(air whooshing) (mouse clicking) (electronic tones beeping) (pleasant piano music) - [Narrator] We are the paradoxical ape. Bipedal, naked, large-brained, long the master of fire,
tools, and language, but still trying to understand ourselves. Aware that death is inevitable, yet filled with optimism. We grow up slowly. We hand down knowledge. We empathize and deceive. We shape the future from our shared understanding of the past. CARTA brings together experts
from diverse disciplines to exchange insights on who we are and how we got here. An exploration made possible by the generosity of humans like you. (upbeat electronic music) (upbeat electronic music) - Thank you everyone for coming. And, I'll just take a moment to tell you a little bit about how we decided to make
a CARTA meeting entirely on human imagination. And, this is one of those things that, it seems to happens only in San Diego, where two people, and I'm talking about myself, who, I'm a professor in pediatrics and cellular molecular medicine, turns out to be in a meeting sitting together with Sheldon Brown, who's gonna here as a first speaker. And, Sheldon Brown comes from visual art. So a scientist, an artist, we start talking, and we realized that we
have something in common. We are both fascinated
by human imagination. So, I make a challenge to Sheldon, and say, "Well, can we put
this in a scientific context?" And, we start planning
about a meeting like that, and we realized that most of the time, when we try to understand something, if it's unique or enhanced, in humans we turn on to compare to our closest relative, leading relative such as the chimpanzee. And, comparing to other
animals is difficult, especially if you are talking about cognition and imagination. So, this time, I think you're going to
hear lots of speakers talking about imagination in modern humans and also in extinct humans
such a the Neanderthals. And, we hope that the combination of all those speakers, all this knowledge, will help us to understand
a little bit about ourselves and answer those questions
that Ageeth posed to us. - So, as Allyson mentioned, we started talking about imagination, and in part because I direct this center, the Arthur C. Clark Center
for Human Imagination here at UCSD, where we're trying to
understand imagination and then think about ways we might more directly address
imagination as a phenomenon. And, so then this comes
around to think about how might we might think about imagination and its role in human origins? And, I think we have
maybe at least two ways to think about this that we're going to be
exploring in today's program. So, one is what are the
dimensions of our imagination that give rise to our humanity? And, these particular characteristics that allowed homo sapiens
to create our anthropic era. And, another is the critical ways in which our imagination creates
knowledge about things that are beyond our
ability to experience them, whether it's about far off places or far off time, both in the future and in the past. And, so in particular, I'm very interested and curious about how we imagine something as distant from our experience as the origin of humanity. But, it begs the question, just what is imagination? And, so imagination, it's kind of a mushy term. It can mean so many things that it might end up
meaning almost nothing. So, is there a way we
can start to think about how we approach understanding the phenomenon of imagination? And, so we might start by looking at what smart people have said about imagination. And, so, the kind of poster
child for a smart person is Albert Einstein, right? And, so Einstein said quite a few things about imagination over his career. And, just one of these is, "Imagination is more
important than knowledge. "Knowledge is limited, "but imagination encircles the world." And, so Einstein might have
been a pretty smart guy, but this actually says almost
nothing about imagination. It's very inspiring. But, the only thing I
really take from this is that imagination is extensive, so that's a characteristic
that I can draw from it. So, maybe someone who has a
little more stakes in the game can give another kind of
shading about imagination. And, Maria Montessori, an educator, so imagination is probably
a very important thing for an educator to say something about, and for Montessori, it was, "Imagination does not become great "until human beings, "given the courage and the strength, "use it to create." So, she's kind of, you know, coming down a little
negative on imagination in this quote. That creativity is important, but imagination might be
a little bit frivolous. And, Carl Sagan, you know, another kind of smart person, gives us another kind of even, maybe another kind of
warning about imagination. That it's gonna take us to places to worlds that never were, which sounds kinda scary, right? But, without it, we can't go anywhere. So, he kind of redeems imagination. That, well, in the end, we probably actually need it even though it's flown us off to someplace that doesn't even exist. But, I kinda start to turn to some things that I think start to shed a little more value on imagination. And, of course, the first
one I pull up is an artist. You know, Mark Twain, who says that, "You can't depend on your eyes "when your imagination is out of focus." And, now to me, this starts to actually
give us something valuable to think about because
it starts to connect the imagination to our senses. And, so there must be
some relationship between experience and imagination. And, so, I think Oliver Sacks kind of puts a number of pieces together that I think are really
critical to think about. That, "every act of
perception is to some degree "an act of creation, "and every act of memory "is some degree an act of imagination." So, we start to connect
perception, memory, and imagination together as interrelated phenomena that are quite important. And, so if we want to start to find, "How might we think through
exploring that connection?" And, I think art is a
really valuable place to think about this. I think of art as this kind
of laboratory of imagination. For a number of reasons, and one mention here by the
philosopher George Raymond. But art, for both how art is made, but equally important for
how art is experienced. And, so as an example, we can start by looking at this fresco in the Church of Saint Ignacio in Rome, and start to trace through
maybe a couple of ways in which the imagination is
working to make this a thing. So, first all, we note that it's this trompe-l'oeil. It's using this perceptual
trick that was figured out called perspective that
tricks us into thinking that something is a space
