Speaker 1: Hey, welcome to Stuff to Blow Your Mind. My name
Speaker 1: is Robert Lamb and I'm Joe McCormick, and it's Saturday.
Speaker 1: Time to venture into the Vault for a classic episode
Speaker 1: of Stuff to Blow Your Mind. This one originally aired
Speaker 1: November two thousand eighteen. This was our interview with the
Speaker 1: emery professor Dietrich Stout about stone age technology. Yeah, this one,
Speaker 1: this one was a lot of fun. We actually had
Speaker 1: an in the studio, so uh, no phone call, uh
Speaker 1: static or anything going on with this one. Uh. He
Speaker 1: was a tremendously interesting to chat with and he even
Speaker 1: engage some discussion on two thousand and one a Space Odyssey,
Speaker 1: which of course was the the Vault episode that we
Speaker 1: aired before this one. Yeah, so we hope you enjoy
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 Ra and I'm Joe McCormick.
Speaker 1: In 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 Laboratory investigates the
Speaker 1: role of technology and human evolution. Dr Stout is also
Speaker 1: Associate director of Emory's cross Disciplinary Center for Mind, Brain
Speaker 1: and Culture, which promotes diverse and integrative research into human
Speaker 1: nature and experience. His research focus on Paleolithic stone toolmaking
Speaker 1: and brain evolution, integrads field research at early Stone Age
Speaker 1: archaeological sites in Ethiopia with laboratory and museum research including
Speaker 1: artifact analysis and experimental replication, functional and structural neuroimaging, behavioral analysis,
Speaker 1: and psychometric testing. Now, if you want to check out
Speaker 1: those centers I mentioned, the Paleolithic Technology Laboratory, you can
Speaker 1: find that at scholar blogs dot Emery dot e d
Speaker 1: u slash Stout Lab, and then the Center for mind
Speaker 1: braining culture. You can just go to c MBC dot
Speaker 1: Emery dot E d U. Yeah, this is a super
Speaker 1: fun interview. I should distress this was an in studio interview. Yeah,
Speaker 1: one of a couple of interviews we recorded about a
Speaker 1: month ago where we said, hey, let's let's reach out
Speaker 1: to some local experts on some various topics. We don't
Speaker 1: necessarily we enjoyed jumping on the phone with with folks,
Speaker 1: but why not have some some local talent come into
Speaker 1: the studio. And that's what we did here. It was
Speaker 1: a lot of fun, uh, and I and you will
Speaker 1: really enjoy it. So I'd say, without any further ado,
Speaker 1: let's go straight to our conversation with Dietrich Stout. Hey, Dietrich,
Speaker 1: thank you so much for joining us on the podcast today.
Speaker 1: Can you start by telling our listeners a little bit
Speaker 1: about who you are and what you do? Yeah. Well,
Speaker 1: I'm an associate professor of anthropology at Emory University. I'm
Speaker 1: also the associate director of the Center for Mind, Brain
Speaker 1: and Culture at Emery as well, which is a center
Speaker 1: that promotes interdisciplinary research on mind, brain and culture. And
Speaker 1: those are basically my interests. I come at it from
Speaker 1: the direction of archaeology and the hope that we can
Speaker 1: learn something from the past about what made us the
Speaker 1: way we are today. So how did you first get
Speaker 1: interested in stone age technology? Well, um, it's not something
Speaker 1: that you typically encounter in most high schools around the country. UH. So,
Speaker 1: you know, when I went to UH to college, I
Speaker 1: really had had no idea of the possibilities that were
Speaker 1: there for anthropology, for the archaeology of human origins. I
Speaker 1: did know that I was interested in the way the
Speaker 1: human mind works, in the nature of human experience. UH.
Speaker 1: And at the time, I thought that meant that I
Speaker 1: wanted to be a philosopher. When I got to school,
Speaker 1: I realized what I said before, that a lot of
Speaker 1: the way we can understand how we are today and
Speaker 1: the nature of human experiences to understand the evolutionary processes
Speaker 1: that brought us to where we are. UH. And I
Speaker 1: had a really great UH professor as a freshman and
Speaker 1: a freshman seminar. He told me to take some archaeology classes.
