychology, another one by the same authors from twenty
fifteen in Frontiers in Psychology, and these papers published the
results of a number of different experiments about the gender
associations of odd and even numbers. Now, some of these
experiments involved explicit judgments, just asking people straight up whether
(10:30):
they felt like specific numbers were more masculine or feminine,
and other experiments looked for indirect associations, like people's tendency
to interpret the faces of babies or unfamiliar foreign names
with different genders when they were labeled with different numbers.
And to note that this indirect measure here does rely
(10:52):
on implicit association tests, which have been subjected to various
methodological critiques over the years. They've undergone some refinements over
time to try to improve reliability. But there's still sort
of debates about how they can be depended on and
in what context. So anyway, caution on relying too much
on the implicit parts of these findings. But the authors
(11:13):
say from the totality of their experiments that on average,
for some reason, people from sample groups within the United
States are more likely to say that odd numbers are
masculine and even numbers are feminine. And while that's the
general trend, there are some exceptions and caveats. While they
say that this pattern was on average true for everyone,
(11:36):
the association was stronger among women, So on average, women
were more likely to view odd numbers as more masculine
and less feminine than even numbers. Weirdly, this is where
it starts getting funny. I thought the numbers in when
the numbers involved were two digit instead of one digit,
men started to drift away from this parody association and
(12:00):
started to say that all numbers were masculine, regardless of parody.
So I don't whenever we look at studies like this,
By the way, I always like raise caution because I
just know from experience a lot of people get real
excited about like gender differences in responses to psychological experiments
and then start overinterpreting, thinking it explains everything about men
(12:21):
and women. Oh, you know why my husband or my
wife acts a certain way, et cetera. And so I
will raise the same caution here. You know, it's just
a few experiments. We're not sure if this is a
super robust finding, and even if it is robust, it's
easy to get carried away just reading too much into
little psychological quirks like this. However, I could not resist
finding it hilarious to imagine a guy looking at numbers
(12:44):
higher than nine and being like, thirty four. Huh, that's
a big number. That's a macho man.
Speaker 1 (12:50):
In between thoughts about ancient real right.
Speaker 2 (12:53):
Yeah, so in reality it's probably not that simple, but
I was laughing for several minutes after I read this. Anyway,
the authors of these studies, so they're making an argument
not that there actually is something objectively or universally gendered
about even and odd numbers, and instead they're sort of
making a case about what they call, quote, the pervasiveness
(13:15):
of gender as a social scaffolding for generating understandings of
abstract concepts. So the way I take that is they're
sort of saying gender is such an important concept to
people that we subconsciously apply it to categories of objects
that have nothing to do with the primary understanding of
masculinity or femininity. It's just like a major way of
(13:39):
making category distinctions that the brain kind of defaults to,
even in situations that don't have anything to do with
biological sex or with the social roles of gender.
Speaker 1 (13:50):
Right right, So yeah, it wouldn't be like the hypothetical
male in question is making a conscious effort to think
about all higher numbers as men. It's a little more
new as a little more subconscious than that.
Speaker 2 (14:05):
Now I mentioned that those studies were done on us
test subjects. I came across an interesting variation with respect
to culture. So there was a twenty twenty one study
in Frontiers and Psychology by Jordan Yakani and Sheen which
found some consistency and some variation across cultures regarding the
perceived gender of numbers. These researchers tested whether the same
(14:30):
patterns of association between number parity and gender would show
up among Arabic speaking people native to the UAE, and
their top level findings were that there were patterns of
gender association with number parity, but on the implicit association
of numbers with faces, the subjects in the UAE were
more likely to associate even numbers with their own gender,
(14:54):
whichever that was so, men seeing even numbers as more masculine,
women seeing even numbers as more feminine. And these findings
indicate that it may be cross culturally common to associate
even in odd numbers with gender, at least in some
weekly held way, to make some kind of weak association
of that kind, but that the association can vary from
(15:18):
culture to culture, which actually makes a lot of sense
to me that I think the idea would sort of
be that gender is a category lens that we're very
quick to apply to all kinds of phenomena outside of
its primary cultural meaning, but exactly how we apply it
probably depends on a lot of subtle influences that can
(15:38):
easily vary person to person and culture to culture, though
apparently within a given language culture, one way of making
the association is probably more common than another. So anyway,
all the warnings I gave up top about not reading
too much into these kinds of findings, but I do
think if this is basically on the right track, it's
an interesting example of the way that we we just
(16:00):
kind of recklessly apply category distinctions across every domain of life,
whether it really makes direct sense or not. You know,
I think we if we ever talked about the idea
on the show before, some people seem to think like
dogs or boys, cats or girls.