when it's just a flat plane. And, they do it here by extending the, the trompe-l'oeil part is because they are extending the
architectural features with this kind of imagined
architectural feature. And, it's also then connects that imagined extension of this church into that entirely imagined
placed called heaven, and so it situates it in a story space which is this incredibly
powerful attraction that we have to our
underlying cognitive need to make sense of things. And, it populates that space
with a bunch of figures that look a lot like the
kind of sweaty, smelly things that are standing all around
us on the floor of the church. But, of course, they're
up there in heaven. But, all of it's just made from these little dobs of paint, right? These little colored pieces of pigment. But, our perception doesn't pay attention to the small detail differences. We abstract from it and cohere it into what we think is the
phenomena that it likely is, which is it's probably
a person or an angel. A fictional person. And, so artists always
exploit these capabilities and deficiencies in our senses to engage our imaginations
on so many levels. And, so we all know
about how cinema works. We don't actually see
things that are moving. We're just seeing static frames that are shown to us so quickly and with some ordered
coherency between them that we can't help but think it's a depiction of something in motion. So, it's depicting something
beyond what it actually is. And, this is has always been a desire and an operation of art. So, even in these cave paintings from 30 thousand years ago the artists start to try
to develop methodologies to show something that's beyond the thing that's actually there. To show something in motion
with this static medium. And, by doing that, they are directly engaging our imagination as much as they're engaging your senses. So, art, we can see, is this collaboration between our senses, our memories, and our imagination, which is also just the equation
for reality itself, right? And, so, if we want to
start to think about how we might understand that. We've started to think
about how imagination is a phenomena that takes us
from one moment to the next, that takes us from those
moments to the near future, and then takes us from that near future to think about the far future. We can also think of it as maybe having different areas that it kind of functions. That goes from the neurological to the cognitive to the social, that takes us from thinking
about kind of personal fate to our local, global,
and even cosmic fates. So, I follow the same mistake
that I just laid on Einstein. Where imagination is
everything everywhere, right? But within this, now we actually have a
little bit of a rubric that we might be able to
explore some things in. And, so later on today, I think you're gonna be
hearing about a project that Allyson is doing that we're collaborating on about thinking about an
underlying neurological basis of human imagination. And, as we have said that there this, as Allyson was mentioning, it would be an interesting thing to be able to think about human
imagination comparatively. And, so here's these great sculptures by the Kennis brothers depicting early homo
sapien and Neanderthals. Can we think about some ways in which that the homo sapien
differs in some capacities from our cousins or early humans? You know, we know from early humans, we see this artifactual record. The Venus of Willendorf. We see other examples
that go continuously back in time and from other places. And, even some examples
from very long ago. And, whether or not these
are kind of extrapolated, we have always made little
fertility goddess figurines, or perhaps we're always looking for fertility goddess figurines. This idea that humans have been making symbolic culture for a long time is one of the underlying things that we think about with imagination. And, even now we start to
find new kind of things that help to fill out that story, so seeing that there
are Neanderthal things, things that we're now
attributing to Neanderthals as part of their symbolic culture. So, might there be ways, besides looking at the
artifactual records, to think about human imagination by looking more directly at the underlying biology of these things? And, so Allyson is like a magician as far as I am concerned. He has come up with these ways in which he can do something quite extraordinary which is take human stem cells, and on the left we have human stem cells that have grown brain organoids, and on the right we have those stem cells but they've been coaxed
to have Neanderthal genes that express Neanderthal neurology. And, so on the right we
have Neanderthal brains. And, so what we're looking
to do is then test them in relationship to how what kind of anticipatory responses they may have to different stimulating environments and see what kinds of
differences they have. And, you can already see there are some morphological differences that are quite evident. So, not only looking at the
kind of neurological structure, I want to give a very quick example of something a little higher order to thinking about at
the cognitive structure where we're looking at other aspects that I think are underlying components of our imaginations. And, one of them is spatial navigation. So, understanding how you are in space and what space consists of has obviously been a very important part of most species survival. And, here what we have started to learn is that we have two mechanisms of how we think about space. One in which we're egocentric, and we kind of think the world
reorients itself around us, and one that is allocentric, where we think the world is
in a fixed coordinate space, and we reorient ourself to it. We use both these mechanisms. And, in fact, when we kind
of switch between them is one in which a place where we really have to open our eyes and kind of re-understand what our relationship to the world is. Now, it turns out those
two kinds of experiences excite different parts of the brain, and we can sense that with EEG devices. So, we've been working with
a team of neuroscientists that develop virtual worlds in which they have kind
of novel structures where we can try to directly switch you into going from one navigational
scheme to the other. And, we do that by what
you're seeing in an example in a video of this experience. You embody one of these avatars. You have a navigational task you have to do in this environment. And, we radically change
it in a very uncanny way to try to keep you highly stimulated in your spatial response to making a coherent experience
from this environment. But, of course, I'll maybe just wait til