Speaker 1: I did, and I still I just remember one lecture
Speaker 1: that my professor gave, and she was talking about these
Speaker 1: ancient stone tools in a particular kind called the little
Speaker 1: vow waw technique, um, And he was pointing out that
Speaker 1: you could see every individual action and and blow against
Speaker 1: the core that this person had done something like fifty
Speaker 1: or a hundred thousand years ago, and you could reconstruct
Speaker 1: what they were thinking, the plans they made, And that
Speaker 1: just struck me as as an incredible window on the
Speaker 1: past and how our minds became the way that they
Speaker 1: are today. And that's what got me started on it.
Speaker 1: And like seeing into a dead person's imagination. Yeah, to
Speaker 1: be able to recapture that, I mean, And now I've
Speaker 1: worked at sites there are half a million years old
Speaker 1: where you can literally trace individual decision making processes. It's
Speaker 1: it's it's pretty incredible. Actually held a core at one
Speaker 1: of these sites. I was looking at it and I
Speaker 1: was wondering why they didn't do something that that I
Speaker 1: would have done with that core, that piece of rock,
Speaker 1: and I twisted it around to look at where I
Speaker 1: was thinking about, and I said that they actually had tried,
Speaker 1: well I was thinking, but it didn't work. So both
Speaker 1: of us made the same mistake, separated by half a
Speaker 1: million years. That's almost a little spooky. Yeah. 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 the time period uh for
Speaker 1: which we have evidence of human behavior in the forms
Speaker 1: of archaeology, but extending way back into the past, so
Speaker 1: that we have information, but it's also an evolutionary time depth.
Speaker 1: And we're talking millions of years, more than three million
Speaker 1: years at this point of time. Uh. So that's what
Speaker 1: gets me excited about the Stone Age. Uh And of
Speaker 1: course 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 Paleolithic,
Speaker 1: obviously we're talking about hominid ancestors then, but not not
Speaker 1: Homo sapiens, right, And so when those 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 would 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 the 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 has 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
Speaker 1: old that worked at some of those sites, but now
Speaker 1: they go back to three point three million years and
Speaker 1: we as yet have very little evidence of what they
Speaker 1: might have done with those tools. Hopefully in the next
Speaker 1: few years there will be the kinds of evidence that
Speaker 1: I was talking about, but it's just not there yet,
Speaker 1: so a lot of unknowns. If I had to say,
Speaker 1: these things are cutting tools, and the most important thing
Speaker 1: probably for early humans to be able to cut was
Speaker 1: animal flesh to access that, but they could have used
Speaker 1: them for 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. M. So that's why we know chimpanzees use
Speaker 1: rocks as tools, and so it's you know, likely that
Speaker 1: are very early ancestors did Um. But yeah, by by
Speaker 1: three point three, we have evidence of them actually fracturing
Speaker 1: rock on purpose in a controlled way to produce cutting edges.
Speaker 1: And that's something that we can definitively separate from a
Speaker 1: natural process, so we know it it occurred at that point. Um.
Speaker 1: Currently if I'm wrong, but are there are there broad
Speaker 1: stroke um classifications for the different levels of tool creation?
Speaker 1: Like I want to say, it's something like nature fact, artifact, etcetera. Uh,
Speaker 1: could you walk our listeners through that? Yeah? Well, um,
Speaker 1: you know, of course you could have on modified rocks
Speaker 1: used as tools, for instance, to crack open and nut
Speaker 1: as Uh. Chimpanzees and some monkeys, macaque monkeys do that
Speaker 1: as well. Um, that's a tool, you know, it's a
Speaker 1: stone tool. Um. But what we see by three point
Speaker 1: three million years is the actual modification of the rock
Speaker 1: on purpose in order to make a different kind of tool. Uh.
Speaker 1: And that's generally a process simply of fracturing the 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 or Mary and
Speaker 1: Louis Leaky worked. Uh. And that's a very simple form
Speaker 1: of stone tool making. Uh. It does require quite a
Speaker 1: bit of coordination. It's not easy to break rocks. Um.