Speaker 1 (16:16):
Yeah. I have caught myself falling into that trap as well,
Like I kind of on a default level assume cats
are girls and dogs are boys until I know differently
concerning individual cats and dogs, and I don't know. One
reason for that is probably that I've only ever had cats,
and those cats have always been girls. I don't know, yeah,
female cats. Sorry, some of them have been very old ladies.
Speaker 2 (16:39):
Then again, at least cats and dogs are like animals.
You know. It's I guess it's even funnier thinking about
the way that we we just wantonly apply these categories,
possibly even to things like abstract numbers and symbols that
that don't even have like you know, bodies or minds
or anything. Yeah.
Speaker 1 (17:00):
The only the other prime example that comes to mind
is when especially a ship but sometimes other vehicles or
gendered as female.
Speaker 2 (17:07):
Yeah, that always seemed funny to me.
Speaker 1 (17:20):
All right, Now for this next little bit, I wanted
to talk briefly about the word odd. I was looking
at other angles on odd and even, and I came
across this excellent write up on Websters, and it points
out that the word in English comes from the Old
Norse word audie odd i, meaning point of land in
(17:41):
the geographical sense. So it's like the point of a triangle,
and so it eventually came to mean triangle, and it
also came to mean odd, as the point of a
triangle triangle must always oppose the two other corners, so
it's like the two other corners are an even pair,
and if they were to leave, then the audi is alone.
Speaker 2 (18:02):
Wow, that's almost poetic. That's like a beautiful etymology.
Speaker 1 (18:06):
Yeah. And eventually from here the term transfers over into English,
and by the fourteenth century it was written down, so
you know, it may have made the journey. It probably
it definitely made the journey earlier than that, but that's
when we have written evidence of it. And initially the
word odd meant without a corresponding mate, so it was
still like tied up with this idea of like to
(18:29):
leave and leave one. But then it comes to mean
irregular or non conformist, and Webster's notes that during the
fifteenth and sixteenth centuries, this usage of odd in English
language was a good thing. It meant you stood out,
you know. It's like, oh, look at that odd character there,
We've got to go chat him up. He has lots
of interesting things to say as he drinketh from his
skull and walketh is bear. But then by the seventeenth
(18:52):
century it comes to lean more toward the eccentric and
even dare we say, the weird, in the sense that
you might be like, let's stay away from the guy
with the bear and the skull. Lord knows what he's
going to talk about. Let's keep a distance. Wow.
Speaker 2 (19:09):
It almost invokes like a story in the sense that
if you imagine there were three people and two of
them left, and now one is odd. Why did the
other two leave? Were they driven away by the behavior
of the first one? Or could they just not handle
the genius?
Speaker 1 (19:25):
Yes, and my apologies to Lord Byron Fans, since he's
barely covered in the centuries reference there. But Webster's also
points out that the use of the noun odd for
a point of land seems to have crossed over a
second time into English during the nineteenth century, though more
exclusively to northern England and Scotland. Oh and one more
(19:47):
little bit here that I ran across. Audi is also
the name of a town in Iceland. And well, I'm
not as sure about the direct linguistic connection here between
what we're talking about and the name of the town
I did run across. The picture of a statue of
Salmon the Wise hitting the Devil, and the devil may
(20:08):
or may not be in the form of a seal
here with a bible. This was I found this a
photograph of this on a blog post by eric O
Scott on the website The Wild Hunt. And this ties
into a past episode because in our series on Shadows
from last October that is going to re air this October,
we talked a little bit about the shadow wizard and
(20:30):
priest semond or Semonder, the Wise, who has various encounters
with the Devil. I don't think we talked about him
hitting the devil with a Bible, but there is an
episode where he ends up having his shadow stolen by
the devil.
