Invertebrate Emotions, Part 2

Humans are feeling creatures, constantly awash in a sea of emotion. We struggle to understand the waters that suffuse us, but what about other denizens of the animal kingdom? What about the octopods? In this Stuff to Blow Your Mind two-parter, Robert and Joe explore the question of invertebrate emotions.

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Episode Transcript

Speaker 1 (00:03):
Welcome to stuct to Blow Your Mind production of My
Heart Radio. Hey, welcome to Stuff to Blow Your Mind.
My name is Robert Lamb and I'm Joe McCormick, and
we're back with part two of our exploration of invertebrate emotions.
In the last episode, we talked about the paper Nautilus

(00:23):
or the argonaut. We read that great Marion More poem.
We talked about what emotions are, the difficulties and studying them,
and we talked about anecdotes about people really seeing personality,
character and emotion in octopuses, but then also scientific studies
looking for certain types of measurable cognitive effects of emotions

(00:44):
or emotion like states in invertebrates like bees. We talked
about the judgment bias test and how bees might have
biases that come about in optimistic or pessimistic ways based
on how they're quote feeling. Yeah, A big part of
the conversation last episode was I think, ultimately about stripping
down emotion to something that doesn't depend upon the subjective

(01:06):
human experience, and in doing so, something that I don't
want to make it sound like we're, oh, we're just
we're cutting out all the important stuff. I think a
lot of what we're cutting out is the poetic stuff,
the the the the extra like self contemplation stuff, and
getting down to the root of what is an emotional state,
How does it affect um our behavior and our expectations,

(01:29):
And then you know, how do we see that echoed
in other organisms? Right? Well, we're cutting out yeah this
by cutting out the subjective element. We're cutting out the
part that would be impossible to study in other animals
and just trying to say what our emotional states as
manifested externally. Yeah, But then of course the difficulty, as
we discussed, is by taking out the subjective aspect of it,
we're taking out the part that is closest to us

(01:50):
and the thing that you instantly think about when we
even say the word emotion of sweet emotion. Oh no,
that song fills me with bad emotion, did you. Oh?
I don't know if I ever gotten to do this
rant before. Y'all know I hate Aerosmith. Oh no, I know, well,
I think you may have mentioned it once in passing. Yeah,
even even the early stuff. I don't know. I mean,

(02:11):
I can be that classic rock radio uncle, like you
know when led Zeppelin comes on, I'm like, yeah, I
feel it, but I don't know that. Something about Aerosmith
just turns my head three sixty degrees. Well, I have
to admit it. Really like in dream On that's that's
if I hear that one on classic rock radio, I'll
tune in and listen. Well, I'm glad you like it. Hey, folks,

(02:33):
this is Joe from the Future swooping in to alter
the past. Sorry about the audio, but I realized on
listening back to this episode that in our excitement about
the topic, we forgot to reintroduce the paper that we
were talking about in the first episode, and then we're
gonna be talking about throughout this one as well. So
that paper was by Clint J. Perry and Luigi Bachi,
a Donna, and it's called Studying Emotion and Invertebrates What

(02:56):
has been done, what can be measured, and what they
can provide. It was published in the Journal of Experimental
Biology in Okay, now back to our original conversation. Okay,
but uh so, the last time we we talked about
one of the main three branches of external ways of
studying emotions and animals. We talked about you know that

(03:18):
they're there are perhaps cognitive effects of emotions, that emotions
affect how you perceive the world and how you think.
That there are behavioral tests of emotions, that emotions affect
how you act, and that there are physiological tests of
emotions that emotions affect involuntary physical reactions in the body.
And we last time we looked at cognition. This time
we're gonna look at the other two. So the first

(03:40):
would be behavioral tests behavioral signs of emotional states. And
one of the things that I think we should first
acknowledge is that I'd say this is the primary way
that we sense emotions in other people. What do people
usually do with their bodies, especially their faces, when they're
feeling various emotions. But as the authors point out quite helpfully,

(04:01):
they say, quote, invertebrates lack the facial musculature for any
real type of comparisons to be made in this regard.
So I think that the jury is in. You can't
tell if a hornet is smiling. You can't tell if
there is disgusted on the face of that crab. Yeah,
I mean, as if a crab had a face anyway. Right, Um,

(04:22):
but my flogging that horse again, it's not really a
horse I flog, but no, no, no, actually you're right.
I think i'd degree the crab. I don't know crabs
pushing it. I don't know if a crab has a face. Yeah,
I mean it definitely has the front of a head.
But that front of a head with the crab is
not really it's not used for communication. Crabs depend on

(04:43):
sound as well as you know. The claw waving and
overall movement displays general body language, but predominantly sound is
their their form of communication. The wasp, for their part, uh,
they depend primarily on smell for a communication. We will
get into that a little bit in the last episode
with the beest. So their commune occasions since realm is
not really our own, um, they exist in a in

(05:05):
a different realm in that regard. Right, But the behavioral
effects of underlying emotional states are not limited to facial
expressions alone, just because that's maybe the main way we
see emotions in other people. Uh. The author's right quote.
A substantial amount of work in mammals has utilized other
bodily expressions and motor behavior in response to stimuli to

(05:26):
assess both valence meaning the pleasantness, and intensity, meaning the
level of arousal of emotions, and I really think the
horse is a great example of this for a couple
of reasons. First of all, the horse is an animal
that is, that lives in close proximity to humans, that
is adored by humans. That is, that is often you
know championed as being this next to the dog and

