Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
This is just such a fascinating thing. We're joined by
doctor James Pampush, PhD, who teaches at High Point University
and his area of study.
Speaker 2 (00:10):
One of his areas of study at least has.
Speaker 1 (00:12):
Been the evolution of facial structures of primates and people.
And he wrote a just a fascinating piece about what
was entitled the Enduring Puzzle of the Human Chin, and
the question becomes white humans and only humans have chins. So, James,
thanks for making time for us, Thanks for joining us
(00:33):
on KWA.
Speaker 2 (00:33):
It's good to have you here. I'm really sorry. I'm late,
Ross I was. I'm in my research space. As you
can see, I can see just lost track of time.
Speaker 1 (00:40):
That's okay, that's all right. I'm glad you're I'm glad
you're researching. And I bet it's something very interesting. Uh really,
I bet it's because this is this is unbelievable. So
how did how did you even get to this question
of why do humans have chins? Well?
Speaker 2 (00:53):
I think it's a I think one of the most
attractive things about it is that we're the only animals
in the history of Earth to exhibit this feature. And
before someone calls in and says oh, my dog or
cat has a chin. The definition of a chin is
you have this extra boss or this bump of bone
(01:14):
at the lower end of your at the bottom of
your jaw that sticks out past your front teeth. It's
super weird, like, no other animals have this, and not
only do no other living animals have it, no animal
ever in the history of life has ever had it.
We're the first critters to ever exhibit this really strange thing.
And so as a consequence, I think a lot of
(01:34):
people are drawn to it because it's so incredibly strange.
That's not what cooked me permanently onto it kind of things.
I became much more. I became very interested in it
because when you start to read about people's explanations for
why we have chins, or you start to ask them
what they think why they think we have chins, it's
(01:56):
really it reveals a lot about how they actually think
the evolutionary process works, and the kinds of biases that
they bring into understanding the underpinnings of how morphology is
built and arranged and works. Okay, so that's why it's
a really it's it's actually a much deeper topic than
(02:17):
just looking at a strange feature, right.
Speaker 1 (02:20):
Okay, so let's do let's do the superficial thing first
and then let's spend a few minutes on the deeper part.
And I know you're probably speculating, but it's probably well,
it would be very well informed speculation. But normally you
think of of physical attributes as having some kind of
evolutionary benefit. I guess they don't always have to. What's
(02:41):
your best guess as to why we have a chin?
And then we'll talk about the other stuff.
Speaker 2 (02:46):
Okay, So we can break chin hypotheses into two big categories,
functional hypotheses, meaning that like they believe that it's there
for a purpose. That's that's sort of what you're asking
me right now. It's like, all right, well, what suppose
it function? Does this thing potentially serve? And the best
ones out there are that it's a sexual ornament that is,
(03:07):
like the opposite sex is attracted to it, and so
therefore having a nice chin means that, like, oh, I'm
going to attract more mates. Okay. Another hypothesis is that
it's useful in chewing or stress or dissipating stress in
the jaw, so that like if we use it, because
you know, we chew a lot. And then the third
(03:28):
one is that it's related to speaking or speech somehow,
And so what it argues is that like, we need
this extra chunk of bone to I don't know, dissipate
tongue movements or anticipate the strain from chewing, and or
or again that it's an ornament. None of these really
(03:50):
stand up well. And the reason is that, well, part
of the reason is methodological. So the core of how
we researchers study a feature like this is using a
technique called the comparative approach. And the comparative approach says,
all right, well, if this thing is useful for doing this,
(04:12):
we do expect all animals who do this to exhibit it.
And you immediately run into a problem with the chin
because we don't have anything to compare it to. There's
no other animal out there that exhibits this thing. So
you're kind of like left grasping at like, all right, well,
we could make a model that does these different things
and to see if the one with the chin performs
(04:34):
better than these other ones. And actually, when you do
something like that, chins are not effective at chewing. It
turns out like the major stress of the jaw when
you close. It is a force called wishboning, where it's
like you're pulling the jaw apart at the back end.
And you could probably experience this when you clench. You know,
the back of your jaw is being pulled apart like
(04:56):
a wishbone would be. And actually having extra bone and
runner your teeth actually exacerbates that problem. It actually extends
the moment arm you have more leverage to do more damage,
you know, So actually don't want that if you're chewing,
you want your chin to be on the backside of
your teeth, in seid of the front. So this is
a good example of like why these things, these different
(05:17):
models are all failures. All right. So it's like I
only have about there's no good functional explanation. I only
have about two minutes here.
Speaker 1 (05:24):
So first I'm just going to give you a theory,
and then I want to take the last bit on
talk to with.
Speaker 2 (05:28):
Some of your deeper things.