Speaker 2 (20:45):
Right doesn't he go to like the Devil's College or
the Devil's School to learn the learn the magical arts.
But then the devil is supposed to grab one of
the students at the end of the semester and keep them.
But semen, they're various tellings, but semen find some way
to kind of trick the devil and escape.
Speaker 1 (21:02):
Yeah. Yeah, and he like goes to snatch his soul
and gets his shadow instead and so forth. So I
don't know, I'm drifting drifting off topic here, but we're
still somewhere in the neighborhood of a lot and even now. Next,
I would like to turn to evens and odds and biology.
This is an area that, uh where you can you know,
(21:24):
I guess with any of this you have to, especially
when you're playing in to biology, you have to think
about like the relationship between numbers and reality, and you
can get, you know, kind of go do a fair
amount of navel gazing on that in and of itself.
But you know, just as we see a tendency for
external symmetry and biological organisms, we at least to some extent,
see a tendency toward even numbers. Again, huge caveat here.
(21:48):
It kind of it can also depend on exactly how
you want to cut it, because you know, you can
take a quick survey of your own body, and chances
are you're going to find some even numbers in play.
You know, two arms, to let, four limbs total, ten fingers,
ten toes, two eyes, two nostrils, and so forth. On
the other hand, I mean, yes, you do have one
(22:09):
mouth and so forth. But you know, the still of
course lines up with the basic idea of bilateral symmetry.
Divide a creature down the middle and you have two
equal sides, though of course we also have to throw
in the other caveat that the average human being is
not perfectly symmetrical, and artificially symmetrical faces tend to read
as uncanny to us.
Speaker 2 (22:28):
For this reason, we actually did a series on biological
symmetry and asymmetry a couple of years back. I don't
recall it was that the series called The Lesser of
Two crab Claws, where.
Speaker 1 (22:40):
I think the fiddler crabs mm hm, yes, Because you know,
there are plenty of examples too in the biological world
which we get into in that series, where there is
a glaring asymmetry. So anyway, it would be a gross mistake. Though,
coming back to odds and evens, if you were to
say that you only see even numbers and organisms. That
is absolutely not true, and they're ultimately far more common
place and satisfying ways to apply numbers more universally to nature,
(23:04):
such as say the Fibonacci sequence so forth. But it's
still interesting to see cases where there is that there
seems to be a tendency toward even numbers, and still
looking at the exceptions to those possible rules and possible tendencies.
One place that start is with chromosomes. So a chromosome
is a DNA package that contains all the genetic material
(23:25):
of an organism, and the chromosome count for individual species
varies greatly, and it has nothing to do with it
doesn't correlate with the apparent complexity of an organism. So
you know, for example, a jack jumper and has a
single pair of chromosomes, while turkey has eighty. A human
of course has forty six, and then you have a
(23:46):
case like and to be clear, you can also get
odd numbers via genetic disorders. But one of the biggest
examples it's often brought up of an odd number of
chromosomes in an organism is the mule. This is a
cross between donkey and a horse of course, and it,
you know, tends out for having sixty three and they're
usually infertile because of this. And there's some other interesting
(24:09):
outliers as well, like the Indian Mutjak, in which males
tend to have seven to the female six. In the
swamp Wallaby you see eleven for males and ten for females,
and there are various other examples of this nature. But
of course this is all hidden to the naked eye.
Limbs stand out far more in human consideration when we're
talking about evens and odds, and so this raises the
(24:31):
question what if anything naturally has an odd number of arms?
