Speaker 1: Welcome to Stuff to Blow Your Mind from how Stuff
Speaker 1: Works dot com. Hey you welcome to Stuff to Blow
Speaker 1: your Mind. My name is Robert lamp and I'm Joe McCormick.
Speaker 1: And today we have for you an interview episode, an
Speaker 1: episode where we sat down and talked to an expert
Speaker 1: on paleolithic technology. And I'm really excited for you all
Speaker 1: to hear this one because this conversation was a lot
Speaker 1: of fun. A stone age technology is so much more
Speaker 1: fascinating than you would think, Yeah, because in looking at it,
Speaker 1: we're looking really at the roots of a human invention
Speaker 1: and innovation, Like where does the entire tree of human
Speaker 1: technology spring from? Yeah, and how did ancient technology shape us?
Speaker 1: So this is going to be a conversation with Dr
Speaker 1: Dietrich Stout. Dietrich Stout is an Associate Professor of anthropology
Speaker 1: at Emory University, where his Paleolithic Technology labor tory investigates
Speaker 1: the role of technology and human evolution. Dr Stout is
Speaker 1: also Associate director of Emory's Cross Disciplinary Center for Mind,
Speaker 1: Brain and Culture, which promotes diverse and integrative research into
Speaker 1: human nature and experience. His research focus on Paleolithic stone
Speaker 1: toolmaking and brain evolution integrates field research at Early Stone
Speaker 1: Age archaeological sites in Ethiopia with laboratory and museum research
Speaker 1: including artifact analysis and experimental replication, functional and structural neuroimaging,
Speaker 1: behavioral analysis, and psychometric testing. Now, if you want to
Speaker 1: check out those centers I mentioned the Paleolithic Technology Laboratory,
Speaker 1: you can find that at Scholar Blogs dot Emery dot
Speaker 1: e d u, slash Stout Lab, and then the Center
Speaker 1: for Mind, Brain and Culture. You can just go to
Speaker 1: c MBC dot Emery dot e d U. Yeah, this
Speaker 1: is a super fun interview. I should stress this was
Speaker 1: an in studio interview. Yeah, one of a couple of
Speaker 1: interviews we recorded about a month ago where we said, hey,
Speaker 1: let's let's reach out to some local experts on some
Speaker 1: various topics. We don't necessarily we enjoyed jumping on the
Speaker 1: phone with with folks, but why not have some some
Speaker 1: local talent coming to the studio. And that's what we
Speaker 1: did here. It was a lot of fun, uh, and
Speaker 1: I think you will really enjoy it. So I'd say,
Speaker 1: without any further ado, let's go straight to our conversation
Speaker 1: with Dietrich Stout. Hey, Dietrich, thank you so much for
Speaker 1: joining us on the podcast today. Can you start by
Speaker 1: telling our listeners a little bit about who you are
Speaker 1: and what you do. Yeah. Well, I'm an associate professor
Speaker 1: of anthropology at Emory University. I'm also the associate director
Speaker 1: of the Center for Mind, Brain and Culture at Emory
Speaker 1: as well, which is a center that promotes interdisciplinary research
Speaker 1: on mind, brain, and culture. And those are basically my
Speaker 1: interests come at it from the direction of archaeology and
Speaker 1: the hope that we can learn something from the past
Speaker 1: about made us the way we are today. So how
Speaker 1: did you first get interested in Stone Age technology? Well, um,
Speaker 1: it's not something that you typically encounter in most high
Speaker 1: schools around the country. Uh. So, you know, when I
Speaker 1: went to uh to college, I really had no idea
Speaker 1: of the possibilities that where they are for anthropology, for
Speaker 1: the archaeology of human origins. I did know that I
Speaker 1: was interested in the way the human mind works, in
Speaker 1: the nature of human experience. Uh And at the time,
Speaker 1: I thought that meant that I wanted to be a philosopher.
Speaker 1: When I got to school, I realized what I said before,
Speaker 1: that a lot of the way we can understand how
Speaker 1: we are today and the nature of human experiences to
Speaker 1: understand the evolutionary processes that brought us to where we are. UH.
Speaker 1: And I had a really great UH professor as a
Speaker 1: freshman and a freshman seminar. He told me to take
Speaker 1: some archaeology classes. I did, and I still I just
Speaker 1: remember one lecture that my professor gave. I know, she
Speaker 1: was talking about these ancient stone tools in a particular
Speaker 1: kind called a little vow wa technique UM, and he
Speaker 1: was pointing out that you could see every individual action
Speaker 1: and and blow against the core that this person had
Speaker 1: done something like fifty or a hundred thousand years ago,
Speaker 1: and you could reconstruct what they were thinking, the plans
Speaker 1: that they made. And that just struck me as as
Speaker 1: an incredible window on the past and how our minds
Speaker 1: became the way that they are today. And that's what
Speaker 1: got me started on it. Like seeing into a dead
Speaker 1: person's imagination. Yeah, to be able to recapture that, I mean.
Speaker 1: And now I've worked at sites that are half a
Speaker 1: million years old where you can literally trace individual decision
Speaker 1: making processes. It's it's it's pretty incredible. Actually held a
Speaker 1: core at one of these sites. I was looking at
Speaker 1: it and I was wondering why they didn't do something
Speaker 1: that that I would have done with that core, that
Speaker 1: piece of rock, and I twisted it around to look
Speaker 1: at where I was thinking about, and so that they
Speaker 1: actually had tried well I was thinking, but it didn't work.
Speaker 1: So both of us made the same mistake, separated by
Speaker 1: half a million years. That's almost a little spooky. Um. So,
Speaker 1: obviously we know that the Stone Age means stone tools.
Speaker 1: But what as an expert in the area, what does
Speaker 1: the Stone Age mean to you? What do you think
Speaker 1: about when when this age is conjured? Uh? Yeah, Well,
Speaker 1: I think really of the time period uh, for which
Speaker 1: we have evidence of human behavior in the forms of archaeology,
Speaker 1: but extending way back into the past so that we
Speaker 1: have information, but it's also an evolutionary time depth. You know,
Speaker 1: we're talking millions of years, more than three million years
Speaker 1: at this point of time. Uh. So that's what gets
Speaker 1: me excited about the Stone Age. Uh. And of course
Speaker 1: you know it's called the Stone Age for a reason.
Speaker 1: Most of what we have are the best evidences of
Speaker 1: stone tools for behavior. Um. So that's what I've focused on.
Speaker 1: And when you think about the very beginning of the
Speaker 1: Paleolithic obviously we're talking about hominid ancestors then, but not
Speaker 1: not Homo sapiens, right, And so when these organisms were alive,
Speaker 1: when when they were trying to survive and and stone
Speaker 1: tools began to play a role in their lives? What
Speaker 1: was that role? What was the earliest role you think
Speaker 1: stone tools played in in these organisms survival? Yeah, well,
Speaker 1: I should say at the outset, there's a lot of
Speaker 1: things we don't really know with any great certainty about
Speaker 1: the earliest Paleolithic. Uh. I think that there is strong
Speaker 1: evidence that some of the earlier tools were used for
Speaker 1: for butchery of animals, because you can recover actual cut
Speaker 1: marks on bones when somebody accidentally nicked a bone as
Speaker 1: they were butchering an animal, and so that's a direct evidence.
Speaker 1: Now what else they were used for is much harder
Speaker 1: to say because the plant materials, all those things are gone.
Speaker 1: So there's very limited evidence of that. And it's only
Speaker 1: in the past couple of years that that it's been
Speaker 1: reported a much earlier site. We used to think the
Speaker 1: earliest stone tools were two and a half million years old.
Speaker 1: I've worked at some of those sites, but now they
Speaker 1: go back to three point three million years and we
Speaker 1: as yet have very little evidence of what they might
Speaker 1: have done with those tools. Hopefully in the next few
Speaker 1: years there'll be the kinds of evidence that I was
Speaker 1: talking about, but it's just not there yet, so a
Speaker 1: lot of unknowns. If I had to say, these things
Speaker 1: are cutting tools, and the most important thing probably for
Speaker 1: early humans to be able to cut was animal flesh
Speaker 1: to access that, but they could have used them for
Speaker 1: a lot of other things, including making other tools. Uh.
Speaker 1: One of the great things about having a cutting edge
Speaker 1: is your ability to shape other tools. For instance, in
Speaker 1: would if you have a knife in the form of
Speaker 1: a stone flake, you can make a spear. You can
Speaker 1: make a digging stick. Again, though the wood's not there anymore.