(05:48):
you know the cat. I guess it is. It is
a friend of humanity. And uh, and my wife being
super into horses and pretty knowledgeable about them, she's just
told me about some of this before, but I was
I also looked up a source on this for this
episode How to Read Your Horses Body Language by Jennifer Williams,
PhD for Acquis Magazine, and Williams points out that if

(06:09):
a novice or to view a skilled horse trainer in action,
they might well guess that this individual is psychic or
has some sort of mystical Cormick McCarthy in connection to
the soul of the horse, you know, the deep, dark,
mystical soil soul of the horse. But it's really all
about knowing how to read these other signs, the overall
body language of the horse, and then these other sort

(06:32):
of non facial or semi facial cues. Well, yeah, I
mean think if you're a dog person, if you've got
a dog in your house, think about like, how finally
a tune you are to your dogs feelings, levels of excitement, motivations,
and and quote emotional states or you know, there's something
that is analogous to these emotional states. Uh that if

(06:53):
somebody who had never met a dog before or hadn't
spent much time around dogs saw you interacting with your dog,
they might well think the same thing. You must be psychic. Yeah,
but no, A lot of it is about picking up
on all of this language, or indeed just knowing what
to look for. So in in the case of the horse,
for instance, um ear position is very important. This is
one of the apparently the first things you tend to
learn about about understanding a horse's emotional state. So that

(07:17):
the ears may face forward, meaning they're interested. They may
be pinned back, meaning they're angry and they're prone to
bite or act you know, aggressively slashed defensively. Uh. They
might be turned out to the side meaning they're relaxed.
They might be turned back but not pinned, and this
means they're listening to something behind them and it also
means they might decide they need to turn around to
go look at it, and horses, being large animals, that's

(07:39):
something to be aware of. Uh. And then they also
might be rapidly swiveling, meaning that they're anxious or at
their you know, at a high level of alertness. But
then on top of that there's also head carriage, head
maybe lowered, elevated snaking. You have to consider four leg
and hind leg movement and position, muzzle activity, which this

(07:59):
some of this it's more in line with what you
might expect from a face, you know, like what are
the nostrils doing? Uh? You know, what what's the mouth doing?
What are they doing with their teeth? That sort of thing.
There is a certain level of like what are their
eyes doing? Uh? You know, to someone that doesn't really
know anything about horses, it's easy to sort of think
of the eyes as being sort of like big empty
glasses without a lot of emotion. But there is stuff

(08:20):
you can read into it. There's the movement of the tail,
and then there's just general whole body stuff like what
is the overall bodily tension of the animal, how is it?
How is it moving? And uh? And you can read
take all of that and read into the emotional state
of the horse. But if you just look at you
know what you might be tempted to call the face

(08:41):
of the horse, You're not necessarily going to pick up
on on all those cues you have. And I think
part of this two gets we have to think about
the human situation. So clearly humans have body language. You know,
there's more than just the facial communication array with human
beings totally, but we do depend on the facial communication
array a lot and do fixate on it to a

(09:01):
very large degree. But basically, what I'm trying to say,
using the horses in an example that there are there
are there are various parts of an organism that you
can look to to to figure out what their emotional
state is, and it may or may not be something
that matches up with the human idea idea of a face. Yes,
so what would be some of these external behaviors that

(09:25):
we could measure in invertebrates? One of the most obvious
behavioral signs of underlying emotional states and animals is retreat behaviors.
So but you know, like in fear or anxiety, animals
will retreat, retracting or covering vulnerable body parts, adopting defensive posture,
and running away. These are some of the clearest ones

(09:46):
to look for in all of animal behavior. And so
the first example cited by the authors here looks at
exactly that. And it's actually a study we've already mentioned
on this show before. It came up in our episodes
titled Devour of Memory. Remember that about about the planaria
and the and the research about whether you could gain
somebody's memories by eating their body. Uh So in this

(10:09):
episode that we mentioned to study about a type of
large sea slug called the California sea hair or Aplasia californica.
Uh And in that other episode the study came up
because it demonstrated associate of learning and classical conditioning in
an invertebrate sea slug. So, you offer a sea hair
some delicious shrimp extract, but in the test group, well,

(10:32):
the sea hair is munching on the shrimp extract, it
gets an electric shock to the head that this painful
stimulus results in not a frown, of course, but measurable
behaviors in the slug. It withdraws its head, it withdraws
its siphon, it inks, and it moves away from the
shrimp at extract, and sure enough if you train it

(10:52):
on these associations when simply when the animals from the
test group are simply presented with shrimp extract, they will
pull back the siphon and move away. By the way,
see hair and the electric shrimp extract would be a
great name for a band. Just to put that out there,
I think that was a Bob Weir side project. Okay um.
But whether or not it makes sense to use the

(11:14):
same word we use for emotions and other mammals quote
the observed behavioral responses to conditions stimuli resemble the actions
of conditioned fear in mammals. Subjectively, it might not make
sense to talk about fear in a sea slug. We
don't know, but it certainly behaviorally looks like fear. It
looks like the same thing we recognize this fear in
mammals or in other humans. Because of course, nothing about

(11:37):
the shrimp extract itself causes pain. It couldn't be a
simple stimulus response. It has to be this association with pain,
the memory of you know, the fear caused by the memory,
and a lot of invertebrate studies into emotions look for
signs of fear because fear is easier to study. Presumable
fear inducing stimuli are relatively easy to create, and behavioral

(11:59):
response says are relatively easy to detect. There's another example
that the author's site here, which is fear research into
Drosophila also known commonly as fruit flies or as vinegar
flies small fruit flies. Uh. This is an extremely common
organism for lab research. You'll find tons of studies modeling
other things in complex organisms as they appear in Drosophila.