And basically the answer is nothing except blank. And I'll
come back to the blank in just a second. But
there's one potential possibility that often comes up if you're
just scanning the names of the popular names of organisms,
and it's one. There's one that came up on a
(24:53):
Monster Fact episode several weeks back. There is a species
of octopus known as the seven armed octopus.
Speaker 2 (25:02):
Now that is an oxymoron, isn't it right?
Speaker 1 (25:05):
Right? Because if you know anything about octopi, it is that,
as the name implies, they have eight arms. So if
you had a seven armed octopus that that would be interesting.
Why does it have why does it seem to have
seven arms? So this octopus is also known as the
septipus or the blob octopus, and it is Halofron atlanticus.
(25:30):
And here's the thing, it actually does have eight arms.
It like, do not believe the popular name. Uh, it's
just that the males specialized fertilization arm. It's hectocoidalus remains
coiled away in a sack beneath the right the right eye.
So this is a specialized arm. In various sephalopods have
(25:53):
these and there it's the kind of arm that will
be used to slip in genetic material or sometimes it
is like left detached and left with the mate. So
this species has a specialized arm for mating, and it
keeps it stored away out of sight behind the right eye.
And so if you're just checking out the specimen and
(26:15):
you don't know what to look for, you might see
only seven arms and assume, well, here we are, it's
a seven armed octopus. But like I said, there are
some examples of animals with an odd number of limbs.
But to find one we have to look to the
marine invertebrates known as c stars, which tend to boast
five arms, though they can't have more depending on the species.
(26:39):
Five arms in a radial presentation. I mean, everyone knows
what a starfish looks like. You've seen SpongeBob. You get
the general idea.
Speaker 2 (26:47):
Oh okay, and here's where we get into the different
types of symmetry that are found in animal body plans. Right.
Because while most animals, and especially most animals we're familiar with,
have a bi ladder really symmetrical body plan it can
be divided down the middle and folded in half, there
are some animals that live, especially in the ocean, that
(27:08):
have a radially symmetrical body plan, meaning it can be
it is symmetrical in that it has copied segments, but
they are copied by going around in a circle instead
of folding in half down the middle.
Speaker 1 (27:20):
Yeah. Yeah, And this is a This is especially interesting
concerning the sea star because this comes back to something
we talked about perhaps last October as well, that, according
to some analysis, particularly a twenty twenty three study publishing
the journal Nature by Formery at All, the c star
(27:41):
is really more of the head with five or more extensions.
They're not really arms. They're more like head projections, which
is an interesting way of looking at it. But another
thing that they point out in this article is that
sea stars evolved from an ancestor that add two fold
or bilateral symmetry, and it develops from larvae that also
(28:05):
have twofold or bilateral symmetry, but they have a typically
you know, fivefold radial adult body plan. So yeah, another
fascinating example. Now, another place to look for even numbers
(28:29):
in a mammal is, of course, look to the nipples.
Humans typically have two of these, though to be clear,
you do have situations where people have, like say, a
third nipple, but generally speaking you're dealing with a two
nipple scenario. If you have a cat, you can. I
don't recommend feeling around because unless you're a professional, because
you will often get clawed for this. But cats have
(28:52):
six to eight nipples, and indeed most mammals have an
even number of nipples. But if you turn to the marsupial,
the American opossum, you will find a famous outlier here
with an array of thirteen nipples.
Speaker 2 (29:10):
Now, don't start putting your cultural associations on the opossum.
No one of its nipples is the unlucky one.
Speaker 1 (29:17):
Now, because when you look at the number of young
they have like it's it's it's the like the ghost
nipples past thirteen that were the unlucky ones, because they
generally have and this is environmentally dependent, they generally have
like twenty young. So not everybody's gonna get a nipple
and survive. But but yeah, you can. You can look
up I don't strongly recommend the opossum nipple google image search,
(29:41):
but you can. You can find some illustrations that I
think are ultimately more helpful and better for you, know,
your sanity, than looking up the actual images of opossom
nipple arrangements. But the illustrations give you the general idea.