Speaker 1: So if they did that, we have a hard time
Speaker 1: knowing for sure. And when you mentioned those dates a
Speaker 1: minute ago that's referring to, Uh, is that that modified
Speaker 1: stone tools we're not talking about like found stone tools. No,
Speaker 1: And in fact, it would be nearly impossible to identify
Speaker 1: and differentiate a found stone tool from a rock at
Speaker 1: this point. Um, So that's all right. We know chimpanzees
Speaker 1: use rocks as tools, and so it's you know, likely
Speaker 1: that are very early ancestors did. Um. But yeah, by
Speaker 1: by three point three we have evidence of them actually
Speaker 1: fracturing rock on purpose in a controlled way to produce
Speaker 1: cutting edges. And that's something that we can definitively separate
Speaker 1: from a natural process, so we know it it occurred
Speaker 1: at that point, Um, correctly if I'm wrong. But are
Speaker 1: there are there broad stroke um classifications for the different
Speaker 1: levels of tool creation, Like I want to say, it's
Speaker 1: something like nature, fact, artifact, etcetera. Uh, could you walk
Speaker 1: our listeners through that? Yeah? Well, um, you know, of
Speaker 1: course you could have on modified rocks used as tools,
Speaker 1: for instance, to crack open and nut as uh as
Speaker 1: chimpanzees and some monkeys maccaque monkeys do that as well. Um,
Speaker 1: that's a tool, you know, it's a stone tool. Um.
Speaker 1: But what we see by three point three million years
Speaker 1: is the actual modification of the rock on purpose in
Speaker 1: order to make a different kind of tool. Uh. And
Speaker 1: that's generally a process simply of fracturing the rock to
Speaker 1: produce sharp shards or flakes of stone that then become knives. Um.
Speaker 1: And so that's loosely called like mode one. Uh. The
Speaker 1: most well known industry that does that is the Old
Speaker 1: One named after Old of I Gorge where Mary and
Speaker 1: Louis Leaky worked. Uh. And that's a very simple form
Speaker 1: of stone toolmaking. Uh. It does require quite a bit
Speaker 1: of coordination. It's not easy to break rocks. Um. They're hard.
Speaker 1: You have to hit them just right and with a
Speaker 1: lot of force. UM. But it's pretty conceptually simple. You're
Speaker 1: not gonna make flakes. Um. And then after that you've
Speaker 1: got what variously is called like mode to or loosely
Speaker 1: called Julian after a site where it was first described
Speaker 1: in Europe, is the manufacture of these things that archaeologists
Speaker 1: call hand axes. And that's where you're not just shattering
Speaker 1: the rock into flakes, but you're actually shaping the rock
Speaker 1: to make a tool. UM. The classic tool from this
Speaker 1: sort of stage or time period is uh the hand axe,
Speaker 1: which would be a flat rock UM with cutting edge
Speaker 1: most of the way around the perimeter and a tip
Speaker 1: at one end can be good again we think for
Speaker 1: a large animal butchery. Uh. And so that's where you've
Speaker 1: moved then to actually having the intention, having a goal
Speaker 1: in mind, and the techniques that you have. The control
Speaker 1: over the stone that's required is more um Uh. Following
Speaker 1: that you have what we call prepared core technologies, in
Speaker 1: which you shape the rock in a careful way so
Speaker 1: that you can remove one final piece that's already pre
Speaker 1: shaped the way you want it to be, and then
Speaker 1: you can do that over and over again, so it
Speaker 1: becomes a very efficient way of making tools. And then
Speaker 1: there's all sorts of variations on that um and that's
Speaker 1: the point in which we think there's a big change
Speaker 1: that they start actually putting these things on sticks, for
Speaker 1: instance hafting. Right, So you have composite tools, and you
Speaker 1: have all sorts of other techniques and materials that then
Speaker 1: enter the process and things become much more complex. So
Speaker 1: you mentioned the hand as, I'm interested to know a
Speaker 1: little bit more about that. I may be mistaken, but
Speaker 1: there there have been identified, I think, different schools of
Speaker 1: hand as construction. Is that right? Well, yeah, I mean
Speaker 1: there are different ways of making something that we call
Speaker 1: a hand ax. Um. Now we also, I would be
Speaker 1: very careful about that. We should always remember that when
Speaker 1: we call slaying a hand act, that's a name that
Speaker 1: we came up with to describe a bunch of things
Speaker 1: that we think are all similar to each other. That
Speaker 1: doesn't necessarily map onto what anybody was thinking in the past,
Speaker 1: or whether they knew each other or or whatever. So
Speaker 1: it's a tool, but we have to be careful about it.
Speaker 1: And you put a name on something, you think you
Speaker 1: understand it. Uh. But yeah, So, as I mentioned, the
Speaker 1: hand acts has a particular form. There's a lot of
Speaker 1: different ways you could achieve that, and a lot of
Speaker 1: different starting points. For instance, I might start with just
Speaker 1: a big rock and then shape that rock into appointed
Speaker 1: in hand ax, uh you know. Or I could start
Speaker 1: with an even larger rock and then I knock off
Speaker 1: a giant flake, you know, more than more than ten
Speaker 1: centimeters long is generally they cut off, and that's almost
Speaker 1: already what I need. You know, it's got a big
Speaker 1: cutting edge all the way around the edge. And then
Speaker 1: I shape that flight just a little bit right. And
Speaker 1: that's a very different way of making a tool that
Speaker 1: in the end probably as a similar function and looks
Speaker 1: quite similar. And then there's all sorts of different sub
Speaker 1: variants of ways of doing that. Uh. So that's what
Speaker 1: I think when you're talking about different schools, is these
Speaker 1: different methods of making the hand access. Now there's as
Speaker 1: a raging debate over what the variation actually means, you know,
Speaker 1: the sort of naive ascension early on was every time
Speaker 1: you find a different way of doing something, that's a
Speaker 1: different quote culture, even though we don't really know what
Speaker 1: we mean by that term at that point. Now now
Speaker 1: there's you know, people saying that these are just recurring
Speaker 1: rediscoveries of simple solutions to the same kind of problems.
Speaker 1: They don't necessarily imply any sort of cultural continuity or
Speaker 1: contact between people. There's even been suggestions that there was
Speaker 1: some kind of large genetic component to the way that
Speaker 1: people made these these hand axes. So now it's up
Speaker 1: for debate. But the variation is what we we study
Speaker 1: to try to understand what was going on in the past.
Speaker 1: That's where we have a sort of an insight into
Speaker 1: what was what was happening. Well, I was definitely going
Speaker 1: to ask you the naive question about whether that's a
Speaker 1: result of culture, But is there so if we don't
Speaker 1: make that assumption that the different forms or shapes or
Speaker 1: approaches to hand axes are necessarily the result of cultural
Speaker 1: traditions or cultural contact, is there anything that you think
Speaker 1: looking at tools like this Stone age tools could possibly
Speaker 1: tell us about the culture of the creatures that made them. Yeah, well,
Speaker 1: and so this is where we have to get into
Speaker 1: the sort of stuff that you can learn through experimental archaeology. UM.
Speaker 1: For instance, how difficult is it to discover and use
Speaker 1: particular techniques, you know, so you know, if they're if
Speaker 1: there's two people that do something the same way, if
Speaker 1: it's an obvious answer, then there's no reason to think
Speaker 1: they learned it from each other. But if it's this
Speaker 1: really sort of obscure and and and hard to learn
Speaker 1: technique that they share, and then it's much more likely
Speaker 1: that they learned it from each other. So I mean,
Speaker 1: so there's this thing in in the issue in a
Speaker 1: uh sort of a geographic patterning um to where you
Speaker 1: have far fewer hand axes in East Asia than you
Speaker 1: do in Africa and Western Asia and Europe. And also
Speaker 1: none of them really to appear to be as refined
Speaker 1: as some of the nicest examples from from further west UM.
Speaker 1: And so people have debaded for a long time with
Speaker 1: this geographical patterning means, and I tend to interpret it,
Speaker 1: you know, in terms of there are some techniques that
Speaker 1: are pretty hard to discover on your own and some
Speaker 1: that are easy, you know, and so you have a
Speaker 1: lot of reinvention of sort of easy hand acts making
Speaker 1: here there in the other place. You know, but these
Speaker 1: particular advanced techniques may only have been invited it once
Speaker 1: or twice or a couple of times, and so their
Speaker 1: geographic spread is more restricted. So that's sort of the
Speaker 1: way that you make a relationship between understanding the way
Speaker 1: that you actually make the tools and then how they
Speaker 1: might spread through ancient populations. So you mentioned experimental archaeology. Um.