Speaker 1: They're hard. You have to hit them just right and
Speaker 1: with a lot of force. Um. But it's pretty conceptually simple.
Speaker 1: You're not gonna make flakes um. And then after that
Speaker 1: you've got what variously is called like mode to or
Speaker 1: loosely called Schulian after a site where it was first
Speaker 1: described in Europe. Is the manufacture of these things that
Speaker 1: archaeologists call hand axes. And that's where you're not just
Speaker 1: shattering the rock into flakes, but you're actually shaping the
Speaker 1: rock to make a tool. UM. The classic tool from
Speaker 1: this sort of stage or time period is UH the
Speaker 1: hand as, which would be a flat rock UM with
Speaker 1: cutting edge most of the way around the perimeter and
Speaker 1: a tip at one end can be good again we
Speaker 1: think for a large animal butchery UH. And so that's
Speaker 1: where you've moved in to actually having the intention, having
Speaker 1: a goal in mind, and the techniques that you have.
Speaker 1: The control over the stone that's required is more um UH.
Speaker 1: Following that, you have what we call prepared core technologies
Speaker 1: in which you shape the rock in a careful way
Speaker 1: so that you can remove one final piece that's already
Speaker 1: pre shaped the way you want it to be uh.
Speaker 1: And then you can do that over and over again,
Speaker 1: so it becomes a very efficient way of making tools.
Speaker 1: And then there's all sorts of variations on that UM.
Speaker 1: And that's the point in which we think there's a
Speaker 1: big change that they start actually putting these things on sticks,
Speaker 1: for instance hafting. Right, So you have composite tools, and
Speaker 1: you have all sorts of other techniques and materials that
Speaker 1: then enter the process and things become much more complex.
Speaker 1: So you mentioned the hand as, I'm interested to know
Speaker 1: a little bit more about that. I may be mistaken,
Speaker 1: but there there have been identified, I think, different schools
Speaker 1: of hand as construction. Is that right? Well, yeah, I
Speaker 1: mean there are different ways of making something that we
Speaker 1: call a hand ax. Uh. Now, we also, I would
Speaker 1: have be very careful about that. We should always remember
Speaker 1: that when we call slanging a hand axt, that's a
Speaker 1: name that we came up with to describe a bunch
Speaker 1: of things that we think are all similar to each other.
Speaker 1: That doesn't necessarily map onto what anybody was thinking in
Speaker 1: the past, or whether they knew each other or or whatever.
Speaker 1: So it's a tool, but we have to be careful
Speaker 1: about it. You put a name on something, you think
Speaker 1: you understand it. Uh. But yeah, So, as I mentioned,
Speaker 1: the hand ax has a particular form, there's a lot
Speaker 1: of different ways you could achieve that, and a lot
Speaker 1: of different starting points. For instance, I might start with
Speaker 1: just a big rock and then shape that rock into
Speaker 1: a pointed, thin hand ax. Uh Or I could start
Speaker 1: with an even larger rock and then I knock off
Speaker 1: a giant flame a you know, more than more than
Speaker 1: ten centimeters long, as generally they cut off, and that's
Speaker 1: almost already what I need. You know, it's got a
Speaker 1: big cutting edge all the way around the edge. And
Speaker 1: then I shape that flight just a little bit right.
Speaker 1: And that's a very different way of making a tool
Speaker 1: that in the end probably as a similar function and
Speaker 1: looks quite similar. And then there's all sorts of different
Speaker 1: sub variants of ways of doing that. Uh So that's
Speaker 1: what I think when you're talking about different schools, is
Speaker 1: these different methods of making the hand access. Now there's
Speaker 1: as a raging debate over what the variation actually means,
Speaker 1: you know, they the sort of naive ascension early on
Speaker 1: was every time you find a different way of doing something,
Speaker 1: that's a different quote culture, even though we don't really
Speaker 1: know what we mean by that term at that point.