(12:22):
So in T. Gibson at All studied fear and Drosophila
caused by the stimulus of an overhead shadow. They used
a rotating opaque paddle. I don't know if it was
a ping pong paddle that I kind of hope it was.
It was some kind of paddle that would be made
to rotate in a circle in in in a steady progression,

(12:42):
repeat passages over a container of these these flies that
would be, say, eating a food source or something. And
the authors found that multiple repetitive exposures to this overhead
shadow caused the flies to fly around more, to hop more,
to freeze more, and to fly away from a food source,

(13:04):
and there was evidence in this study that the passing
shadow led to a generalized internal state. The more times
the shadow passed over, the more avoidance responses happened. So
it looks like within the flies, it wasn't just stimulus response.
The shadow passes, then you fly away. If you are
repeatedly subjected to this stress inducing stimulus, the flies appear

(13:27):
to enter a state where they're just They're just in
a semi permanent way agitated. They're flying around, they're they're
leaving the food source. It looks like they have the
internal state of being afraid, and the avoidance responses remained
remained more elevated even after the stimulus stopped. The shadow
would stop passing over, and for some time afterward, the

(13:48):
flies acted more agitated, more likely to fly away from
the food source than flies with less exposure to the shadow.
And this makes it seem as if the avoidance reactions
were not just the direct and get response to the shadow,
but also influenced by this internal state within the flies
nervous systems, which is similar to how fear works and
humans and other vertebrates. Something jumps out and scares you,

(14:11):
you have an immediate response maybe you shriek, maybe you
pee a little, you know, maybe maybe you jump, But
then you also remain in a state you're on edge
for several minutes afterwards, showing these anxiety behaviors even when
the scary thing is gone or no longer represents a threat. Unfortunately,
this is a lot of how we live our lives actually, right, Like,

(14:32):
there's something that kind of like startles you, gets you
on edge, and maybe it's not even something that would
be a physical threat. Maybe it's just a conceptual threat.
You know, you get an email or a tweet or
anything that kind of puts you on edge, and then
you just stay that way for a good long while. Yeah, yeah,
all day generally. Yeah, what happens when you reach for
your phone first thing in the morning, right, And I

(14:53):
think that that's an important thing. It calls to to
attention the difference between fear and anxiety. Year of course,
is a response to the perception of an immediate threat,
a clear and present danger, and it results mostly in
escape behaviors by animals. You're trying to, you know, defend
yourself and get away, Whereas anxiety is related to fear

(15:15):
but slightly different. Fear is a response to the clear
and present danger. Anxiety is a response to ambiguous, imagined,
or potential threats. When there's a threat that's not necessarily
right in front of you, but you imagine it might
be waiting nearby, it might be around the corner. It's
kind of lurking in the the the information sphere around you,

(15:38):
as opposed to being right there in front of you. Uh.
And of course, the bringing back to the human experience,
we have no shortage of fear is just sort of
rotating around us in the information sphere, and this state
of anxiety actually brings us to the crowd ads. I know,
we promised we'd we'd get there eventually. A k A crayfish,
a k A. Mudbugs. Did you call girl calling him bugs? No,

(16:01):
this is what I've just heard them called. Did you
catch them in the creek? No? I know I was
never around them growing up, but I have family that
lives in southern Mississippi, and you know they're they're all
about them, uh down there. In fact, I've been to
and this will this will be like an image to
come back to. As we discussed their possible emotional states,
I went to a Marty Gropp parade not the main

(16:24):
Marty graparade, but I like, you know, one leading up
to it in southern Mississippi, and there were like games
where live crawfish were were thrown by children, Like they
would throw crawfish back and forth at each other and
then occasionally fall onto the concrete and all and um. Yeah,
at the time I thought it was weird and kind
of barbaric. So maybe I'll feel even more so as

(16:44):
we discussed their their their inter emotional states here, so
it gets turned inward as well. Though. Do you ever
play the game, I assume you didn't or see people
play the game where you just let a crawdad pinch,
you know, just like let it pinch your nose or
your finger or something. No, did you do this crowing up? Uh? No,
but I had friends who did. Where was this in Tennessee?

(17:05):
They were crawl crawdads just in the creeks. I guess
there were probably a different species, I'm not quite sure
than the one we're about to talk about, but yeah,
there were some kind of crayfish shaped organism living in
the creeks, freshwater creeks. Yeah, okay, yeah, yeah. My main
experience with them is just occasionally eating them as an
adult um. But that's about it. Never got to like

(17:25):
play with them as a child. But for anyone out
there who does doesn't it still doesn't know what we're
talking about. It's essentially a small crustacean like a fresh
a small fresh water generally lobster, right, tiny lobster. The
specific UH species that's going to come up in the
in the research we're getting to is Procamboris clarkey. And yes,
these are the crawl fish of the famed Louisiana crawfish boil.