Speaker 1: I know a lot of people probably when they think
Speaker 1: about the data collection part of archaeology, they probably think
Speaker 1: primarily about digging. Um. But but tell us a little
Speaker 1: bit about what experimental archaeology means and what what what
Speaker 1: kind of things that has helped us understand that we
Speaker 1: couldn't understand just from looking at actual artifacts. Yeah. Well,
Speaker 1: you know, what you can understand from just looking at
Speaker 1: the artifact is actually a bit limited. You know, these
Speaker 1: things they don't they don't come out of the ground
Speaker 1: with with labels on them. Uh uh. You know. I
Speaker 1: like to do this when I give a presentation that
Speaker 1: you show a picture full of a table full of
Speaker 1: a bunch of old one stone tools and say like Okay,
Speaker 1: now what does this tell us? And in most people,
Speaker 1: you know, you can't even tell that there are anything
Speaker 1: other than just rocks if you're not used to looking
Speaker 1: at them. So what you have to do to understand
Speaker 1: what these tools that we dig up can actually tell
Speaker 1: us is, uh, basically experimental archaeology. We use analogies, We
Speaker 1: try to learn how to make them ourselves, and then
Speaker 1: you can manipulate. Well, if I make it this way,
Speaker 1: then it looks like that. If I make it this way,
Speaker 1: it looks like that. If I use it this way,
Speaker 1: this happens to it. Um. So then we make these analogies,
Speaker 1: these sort of inferential arguments that processes we can observe
Speaker 1: and manipulate experimentally now are the same ones that produce
Speaker 1: the same effects in the past. Uh. I mean, if
Speaker 1: you think about it, we do this you know any time,
Speaker 1: even in more recent time periods, when you look at
Speaker 1: an artifact, I mean, you're making an analogy with something
Speaker 1: you're familiar with. Usually even it's just implicit. You know, obviously, um,
Speaker 1: this is a sword. You know, I've seen things like
Speaker 1: that before, and now you don't really know that you're right,
Speaker 1: but it's similar enough to things with which you're familiar.
Speaker 1: That that that's you know, that's reasonable. When you dig
Speaker 1: off something from two and a half million years ago,
Speaker 1: you've got nothing to go on, right, So we have
Speaker 1: to actually do some of this work to establish robust
Speaker 1: or strong analogies that we can use. Now you've mentioned
Speaker 1: your own experiences creating stone tools. How long does it
Speaker 1: take you to create a hand axe? Oh? Yeah, I
Speaker 1: mean it takes me maybe half an hour. I'm a
Speaker 1: little bit slow with that. Uh, and uh, you know,
Speaker 1: it depending on how nice you want to make it.
Speaker 1: And that's already assuming that I'm I'm sitting in my
Speaker 1: outdoor lab with a pile of rocks right next to me,
Speaker 1: and I just start making the thing. You know, if,
Speaker 1: of course, in prehistory you would have had to go
Speaker 1: get the rocks and all these other things to take
Speaker 1: a lot more time. But yeah, uh something that's that's
Speaker 1: quite good. It at it nine twelve to fifteen minutes,
Speaker 1: you can yeah. Yeah, So you mentioned that we think
Speaker 1: a lot of these early stone tools were used in
Speaker 1: butchering meat. Have you ever had food prepared with stone
Speaker 1: tools you've made? Uh, well, let's see myself. Uh yeah,
Speaker 1: only actually recently, one of my colleagues had a pig
Speaker 1: roast where we used some of the stuff that I
Speaker 1: had made. Yeah, but back in uh in in graduate school,
Speaker 1: and it's quite common in these labs and places where
Speaker 1: people do this sort of work to have the occasional
Speaker 1: animal roast where you uh and you you learn things
Speaker 1: like you know that obsidian um is really sharp and great,
Speaker 1: but it also crumbles and leaves little bits of like
Speaker 1: glassy kind of gridgy stuff. Yeah, not so great. I
Speaker 1: like flint, right, So do we find uh, do we
Speaker 1: find little grains of obsidian and ancient teeth? I'm not aware. Um,
Speaker 1: you know, there's always I'm not well versed in later
Speaker 1: prehistory and so as possibly there's something out about that
Speaker 1: I'm not aware of them actually getting any dental wear
Speaker 1: from the stone tools. Of course, you get very similar
Speaker 1: looking dental where when you you eat like a TUBERSI
Speaker 1: dug out of sandy ground, so you do get cut
Speaker 1: marks on teeth, which is very interesting because uh way
Speaker 1: commonly to eat things if you don't use silverware or
Speaker 1: chop sticks or anything like that, is you hold it
Speaker 1: up to your mouth, you clench it in your teeth,
Speaker 1: and you cut away from from there, so you're cutting
Speaker 1: right next to your mouth, and occasionally they did hit
Speaker 1: their teeth um, and so you get these little little
Speaker 1: cut marks on the front teeth and fascinatingly sorry, yeah,
Speaker 1: a lot of things can take the gross but one
Speaker 1: of the one of the cool things you can actually
Speaker 1: infer which hand was used, because there's a you know,
Speaker 1: a sort of an ergonomics. You're slicing down and in
Speaker 1: one direction, so you can tell. And so people have
Speaker 1: used that to identify really examples of predominantly right handed populations.
Speaker 1: Even the gross stuff, there's always something you can you
Speaker 1: can get out of it. You know, we encourage you
Speaker 1: to mention all the gross stuff. We're not we shy
Speaker 1: away from that here. So how is the study of
Speaker 1: modern stone tool users such a such as a stone
Speaker 1: tool users in New Guinea? How has this informed our
Speaker 1: understanding of ancient stone tool use. Basically, the whole goal
Speaker 1: of experimental archaeology is to generate analogies that we can
Speaker 1: observe in the modern day, uh to understand the past. Um.
Speaker 1: One of the things we have to be careful about, though,
Speaker 1: is that when you design experiments and you control things,
Speaker 1: you build in a lot of your own assumptions, even
Speaker 1: if you're not aware of them, about how things are
Speaker 1: done or why things are done and so forth. You're
Speaker 1: also dealing with a very artificial environment in the lab
Speaker 1: and without any social context or anything like that. UM.
Speaker 1: So another source of analogy UM that you can use
Speaker 1: to understand the past is UH ethnographic observation UM. And
Speaker 1: by that, I would stress it you you can include
Speaker 1: also people, for instance, in the United States that do
Speaker 1: this as a hobby. There's a community, there's things we
Speaker 1: can learn from them. I was lucky enough to UH
Speaker 1: to visit some modern tool acres in New Guinea that
Speaker 1: are part of a different tradition UH back in I
Speaker 1: was there UM. And one of the things that that
Speaker 1: that just broadens the number of different examples of ways
Speaker 1: to do things UM that we can use to understand
Speaker 1: the past UM. And one of the one of the
Speaker 1: really cool things about it was I was expecting this
Speaker 1: to be a very uh you know, very foreign experience,
Speaker 1: experience to be in the highlands of New Guinea, and
Speaker 1: but once we got to the stone tools, they talked
Speaker 1: about a lot of the same things that I, as
Speaker 1: an archaeologist, was already used where they had names for
Speaker 1: the for the same kinds of features of the stone
Speaker 1: tools and they Uh so there's a real common ground
Speaker 1: there because we were all based on things that happened
Speaker 1: when you try to break stone in a controlled way.
Speaker 1: And then that's very validating for an archaeologist because it
Speaker 1: means we can expect that, even moving them to the
Speaker 1: total unknown of the past, there's gonna be these constants
Speaker 1: that shaped human behavior, and if we can understand them today,
Speaker 1: it looks like they affect different people from very different
Speaker 1: cultural backgrounds in similar ways, and so so that's very validating. Um.
Speaker 1: The other thing that was really exciting there is is
Speaker 1: just how they incorporated stone toolmaking into their own particular
Speaker 1: cultural and social context um, which obviously, if you study
Speaker 1: hobbyists in the industrialized West is one context, but this
Speaker 1: was horticultural context. And the way they had a sort
Speaker 1: of a system of apprenticeship for learning this, and the
Speaker 1: just the amount of time that it takes to become
Speaker 1: an expert in the they had a particularly you know,
Speaker 1: advanced kind of toolmaking, um. But the the the sheer
Speaker 1: effort and the social values they attached to sticking with
Speaker 1: it and practicing the support they provided for learning that way,
Speaker 1: I thought. I found that to be all very inspirational
Speaker 1: UM for my own research. So in in in dealing
Speaker 1: with the stone toolmakers in New Guinea, UM, I'm assuming
Speaker 1: there was a there was a language barrier, there is
Speaker 1: a translator. What was How did did that reveal anything
Speaker 1: or back up anything that you any pre existing thoughts
Speaker 1: about the effects of tool use and toolmaking on language
Speaker 1: and uh and then the origins of language. Yeah, well
Speaker 1: I think it was there's there's been an idea for
Speaker 1: for some time, UM, which were increasingly are articulating that. Uh.