the last clip plays here. In doing that, we sense what kind of
navigation they're using and then try these tricks to trick them to switch them into the other. But, I also want us to
be aware of this idea that it's easy for us to
study humans in a certain way, but we can also fall into
this kind of circular trap of human exceptionalism, you know. That we're the only
thing with imagination. So, I think certainly we are
exceptional in many ways, but trying to characterize and understand where it makes sense
to kind of think about what's different from
us versus other species is a critical issue. So, for instance, I know my dog has this amazing imagination, you know? Every time I pretend to throw the ball, it imagines that I've thrown the ball. And, I've done this with
that dog a thousand times, but there's obviously something about the anticipation of throwing the ball that it's more important for
him to fail a thousand times because it allows him to
succeed just a little bit better the other few times that I do it. Imagination, maybe there's
even roots in things that don't even have a
neurological systems. So this is a white blood cell navigating through a complex
environment of red blood cells, trying to chase down a virus. And, if you watch how these microbes move, they seem to at times look
to cut them off at the pass and anticipate their moving
one way versus the other. And, this is without
any kind of neurology. So, imagination is this
tricky thing to think about just as all these other phenomena like cognition, consciousness. To try to think about we often bring, we first, of course,
bring to these questions our own experiences and understanding, and we have to be quite imaginative to kind of think outside of that. And, it can get us into some problems. So, for a long time, I think it was one of
the prevailing sentiments of Neanderthals was they
didn't have a symbolic culture. And, so this is from a recent exhibition at the Australian Museum that talked about that
they lacked the depth of symbolic and progressive thought displayed in modern humans. And, that was before a number
of artifacts were discovered that may have kind of make us kind of have a more complex relationship
to that question. So, in my work, I try to think about things that might be able to augment our imagination. And, we're starting to do a lot of things with artificial intelligence. For the fourth time around that artificial intelligence is suddenly the next big thing. But, we're working with ways to think about how to model aspects of human imagination through things like genetic algorithms and neural nets, and we bring to that a kind
of human-centric approach. But in the end, the kind of effective measures may cause us to really come up with a completely different kind of imagination than a human-based model. So, the last thing I want to talk about in relationship with this is then how stories kind of work in this. So, we're the Arthur C. Clarke Center, and an aspect of that is
the value of science fiction as this way to kind of
cause us to radically think about new kinds of human conditions. And, so some of the work we do with that, this is an example of a project we did with a science fiction author, Kim Stanley Robinson, and a performance artist, Marina Abramovic, where we took Marina Abramovic methods which take things that
usually take a few seconds and try to extend them into experiences that last over a few hours, and Stan Robinson's work who's trying to get us to understand what it would be like to
experience a phenomena that lasted a thousand years, like to travel to another star. And, the ability to kind of
put these two temporal shifts in relationship to each other gave people a far more
visceral understanding of the experience of temporality. And, so these things like stories and performance and ritual art may have been things that
we think really discovered once we started to extend
the day into the night. And, then think about what
we do with that nighttime. We come up with ways to make better sense out of everything that
happened in the daytime. And, so these stories, while they sometimes
were completely fictional and talked about worlds that never were, sometimes they actually
brought sense to things that we previously
wouldn't have connected. And, of course, as we moved forward in time, we've just come up with
more and more proliferations about those campfires. And, more and more ways to
tell stories around them. Now, it's often thought that
language came before art, but I have another theory that I think language came about so that art could be
critiqued and explained. (audience laughing) And, this is the artist Joseph Beuys. He's trying to explain
art to a dead rabbit. So, Picasso kind of gave us this idea. He said, "We all know
that art is not truth. "Art is a lie that makes
us realize the truth." And, so this is the
astonishing thing, I think. That our imaginations, our ability to conjure
meaning from occurrences has given us this ability to
create all that we've created. And, so how this happened and where this will take us couldn't be more important or more exciting to think about, and I look forward to digging into that for the rest of the day. So, thank you. (audience applauds) - Alright, I'm gonna thank the organizers for inviting me, and for providing this
incredible opportunity for all of us to be together and to imagine. It is the human capacity
to move between the worlds of what is and what could be that marks the emergence of a particular evolutionary
context and history for the genus homo. Us, humans. I argue that it's the
human capacity to imagine, to be creative, to hope and to dream, to infuse the world with meanings, and to cast our aspirations far and wide limited neither by personal experience nor material reality that has enabled our lineage, the genus homo, to develop a particular niche, a particular way of being in the world, where imagination plays a central role. Humans are very creative, and we use our imagination to be so. This has an evolutionary history. The real challenge to
understanding human evolution then is not just the tracing
of the bones and stones of the 2.6 million year
history of our genus. Instead, it is understanding those changes alongside the reality that our lineage is a lineage that went from the
makers of basic stone tools, to the creators of amazing cave art, to the constructors of massive cities, and the dominant force
shaping the ecosystem today. Our lineages transition from a cluster of medium-sized, fang-less,
horn-less, claw-less, semi-naked or fully naked ape-like things with a few rocks and some sticks to a species who invented domestication, economies, cities, nations,