Speaker 1 (05:30):
I think chin's evolved because without them, football players helmets
would not be able to stay on because the chin
strap wouldn't have anything to hold on to. And I
think that's as good a theory as anything else you
just said. So that's that's my theory, and I'm going
with it.
Speaker 2 (05:45):
True, that's not bad. Nose has evolved for glasses and
there you go. There you go.
Speaker 1 (05:51):
So okay, so take them innute now, and literally I've
got about.
Speaker 2 (05:53):
A minute and a half.
Speaker 1 (05:54):
But take a minute and talk about how the chin
shows in interesting and perhaps incorrect ways of thinking in
the world of people who are thinking about evolution.
Speaker 2 (06:06):
Okay, it's quick, the speed run on this as fas
I can do it. The main way that people study
evolution is by trying to apply natural selection to different
problems to be able to say, oh, well, this morphology
functions to do this thing, and therefore natural selection chose
for it. And then that's like how we mostly explain
(06:29):
the different aspects of the being, but it ignores like
how you grew it, and that's often more primary, Like
can you make this thing is a more basic question
than whether or not the thing can do the job
once you've made it, And so like one way of
doing one better way of looking at it is perhaps well,
how did we make a chin and like through the
(06:52):
developmental processes, and what might that tell us about why
it's there, especially in light of the fact that we
can't explain it functionally, and so like it really reveals,
like how people think about the evolutionary process. Do they
think about natural selection as being like an engineer, in
which case it can build anything it wants, or is
it more of a tinkerer who has to like monkey
(07:13):
around the edges of whatever's already in place. And so
it's really revelatory about how people think about the evolutionary
process writ large. And if we had more time we
could talk about it.
Speaker 1 (07:25):
Let me just try to squeeze in one last quick
thing here in your research about this, and you're talking
to people about this, since it's not easy to explain
the presence of a chin based on the way people
usually think about this, do you ever have people say
that because there's no typical traditional evolutionary explanation, it must
be a sign of creation.
Speaker 2 (07:47):
Yeah, sometimes people make complaints like that. They say, like, oh, well,
look science is incapable of explaining this thing. Therefore God
must have intervened. And like even Newton was used to
doing that, Like when he couldn't explain like the way
some orbits decayed, he said, all right, God's invisible hand
must be coming in here, and really, that's just like
(08:09):
I mean, it's just like trying to plug a hole
with something that makes you feel good. I suppose like
really not being able to answer something really is like
how you know that you're working on something important
This is just such a fascinating thing. We're joined by
doctor James Pampush, PhD, who teaches at High Point University
and his area of study.
Speaker 2 (00:10):
One of his areas of study at least has.
Speaker 1 (00:12):
Been the evolution of facial structures of primates and people.
And he wrote a just a fascinating piece about what
was entitled the Enduring Puzzle of the Human Chin, and
the question becomes white humans and only humans have chins. So, James,
thanks for making time for us, Thanks for joining us
(00:33):
on KWA.
Speaker 2 (00:33):
It's good to have you here. I'm really sorry. I'm late,
Ross I was. I'm in my research space. As you
can see, I can see just lost track of time.
Speaker 1 (00:40):
That's okay, that's all right. I'm glad you're I'm glad
you're researching. And I bet it's something very interesting. Uh really,
I bet it's because this is this is unbelievable. So
how did how did you even get to this question
of why do humans have chins? Well?
Speaker 2 (00:53):
I think it's a I think one of the most
attractive things about it is that we're the only animals
in the history of Earth to exhibit this feature. And
before someone calls in and says oh, my dog or
cat has a chin. The definition of a chin is
you have this extra boss or this bump of bone
(01:14):
at the lower end of your at the bottom of
your jaw that sticks out past your front teeth. It's
super weird, like, no other animals have this, and not
only do no other living animals have it, no animal
ever in the history of life has ever had it.
We're the first critters to ever exhibit this really strange thing.
And so as a consequence, I think a lot of
(01:34):
people are drawn to it because it's so incredibly strange.
That's not what cooked me permanently onto it kind of things.
I became much more. I became very interested in it
because when you start to read about people's explanations for
why we have chins, or you start to ask them
what they think why they think we have chins, it's
(01:56):
really it reveals a lot about how they actually think
the evolutionary process works, and the kinds of biases that
they bring into understanding the underpinnings of how morphology is
built and arranged and works. Okay, so that's why it's
a really it's it's actually a much deeper topic than
(02:17):
just looking at a strange feature, right.
Speaker 1 (02:20):
Okay, so let's do let's do the superficial thing first
and then let's spend a few minutes on the deeper part.
And I know you're probably speculating, but it's probably well,
it would be very well informed speculation. But normally you
think of of physical attributes as having some kind of
evolutionary benefit. I guess they don't always have to. What's
(02:41):
your best guess as to why we have a chin?