Speaker 1: One of the things that may have led to the
Speaker 1: evolution of language in terms of UH an evolutionary pressure
Speaker 1: or favoring language evolution is is they need to be
Speaker 1: able to teach each other. UH, and particularly the ability
Speaker 1: to teach people that you're related to, because then you
Speaker 1: get sort of the genetic benefit and all that kind
Speaker 1: of thing. UH. And in in New Guinea, it was
Speaker 1: really uh striking the amount of social support UM in
Speaker 1: various ways that was provided for people learning. UM. I
Speaker 1: found that very informative. So of course language, you know, talking,
Speaker 1: I have to do this, don't do that, or we
Speaker 1: call this this, you know. And and um also use
Speaker 1: of language to tell stories, um, which establishes you know,
Speaker 1: sort of these cultural norms. They tell a story about
Speaker 1: someone who is a great toolmaker because he spent all
Speaker 1: of his time practicing and he neglected his yields and
Speaker 1: didn't talk to his wife, you know, and all that
Speaker 1: sort of stuff. UM. And that the socializing that they do.
Speaker 1: They sit together and it makes it fun. Um. All
Speaker 1: of these things are really important to learning something that's
Speaker 1: very frustrating and difficult. Um. You know, maybe you can
Speaker 1: think of analogies see in your own experience. Uh. And
Speaker 1: so that that was really really cool. And then just
Speaker 1: the uh also all of the gesturing of the pointing,
Speaker 1: and just the context of having particular places where you
Speaker 1: do things. You know, this is where we go to
Speaker 1: get the rocks, this is where we all sit down
Speaker 1: and make tools together. There was a structure, so there
Speaker 1: was so much about what they were doing socially that
Speaker 1: resulted in the the sustaining of this technology. And I thought,
Speaker 1: you know, obviously you can't just project that into a
Speaker 1: particular past context, but we need to expand our thinking
Speaker 1: broadly to think about these other dimensions that may be
Speaker 1: implied by some of the ancient stone tools that we find. Okay,
Speaker 1: time to take a quick break, but we will be
Speaker 1: right back with more of our conversation. Thank thank Alright,
Speaker 1: we're back. Let's jump back in now. Obviously this is
Speaker 1: a different question from how the crafting of stone tools
Speaker 1: might have changed our neuro anatomy over time. But I
Speaker 1: wonder does making stone tools just change the way you
Speaker 1: in your life think about your relationship with the earth,
Speaker 1: Like do you do you find yourself out walking and
Speaker 1: looking down and saying, oh, there's a good one. No,
Speaker 1: that's not a good one. Yeah, yeah, I mean, I
Speaker 1: mean now, I mean, particularly if you've been doing a
Speaker 1: lot recently, you can't see a rock without picturing breaking,
Speaker 1: you know. It's a uh And of course just doing
Speaker 1: being an archaeologist does that too. Um. You know, I'm
Speaker 1: always looking at little pebbles and my wife will catch
Speaker 1: me looking at the landscaping, you know, and like that
Speaker 1: would be a good hammerstone or something like that, you know.
Speaker 1: Uh So so yeah, it does influence uh some of
Speaker 1: the resources that you're aware of that are really not
Speaker 1: particularly relevant for most people in their daily lives. But
Speaker 1: we're once incredibly central. Well, I think about ways that
Speaker 1: that that type of thinking um can take on more
Speaker 1: complex kind of mental dimensions. Like I think about the
Speaker 1: way when I go shopping, Uh, if I'm like picking
Speaker 1: out produced to cook with, I could see like a good,
Speaker 1: fresh piece of produce and I attribute moral goodness to that,
Speaker 1: and I see like a bad, rotten piece of produce
Speaker 1: and I attribute moral badness to it. Do do you
Speaker 1: do you ever feel inklings of that kind of thing
Speaker 1: with rocks? Oh? Well, there's a certainly I don't know
Speaker 1: about the moral dimensions, and certainly a real aesthetic to it.
Speaker 1: I mean, you know, I don't know if you're familiar
Speaker 1: with with Flint, but it's a beautiful rock and the
Speaker 1: the sound that it makes and the way that it
Speaker 1: breaks when it when it does what you wanted to uh,
Speaker 1: is just infinitely pleasing, you know. And Uh, I just
Speaker 1: got some some really nice bassualt as well, which is
Speaker 1: a very different kind of of rock and has different
Speaker 1: but also really just aesthetically pleasing And you get a
Speaker 1: real pleasure out of out of working in. Yeah, so
Speaker 1: you said you can you can hear the difference between
Speaker 1: a good break and a bad break. Yeah, yeah, this
Speaker 1: is a question. I mean, I think it's important, and
Speaker 1: I've talked to people who are much more experienced stone
Speaker 1: toolmakers than I am that that really emphasized that, you know,
Speaker 1: the sound is important. And in fact, we're just in
Speaker 1: the process of developing an online tests that people can
Speaker 1: take where we play the sounds of a stone flake
Speaker 1: coming off and you use a little slider to say
Speaker 1: how big you think it was. Uh So we're trying
Speaker 1: to see how much information is actually present in those sounds. Uh,
Speaker 1: I know, I know that when we're sitting around napping,
Speaker 1: everybody's looking napping being a term we used to talk
Speaker 1: about stone toolmaking, not to be confused with falling asleep,
Speaker 1: but it's knocking, yeah, and napping. I don't know if
Speaker 1: it's German or something. They don't even know where it
Speaker 1: comes from, but yeah, knocking the flakes off. Anyway, we're
Speaker 1: sitting around knocking the flakes off, and uh, you know,
Speaker 1: all staring down at what we're doing, and then somebody
Speaker 1: will strike off a really nice large flake and it
Speaker 1: makes this flat, popping sound and everybody just looks up
Speaker 1: over it. Then so all right, you know, uh so anyway, long, Sorry,
Speaker 1: the the we think the sound is is probably really important,
Speaker 1: and we're trying to probe that it. It keeps coming
Speaker 1: up also in uh some of the neuroimaging research that
Speaker 1: we do, or we look at uh stone toolmaking, and
Speaker 1: we get these activity in areas that are more classically auditory.
Speaker 1: And initially wasn't expecting that, but of course it makes sense.
Speaker 1: That is interesting. And the stuff about the toolmaking process
Speaker 1: giving you all these sort of aesthetic values when you
Speaker 1: look at rocks or when you hear the sounds rocks make.
Speaker 1: Does that, um lead you to draw any connections between
Speaker 1: the origins of tool crafting in the origins of art um? Yeah, sure,
Speaker 1: you know, in a informal sort of way. Um. And
Speaker 1: and and you know people have have written about these ideas.
Speaker 1: And this is another area sort of of contention, particularly
Speaker 1: with the hand axes. Uh. They're beautiful, right, they did.
Speaker 1: They're very appealing. Um. And there's some argument that in fact,
Speaker 1: there are much too beautiful and appealing from no apparent
Speaker 1: functional benefit, that this must be one of our earliest
Speaker 1: examples of you know, aesthetic sense. UM. But as I
Speaker 1: mentioned that, it's awfully hard to demonstrate that in a
Speaker 1: really compelling way to skeptics. Uh. Um, it's it's it
Speaker 1: is hard to say. You do get these glimmerings of
Speaker 1: interesting things like, uh, you know, to make a hand
Speaker 1: act and will be a fossil impression of a shell
Speaker 1: that they leave right in the middle of the center
Speaker 1: of one of the sides. You know, it's sort of
Speaker 1: like they showed it off or was that an accident?