(17:48):
So I don't know if they were if they were
boiled up with some zatarans and eating after the test.
I should also add that sometimes you'll see crayfish in
aquarium settings and it can be quite beautiful as well,
So you know, I don't think human and humans humanities
relationship with the crayfish is mostly uh, mostly something that

(18:08):
revolves around eating them, but sometimes you'll see them as pets. Now,
to come back to the idea of anxiety, we were
talking about the difference between fear and anxiety. You know,
we're saying fear often results in escape behaviors. Anxiety is
often thought to result in conservative or defense behavior, for example,
to limit openness and to limit exploratory behavior. Animals in

(18:30):
an anxious state are more likely to seek out closed, familiar,
and protected in environments, whereas animals in a non anxious
state are more likely to explore unfamiliar and open environments.
And one type of experiment that has been used to
study anxiety and animals like rats and mice and now
in crayfish, is the elevated plus maze. So, Robert, had

(18:52):
you ever seen one of these before? I don't think
I'd encountered one of these before, and I don't remember
encountering one in a study. I've certainly never been in one. Uh. So,
you imagine a simple platform in the shape of a
plus sign. You've got two arms of the plus sign
that are enclosed by walls, and then the other two
arms are open. They're just straight platforms without walls. And

(19:15):
this shows up in all kinds of studies. How an
animal moves within an elevated plus maze or EPM can
be manipulated by lots of variables that are thought to
control anxiety. The more time the animal spins in the
closed section enclosed by the walls, you know, sort of
protected and hidden, usually the more anxious it is thought
to be, and many animals, maybe most small animals, tend

(19:38):
to prefer dark, enclosed places. These are the types of
places that they are more likely to be protected from
predators in their natural environments. Like the rat in your house,
it likes to hide inside the walls and behind the
fridge and stuff. It doesn't like to hang out in
the middle of the floor, right, like a wide open
spaces that's where a hawk can swoop down and q

(20:00):
out that sort of thing. Right, It will only venture
out into the open spaces in order to explore and
seek rewards. It might go out there if there's food
in the middle of the floor, um, But if it
sees something scary, what does it do? It runs to
an enclosed space. The more an animal like a rat,
has an induced state of anxiety due to an ambiguous
or possible threat, the more it will tend to confine

(20:21):
itself to dark, enclosed spaces. And conversely, the less anxiety
it has, the more it will feel free to explore
open spaces. Uh and the e p M is widely
used in studying animal anxiety and in the testing of
anti anxiety medications. Now Here's where the crowd ads come in.
So the elevated plus mayze has been widely used in

(20:42):
anxiety research like we're saying, and almost all these studies
have been on vertebrates, but since there have been at
least two studies using the plus mayze test on crayfish. Again,
this is procam Borus Clarkey, and the updated design used
an elevated plus mayze submerged in water with the enclosed
arms shaded so that they were dark because in their

(21:05):
protected environments, the crayfish like dark places. That's a natural
defensive preference they have. So there were a couple of studies.
One was Fawcett at All in fourteen and one was
back quay casinave at All in seventeen, and they both
found that if you subjected the crayfish to frightful stimuli

(21:25):
ahead of time, they would spend more time in the shielded, dark,
enclosed areas of the elevated plus may So the examples
were mildly painful shocks and harassment by a larger crawfish.
So like if you take a smaller crayfish and then
subject it to a bigger one doing dominance displays the
one the little one, the one that is being harassed

(21:46):
will tend to spend more time in the enclosed area
and less time exploring the open platforms and the author's
right quote. These behavioral results fulfill criteria normally designated for
anxiety and mammals, including being innate, being unconditioned, occurring in
the absence of a stressor, and expressed in a novel context. Alright,

(22:06):
so in this experiment we see the evidence that a crayfish,
something we don't think of as having emotional states, really
ultimately has something very similar to the the fear that
is experienced by a mouse or a rat, and therefore
very similar to what we experience. Right, So it's not

(22:27):
just stimulus response. I mean you could you might imagine
that an animal without emotional states could say, retreat in
the immediate term from something that's threatening it by going
into an enclosed space, but even afterwards it seems to
remain in this internal state where it prefers to stay
in the close, protected spaces and does less exploring than

(22:48):
a control crayfish if it has at some recent time
been threatened or harassed. It sounds like a familiar story. Yeah, yeah, Like,
like I say, if we take away sort of the
the holy human qualities of fear. Uh, and look at
it objectively, like that's what we're looking at here, we're
looking at the fear of the crawfish. Well, maybe we

(23:10):
should take a quick break and then when we come
back we can discuss the joy of the fire ant.
Thank thank alright, we're back. So the authors of this
study we've been looking at point out one shortcoming of
the existing body of research on animal emotions, and it's
that it is, as on the whole, overly focused on
negative emotions. Quote. It is argued that the reasons that

(23:33):
positive emotions have been neglected in research are because they
are few in number, reflected even in the imbalance of
English language words for negative over positive emotions, and are
harder to differentiate. The asymmetry might also stem from our
understanding that natural selection has shaped emotions more for survival
than for prosperity. There are many more threats than treats

(23:56):
in our environment. Also, they point out that we're looking
for tests mirroring work done on humans. Most psychological and
clinical work in the history of science has been focused
on solving problems rather than on studying ways in which
people are doing fine all of which I think is
probably true. I mean, I think all of those reasons
are valid. But despite these limitations, it would be great

(24:19):
to have more research attempting to understand positive emotions or
the state's analogous to positive emotions in non human animals
and invertebrates like it. It's just kind of a bummer
and kind of limiting when it's overwhelmingly research on fear
and aversion. Yeah, that that's an interesting point about like
even the the the English language bias for negativity as