religion, warfare, and peace. That is the challenge of
understanding human evolution. Now, let me put humans in context here before you think I'm talking only about human exceptionalism. That is, we know there
are may other species that use tools, that have incredibly complex social lives, that use sound as communication traveling across incredible distance, and that have cultural varieties that actually impact the way
in which their genomes shift. Here's an example of hunting patterns across latitudinal variation in orca pods that has actually had a huge change in the structure of their genomes. So, gene culture co-evolution doesn't just occur in humans. It occurs in many organisms. However, we have studied
other complex organisms like chimpanzees and whales and orcas for a long time, and we know a lot about what they do and what they don't do. We know that chimpanzees
don't have cash economies, governments, religious
institutions, creeds, or fanatics. They don't arrest and deport each other. And, they don't create massive economies of material and social inequality. They don't change planet-wide ecosystems, build cities, make airplanes, drive thousands of other
species to extinction, or give CARTA talks. (audience laughing) But, we do. We are a particular mammal, a particular primate, a particular hominoid kind of ape that is able to look
at the world around us and see it as it is, imagine entirely new possibilities, and convert those imaginings
into material reality. We've evolved the capacity
to be the most compassionate, the cruelest, the most creative and the most destructive of all life on this planet, and we demonstrate these abilities often. How this difference came to be matters. And, it is by delving into humanity's very distinctive history that we are able to understand
why we are the way we are. There's incredibly good evidence that over the last two million years the members of the genus Homo, all of those things that have something to do
with our specific ancestry, underwent significant
changes in their brains, their bodies, their behavior and they created a new niche, a new way of existing, both ecologically and
socially in the world. This is a human niche, and this niche involved
a particular evolution of something called the human imagination. Human imagination, I would like to argue, is as important as the bones and stones in understanding the
processes and patterns of human evolution. Alright, here is a summary of a whole bunch of interesting
things that have happened over the last two million
years to our lineage. What I want to point out here, and I'll provide some specific examples, is that this is not just about linear, even though it's a line (laughs), linear evolution. This is about the changing relation between individuals, between individuals in the material world, between individuals, the material
world, and their cognitive interpretations of that material world, and that cycle getting more and more dense as we changed, as we changed the world around us, as we changed one another, we began an intricate dance which is culminating today, and, hopefully, will
continue into the future. So, rather than talk about
this shifting in crania or other morphologies, let's spend a little time with a few of the pieces
of evidence we have of our evolutionary history that talk about this incredible dynamic, this feedback between the material, the social, the cognitive, and
our evolutionary histories. So, we know that significant
dietary changes happened fairly early on in our history. But those significant dietary changes enabled, for example, our
brains to get much larger and a variety of other things; however, we sometimes forget that those significant dietary changes are really associated
with the use of tools. Now, I'm gonna show you some tools here. Up here in your upper left corner, this is an Oldowan tool. It's about 1.8 million years old. I'm sure none of you are impressed. It is a rock with some sharp edges. But, you should be. Nothing else in the
history of this planet, aside from our lineage, has ever had the capacity to take a stone, to look at that stone, and to imagine something
else inside that stone. To take another object and work it on that initial stone to create something anew from inside. That's fairly impressive. And, we know how difficult
some of these processes are. If you look at the next illustration here, you will notice that this is actually a reconstruction of all of
the mapping of a stone tool. Right? So what we actually do is you go the detritus, the debris, and you piece it back together so you can look at every single strike. Now, when I say we, I mean the graduate students
that actually do the work. Not the professors. (audience laughing) But, what you then know is you can see that the individual stone tool maker, even for these fairly old stone tools, here we're getting into the Acheulean stone tool industry, looking something a bit more like this, what we can see is that you take it, you have the platform, you look at it, you strike it. You've totally, radically
altered the whole shape. You now have to reimagine
the entire thing, hit it in the next place, hit it in the next place. And, when we construct those together, it is unbelievably difficult. It takes a student today months to learn how to be a good stone tool maker, and that is with video training, with the rocks already brought to you, and without any large
predators trying to eat you while you do your work. (audience laughing) We can underestimate
how important this was. Think about what I just said. Not all stones are equally
good for making stone tools, so to make stone tools, even the most basic ones, you have to be able to find decent stones and replicate that finding. You have to go back and
get them again and again. Then, you have to carry- I don't know how many
of you carry regularly 20 or 30 kilos of stones with you, but that's a lot of work. Dispersing that socially
is very important. Then you have to make stone tools, and in an environment that is packed with very large things with large teeth that want to eat you, and remember you are very small, naked, and you've got some rocks
and some few sticks. When you make stone tools, it makes a lot of noise. So, you've got everything
sort of stacked against you. How did our ancestors figure this out? How did they work through it? Imagination, collaboration, cooperation. Really focusing in on the social. But really, interestingly, current work looking at what it means to make stone tools by Dietrich Stout and a
number of other groups have demonstrated that when