Speaker 1: Yuh Um, it is hard to say. Um, but certainly
Speaker 1: from our perspective, the symmetry and many of the aspects
Speaker 1: of these tools are very aesthetically pleasing, so we'd like
Speaker 1: to speculate that there's some relationship. There is there any
Speaker 1: indication with any of the any particular hand axes that
Speaker 1: are particularly beautiful to modern eye that they were in
Speaker 1: any way merely ritualistic, that they I mean, they were
Speaker 1: not used. Yeah, So it's a it's a bit hard
Speaker 1: because it's actually not always possible to show that that
Speaker 1: many of the hand axes were used. You need particular
Speaker 1: preservation conditions and evidence to actually demonstrate that something was used,
Speaker 1: so we rarely get that. On the other hand, um,
Speaker 1: there are examples of things that look like they couldn't
Speaker 1: have been used. Um. These are very rare where there
Speaker 1: would be like this really giant hand acts like the
Speaker 1: length of my forearm, you know, that somebody made, and
Speaker 1: in our imagination, it's pretty hard to come up with
Speaker 1: a functional reason to do that. So it seems to
Speaker 1: have been somebody showing off or just trying to produce
Speaker 1: a piece that is somehow appealing to them or something
Speaker 1: like that. Yeah, it's it's it's elusive. Um, they're these
Speaker 1: these glimmerings of it. So we've already mentioned a little
Speaker 1: bit the possible relationships between tool use and UM and
Speaker 1: the development of human neuro anatomy. Uh, do you talk
Speaker 1: a little bit more about that, like what some of
Speaker 1: the leads are and what is the evidence directly for
Speaker 1: those connections. I know some of it has to do
Speaker 1: with just like correlation of timelines, right right, Well, I mean,
Speaker 1: so there's a basic awareness so we've had for for
Speaker 1: a long time that you know, there's a broad general
Speaker 1: trend towards brain size increase over human evolution, with many
Speaker 1: exceptions and side branches and so forth that we're discovering now. Um,
Speaker 1: but yeah, I mean, our brains are bigger than any
Speaker 1: of the brains were two millioneers, and there is a
Speaker 1: trend there also, you know, the tools over time with
Speaker 1: many exceptions and places where it didn't happen and so forth.
Speaker 1: But the most elaborate sophisticated tools around a hundred thousand
Speaker 1: years ago, we're much more complex than the most elaborate
Speaker 1: sophisticated tools that were around two million years ago. So
Speaker 1: there's a trend there, and there there's two trends side
Speaker 1: by side, and you know, like think maybe they're related
Speaker 1: to each other. Um. Now exactly how they're related to
Speaker 1: each other is a more difficult question. You know, did
Speaker 1: the brain get bigger and for other reasons that then
Speaker 1: spill over into being able to make tools or where
Speaker 1: the tools really important? So that like if you could
Speaker 1: make a if you're a little bit faster at making
Speaker 1: a tool, more reliable at making a tool, you had
Speaker 1: a little bit of a reproductive advantage, then you know,
Speaker 1: than than then maybe the tools drove it um And
Speaker 1: those are hard to uh discern exactly. So that's why
Speaker 1: we we try to do some of these experiments where
Speaker 1: we relate the actual process of making tools. We try
Speaker 1: to figure out, well, what does it demand cognitively neurally?
Speaker 1: If there were pressure on being able to make these tools.
Speaker 1: These are the things then that would respond to it.
Speaker 1: So that's we're just trying to sketch out some of
Speaker 1: the basics still at this point, I think to make
Speaker 1: that link and to do that, You've done some research
Speaker 1: with the neuroimaging and and how that relates to thinking
Speaker 1: about tools to making tools. Could you tell us some
Speaker 1: more about that. Yeah, So, Uh, We've done a couple
Speaker 1: of different things. UM. One is what most people are
Speaker 1: probably more familiar with, which is a functional neuroimaging, which
Speaker 1: typically works somehow related to to blood flow in the
Speaker 1: brain responsive neurons, so when they're active UM, and so
Speaker 1: we can isolate those areas of the brain UM that
Speaker 1: are more active when you make a particular kind of tool,
Speaker 1: you know, for instance, the hand actions that I was
Speaker 1: talking about versus the earlier, simpler, older one style tools,
Speaker 1: and we can say, oh, well, this is the neural
Speaker 1: system related to these forms of cognition UM that is
Speaker 1: required to do that. So if there was something that
Speaker 1: changed in the past associated with this technology, is most
Speaker 1: likely to be those systems. Uh. Then the other thing
Speaker 1: that we do is actually structural stuff UM. And that
Speaker 1: comes in two flavors. Also, you can, uh, you can
Speaker 1: look at plastic changes in the brain that are caused
Speaker 1: by a behavior. And this is something that in the past,
Speaker 1: I guess about twenty years or so, people really become
Speaker 1: aware that, even over short periods, doing things learning to juggle,
Speaker 1: actually changes the physical structure of your brain, especially things
Speaker 1: like white matter uh that sort of the cables that
Speaker 1: connect things in your brain. UM. And so we've applied
Speaker 1: that also to stone toolmaking uh and seeing that training
Speaker 1: to make hand access, for instance, will increase certain white
Speaker 1: matter pathways in the brain. UH. Interestingly enough, these are
Speaker 1: also white matter pathways that are larger and modern humans
Speaker 1: versus chimpanzee. So we know that it's something that has
Speaker 1: evolved in our history and we can relate it to
Speaker 1: a behavior that also is observable to have come along
Speaker 1: at a certain time in our history. So we started
Speaker 1: to strengthen this sort of infrenial Well, maybe these things
Speaker 1: are related to the evolution of that pathway. UM. The
Speaker 1: other thing that we can do that we're really just
Speaker 1: starting to look at is uh individual differences in structure
Speaker 1: and function of people. So if you get a large
Speaker 1: enough sample, there are small differences for instance, in the
Speaker 1: rapidity with which people learn uh different kinds of stone toolmaking,
Speaker 1: you know, and you can then correlate with starting differences
Speaker 1: in their brain structure or the way that their brain
Speaker 1: changes over time. And I think that's really exciting because
Speaker 1: we can then also relate that to uh cognitive tests.
Speaker 1: So you know, some of the initial stuff that we're
Speaker 1: getting is you know, so if you're particularly good at
Speaker 1: uh planning. For instance, there's a task called the Tower
Speaker 1: of London, which you move sort of rings around on
Speaker 1: three pegs and you have to do it in a
Speaker 1: particular order. Uh. If you're good at that, you learn
Speaker 1: stone tool making faster slightly. Uh yeah. I think that's
Speaker 1: really really fast because we're actually making these links between
Speaker 1: particular cognitive operations and kind of types of stone toolmaking
Speaker 1: that we can see in the archaeological record. Now, now
Speaker 1: that the test subjects who learned how to make stone
Speaker 1: tools and then you saw the changes in the brain, Um,
Speaker 1: were any of them engaged in any activity that was
Speaker 1: comparable to stone tool use or construction, like carp injury
Speaker 1: or anything prior? Uh yeah, Um, so we actually have
Speaker 1: uh data on that that we haven't analyzed yet. We
Speaker 1: have people right about their other hobbies and activities. And
Speaker 1: actually we've got a big pile of stuff we've still
Speaker 1: got to go through in that study. Um but you know, uh,
Speaker 1: sort of anecdotally, I do know that there were people
Speaker 1: from a bunch of different kinds of professions, like we
Speaker 1: had teachers, we did have one sculptor in the project,
Speaker 1: and so there we don't yet, um have any hard
Speaker 1: conclusions about that, because we need to work with the data.
Speaker 1: But one general impression I got there was a little
Speaker 1: bit counterintuitive, is that if you have more experience with
Speaker 1: some of these things that you might think of as
Speaker 1: being you know, conducive to knowing how to make stone tools,
Speaker 1: you can actually interfere if you're sort of setting your ways. Um.
Speaker 1: Um So, but there's a lot more to be done
Speaker 1: with that. And one of one of the things that
Speaker 1: it bothers me is we always do these studies, you know,
Speaker 1: with the the typical college undergraduates, and they're not really
Speaker 1: known for being particularly good with their hands. So, um,
Speaker 1: I would really like to expand into different populations in
Speaker 1: different ages. And but you know, we're just getting started,
Speaker 1: because that's where you would find individuals who were, say,
Speaker 1: skilled craftsman craft people in other in other areas, right, yeah, yeah, yeah,
Speaker 1: and just just people that are more commonly doing work
Speaker 1: with their hands, you know. Um. Now, I work with
Speaker 1: people out when we go do excavations in Ethiopia and
Speaker 1: the aar Um you know is there's their pastoralists. They
Speaker 1: have herds of animals and they you know, they make
Speaker 1: little walls out of stone all the time, and I
Speaker 1: mean they're a lot more handy. They might pick it
Speaker 1: up a lot faster. So obviously getting the population you
Speaker 1: want is one experimental challenge. I would imagine another one
Speaker 1: if you're if you're trying to do neuroimaging while people
Speaker 1: are engaging in tool tool making. The I mean, don't
Speaker 1: you have to hold still say for from R I, Yes,
Speaker 1: for fm R I you do. Um. So there is
Speaker 1: you know, a couple kinds of workarounds. One of them
Speaker 1: is the the the the the earliest studies that we did,
Speaker 1: you know, about eighteen years ago or more. Now, we
Speaker 1: used a technique called f DG pet UM and positron
Speaker 1: emission tomography UM is something they don't use a lot
Speaker 1: for research anymore, and brain activation. But one of the
Speaker 1: things that lets you do is we injected a radiological
Speaker 1: tracer UH into their bloodstream and this is a glucose
Speaker 1: analog UH and so it's taken up by basically hungry
Speaker 1: cells in the body like they think it's glucose. Happens
Speaker 1: in the brain and neurons UM and then it emits
Speaker 1: radiation small amounts, but this can be this can be
Speaker 1: detected by you know, a sensor array around the head.