(24:41):
opposed to positivity. Uh, it makes me think of going
to our our neighborhood reality the only video rental store
in the city or state video Drome. Video Drome has
a sizeable horror selection, and I love to lose myself
in it. But what is the opposite of the horror section?
There's not really one, I guess what the maybe the

(25:02):
comedies but Robert Altman section though maybe that. I mean,
even you know, any comedy, any drum, anything that's not
like straight up like little Kids cinema, I mean, to
whatever extent that exists, Like anything that's not just teletopies
is going to have risk and danger, and these negative
emotions that are there to at least propel the corresponding

(25:23):
positive ones. Yeah, I think you're exactly right, And I
think the point they're making is a good one. That
it's not necessarily that there's more you know, uh, negative
emotion than positive emotion and human life, but that for
some reason we're more we're happier to let positive emotions
all kind of blend together and be the same thing.
They're all just you know, there are million different forms
of happiness and joy, but we don't have as many

(25:45):
differentiated words for those states, you know, whereas you know,
we're we're very into getting down in the nitty gritty
of different types of ways to feel bad. Well, I
guess one of the it kind of comes back a
little bit, probably to some we've discussed before, the idea
that when you're happy, if you contemplate about your happiness,
if you stop to consider your happiness, then it goes away.

(26:09):
But if you don't need to think about it too much,
you don't really have enough time to get to nuanced
in the language, whereas a negative, a good negative emotion
will just really sit there and you can get to
know it. You can you can really uh, you know,
formalize your relationship with it. Yeah. Now. On the other hand,
there have been a few studies that have gone against
this trend of focusing overwhelmingly on negative emotions in these

(26:32):
animal studies. For example, in the last episode, we talked
about the one cognitive tests, the judgment bias test, that
at least appeared to show the cognitive effects of something
like pleasure or happiness in the bumblebee. You remember, it
was like, if you give the bumble bee a free treat,
give it some free sugar, it will tend after that
to at least appear to have an optimistic bias to

(26:54):
interpret ambiguous information as as being something good or approachable.
The next line of research involves the behavior and ants
that some researchers think may be associated with an internal
state analogous to happiness or joy. Uh So, what might
the dreaded fire ant have in common with your favorite
cute puppy wagging? Butt wagging? Do tell? Do tell? Alright? So,

(27:19):
the red imported fire ant or Solenopsis invicta has displayed
a very interesting behavior observed by a number of researchers.
Reported in a study in Steen by Debbie Castle, christophord Liu, hun,
Daniel Schiffmann, and S. Bradley Vinson called a study on
abdominal wagging in the fire ant Solenopsis invicta with speculation

(27:42):
on its meaning in the Journal of Bioeconomics. So, the
researchers were just watching lots of hours of video taken
from inside a fire ant nest, and from these observations
they started to notice a pattern of behavior where the
ants inside the nest would basically stick their butt up

(28:02):
in the air and wave it around. Quote they position
and move their abdomen up and down at forty five degrees,
and they called this behavior wagging. Now, raising and wiggling
the abdomen has uses in other contexts for fire ants.
You may have seen fire ants doing this defensively. The
abdomen or back segment of the body is also known

(28:24):
as a gaster which is great like Charles Dickens name,
you know, like like William Gaster uh. And outside the
nest the behavior is known as gaster flagging. The flagging
usually involves raising the abdomen up higher something more like
nine d degrees. Flagging is apparently used during foraging to
disperse venom into the air, and it's believed to deter

(28:46):
other insects like competitor ants from the foraging area. So
you're out trying to gather food for the colony, and
then some other ants come in. You will stick your
butt up in the air and spit some venom out
into the air to try to drive the other ants off.
There's also some evidence that some abdominal wagging or gaster
flagging emits a sound as the gaster joint rubs across itself,

(29:09):
and this would be a tiny, high pitched squeak. We're
not sure what role this sound plays, but it's possible
that as a it has a role in communications, such
as calling for help when an ant is trapped or
when it's in trouble. However, Castle at All believe that
in their observations the inside the nest, wagging behavior was
not defensive in any way. Within the nest, they found

(29:31):
that the wagging emitted neither sound nor venom, no squeaks,
no toxins, and the stinger was never extended during this period.
So if they're just wagging around and it has nothing
to do with the other types of wagging that these
ants normally do, what's going on. Furthermore, they found that
the inside nest, wagging happened primarily when the ants were

(29:52):
engaged in two activities, eating sugar or tending to the brood,
in other words, taking care of the young. Well, those
are two pleasurable experiences just for humans, sure, And they
did not find any evidence of nestmates reacting to the wagging,
so they couldn't detect any role for communication in the wagging.
So what's it for. Well, the author's hypothesized that quote

(30:16):
this in nest behavior might be analogous to facial expressions
and bodily postures of hedonic pleasure in humans and other
mammals during pleasurable events. So that's a very interesting idea.
Perhaps a fire aunt smiles by wagging its gaster in
the air. Now we should definitely acknowledge, and the researchers

(30:37):
do acknowledge that this is far from proven. That there
are a few other possibilities to Maybe the wagging is
some kind of mechanical reaction in the body to certain
uses of the mouth parts. Soon the mouth parts would
be engaged during eating or during tending to the brood.
Maybe something's happening that just happens to make their butt
wiggle in the air at the same time. So it

(30:58):
would help if this could be paired with other types
of tests. For example, would consuming sugar water or tending
to the brood also caused the fire ants to have
an optimistic bias in judgment bias tests. That would probably
strengthen the case for this wagging as a bodily expression
of something like pleasure or happiness. But I love the possibility.
Maybe the ant smiles with its But but again, this