you make these stone tools certain areas of neuro biological activity are accentuated, and there's some corollary patterns. Now, what are these areas? Frequently these are
areas that are associated with higher functioning and memory, with planning, and, interestingly enough, with language. But, wait, don't order yet, because it's not just
the making of stone tools that does this things in your brain, which probably means they have a deep ancestry for doing that, but also if you are
watching a stone tool maker you mirror some of those functions. And, here is the critical
component of stone tools. It's not about the tools themselves. It's about the social context in which they were made and used. We can debate whether or not teaching occurred 1.5 million years ago. What we can't debate is these complex stone tools were made 1.5 - one million
500 thousand years ago, that you or I could not make
without being instructed. Was there language? I don't think so. But there was a broad bandwidth of highly dense information transfer that was social, and it was imaginative. Now, around this time period, and between about 1.5
and a million years ago, as I pointed out, that niche is constantly
sort of augmenting as more ways of dealing
with the world occur. That density and those
feedbacks continue to shape our bodies, our lives, our cognition. We know that by about
half a million years ago, you know, give or take 50 thousand years. I like to work in big numbers. We had an incredible
capacity to collaborate in ways that seemed to exceed the collaboration of many other organisms. We had an incredibly complex
cooperative parenting where males and young were
also caring for offspring. We had a pattern of the whole communities responding to environmental pressures, not just individuals. And, we had evidence of
augmentation and enhancement in our imaginative capabilities. For example, and we'll hear more about
this later today, fire. We heard about it already
in the previous talk. People underestimate fire all the time. Yes, fire is wonderful because it allows us access to nutrients that we wouldn't have
otherwise by heating food. It also allows us to
modify stones and wood to alter their physical structures so that we can better use them. But, more importantly, as is already mentioned, fire turns night to day. Fire releases us from the
constraint of the sun. Fire enables and expansion
of the time we have to be together, to think together, to imagine together. But it's not just evidence of fire, which maybe goes as far back
as 1.6 million years ago. We have glimmerings, elements. But it really isn't until about four or five hundred
thousand years ago, three hundred thousand years ago, that we start to see it
with increasing regularity. But, it's not just fire, and, really from my perspective, cool stone tools. Here's a nearly 300
thousand year old clam shell from Java that at some point something in the lineage Homo picked up, grabbed another object, and doodled on it. Most people, just like that early Oldowan
stone tool I showed you, are not impressed by doodles. But, you should be. Think what it means to doodle. Think what it means to take an object, to take another object, and to alter the surface
to create a new sensation. We see this over the last
300, 400 thousand years. We see glimmerings earlier, but it's really over this last three to four hundred thousand years that we start to see this
with much higher density. At that same time period, we also have two very interesting, okay, not very many, but two very interesting events here at (unclear) about
400 thousand years ago we have a number of
bodies found in one place, a deep pit. In that deep pit are a couple cave bears that
looked like they fell in and a couple other things that had been gnawing on the bones, but nothing else except for, as you can see here, this beautiful hand ax about this big. It's made from a stone that is not local. And, it is gorgeous. It was carved and thrown in, never used. What does that mean? We won't ever know. But, I bet it had something to do with the imagination and the creativity and meaning for that group of people. And, more recently, about say between 200 and
300 thousand years ago, we have another evidence of
possible movement of bodies into an underground cave. People debate whether it's burial or not. I don't want to get into that debate. But, I do want to point out that we had glimmerings earlier on. But all of these things, burials, art, creative imagings, incredible manipulation of the world, all has a deep evolutionary history and didn't just show up
when our species shows up 'cause everything I've just showed you predates homo sapiens sapiens. But, by the last 30 to
50 thousand years or so we find clear examples of identity, clear examples of
individuals taking items, reshaping them to create
a completely new reality, a new imagination, a new way to be in the world. And, it is my, and many others' arguments, that this new way to be in the world, these new senses of identity, this new deployment of imagination, had a huge impact on those feedback loops between our ecology, between our materials, between our bodies, between our cognition, and between our societies. So, the human niche is, of course, centrally located and focused. Our studies of understanding
human evolution has to be about our brain, and our DNA, and our morphology, and our bodies, but it also has to be about
all of the different ecologies that humans have spread
across the entire planet. So, it's our brains, our
bodies, our ecologies, and, and you already all know this, our perceptual realities. The way we see the world. The way we think about the world. The way we feel the world is as important as our bones, our muscles, and our DNA, because part of that system and that feedback, that complex dynamic that is the human, involves the imagination. So, the human niche includes creativity, cooperation and imagination. Meaning, especially making meaning, matters as an agent in the processes of our evolutionary histories. It is specifically feedback systems between behaviors, ecologies, cognitive and bodily
systems involved in teaching and learning and meaning
making, communicating, that facilitated a new
niche that had huge impacts. For example, it set up our brains. It structured them in a way that Michael Arbib calls
language ready, right? You don't just get language. It has to evolve. And, the cognitive and
neuro biological structures have to be there. And, part of that is this. We also have communities
of shared imagination. Seeing these multiple iterative events of meaning making across space and time shows that communities of humans, and I'm using the term broadly because I don't necessarily