Speaker 1: So basically you can give somebody this injection, have them
Speaker 1: do anything you want really, like they could run around
Speaker 1: the block and but we have them sitting in a
Speaker 1: chair and make stone tools in an nonconstrained way. Then
Speaker 1: you walk them over to the scanner about half an
Speaker 1: hour later, I have I've been doing this for half
Speaker 1: an hour UH and you collect an image of where
Speaker 1: the gluco is built up right. UM. So this is
Speaker 1: great because you can do it UM and have them
Speaker 1: do real tasks outside the scanner. UM. But it's limited
Speaker 1: because you know, you've got time averaged over half an hour,
Speaker 1: and you can only do a couple of different conditions
Speaker 1: because it does involve radiation exposure and you don't want
Speaker 1: to give anybody too much and so you know, UM,
Speaker 1: the fm R. I you mentioned you have to be still,
Speaker 1: but we can take advantage of the fact that. Let's
Speaker 1: get a little theoretical, but neuroscientists have largely converged on
Speaker 1: the idea that one of the ways we understand what
Speaker 1: we see other people do is to internally simulated ourselves
Speaker 1: in fact using the same neural systems. UH. And this
Speaker 1: is probably an important way that we learn from others
Speaker 1: as well, which is an important research question too. But
Speaker 1: we can take advantage of that, and we show people
Speaker 1: films of toolmaking in the scanner, and so this is
Speaker 1: most directly relevant to observational understand ending and learning from
Speaker 1: other individuals. UM. But it does pretty much use overlapping
Speaker 1: systems with execution, and we've shown that, so that's another
Speaker 1: sort of work around. And UH, colleague of mine, Shelby Putt,
Speaker 1: is using something called functional near infrared spectrography ay F
Speaker 1: near as anyway is what I what I remember, UM,
Speaker 1: and that actually uses near infrared visible light that can
Speaker 1: penetrate the cranium and get some information on blood flow
Speaker 1: from superficial areas of the brain, and that you can
Speaker 1: wear while you're doing something as well. So there's some
Speaker 1: a few workarounds that you can do to actually use
Speaker 1: neuroimaging techniques, and I wonder, um, are there I don't
Speaker 1: know if anybody's looked at this, but would there be
Speaker 1: differences in the brain between um, doing doing a task
Speaker 1: and stone tool creation and simply imagining the task because
Speaker 1: of all, you know, we've looked on the show a
Speaker 1: bunch of times about simply imagining doing something is very
Speaker 1: similar in the brain to actually doing it. Yeah. UM,
Speaker 1: so it's similar in very interesting and important ways, but
Speaker 1: also different in important ways, and particularly in the context
Speaker 1: of stone toolmaking, where some of the things that were
Speaker 1: interested in are the actual skill to really deliver the
Speaker 1: right amount of force to the right place. Um, we
Speaker 1: want to actually tap into that somehow. Um. We did
Speaker 1: do an experiment though, um, in which we were more
Speaker 1: interested in the uh, the kind of planning aspects and
Speaker 1: the evaluation aspects, and we had just people looking at
Speaker 1: stone tools and answering questions about what would be the
Speaker 1: good thing to do next, which is basically asking them
Speaker 1: to mentally imagine and simulate the actions, and you tap
Speaker 1: into different aspects of the task demands there. So we
Speaker 1: can use both. But but there are aspects of stone
Speaker 1: tool making that are very reliant I think on actually
Speaker 1: doing it. All right, we're gonna take a quick but
Speaker 1: we're gonna jump right back in with our interview. Thank
Speaker 1: thank alright, we're back. Just recently, I happened to be
Speaker 1: reading a couple of papers in UM, I think Frontiers
Speaker 1: in Psychology. I believe about the possible role of UM,
Speaker 1: possible role of tool use in the development of consciousness. Uh.
Speaker 1: The the idea under this new framework was that maybe
Speaker 1: consciousness has something to do with creating states of objectivity
Speaker 1: in the mind where you can sort of like imagine
Speaker 1: and correctly judge the properties of an object that is
Speaker 1: not yourself. UM. I don't know if you've read that, Mariano. No,
Speaker 1: this was Oh I'm sorry. I can't remember the guy's name,
Speaker 1: but he's from Europe somewhere. I think he might have
Speaker 1: been mas streaked. Okay, yeah, I don't I don't know that,
Speaker 1: but um yeah, I mean there are potential uh links
Speaker 1: between consciousness. This is great for me. Actually, I I
Speaker 1: told you how I, you know, got into this. I
Speaker 1: thought I wanted to be a philosopher and all this
Speaker 1: certain I'd love to get around the consciousness. They say,
Speaker 1: you know, you wait till after you have tenure, maybe
Speaker 1: wait to get longer than that. You know, maytel you're
Speaker 1: all the time. Um, but I do think there is
Speaker 1: a potential that there there might be some way we
Speaker 1: could gain insight there. You know, if you think about
Speaker 1: what are the things that actually require consciousness, Like what
Speaker 1: is consciousness actually good for? Um? And you know some
Speaker 1: people have said basically nothing, uh you know, but but
Speaker 1: if there is something that it's good for, it's for
Speaker 1: tasks that require attention. I mean, that's what consciousness is.
Speaker 1: It's attending to things, uh, really getting the whole brain
Speaker 1: on board, uh, you know, and focusing on on this
Speaker 1: one thing. Um. And I think that uh, learning a
Speaker 1: skill like stone toolmaking is the kind of thing that
Speaker 1: demands that concentrated attention. And if consciousness is the way
Speaker 1: that you get that, if consciousness is the feeling that
Speaker 1: you have when you fully attend to things, then then
Speaker 1: then maybe there is a relationship there. I mean some
Speaker 1: of the other things people you can as you know,
Speaker 1: you can get into a car and uh start thinking
Speaker 1: about something else and drive to work when you meant
Speaker 1: to go to the store and so forth, which is
Speaker 1: you know, this sort of zombie stuff is pretty scary.
Speaker 1: Actually the things that you can do without being aware
Speaker 1: of it, um. But things people can't do are sort
Speaker 1: of sustain hopefully conversations like what we're having here. Uh,
Speaker 1: you know, the stay focused, um, very skilled activities. I mean,
Speaker 1: if you're like a race car driver, you wouldn't drift
Speaker 1: away and think about something else that demands your attention,
Speaker 1: demands consciousness. UM. So I think when we pick up
Speaker 1: tasks in the past UM that required people to really
Speaker 1: focus and attend UM, we might be picking up things
Speaker 1: that are diagnostic of the need for conscious states. Of course,
Speaker 1: one of the interesting things about tasks like that, like
Speaker 1: work with your hands, is that it requires a lot
Speaker 1: of consciousness when it's new to you, and over time
Speaker 1: requires less and less exactly. And that's why you know,
Speaker 1: unfortunately we we really have to focus on study being
Speaker 1: uh people who are learning um rather than you know,
Speaker 1: expert performance is still interesting in many ways, UM, but
Speaker 1: if you want to get at the real demands for
Speaker 1: something like conscious attention, that's going to happen when you're
Speaker 1: figuring it out later on. And I mentioned to some
Speaker 1: of the people that can make a hand act really well,
Speaker 1: and like, you know, twelve minutes, they don't have to
Speaker 1: think about it at all. Um, Someone like me, I
Speaker 1: have to attend to it so much that what always
Speaker 1: happens is I, you know, I I give demonstrations of napping,
Speaker 1: and then I will always wind up cutting myself because
Speaker 1: trying to talk about it and do us you know,
Speaker 1: and you're not focusing on it. Um. So yeah, it
Speaker 1: is the more skills you get, the more you can
Speaker 1: ignore the low level stuff and think about something else,
Speaker 1: you know, like making it a really appealing hand ax
Speaker 1: versus just trying to get something you can use. Do
Speaker 1: you happen to find that the most beautiful hand axes
Speaker 1: are also the best to like, the most functional, useful
Speaker 1: or those things generally aligned or not aligned. You'd be
Speaker 1: surprised the things that we don't know about stone tools
Speaker 1: because of the amount of time that it takes to
Speaker 1: do proper experimentation and actually test these sorts of things.
Speaker 1: So that's something that people are interested in, but there's
Speaker 1: only been a handful of experiments, um that actually looked
Speaker 1: at you know, is the symmetry of the hand acts
Speaker 1: make it a more or less effective butchery tool? Um,
Speaker 1: does the straightness of the edge matter? Um? Do any
Speaker 1: of the things to the thinness of it matter? Uh?