Speaker 1: Now now there's you know, people saying that all these
Speaker 1: are just recurring rediscoveries of simple solutions to the same
Speaker 1: kind of problems. They don't necessarily imply any sort of
Speaker 1: cultural continuity or contact between people. There's even been suggestions
Speaker 1: that there was some kind of large genetic opponent to
Speaker 1: the way that people made these these hand axes. So
Speaker 1: now it's up for debate. But the variation is what
Speaker 1: we we study to try to understand what was going
Speaker 1: on in the past. That's where we have a sort
Speaker 1: of an insight into what was what was happening. Well,
Speaker 1: I was definitely going to ask you the naive question
Speaker 1: about whether that's a result of culture, but is there
Speaker 1: So if we don't make that assumption that the different
Speaker 1: forms or shapes or approaches to hand axes are necessarily
Speaker 1: the result of cultural traditions or cultural contact, is there
Speaker 1: anything that you think looking at tools like this Stone
Speaker 1: age tools could possibly tell us about the culture of
Speaker 1: the creatures that made them. Yeah, well, and so this
Speaker 1: is where we have to get into the sort of
Speaker 1: stuff that you can learn through experimental archaeology. Um, for instance,
Speaker 1: how difficult is it to discover and use particular techniques?
Speaker 1: You know, so you know, if there if there's two
Speaker 1: people that do something the same way, if it's an
Speaker 1: obvious answer, then the no reason to think they learned
Speaker 1: it from each other. But if it's this really sort
Speaker 1: of obscure and and and hard to learn technique that
Speaker 1: they share, and then it's much more likely that they
Speaker 1: learned it from each other. So I mean, so there's
Speaker 1: this thing in in the issuely and uh sort of
Speaker 1: a geographic patterning um to where you have far fewer
Speaker 1: hand axes in East Asia than you do in Africa
Speaker 1: and Western Asia and Europe. And also none of them
Speaker 1: really to appear to be as refined as some of
Speaker 1: the nicest examples from from further west. Um. And so
Speaker 1: people have devided for a long time with this geographical
Speaker 1: patterning means, and I tend to interpret it, you know,
Speaker 1: is in terms of there are some techniques that are
Speaker 1: pretty hard to discover on your own and some that
Speaker 1: are easy, you know. And so you have a lot
Speaker 1: of reinvention of sort of easy hand acts making here
Speaker 1: there in the other place, you know. But these particular uh,
Speaker 1: advanced techniques may only have been invited it once or
Speaker 1: twice or a couple of times, and so their geographic
Speaker 1: spread is more restricted. So that's sort of the way
Speaker 1: that you make a relationship between understanding the way that
Speaker 1: you actually make the tools and then how they might
Speaker 1: 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: I like to do this when I give a presentation
Speaker 1: and to show a picture full of a table full
Speaker 1: of 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 all that there are
Speaker 1: anything other than just rocks if you're not used to
Speaker 1: looking at them. So what you have to do to
Speaker 1: understand what these tools that we dig up can actually
Speaker 1: tell us is uh, basically experimental archaeology. We use analogies,
Speaker 1: We try to learn how to make them ourselves, and
Speaker 1: then 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, seeing things like that
Speaker 1: 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: up something from two an a million years ago, you've
Speaker 1: got nothing to go on, right, So we have to
Speaker 1: actually do some of this work to establish robust or
Speaker 1: strong analogies that we can use. Now you've mentioned your
Speaker 1: own experiences creating stone tools. How long does it take
Speaker 1: you to create a hand axe? Oh? Yeah, I mean
Speaker 1: it takes me maybe half an hour. I'm a little
Speaker 1: bit slow with that. Uh and uh, you know it
Speaker 1: depending on how nice you want to make it. And
Speaker 1: that's already assuming that I'm I'm sitting in my outdoor
Speaker 1: 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 take a
Speaker 1: lot more time. But yeah, uh, something that's that's quite
Speaker 1: good at it nine twelve to fifteen minutes, you can yea. Yeah,
Speaker 1: So you mentioned that we think a lot of these
Speaker 1: early stone tools were used in butchering meat. Have you
Speaker 1: ever had food prepared with stone tools you've made? Uh, well,
Speaker 1: let's see myself. Uh yeah, only actually recently one of
Speaker 1: my colleagues had a pig roast where we used some
Speaker 1: of the stuff that I had made. Yeah, but back
Speaker 1: in uh in in graduate school. And it's quite common
Speaker 1: in these labs and places where people do this sort
Speaker 1: of work to have the occasional animal roast where you uh,
Speaker 1: and you you learn things like you know that obsidian
Speaker 1: um is really sharp and great, but it also crumbles
Speaker 1: and leaves little bits of like glassy kind of gridgy stuff. Yeah,
Speaker 1: not so great. I like flint better. So do we
Speaker 1: find uh, do we find little grains of obsidian and
Speaker 1: ancient teeth? I'm not aware. Um, you know, there's always
Speaker 1: I'm not well versed in later prehistory, and so it's
Speaker 1: possibily there's something out there about that. I'm not aware
Speaker 1: of them actually getting any dental wear from the stone tools.