mean homo sapiens, were capable of working together to remake the world in their and from their imagination. So, meaning making, imagination, communication, creativity,
and community are central. That's my pitch. However, all of this
stuff sounds very positive and really, really exciting. I would like to say that our capacity to be with one another, to share our minds to imagine, to think forward as a central
part of our evolutionary niche also brings with it a few problems. Imagination made humans exceptional but also potentially extremely dangerous. We have interconnected the world in a way that nothing on this plant has ever done. And, through that interconnection, we are reshaping what the
world actually looks like. Here's a global human density map. This is a better map that you look at because this is the way we're
shaping the actual surface and functioning of the earth. We have imagined ourselves into a position where it is in the balance. Our ecologies, our
capacities, our creativities, are nearing or bringing up to the point where decisions have to be made and have to be imagined. We know today, for example, in the United States. We have systems of racism, misogyny, and inequality unknown before. So, we need to understand how our imagination and creativity has gotten us to this state always remembering that, in fact, that imagination and creativity is the one thing that
can get us out of it. Being together with one another, thinking together, creating, imagining, seeing
the world as the way it is, imagining other possibilities, and at least trying to make them happen. That's what got humans
to where we are today. Thank you. (audience applauding) - It's such an honor to be here among all these brilliant speakers, so thank you so much for having me. Human beings occupy two worlds. The real world is what actually happened in the past is happening right now, and will actually happen in the future. And, while we certainly
thing about that world, we also spend this enormous about of time considering all the many possible worlds, what philosophers and psychologists typically refer to as counterfactuals. That is, all the ways that the world could have been but wasn't, and all the ways that the
world could be but aren't. And, not only counterfactual
thinking pervasive in our everyday thought, perhaps you're doing it right now, but engaging with these
imagined possibilities deeply affects us. It affects our decisions. It affects our judgements. And, it affects our emotional experiences. And, from an evolutionary perspective, this initially seems a
bit surprising, right? Well, it's obvious why engaging deeply with our actual real experience would give us some sort of edge, it's less obvious what we get from engaging so
profoundly and emotionally with these imagined worlds as well. And, this seems particularly paradoxical when you consider the
huge proportion of time that very young children are engaging with these imaginary worlds. In fact, as soon as babies can talk, they immediately begin
talking about the possible in addition to the real. They begin to spontaneously
produce symbolic play substituting things like
the mouse from a computer for a telephone. Very early on, around 18 months. There's even evidence that 15 month olds are recognizing pretend sequences that are produced by adults
in their environments, so that's pretty early. So, why, right? Why would very, very young children who, by their very definition, have so much that they have to learn about the actual world spend so much of their time
and energy and resources, not to mention the resources
of their caregivers, who are responsible for them, engaging with unreality. Right? We have to answer this question. So, classically psychologists including the father of developmental psychology, Jean Piaget, but also our friend, Sigmund Freud here, who pops up all over the place, offered some pretty
uncharitable characterizations of pretend play in childhood. They essentially
attributed it's prevalence to children's inability to differentiate between the products of their
imaginations and reality. Between fantasy and reality. Decades of research have show that, to the contrary, children are actually quite
proficient and sophisticated at distinguishing between real
objects, events, and people and those that are products
of their imagination and the imaginations
of others around them. I'm gonna give you just
one example of a study, this was conducted by Jacqui Wooley, just to show you how this work
is typically done with kids. A child might enter a
room with three boxes. They'll watch as an experimenter
puts a pencil in box one. Box two is left empty. In box three, the child is told to imagine that there's a pencil inside the box. Afterwards, the experimenter
may ask the child a bunch of questions and engage with them. One of those questions will be, "Is there a pencil in box three?" And, children have no problem with this. They say, "Yeah, sure." They have no issue with
transporting themselves into this imaginative space in which there's a pencil
inside of box three. But, if some person comes
in from the other room who wasn't engaged in this
fictional context initially and says, "Hey, I need a pencil. "Can you give me one?" Children even as young as two aren't going to make the mistake of looking in box three, right? They know there's no
actual pencil in there. Instead, they reach into box one and give the experimenter what it is that they actually asked for, right? So, even though children
spend hours and hours of their lives pretending, they know that they're pretending, and this ability then to adopt this counterfactual or false premise, like there's a pencil inside of this cup, to make inferences about
events that might happen in a world in which there
were a pencil in the cup, but also to separate, right, that imagined space from the real world, is already present from as
early as two years of age. This is very, very early on. In fact, there's other prominent
feature of pretend play that suggest that it's
the result of competence rather than cognitive limitations. So, it's largely unique to human beings. It's often social in nature, like many of our more complex functions. It becomes increasingly
elaborate over time. You'd expect the opposite, right, if it was the result of
a cognitive limitation. Young children do this
object substitution. As they get a little bit older, they don't even need objects to scaffold their pretend play with. They just imagine things, completely imaginary events. A little bit later, they might develop an imaginary
friend or companion, right? This is an entity that has