Speaker 1: And to the extent that has been shown, like the
Speaker 1: things like symmetry don't seem to really matter very much
Speaker 1: for the function uh the UH the evenness of the
Speaker 1: edge does seem to be important, and that might be
Speaker 1: aesthetic for some people. UM. The sort of extreme thinning
Speaker 1: of the hand axes that we find very appealing, I
Speaker 1: think because it's hard to do, is something that you know,
Speaker 1: maybe somewhat beneficial because you have the tool you're carrying
Speaker 1: around is lighter. Um. But thus far, there's not a
Speaker 1: lot of evidence that things we think of is really
Speaker 1: aesthetically important about hand axes are particularly functionally important. So
Speaker 1: there is another question we may not know the answer to.
Speaker 1: But do you think in general, is it more widely
Speaker 1: assumed that people in the uh prehistoric times would make
Speaker 1: a hand axe and and that would be their hand
Speaker 1: accidentally carried around with them, or is it something that
Speaker 1: would be made on site when it was needed. Yeah,
Speaker 1: I mean, I think it's important to uh, for archaeologists
Speaker 1: and for everybody to to remember when we think about
Speaker 1: the past that these is a huge amount of time
Speaker 1: over a large area. Um and they probably did just
Speaker 1: about everything at one uh time or another. Um I.
Speaker 1: It's some sites where you're sitting close to raw materials,
Speaker 1: you know, like there's a site of box grove. It's
Speaker 1: it's pretty close to these chalk cliffs where the flint
Speaker 1: is coming right out. They seem to have used them
Speaker 1: lightly and discarded them, probably made them pretty close to
Speaker 1: the time that they were going to use them, and
Speaker 1: that sort of thing. Um elsewhere, they may have actually
Speaker 1: carried them around for when you don't have as much rock.
Speaker 1: You know, when you're going far from the source, you
Speaker 1: probably take the hand next with you, and when it
Speaker 1: gets dull, you re sharpen it and all these sorts
Speaker 1: of things. Maybe you keep using it till you've whittled
Speaker 1: it down the way we do a pencil nub, you know.
Speaker 1: Uh So this is an area people try to understand,
Speaker 1: um basically the economics. This is sort of an economic question.
Speaker 1: Uh you know, when does it make sense to just
Speaker 1: toss the hand as versus you know, carrying it with
Speaker 1: you and resharpening it. And it seems to be driven
Speaker 1: by the things you would expect it to be driven by.
Speaker 1: Like distances from raw materials and the kind of activities
Speaker 1: that you're doing. So you probably get asked this question
Speaker 1: a lot, especially this year since it's such a milestone
Speaker 1: year for the film. But we recently talked about the
Speaker 1: about two thousand and one of Space Odyssey on the show.
Speaker 1: UM what are your thoughts about two thousand one of
Speaker 1: Space audi specifically of course, these scenes of these these
Speaker 1: ancient creatures engaging in tool used for the first time. Yeah, well,
Speaker 1: I mean, as you may you may be aware of
Speaker 1: that two thousand one was actually UH produced in consultation
Speaker 1: with archaeologists and paleo anthropologists, so it was informed by
Speaker 1: current UH speculations hypotheses about the origins of technology at
Speaker 1: the time. UM. I think that we have a a
Speaker 1: different view now. UM. I think if you would ask
Speaker 1: most most archaeologists about the origins of tool use and technology,
Speaker 1: they get very excited about things like cooperation and collaboration
Speaker 1: UH as as being a real turning point for for humans,
Speaker 1: and we are very cooperative species and this makes a
Speaker 1: lot of things possible. Whereas that vision UM was much
Speaker 1: more about the importance of killing each other UH and
Speaker 1: the sort of you know, the the killer ape basically,
Speaker 1: And if you want to take a step back from that,
Speaker 1: there's a lot of my my other colleagues and in
Speaker 1: anthropology and other disciplines who might point out that these
Speaker 1: things are heavily influenced by our own social views at
Speaker 1: the time about what's important, because some of it's is,
Speaker 1: you know, uh, myth make about human origins and what
Speaker 1: we think human nature is, and after World War Two
Speaker 1: it seemed pretty obvious we're all about killing each other.
Speaker 1: Right now, we'd like to think it's about cooperation. Uh.
Speaker 1: I don't want to get too heavy on that, because
Speaker 1: there actually is uh empirical are there are empirical arguments
Speaker 1: that can be made about this, in particular looking at
Speaker 1: comparisons across species and the importance of cooperation versus competition
Speaker 1: in different contexts. So there is a framework for for
Speaker 1: doing this. But it is interesting to think about our biases.
Speaker 1: But are certainly two thousand one fantastic film. I like,
Speaker 1: I wish the introductory segment we're a little bit quicker
Speaker 1: because I like to use it in my classes, but
Speaker 1: we have to sit there for like half a students
Speaker 1: aren't up for it. Um. Yeah, So I think it's Uh,
Speaker 1: they did their best to work with the current understanding
Speaker 1: at the time. It's a great movie. This is another
Speaker 1: realm where we might ask you to speculate if you're comfortable.
Speaker 1: But one of the things we talked about with two
Speaker 1: thousand one was the idea that you know, so when
Speaker 1: the ape like creature is first encounter the monolith in
Speaker 1: the in the savannah, UM, they they are changed in
Speaker 1: some way. But it's often assumed that maybe this is
Speaker 1: some alien technology that goes in and changes something in
Speaker 1: their brain. But an interpretation we talked about in the
Speaker 1: episode is one that that's actually not what happens. That
Speaker 1: what happens is they see this object in their environment
Speaker 1: that it's nothing like the rest of their environment. It
Speaker 1: looks completely artificial, and it's simply seeing that spurred something
Speaker 1: in their imagination that allowed them to to take up
Speaker 1: the tools. UM. And that makes me wonder about what
Speaker 1: what what would you imagine could be the role of
Speaker 1: simply seeing things in the environment to inspire the taking
Speaker 1: up and creation of tools. Yeah, I mean it's probably, uh,
Speaker 1: probably very important. I think this is the kind of
Speaker 1: thing that that archaeologists are loath to actually talk about
Speaker 1: because you're talking about like, uh, you know, individual acts
Speaker 1: of invention um that happened in the past, whereas the
Speaker 1: sort of the record that we have is this really
Speaker 1: really high level, averaged sort of sort of thing. Um.
Speaker 1: So it's hard for us, I mean, but clearly, you know,
Speaker 1: we shouldn't forget these things are inventions. They're not like
Speaker 1: mutations or just inevitable things that happened like somebody at
Speaker 1: some point had a new idea and did it. And
Speaker 1: then whether they were inspired by particular things in their environment.
Speaker 1: We like to think about, well, what kind of what
Speaker 1: were the kinds of things that they commonly encountered, and
Speaker 1: we could have some leverage to talk about that. You know,
Speaker 1: if they moved into a bit of a of a
Speaker 1: foraging niche, then they may be around these animal bones,
Speaker 1: you know, if there are stones available. Uh, if they
Speaker 1: cracked nuts um occasionally, as chimpanzees do, you're going to
Speaker 1: accidentally fracture the rock and and you know you could
Speaker 1: imagine imagine an aha moment there. But those are things
Speaker 1: that are very difficult to actually get to. Um. What
Speaker 1: I what I will say about the vision in in
Speaker 1: two thousand one is that it is an idea of
Speaker 1: a transformative moment um, and this is something that was
Speaker 1: also very current and maybe is to a certain extent,
Speaker 1: the idea that the invention of the earliest stone tools
Speaker 1: should be some kind of transformative, great leap forward that
Speaker 1: you know, that changed everything, and that doesn't seem to
Speaker 1: be the case. Actually. I mean, we now have one
Speaker 1: site at three point three million where they made stone tools,
Speaker 1: the next one is at two point six million, with
Speaker 1: nothing in between. Now we're going to find eventually something,
Speaker 1: but it's not a lot. It didn't like take off
Speaker 1: and go crazy, and and even at the two point
Speaker 1: six there's just a few and it's not around two
Speaker 1: million years ago that they start doing this regularly in
Speaker 1: a lot of places. So there's this huge long period
Speaker 1: of time where they're again stone tools. Maybe you could
Speaker 1: do it sometimes when it's worth it, I don't know.