Speaker 1: Of course, you get very similar looking dental where when
Speaker 1: you you eat like a tubersy dug out of sandy ground,
Speaker 1: so you do get cut marks on teeth, which is
Speaker 1: very interesting because a way commonly to eat things if
Speaker 1: you don't use silverware or chop sticks or anything like that,
Speaker 1: is you hold it up to your mouth, you clench
Speaker 1: it in your teeth, and you cut away from from there,
Speaker 1: so you're cutting right next to your mouth, and occasionally
Speaker 1: they did hit their teeth um, and so you get
Speaker 1: these little little cut marks on the front teeth and spatingly. Sorry, Yeah,
Speaker 1: a lot of things gross, but one of the one
Speaker 1: of the cool things. You can actually infer which hand
Speaker 1: was used because there is a you know, a sort
Speaker 1: of in ergonomics. You're slicing down and in one direction,
Speaker 1: so you can tell, and so people use that to
Speaker 1: identify early examples of predominantly right handed populations. So even
Speaker 1: the gross stuff, there's always something you can you can
Speaker 1: get out of it, you know. We encourage you to
Speaker 1: mention all the gross stuff. We're not We don't 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 is this informed our
Speaker 1: understanding of ancient stone tool use? Basically, the whole goal
Speaker 1: of experimental archie apology is to generate analogies that we
Speaker 1: can 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 tress 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 toolmakers in New Guinea that are
Speaker 1: part of a different tradition uh back in I was there,
Speaker 1: um and one of the things that that that just
Speaker 1: broadens the number of different examples of ways to do
Speaker 1: things UM that we can use to understand the past. UM.
Speaker 1: And one of the one of the really cool things
Speaker 1: about it was I was expecting this to be a
Speaker 1: very uh you know, very foreign experience, experience to be
Speaker 1: in the highlands of New Guinea, and but once we
Speaker 1: got to the stone tools, they talked about a lot
Speaker 1: of the same things that I, as an archaeologist was
Speaker 1: already used, where they had names for the for the
Speaker 1: same kinds of features of the stone tools and they
Speaker 1: uh So there's a real common ground there because we
Speaker 1: were all based on things that happened when you try
Speaker 1: to break stone in a controlled way. And then that's
Speaker 1: very validating for an archaeologist because it means we can
Speaker 1: expect that even moving them to the total unknown of
Speaker 1: the past, there's gonna be these constants that shaped human
Speaker 1: behavior and if we can understand them today, it looks
Speaker 1: like they affect different people from very different cultural backgrounds
Speaker 1: 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 tool making into their own
Speaker 1: particular cultural and social contextu UM, which obviously, if you
Speaker 1: study hobbyists in the industrialized West is one context. But
Speaker 1: this was horticultural contact. And the way they had a
Speaker 1: sort of a system of apprenticeship for learning this, and
Speaker 1: the just the amount of time that it takes to
Speaker 1: become an expert in the they had a particularly you know,
Speaker 1: advanced kind of toolmaking UM. But the the this year
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, and I'm
Speaker 1: assuming there was a there was a language barrier, there
Speaker 1: is a translator, Well what was how did did that
Speaker 1: reveal anything or back up anything that you any pre
Speaker 1: existing thoughts about the effects of tool use and toolmaking
Speaker 1: on language and UH and then the origins of language. Yeah,
Speaker 1: well I think it was. There's there's been an idea
Speaker 1: for 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 an evolutionary press or
Speaker 1: favoring language evolution, is is the need to be able
Speaker 1: to teach each other, uh, and particularly the ability to
Speaker 1: teach people that you're related to, because then you get
Speaker 1: sort of the genetic benefit and all that kind of thing. Uh.