So I've seen this described as two arches of six nipples,
(30:03):
with one nipple located centrally. I've also seen it talked
about in terms of being like a U shape or
circular shape inside of the female opossum's pouch. Now, there
are various other classifications of the un and odds we
might get into there. Of course, odd toed and even
toed ungulates. Tapers, for example, have four hoofed toes in
(30:24):
the front and three hoofed toes in the back. Most
rhino species have three digits on each foot and in general, though,
and we've gotten into this a bit in the past,
especially when we talked about horse hoofs, evolution has resulted
in digit numbers greater and less than the human five
that we take for granted, you know, because you can
(30:45):
look at the horse's hoof and see it as a
single toe, a single great toe foot. And we see
the opposite as well in some other organisms, with the
development of a sixth pseudothumb. This is you can find
these in the giant panda, for example, where this has evolved.
It's not truly an additional digit on the hand, but
(31:06):
it is basically like doing the work of an extra
partially evolved digit to aid in the NonStop consumption of bamboo.
And then we also see a remarkable pseudo thumb emerge
on the hand of the II lemur. So the II
(31:27):
lemur may be a lemur that a number of view
familiar with from various nature documentaries, because it is a
very weird, goblin esque looking creature. It's it's it's wonderful,
I say it is. It is weird. In all of
the great ways that an animal can be weird. You know,
it is nocturnal. Uh, it again looks kind of like
a goblin, and it has these very specialized hands that
(31:49):
feature a super long middle finger, which it uses. Uh.
It uses it specialized hands to like cap on wood
and then uses that that super long middle finger to
reach in and dig out grubs and wood burrowing insects
to eat.
Speaker 2 (32:04):
Yeah, so it sort of has nose Feratu hands. But
I can't emphasize enough that the face in many photos
is going, oh dude, it's like very big wide eyes
and the mouth open like it is shouting at you
in excitement and surprise.
Speaker 1 (32:23):
Yeah. So it's the situation those seems to be pretty
fascinating here because they have this super specialized again long
middle finger. It basically has a single use. It's essentially
a unit tasker. But that means that they need a
little more help climbing. So it's like, you know, it's
like they had a callub evolution and say, look, I
need to put an order in for an extra digit.
(32:43):
Why you already have five digits. Well, yes, but I've
specialized one to the degree that it can no longer
help me in climbing. Trees, So do a search for
II hands II fingers to get a sense of what
I'm talking about here. And that's exactly what I was
doing when I found a mention of a study that
(33:05):
I had not run across before. I thought I knew,
like all the main cool things about the ei. But
as it turns out that elongated middle finger is proportioned
as such. First of all, that it would be like
us having a foot long middle finger. But not only
do they use this to fish out wood boring insects
and grubs, but according to Anne Claire Fabre and this
(33:30):
is an evolutionary biologist at the Natural History Museum of
burn as cited in a Cassidy Ward article for Sci
Fi in twenty twenty two, they also use this finger
to pick their own noses, and they get the whole
finger in there to the point that they're able to
reach all the way back through their sinuses to the
back of their throats and then back out again. The
(33:51):
most prodigious nose picking in nature. It has to be right,
certainly with fingers with digits. You know, there may be
other strong candidates. They're involving animals with very like prehinsile
tongues and so forth.
Speaker 2 (34:05):
But they zoologists right in with better nose picking in
the animal world.
Speaker 1 (34:10):
I mean, this has got to be one of the
top cases. So I mean, that's okay. So I'm getting
off off topic a little bit from the evens and
the odds here, but that study or and or that
sci fi article is definitely worth picking up, in part
because they include an illustration of just how far the
finger is thought to go into the skull, and you
(34:30):
get like a cutaway of the II's skull to show you,
like how deep it goes, all the way to the
back of the throat. Pretty fascinating.