Speaker 1: And so it wasn't like this sort of you know,
Speaker 1: gun that went off and everything changed, which is a
Speaker 1: different perspective than what we used to have. Well, it
Speaker 1: thinks it makes me think about even today and in
Speaker 1: modern society. You know, you have a new business as
Speaker 1: a new type of product, and it's always losing money
Speaker 1: at first, right, Uh, it makes me wonder if, yeah,
Speaker 1: were these things um more trouble than they were worth
Speaker 1: to begin with, and how if that's the case, how
Speaker 1: would you get through that? You know, how would you
Speaker 1: trust it to keep making them? Yeah? I mean it's
Speaker 1: hard to say. I think you know, my my favorite
Speaker 1: sort of pet hypothesis right now is that, yeah, it
Speaker 1: was just too too hard, in particular the investment in
Speaker 1: learning how to do this, uh, you know they did.
Speaker 1: Those were smaller brand individuals. They didn't have the same
Speaker 1: learning capacities that we have, and for whatever at the time,
Speaker 1: I think there was too steep a cost. I mean,
Speaker 1: occasionally it seemed worth it, um, but only a few
Speaker 1: individuals would learn, and and then they had to spend
Speaker 1: so much time figuring it out that you know, it
Speaker 1: was didn't really give them that much of an advantage.
Speaker 1: And then it was just lost in a small population,
Speaker 1: and nobody did it for however long you know, um,
Speaker 1: but you on long enough, and there may have been
Speaker 1: some selection either on the toolmaking or on other things
Speaker 1: that they were doing that eventually lowered the costs for
Speaker 1: them a little bit. It wasn't quite such a stretch
Speaker 1: to be able to do this, and that's where I
Speaker 1: have the chance of it actually paying for itself and
Speaker 1: then it would take off. So that's currently because when
Speaker 1: it does take off around two million years ago, it's
Speaker 1: very close in time to the appearance of Homo erectus,
Speaker 1: which has a larger brain and body, So you know, coincidence.
Speaker 1: But they've messed around for a long time until something
Speaker 1: changed about the cost benefit equation. I think, Ye, so
Speaker 1: many tantalizing mysteries. I'm just imagining these sort of many
Speaker 1: dark ages. Uh, and they're learning huh. Yeah, I mean
Speaker 1: if you think of these small groups very isolated, you know,
Speaker 1: I mean, somebody could have a great idea and then
Speaker 1: you know, they have a bad year and everybody dies,
Speaker 1: and that we think of it again for five years.
Speaker 1: I'm sorry, we keep asking you to speculate about stuff. Uh,
Speaker 1: these are the kind of questions we love to ask.
Speaker 1: But yeah, I mean, obviously people should understand that there
Speaker 1: there are tons of limitations on what we can know
Speaker 1: empirically about things this far in the past. So besides
Speaker 1: what we've talked about so far, what else do you
Speaker 1: find most fascinating about studying Stone age technology? Like what
Speaker 1: really gets your gears going about it. I mean, I guess,
Speaker 1: uh one thing, maybe it's a bit a bit technical.
Speaker 1: We we we started to talk about the relationship between
Speaker 1: stone toolmaking and language, and one of the ideas that
Speaker 1: we discussed is that it created selective pressures that benefit
Speaker 1: for being able to communicate better, which eventually led to language.
Speaker 1: But there's another idea that, uh, that there's a more
Speaker 1: direct connection between toolmaking language because they might depend upon
Speaker 1: some of the same cognitive and neural systems. Right. Uh
Speaker 1: So this is an old idea, you know, relating to
Speaker 1: the idea that there's kind of a syntax of action,
Speaker 1: that the way we structure sequential actions is similar to
Speaker 1: the way we structure words and a sentence. In fact,
Speaker 1: words and a sentence are sequential actions. Uh. So there's
Speaker 1: clearly some really important differences. Um. But there's also the
Speaker 1: possibility that some of the systems that we use just
Speaker 1: to put together complex sequence of actions and toolmaking are
Speaker 1: also important to language evolution, so that if you had
Speaker 1: selection acting on toolmaking, it would provide a foundation from
Speaker 1: which then you could get language evolution. And you know,
Speaker 1: some of the work that we've done generally uh supports
Speaker 1: that idea that there is overlap, particularly in what people
Speaker 1: call Broca's area of the inferior frontal gyrus, which is
Speaker 1: related to language processing but also uh to putting together
Speaker 1: complex actions of other kinds. UH. And so currently what
Speaker 1: we're working on is actually putting a people in the
Speaker 1: scanner or showing them videos of toolmaking, have them listen
Speaker 1: to language. UH. We use computational methods to to parse
Speaker 1: the structure of the language and the structure of the toolmaking,
Speaker 1: and we see if the kind of the syntactic structure
Speaker 1: that we see in the toolmaking and in the language
Speaker 1: produces the same responses in the brain. And UH, that's
Speaker 1: not done yet, but so far we have some encouraging
Speaker 1: results along those lines. So this this idea that uh,
Speaker 1: basic action sequencing and statistical learning that you would have
Speaker 1: for putting together complex actions provided the foundation for language
Speaker 1: evolution is something that I would like to continue pursuing.
Speaker 1: That's fascinating. I mean, if you even if you just
Speaker 1: think about your experience in there, there are ways that
Speaker 1: putting together a sentence can sometimes feel somewhat analogous to
Speaker 1: step by step activities with the hands, like the way
Speaker 1: that uh, you know if you're used to speaking, or
Speaker 1: if you're used to doing an activity, it can happen
Speaker 1: like we were talking about, mostly unconsciously. But then there
Speaker 1: are those moments where you feel you're maybe ready to
Speaker 1: break the sentence or something, and you slow down and
Speaker 1: it becomes more conscious. Um. Anyway, that's just what made
Speaker 1: that made me think of very much. So, Uh. You
Speaker 1: know that Morton Christensen is another colleague of It's written
Speaker 1: a bit about the concept of language as a skill,
Speaker 1: and you think about it, uh, trying not to think
Speaker 1: about it while I'm speaking, and that that's the point,
Speaker 1: because if you're attending to exactly how you're enunciating the
Speaker 1: words and so forth, you lose the threat of what
Speaker 1: you're trying to say. So you need to be able
Speaker 1: to very rapidly translate sort of a high level in
Speaker 1: tension into very particular motor actions. And then when you
Speaker 1: talk to me, I have to very rapidly translate what
Speaker 1: you're saying into a sort of a loose summary. I mean,
Speaker 1: I can't remember exactly what you said five minutes ago,
Speaker 1: but hopefully I have a general idea of what we've
Speaker 1: been talking about. Uh. And so this is skill, it's
Speaker 1: It's just like when you uh, A famous example a
Speaker 1: is you know, skiing down a mountain slope. I mean, initially,
Speaker 1: if you don't know what you're doing, you're focused on
Speaker 1: how you're positioning your feet and so forth. Later on
Speaker 1: you can ignore that and focus on, you know, skiing
Speaker 1: the slope, and and so your focus of attention moves.
Speaker 1: Um in this the same language and toolmaking, and I
Speaker 1: think the neural systems are related to each other. Yeah,
Speaker 1: it's kind of like how if you I think they're
Speaker 1: actually even studies of this that if you focus too
Speaker 1: consciously on, say like shooting a basketball, you get worse
Speaker 1: at it. Yeah, yeah, exactly experienced the flow. Yeah, you
Speaker 1: have to, you have to. You have to automate a
Speaker 1: lot of it. Yeah. Well, Dietrich, this has been so great.
Speaker 1: Thank you so much for joining us today. Thank you,
Speaker 1: thank you. I really enjoyed it, alright, So we hope
Speaker 1: you enjoyed our conversation with Dietrich Stout. I know Robert
Speaker 1: and I did. Um. So if you want to follow
Speaker 1: up and check out any of the centers we mentioned,
Speaker 1: like the Center for Mind Braining Culture that's c MBC,
Speaker 1: dot Emery dot E d U but you can also
Speaker 1: we'll put a link to that on the landing page
Speaker 1: for this podcast. You can also check out the Paleolithic
Speaker 1: Technology Laboratory site at scholar Blogs dot Emory, dot e
Speaker 1: d U slash stout lab. And then there was one
Speaker 1: more thing that Dietrich emailed me about. So he talked
Speaker 1: in the interview about the role of sound in toolmaking,
Speaker 1: and so he sent me actually a link to a
Speaker 1: study where you can be a participant in trying to uh.
Speaker 1: It's a study where they ask you about your experience
Speaker 1: with certain types of you know, like playing a musical
Speaker 1: instrument or something like that, and then you get to
Speaker 1: listen to different stone napping sounds and estimate the size
Speaker 1: of the chip that was produced by the sound you're
Speaker 1: listening to. I guess, not produced by the sound, but
Speaker 1: that the sound was correlated with And we'll make sure
Speaker 1: the link for that is on the landing page as well.
Speaker 1: In the landing page for this episode, you will find it.
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