Speaker 1: And in New Guinea it was really uh striking the
Speaker 1: amount of social support, um in various ways that was
Speaker 1: provided for people learning. UM. I found that very informative.
Speaker 1: So of course language, you know, talking I have to
Speaker 1: do this, don't do that, or we call this this,
Speaker 1: you know, and and um also use of language to
Speaker 1: tell stories, which establishes, you know, sort of these cultural norms.
Speaker 1: They tell a story about someone who is a great
Speaker 1: toolmaker because he spent all of his time practicing, and
Speaker 1: he neglected his fields and didn't talk to his wife,
Speaker 1: you know, and all that sort of stuff. UM. And
Speaker 1: that the socializing that they do, they sit together and
Speaker 1: it makes it fun. Um. All of these things are
Speaker 1: really important to learning something that's very frustrating and difficult. Um,
Speaker 1: you know, maybe you can think of analogies in your
Speaker 1: own experience. Uh. And so that that was really really cool.
Speaker 1: And then just the uh also all of the gesturing,
Speaker 1: the pointing, and just the context of having particular places
Speaker 1: where you do things. You know, this is where we
Speaker 1: go to get the rocks, this is where we all
Speaker 1: sit down and make tools together. There was a structure,
Speaker 1: so there's so much about what they were doing socially
Speaker 1: that resulted in 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 and 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 than Alright, we're back,
Speaker 1: let's jump back in now. Obviously this is a different
Speaker 1: question from how the crafting of stone tools might have
Speaker 1: changed our neuro anatomy over time. But I wonder does
Speaker 1: making stone tools just change the way you in your
Speaker 1: life think about your relationship with the earth, Like do
Speaker 1: you do you find yourself out walking and looking down
Speaker 1: and saying, oh, there's a good one. No, that's not
Speaker 1: a good one. Yeah, yeah, I mean, I mean now,
Speaker 1: I mean, particularly if you've been doing a lot recently,
Speaker 1: you can't see a rock without picturing it breaking, you know,
Speaker 1: it's a uh And of course just doing being an
Speaker 1: archaeologist does that too. Um. You know, I'm always looking
Speaker 1: at little pebbles and my wife will catch me looking
Speaker 1: at the landscaping, you know, and like that would be
Speaker 1: a good hammerstone or something. Okay, you know, uh so
Speaker 1: so yeah, it does influence. Uh some of the resources
Speaker 1: that you're aware of that are really not particularly relevant
Speaker 1: for most people in their daily lives, but we're once
Speaker 1: incredibly central. Well, I think about ways that that that
Speaker 1: type of thinking, um can take on more complex kind
Speaker 1: of mental dimensions. Like I think about the way when
Speaker 1: I go shopping. Uh, if I'm like picking out produced
Speaker 1: to cook with, I can see like a good fresh
Speaker 1: 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, so certainly, uh, 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 uh,
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 I just got
Speaker 1: some some really nice bassault as well, which is a
Speaker 1: very different kind of of rock and has different but
Speaker 1: also really just aesthetically pleasing and you get a real
Speaker 1: pleasure out of out of working in Yeah. So you
Speaker 1: said you can hear the difference between a good break
Speaker 1: and a bad break. Yeah, yeah, this is a question.