(31:21):
would this would come down to as some physical body
language that is observable that would potentially demonstrate the emotional
state of the creature, right, and it would be helpful
if you could pair it with other things that were
presumed to be associated with that same state. Now, another
one about positive emotions comes back to bumble bees, which

(31:43):
we mentioned in the last episode. Remember earlier there was
this research seeming to indicate that giving a bumblebee some
free sugar would result in an optimistic bias in these
cognitive tests. Another test on bumblebees looked at the effects
of sugar water on behavior after a stressful event. So
in the yild, bumblebees are subject to ambushes by certain
sit and wait predators, such as the crab spider, have

(32:07):
you ever seen a crab spider in action. I'm not well.
So they will tend to wait on a flower, uh,
and they'll just kind of blend in there among the
petals that they've got these wide legs, uh for a
big hug. And then when the bee lands on the
flower to try to get some nectar, the crab spider
will grab it with its legs and try to bite

(32:28):
down and kill it. And a lot of times in
natural encounters, the bee is briefly captured by the spider
but then manages to escape. So in a experiment, Perry
at All created a simulation of a crab spider attack
by putting together a mechanism that would ambush and trap
a bumblebee for three seconds before releasing it unharmed. Now, obviously,

(32:51):
after a stressful brush with death like this, the bee
will take some time before it again begins to forage
and start landing on flowers and stuff. And what Perry
had All found was that a treat of sugar water
given before the attack would shorten the duration of this
cool down period after the spider attack. So if a

(33:11):
bee gets a sweet treat before a simulated spider attack,
it takes the be less time to reinitiate landing on
flowers and feeding after this stressful event. Now, again, there
could be other interpretations of what's happening here. Maybe somehow
the nutrition and the sugar makes the bee physically stronger
and less vulnerable, etcetera, And maybe something like that. But

(33:33):
one possibility is that the pleasurable stimuli of the sugar
water puts the bee in something analogous to a better
mood or emotional state, making it more resilient to stressful setbacks,
which I think is something that we're probably all familiar
with ourselves. Right. You know that your emotional state is
uh dictate strongly how you will react to negative incoming events.

(33:56):
The same thing that floors you one day, I'll just
kind of bounce off you another right right, Or if
you've had a particularly bad day, then bad news is
going to you know, have a more negative effect on
your well being right now. The authors identify vocalizations and
sound as a possibly very fruitful behavioral avenue for future
research and invertebrate emotions, noting that Charles Starwin himself speculated

(34:19):
in eighteen seventy two that quote insects might potentially communicate
emotions such as anger, terror, jealousy, and love through their stridulation,
you know, the great rubbing together sounds that insects make.
So what does a jealous cricket sound like. I'm not sure,
but it's easy to imagine all the various anthropomorphic interpretations.

(34:41):
So regarding our our, our ideal cartoon cricket, I'm sure.
Do you even remember how in the original Pinocchio, Pinocchio
kills the cricket with a hammer? What? Yeah, the cartoon
or no story? Not? No, no, not in the movie.
The movie changed it and made it nicer in the
original story, Jimmy Cricket, Yeah, oh man, I don't remember

(35:01):
if he's named Jiminy Cricket. I think he's just a
magic cricket and Pinocchio kills him with a hammer. I
didn't know that Pinocchio is in one of his bad phases. Uh.
You know, I don't think I like Pinocchio. I don't
have a lot. I don't have a strong affinity for
the Disney version either. The only thing that I have
a strong affinity for is Jimmy crickets role in the
Mickey Christmas Carol, in which he plays what the ghost

(35:24):
of Christmas past I believe. I don't. I don't know
if I've ever seen that. Oh, you should see. It's
like thirty minutes long, and it's it's a pretty good
streamlined adaptation of a Christmas Carol. Oh, I'm sure it's
better than the other thirty minute version of a Christmas
Carol I've seen, which is called the Christmas Carol and
it's narrated by Vincent Price. It's very bad. Oh man, Well,
later this year, when Christmas rolls around again, I think

(35:47):
we should do an episode on a Christmas Carol. I
think there's a lot of discuss there. Okay, well, maybe
we should take a break and then when we come
back we can talk about physiological tests. Alright, we're back,
So are entering the final phase here. We're going to
be discussing physiological tests for emotion. Right, So we've talked
about cognitive tests, We've talked about behavioral tests. Physiological tests

(36:10):
for emotion. Uh. In people, they look for correlates between
reported emotional states and automatic responses in the body. So,
for example, somebody jumps out at you with a werewolf mask,
You're not just gonna jump back. It's not just gonna
maybe give you a pessimistic bias, But you will also
have increased heart rate, release of stress hormones like norap
and effer and cortisol, dilation of the pupils in the eye.