And then we'll talk about the other stuff.
Speaker 2 (02:46):
Okay, So we can break chin hypotheses into two big categories,
functional hypotheses, meaning that like they believe that it's there
for a purpose. That's that's sort of what you're asking
me right now. It's like, all right, well, what suppose
it function? Does this thing potentially serve? And the best
ones out there are that it's a sexual ornament that is,
(03:07):
like the opposite sex is attracted to it, and so
therefore having a nice chin means that, like, oh, I'm
going to attract more mates. Okay. Another hypothesis is that
it's useful in chewing or stress or dissipating stress in
the jaw, so that like if we use it, because
you know, we chew a lot. And then the third
(03:28):
one is that it's related to speaking or speech somehow,
And so what it argues is that like, we need
this extra chunk of bone to I don't know, dissipate
tongue movements or anticipate the strain from chewing, and or
or again that it's an ornament. None of these really
(03:50):
stand up well. And the reason is that, well, part
of the reason is methodological. So the core of how
we researchers study a feature like this is using a
technique called the comparative approach. And the comparative approach says,
all right, well, if this thing is useful for doing this,
(04:12):
we do expect all animals who do this to exhibit it.
And you immediately run into a problem with the chin
because we don't have anything to compare it to. There's
no other animal out there that exhibits this thing. So
you're kind of like left grasping at like, all right, well,
we could make a model that does these different things
and to see if the one with the chin performs
(04:34):
better than these other ones. And actually, when you do
something like that, chins are not effective at chewing. It
turns out like the major stress of the jaw when
you close. It is a force called wishboning, where it's
like you're pulling the jaw apart at the back end.
And you could probably experience this when you clench. You know,
the back of your jaw is being pulled apart like
(04:56):
a wishbone would be. And actually having extra bone and
runner your teeth actually exacerbates that problem. It actually extends
the moment arm you have more leverage to do more damage,
you know, So actually don't want that if you're chewing,
you want your chin to be on the backside of
your teeth, in seid of the front. So this is
a good example of like why these things, these different
(05:17):
models are all failures. All right. So it's like I
only have about there's no good functional explanation. I only
have about two minutes here.
Speaker 1 (05:24):
So first I'm just going to give you a theory,
and then I want to take the last bit on
talk to with.
Speaker 2 (05:28):
Some of your deeper things.
Speaker 1 (05:30):
I think chin's evolved because without them, football players helmets
would not be able to stay on because the chin
strap wouldn't have anything to hold on to. And I
think that's as good a theory as anything else you
just said. So that's that's my theory, and I'm going
with it.
Speaker 2 (05:45):
True, that's not bad. Nose has evolved for glasses and
there you go. There you go.
Speaker 1 (05:51):
So okay, so take them innute now, and literally I've
got about.
Speaker 2 (05:53):
A minute and a half.
Speaker 1 (05:54):
But take a minute and talk about how the chin
shows in interesting and perhaps incorrect ways of thinking in
the world of people who are thinking about evolution.
Speaker 2 (06:06):
Okay, it's quick, the speed run on this as fas
I can do it. The main way that people study
evolution is by trying to apply natural selection to different
problems to be able to say, oh, well, this morphology
functions to do this thing, and therefore natural selection chose
for it. And then that's like how we mostly explain
(06:29):
the different aspects of the being, but it ignores like
how you grew it, and that's often more primary, Like
can you make this thing is a more basic question
than whether or not the thing can do the job
once you've made it, And so like one way of
doing one better way of looking at it is perhaps well,
how did we make a chin and like through the
(06:52):
developmental processes, and what might that tell us about why
it's there, especially in light of the fact that we
can't explain it functionally, and so like it really reveals,
like how people think about the evolutionary process. Do they
think about natural selection as being like an engineer, in
which case it can build anything it wants, or is
it more of a tinkerer who has to like monkey
(07:13):
around the edges of whatever's already in place. And so
it's really revelatory about how people think about the evolutionary
process writ large. And if we had more time we
could talk about it.
Speaker 1 (07:25):
Let me just try to squeeze in one last quick
thing here in your research about this, and you're talking
to people about this, since it's not easy to explain
the presence of a chin based on the way people
usually think about this, do you ever have people say
that because there's no typical traditional evolutionary explanation, it must
be a sign of creation.
Speaker 2 (07:47):
Yeah, sometimes people make complaints like that. They say, like, oh, well,
look science is incapable of explaining this thing. Therefore God
must have intervened. And like even Newton was used to
doing that, Like when he couldn't explain like the way
some orbits decayed, he said, all right, God's invisible hand
must be coming in here, and really, that's just like
(08:09):
I mean, it's just like trying to plug a hole
with something that makes you feel good. I suppose like
really not being able to answer something really is like
how you know that you're working on something important
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