a consistent psychology that they interact with over time. A rich and complex
psychology and social life. Even later in late childhood, in adolescence even, children engage with paracausims, little micro worlds that they construct of their own design. And, of course, as we know, this extends into adulthood as well. We all appreciate fictional artifacts, and this is continuous
throughout the lifespan. Okay, so, given that very young children engage with imaginary worlds, which seems obvious, and that this engagement doesn't stem from their confusion which is a bit less obvious, but not so much anymore, then why are they doing it? Why are they doing it, right? And how are they doing it? Well, we know that play is characteristic of young animals across
a wide range of species, and that the behaviors
that are involved in play are also those that are
typically most important for adults of that species. And, in this way, play is a form of exploratory learning. So, the immature animal can explore and practice
alternative forms of action in a low-cost, low-risk environment without any of the pressures of having to actually
achieve a particular goal like staying alive, for example. And, in fact, one of the most distinctive features, biological features of human beings, is our unusually long
period of immaturity. Compared with our closest
primate relatives, we've evolved to have
this dramatically extended protected period of childhood. Early, middle, late adolescence. After we go to college, right? We're still protected in the
spirit of immaturity. (laughs) And, what we're encouraged
to do is explore during this period of time. We're engaging in this
exploratory learning. So, while it's sort of easy to see how physical forms of exploratory play, like play fighting and
hunting and climbing, might translate into later adult skills, pretend play is sort of
by it's very definition severed from reality. So, in order to make this analogy with other forms of play work, we have to really identify the role that this particular type of cognition, this counterfactual type of cognition, plays in cognition. So, to put this in the form of a question, why might it be beneficial to draw conclusions from false premises like there's a pencil in the cup? So, to answer this question we can consider how children's
minds are constructed to support and also to
encourage their generation of a wide array of
alternative possibilities. And, it turns out that new ideas about children's earliest
learning mechanisms suggest that the very same abilities that allow children to learn
so much about the world and to reason so powerfully about it also allows them to imagine
alternatives to that world, and, more specifically, it's the ability to represent cause and effect relationships that seems to underpin some of the ability to imagine possible worlds. And, not only that, but the ability to imagine possible worlds feeds back to facilitate our reasoning about cause and effect relationships. So, the rest of this talk I'm going to, very quickly, try to unpack the sort
of theoretical grounds for making this claim. So, by about five years of age, children have already developed
complex causal theories in a variety of domains. Everything from understanding biological principles to other minds, to the nature of physical forces and properties in the world. And, the question that
motivates my research, but also just sort of the field of cognitive
development in general, is how this ever happens. How is it that young
children are able to learn these abstract, structured, causal representations of the world so quickly and accurately given the relatively limited information that's available to
them from their senses? What's the origin of this knowledge? And, one classic answer from
developmental psychology points to the similarities between children's learning and learning in science. And, the idea here proposes that children's early theories share in a meaningful way structure, function, and dynamics to theory change in science. And, in particular, that children, just like little scientists, are implicitly formulating hypotheses about the world and then testing and rationally revising those hypotheses in light of new evidence that they observe. So, this sounds a bit far
fetched when you first hear it. To help you imagine this, I'm going to show you
a video of this idea. What this child is doing in this video is playing with a "blink it detector" which is a toy that we
typically use in my lab. This is just a flexible causal system. It's a box that lights up, which is the effect, for certain things, which is the cause, and it allows us to explore children's causal inferences really well. So, I'm just going to let you watch. And, I want you to keep an eye out for this child engaging in
hypothesis testing behavior similar to a scientist. - Putting this on the box. This on the box. This makes that light up the box. How 'bout this? And, that makes the other side. - [Caren] Here's a new hypothesis. - Uh oh. Nothing. This one lighted up, and this one's not. So, that means. - [Caren] Here's another. - What's making this light up? - [Caren] There's a familiar expression to those of us who do science. (audience laughing) (audience laughing) - [Caren] Despair. - Oh, wait. Because this needs to be like this. And, this needs to be like that. That's why. Hmm. Probably the boxes are the wrong way. - [Caren] This was the child's idea. Pretty imaginative. (audience laughing) And, like in science, it ends with embarrassment
in front of our peers. (audience laughing) So, even though these ideas
about children's learning have been around for some time, recently there's been some major advances in our ability to formally describe the cognitive processes
that might be taking place. And, the way that this is done is by integrating
developmental psychology, so this kind of work, with computational theories. So, one of the central
ideas in this framework is that children's
intuitive causal theories can be expressed in a kind of causal map or abstract picture of how the world works. A little bit like this, right? So, for example, sunlight and water cause plants to grow. Forces and contacts cause
objects to move through space. Desires and beliefs cause someone to act towards a particular goal. And, in many ways these causal maps are analogous to the more
familiar spacial maps that depict the various
locations of objects in relation to one another. This is a cognitive feature that we share with other animals, including rodents like depicted here. So, having a spacial map is useful, right? And, this was mentioned earlier because it allows for this non-egocentric representation of knowledge. It doesn't matter where