(36:32):
You might be a bit, you know, a bunch of stuff.
And a lot of this is because it's not just
that you saw a werewolf. It's that your body is
preparing you to fight a werewolf or run from a werewolf. Right,
the fight or flight response kicks in and and it
entails this cascade of automatic reactions in the body, things
that you don't control behaviorally. They just happen without your

(36:53):
say so. And these physiological responses can usually be measured
objectively pretty easily, which is very handy. How our physiological
responses alone can be they can be hard to use
to identify individual emotions. For example, if you're measuring a
heart rate, heart rate might increase in response to anxiety
or to joy. The fact that the heart speeds up

(37:14):
it's beating tells you there's some kind of arousal, but
it doesn't necessarily tell you which. One person's heart could
just be full of song. Right. So, sometimes if you
look at enough different physiological responses at the same time
and compare them. You can start to zero in on
specific emotions, but not always UH. And just like it's
hard to translate research on human facial expressions to invertebrates,

(37:38):
it's also hard to do so with human physiological responses
to emotions. UH. The authors write, quote, most of these
types of measurements are quite difficult to apply to invertebrates
given their often miniature size and hard carapasts, and in
the case of insects, an open circulatory system where heart
rate is not increased. But there has been some interesting research. Nonetheless,

(38:00):
they cited a bunch of it just to pick out
a couple of examples. Kita at All In two thousand
eleven did research on fear conditioning, this time in pond snails,
very expressive species. UH. They conditioned the pond snails with
an association between sugar water, which normally you give some
give some sugar water to them and they will start

(38:20):
feeding behaviors. But they negatively conditioned this with potassium chloride
associations and potassium chloride causes withdrawal of the body into
the shell. UH. Not only did fear conditioning work, the
snails began to react to the sugar by withdrawing, but
physiological monitoring also found that conditioned exposure to the sugar

(38:42):
caused the heart to skip a beat quote, suggesting physiological
responses similar to fear in mammals. So you train them
to associate potassium chloride, this noxious chemical, with the sugar,
then later you just present them with sugar. Not only
do they not go for the sugar, it makes their
hearts skip up eat though I do think it's interesting
to note potassium chloride is literally a heart stopping poison.

(39:05):
It's been used to cause cardiac arrest and lethal injections.
Of course, there was no potassium chloride in the sugar
once it was conditioned, but maybe that's just a coincidence.
But the idea is that been presented with the with
the sugar, then after being exposed to the potassium chloride,
there is this this moment of physiological fear in response. Right,

(39:26):
the body reacts in a way similar to mammals reacting
to the werewolf mask, but this time it's just sugar
that the snail has come with training to associate with
a bad chemical. So it seems that the majority of
research on physiological correlates of invertebrate emotions has to do
with the presence of what are called biogenic amines, which

(39:47):
are thought to play a major, if not comprehensive role
in the creation and control of emotions in the human brain,
especially the hormones and neurotransmitters serotonin, dopamine, and nora adrenaline.
Now as important as these three substances clearly are in
our emotional lives, unfortunately it is not as simple as

(40:07):
saying one is a happiness drug in the body and
one is a fear drug, etcetera. They play complex interacting
roles in everything from attention and arousal to reward, motivation,
and sleep, and the manipulation of emotions is generally not
as simple as just saying like, well, you need more
of one of these things, but manipulating the presence of

(40:30):
one or more of these neurotransmitters can have some measurable
effects on emotions. For example, invertebrate nervous systems also appear
to make use of these biogenic amines or analogs to them.
For example, in bees, the hormone octopomy and appears to
play a role similar to that of nora adrenaline and humans,
and so they cite one possible example of these physiological parallels.

(40:52):
Quote Bates and and colleagues in two thousand eleven assessed
how systemic biogenic amine levels changed in response to a
presumed negative emotional event hemal lymph. And remember that's like
insect blood. Hama lymph was collected from honey bees after
simulating a predator attack shaking bees on a vortex for

(41:12):
sixty seconds. And this is like the thing we talked
about in the last episode, where you'd shake the colony
to simulate an attacked by a honey badger. Picking up
with the quote. Analysis of the hemolymph using high performance
liquid chromatography or HPLC showed that systemic levels of the
biogenic amines dopamine, octopamine, chemical chemically similar to noor, adrenaline,

(41:34):
and serotonin all decreased in response to bees being shaken vigorously.
In humans, it seems that depletion of biogenic amine serotonin, noor, adrenaline,
and dopamine is responsible for features of depression in the
monoamine hypothesis of depression, and also in fourteen, Faucet and
colleagues reportedly used chemical manipulation of serotonin levels to alter

(41:57):
anxiety associated behaviors of crayfish, like in the plus maze scenario.
One last one period, all In found that manipulation of
dopamine levels seemed to affect the apparent positive emotional state
of bumble bees. Remember the sugar causing the bumble bees
to have an optimistic bias. Well, here quote the optimistic

(42:19):
behavior scene and the judgment bias test in response to
pretest sugar reward was abolished when the bees were topically
treated with the dopamine receptor antagonist flu finazine. And apparently
the same treatment eliminated the positive effect of pretest sugar
during the simulated attack by a crab spider. So if
you do something to this insect's dopamine levels by by

(42:42):
putting in this disruptor of dopamine, you somehow seemed to
interfere with the bees ability to have an optimistic bias
in response to getting some sugar. Interesting. So, basically, the
more we reveal about sort of the underlying chemistry of
these emotional states, uh as that they are in humans
and as they are in these various invertebrate species, it

(43:03):
just reveals that, yeah, we have emotional states occurring in
these organisms at least the physiological correlates of them. Right again, Yeah,
we can't begin to get into the subjective aspect of it,
which you know made you know very I don't think
it's a stretch at all to say that whatever a
crawfish is experiencing is fear, is different than what a

(43:23):
human is experienced in his fear. It can't it can't
contemplate the fear at the same level that that a
human can. But like the root of it, like the
root chemical and physical, physiological, um manifestation of that emotion
is essentially the same. Right. And I think now we've
seen maybe not conclusive, but pretty good evidence in three