Speaker 1: I mean, I think it's important, and I've talked to
Speaker 1: people who are much more experienced stone toolmakers than I
Speaker 1: am that that really emphasized that, you know, the sound
Speaker 1: is important, and in fact, we're just in the process
Speaker 1: of developing and online tests that people can take where
Speaker 1: we play the sounds of a stone flake coming off
Speaker 1: and you use a little slider to say how big
Speaker 1: you think it was. Uh, So we're trying to see
Speaker 1: 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 tool making, not to be confused with falling sleep,
Speaker 1: but it's knocking the flakes, yeah, and napping. I don't
Speaker 1: know if it's German or something. They don't even know
Speaker 1: where it comes from, but yeah, knocking the flakes off. Anyway,
Speaker 1: we're 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 all right, you know. Uh so anyway, long,
Speaker 1: so the the we think the sound is is probably
Speaker 1: really important, and we're trying to probe that it. It
Speaker 1: keeps coming up also in some of the neuroimaging research
Speaker 1: that we do, or we look at, uh, stone toolmaking,
Speaker 1: and we get these activity in areas that are more
Speaker 1: classically auditory and initially wasn't expecting to, but of course
Speaker 1: it makes sense. That is interesting and the stuff about
Speaker 1: the toolmaking process giving you all these sort of aesthetic
Speaker 1: values when you look at rocks or when you hear
Speaker 1: the sounds rocks make. Does that, um lead you to
Speaker 1: draw any connections between the origins of tool crafting in
Speaker 1: the origins of art um. Yeah, sure, you know, in
Speaker 1: a informal sort of way. Um. And and and you
Speaker 1: know people have have written about these ideas, and this
Speaker 1: is another area sort of of contention, particularly with the
Speaker 1: hand axes. Uh. They're beautiful, right, they did. They're very appealing. Um.
Speaker 1: And there's some argument that in fact, they are much
Speaker 1: too beautiful and appealing from no apparent functional benefit, that
Speaker 1: this must be one of our earliest examples of you know,
Speaker 1: aesthetic sense. Um. But as I mentioned that, it's awfully
Speaker 1: hard to demonstrate that in a really compelling way to skeptics. Uh. Um,
Speaker 1: it's it's it is hard to say. You do get
Speaker 1: these glimmerings of interesting things like, uh, you know, to
Speaker 1: make a hand act and they'll be a fossil impression
Speaker 1: of a shell that they leave right in the middle
Speaker 1: of the center of one of the sides. You know,
Speaker 1: it's sort of like they showed it off or was
Speaker 1: that an accident? Yuh Um. It is hard to say, um,
Speaker 1: But certainly from our perspective, the symmetry, and many of
Speaker 1: the aspects of these tools are very aesthetically pleasing, so
Speaker 1: we'd like to speculate that there's some relationship. There is
Speaker 1: there any indication with any of the any particular hand
Speaker 1: axes that are particularly beautiful to modern eye, that they
Speaker 1: were in any way, uh, merely ritualistic, that they I mean,
Speaker 1: they were not used. Yeah, so it's a it's a
Speaker 1: bit hard because it's actually not always possible to show
Speaker 1: that that many of the hand axes were used. You
Speaker 1: need particular present vaction conditions and evidence to actually demonstrate
Speaker 1: that something was used, so we rarely get that. On
Speaker 1: the other hand, um, there are examples of things that
Speaker 1: look like they couldn't have been used. Um, these are
Speaker 1: very rare where there's be like this really giant hand
Speaker 1: acts like the length of my forearm, you know, that
Speaker 1: somebody made, and in our imagination, it's pretty hard to
Speaker 1: come up with a functional reason to do that. So
Speaker 1: it seems to have been somebody showing off or just
Speaker 1: trying to produce a piece that is somehow appealing to
Speaker 1: them or something like that. Yeah, it's it's it's elusive. Um,
Speaker 1: there's these these glimmerings of it. So we've already mentioned
Speaker 1: a little bit the possible relationships between tool use and
Speaker 1: UM and the development of human neuro anatomy. Uh, could
Speaker 1: you talk a little bit more about that, like what
Speaker 1: some of the leads are and what is the evidence
Speaker 1: directly for those connections. I know some of it has
Speaker 1: to do with just like correlation of timelines, right right, Well,
Speaker 1: I mean, so there's a basic awareness, so we've had
Speaker 1: for for a long time that you know, there's a
Speaker 1: broad general trend towards brain size increase over human evolution,
Speaker 1: with many exceptions and side branches and so forth that
Speaker 1: we're discovering now. Um, but yeah, I mean, our brains
Speaker 1: are bigger than any of the brains were two millioners ago,
Speaker 1: and there's a trend there. Also, you know, the tools
Speaker 1: over time, with many exceptions and places where it didn't
Speaker 1: happen and so forth, but the most u elaborate sophisticated
Speaker 1: tools around hundred thousand years ago. We're much more complex
Speaker 1: than the most elaborate sophisticated tools that were around two
Speaker 1: million years ago. So there's a trend there. And there
Speaker 1: there's two trends side by side, and you know, I
Speaker 1: think maybe they're related to each other. Um. Now exactly
Speaker 1: how they're related to each other is a more difficult question.