I am in this space. I can still represent the space. This means that it's flexible, right? I can plan my route in advance and think about the different ways that I might approach this problem. And, it becomes updated as new information about
this space becomes available. So, in a similar way, having a causal map provides a complex representation of
the causal relationships, or an abstract picture of how one thing might be causally connected to another, and, just like our spatial maps, it's update as new information
becomes available to us. So, you can think of each of these different causal models as a particular hypothesis
that we might hold about the true causal
structure of the world. So, for example, if I notice that the flowers in my window begin to wilt, I might entertain several
possible causal models, each of which generate their own patterns of predictions, right? So, it could be that too much sunlight is causing both the dry
soil and the wilted flowers, or it could be that the sunlight is actually causing the dry soil, and it's the dry soil that's
causing my flowers to wilt. And, if I'm holding a causal model that happens to be correct, then the predictions that it generates will be accurate with respect to my observations in the world, right? But, if it's incorrect, if I hold the wrong causal model, my predictions are going to fail me, and this will prompt me
to adjust my causal model to better approximate
the true causal structure of the world. So, in effect, this process, the process of early learning, might be conceived as a process of comparing possible worlds and updating those possibilities in light of new evidence
as you observe it. And, critically, these causal maps also include a means for representing possible future actions
for planning in the world. So, if we return to the
two sort of versions of the wilted flowers
that I described earlier, even though each of these representations have the same variables, right - sunlight, soil, flowers - the differences in their structure lead to really different effects following some action that
I might take on the world. Let's say I intervene on my dry soil by watering my plants. Hopefully, what you can see here is that depending upon which of the two causal structures is an accurate
representation of the world, watering my plants here in the first one is going to have no effect
on my flowers, right, because it's the sunlight that's directly causing them to wilt. In the other case, though, watering the soil will
actually have some effect. And, importantly, these interventions could be real. I could actually do them. Or, they can be imagined,
hypothetical actions. I can just sort of think what it would be like if I were to intervene on the world in a particular way. And, it turns out that the evidence shows that even preschool aged children are able to do this. They're able to reason about intervention, both in the real world and also in their imaginations. So, this gives us an
extremely powerful tool for planning and considering the outcomes of potential outcomes in advance. We start with a premise
that might be false with respect to the world, and then we just reason about the implications of
that premise downstream. This leads us to the ability to design new interventions and to literally change the future for ourselves and our environment. So, now we have to push the
pause button for a minute because this all sounds really,
really complicated to us. All of these things are, of course, happening implicitly not explicitly, but you might be wondering whether or not kids could actually do this. So, if we return to
pretend play for a minute, we see that children are routinely considering premises that contradict their own knowledge. They ignore the fact that
the tea cup is empty, and they proceed to
wipe up the imagined tea when the cup is overturned anyway. Any time, really, that children are acting out the outcome of pretend events, they're necessarily setting aside their interpretation, their causal model, of the real world and reasoning about
the causal consequences of some pretend premise. Some other possible world. And, in fact, it's causation itself that gives fantasy its logic. Despite the fact that children could, in principle, pretend about anything at all. It's pretend, after all. If you've ever hung out with children, you know that they don't
actually usually do this. Instead, some research
by Paul Harris has shown that if a child pretends
to spill the sugar during their tea party, they're gonna opt to
sweep it up with a broom. If they spill the milk, then they'll grab the mop, right, or a sponge. And, it's precisely this unique blend of knowledge and imagination that really characterizes early pretend play in childhood. And, in fact, the cognitive processes that are involved in pretend play aren't only useful for planning. They're also critical for learning. So, for example, children who create imaginary companions tend to show increased theory of mind. So, this is just an
increased understanding of the cause and effect relationships that dictate the psychological
and social world. So, I propose then that pretend play is really just a precocious display of children's developing
abilities in causal reasoning. It arises out of those
abilities quite actually. And, that engagement in imaginary worlds actually feeds back to serve as an engine of learning as well, promoting these abilities that we need. So, to sort of summarize the
logic in a single slide here. The long period of protected immaturity winds up leading to increased time for exploratory learning through play. Exploratory play allows for more flexible kinds of learning mechanisms that support the
development of causal models that slowly adjust to the
environment over time. These models support
counterfactual reasoning. It's sort of inherent to the model to think about ways
that you might change it in order to think of
thing could be different. And, this is initially
expressed in young children in the context of pretend play really as early as they start to talk. And, finally that reasoning
about these possibilities feeds back to support the very mechanisms that underlie causal learning in humans. So, I'm gonna end with a quote from my colleague, Alison Gopnik, with whom I'm coauthored all of my work in this area. And, I'd like to thank
you for your attention. (audience applauding) (upbeat electronic music)
This symposium explores the evolutionary origins of human imagination, its impact on the sciences and arts, the consequences of imagination impairment, and the fundamental genetic and neurological basis of human imagination.