(43:43):
different branches, not just the physiological which we were just
talking about, but earlier the cognitive and in the behavioral spheres.
And I think we should emphasize again you know what
you're getting at. None of these tests are perfect. Even
if all the results are robust, replicable, they hold up
over time, they still don't necessarily tell us anything about
what it's like to be a bumblebee or a crayfish.
I think there's always going to be that gap that

(44:05):
we are perhaps jumping with the rocket boots of anthropomorphic projection.
But for now, experiments like these are the best evidence
we have to try to figure out what kinds of emotions,
if any, are present in insects, crustaceans, gastropods, and all
manner of creatures without a spine, And those things we
learned could be very helpful in helping us understand how

(44:27):
emotions in mammals, including humans, developed over evolutionary time, because there,
you know, we we look at modern invertebrates and see
nervous systems. You know that their brain structure is very
similar to what we think our ancestors may have had
at certain times in history. We can learn what the
chemical mechanisms of emotional motivation states are, how they came

(44:49):
to be. Humans ain't crawd ads, but crawd ads can
still teach us a lot. I think now at this
point that one question a lot of people they have is, okay,
what sorts of animals don't have emotions? Then? Like, is
there is there any level that we can say, all right,
here's the cut off point? Um? You know, it's it's
an interesting question to consider. Um. And I was poking

(45:12):
around and basically one thing I have to realize is
that is, like we said earlier the quest for invertebrate
emotions is is not as expansive as as other areas
of emotional research, certainly in higher organisms. So there's just
a lot of data we don't have. Um. So you know,
I don't know when you get down to like single

(45:32):
cell organisms, I don't see. I didn't didn't find any
papers arguing for emotional states there, no, uh and even
in the weirdly like we think octopuses are more complex, uh,
you know, in terms of intelligence than these other than
like insects and crayfish are. But I wasn't really finding
much in the way of studying emotions and octopuses. It

(45:54):
was mostly in these simpler organisms. So yeah, there's clearly
still lots of ground to cover. Uh. Now, I mean,
you know, it's one of the I don't think anybody's
actually arguing that, say, a slime mold has emotions either.
But we have discussed in the show how a slime mold, uh,
an organism without like a central nervous system is still
able to learn, it's still engaging in things that are

(46:16):
are are like problem solving. So you know, the stuff
like that adds uh some complexity to this question. But
then another thing that came to mind. Uh, plants the
topic itself. I think we'll have to wait wait for
another episode. But plants can essentially here, see, smell, and
respond to stimuli, and they are, according to a University

(46:37):
of Missouri in Columbia plant science professor Jack C. Schultz,
essentially quote just very slow animals. Um which uh, which
is it is? It is hilarious, But at the same
time it you know, you you you look at say
time time lapse footage of save vines in action and

(47:00):
and flowers and uh and so forth. There just the
movements of of of plants in general. And this does
have that seem to have a ring of truth to
it that this is this is an organism that is
not as still as we uh as we may think.
We touched the this briefly, and though the recent Tolkien episodes,
you know, the the idea of the end, the moving tree,
the tree that thinks and reasons um, may not be

(47:22):
as far fetched as as some of us think. But
as for emotions and plants, uh, there's actually some fascinating
research there as well. But that is another story and
shall be told another time. So hopefully we give everybody
some food for thought here about our own emotional states,
what the human emotional state is and what it isn't

(47:43):
and then to what degree we can perceive and attribute
emotional states to other organisms, even though you know the
lowly crawfish. I mean, I wonder if understanding the way
that that anxiety might affect be ease or crawfish or
something like that, could in wait, help give you a

(48:04):
foothold in controlling your own emotions. I mean again, this
is something we we sort of began the last episode
talking about how the emotions are from our brains. They
are within us, but often it can feel as if
we are in them. You know, there is see on
which we're afloat and we have no power over them, right,
or their external forces like something from out of Greek mythology,

(48:25):
or you know, some sort of a you know, a
fundamentalist um you know, Christian worldview, Angel on one shoulder,
devil on the other, affecting our mental states. But no,
it's it's all within and it is and it is
you know, a part of the same navigation, a reality
that is taking place in all these other organisms as well.
And yeah, therefore, if we demystify it a bit, if

(48:45):
we sort of take a step back from it and
in fact increase awareness of what it is. Then. Yeah,
that gives us, I think, a tremendous strength. You know,
it keeps basically keeping uh, keeping our our irksome brains
from the evening ourselves about what we are. You are
that churning ocean, Yes, which perhaps is some ambiguous information

(49:08):
that you may either see in a negative or a
positive light, depending on your predisposition. All right, so obviously
you all have emotions, and you all have various interactions
with animals, be at a dog, a cattle, horse, or
a crayfish, or or or a b So we would
love to hear from everyone out there on the topic
that we've discussed in these two episodes of Stuff to

(49:31):
Blow Your Mind. Hey, even if you have some thoughts
about plants, go ahead and go ahead and let us
know about those. Uh. In the meantime, if you want
to check out other episodes of Stuff to Blow your Mind,
where can you find this show? Well, you can find
this show anywhere you find podcasts wherever that happens to be.
Just make sure you rate, review, and subscribe. Those are
the acts that help us out huge things. As always

(49:51):
to our excellent audio producer, Seth Nicholas Johnson. If you
would like to get in touch with feedback on this
episode or any other, to suggest a topic for the future,
or just to say hi, you can email us at
contact at stuff to Blow your Mind dot com. Stuff

(50:12):
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