Speaker 2 (34:38):
You really wouldn't want to, like trip and fall while
you're doing that.
Speaker 1 (34:41):
No, all right, I have one more biological tie in
here concerning odds and evens and animals, and this has
nothing to do with the actual biology of the species.
It's all about the way we categorize them. We have
what are called tautonyms. This is when you have a
speed sees alike Rattus rattus, in which both parts of
(35:04):
the name are identical. The genus is rattus and the
species is also rattus, So you have Rattus ratus or
are rattus.
Speaker 2 (35:13):
Yes, we've discussed a number of these before, But.
Speaker 1 (35:16):
Then there's a step beyond mere tautonyms. There are triple tautonyms.
This is where the scientific names end up, I think,
being rather hilarious at times, and resembling as well magical
spells of summoning, bringing to mind incantations of beetle juice
and bloody Mary, where you're saying something three times in
(35:39):
a row, and anything said three times in a row
will start sounding silly. For instance, there is a buffo
bufo buffo, the European toad, so it's genus buffo, and
then the species is Buffo bufo beautiful. We also have
the black rat that's Rattus ratus ratus, and then we
have the South African giraffe or giraffa Giraffa.
Speaker 2 (35:59):
Giraffe sounds the most like a spell.
Speaker 1 (36:01):
And there are other fun examples as well, like the
European eagle owl Boobo Boobo boobo, the Eurasian magpie or
Pika Pika Pika, and these are all again richly amusing,
because anything you say three times it's just gonna sound silly.
Speaker 2 (36:15):
Wait, isn't that what Pikachu says?
Speaker 1 (36:17):
Pikachu's definitely, says Pikapka. I don't know if there's a
third Peka in there or not for.
Speaker 2 (36:21):
When Pikachu really means it.
Speaker 1 (36:23):
Yeah, another interesting thing about this is you'll only find
these in zoology because they are forbidden in botany under
the International Code of Botanical Nomenclature. So you're not going
to find anything like cannabis, cannabis, cannabis because it's just
forbidden that we don't do that in botany. Leave that
(36:44):
to the zoologists. They're the silly ones.
Speaker 2 (36:46):
Well, I like this. I think the botanists should do it.
Maybe they just don't have the guts.
Speaker 1 (36:51):
Yeah, I didn't get in deep enough to find out
like when this law was laid out and like how
for what reason? Like why did they really need to
take a stand on this. But maybe we'll have to
get into that another time.
Speaker 2 (37:03):
I'm just kidding with you botanists. I know you have
plenty of courage. All right, Does that do it for
this series? On even an odd.
Speaker 1 (37:11):
I believe so. Yeah, like you said, we've had our
third episode. We had a nice odd number of episodes
for it, so I think we're good to go.
Speaker 2 (37:19):
Obviously, there are even an odd instances of pretty much everything.
So we could keep going forever, but we got to
stop somewhere exactly.
Speaker 1 (37:27):
Yeah, yeah, So we'll go ahead and you call it here.
We want to remind everybody that's Stuff to Blow Your
Mind is primarily a science and culture podcast, with core episodes,
publishing and the Stuff to Blow Your Mind podcast feed
on Tuesdays and Thursdays, short form episodes on Wednesdays. On Fridays,
we set aside most series concerners to just talk about
a weird film on Weird House Cinema, and then we
(37:50):
have some bald episodes or reruns at air on Saturdays
and Mondays.
Speaker 2 (37:55):
Here's thanks, as always to our excellent audio producer JJ Posway.
If you would like to get in touch with us
with feedback on this episode or any other, to suggest
a topic for the future, or just to say hello,
you can email us at contact at stuff to Blow
your Mind dot com. Stuff to Blow Your Mind is
(38:19):
production of iHeartRadio.
Speaker 1 (38:21):
For more podcasts from My Heart Radio, visit the iHeartRadio app,
Apple Podcasts, or wherever you're listening to your favorite shows.
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