Speaker 1: You know, did the brain get bigger and for other
Speaker 1: reasons that then spill over into being able to make
Speaker 1: tools or where the tools really important? So that like
Speaker 1: if you could make a if you're a little bit
Speaker 1: faster at making a tool, more reliable at making a tool,
Speaker 1: you had a little bit of a reproductive advantage, then
Speaker 1: you know, then then then maybe the tools drove it.
Speaker 1: Um And those are hard to uh discern exactly. So
Speaker 1: that's why we we try to do some of these
Speaker 1: experiments where we relate the actual process of making tools.
Speaker 1: We've tried to figure out, well, what does it demand
Speaker 1: cognitively neurally if there were pressure on being able to
Speaker 1: make these tools, these are the things then that would
Speaker 1: respond to it. So that's we're just trying to sketch
Speaker 1: out some of the basics still at this point, I
Speaker 1: think to make that link and to do that, you've
Speaker 1: done some research with the neuroimaging and and how that
Speaker 1: relates to thinking about tools to making tools. Could you
Speaker 1: tell us some more about that. Yeah, so, uh, we've
Speaker 1: done a couple of different things. UM. One is what
Speaker 1: most people are probably more familiar with, which is a
Speaker 1: functional neuroimaging, which typically works somehow related to to blood
Speaker 1: flow in the brain responses of neurons, so when they're
Speaker 1: active UM. And so we can isolate those areas of
Speaker 1: the brain UM that are more active when you make
Speaker 1: a particular kind of tool, you know, for instance, the
Speaker 1: hand actions that I was talking about versus the earlier, simpler,
Speaker 1: old one style tools, and we can say, oh, well,
Speaker 1: this is the neural system related to these forms of
Speaker 1: cognition UM that is required to do that. So if
Speaker 1: there was something that changed in the past associated with
Speaker 1: this technology, is most likely to be those systems. Uh.
Speaker 1: Then the other thing that we do is actually structural
Speaker 1: stuff UM, and that comes in two flavors. Also, you can, uh,
Speaker 1: you can look at plastic changes in the brain that
Speaker 1: are caused by behavior. And this is something that in
Speaker 1: the past, I guess about twenty years or so, people
Speaker 1: really become aware that, even over short periods, doing things
Speaker 1: like learning to juggle actually changes the physical structure of
Speaker 1: your brain, especially things like white matter that sort of
Speaker 1: the cables that connect things in your brain. UM. And
Speaker 1: so we've applied that also to stone tool making UH
Speaker 1: and seeing that training to cand access, for instance, will
Speaker 1: increase certain white matter pathways in the brain. UH. Interestingly enough,
Speaker 1: these are also white matter pathways that are larger and
Speaker 1: modern humans versus chimpanzee. So we know that it's something
Speaker 1: that has evolved in our history, and we can relate
Speaker 1: it to a behavior that also is observable to have
Speaker 1: come along at a certain time in our history. So
Speaker 1: we started to strengthen this sorts of infrenial. Well, maybe
Speaker 1: these things are related to the evolution of that pathway. UM.
Speaker 1: The other thing that we can do that we're really
Speaker 1: just starting to look at is uh individual differences in
Speaker 1: structure and function of people. So if you get a
Speaker 1: large enough sample, there are small differences, for instance, in
Speaker 1: the rapidity with which people learn uh different kinds of
Speaker 1: stone toolmaking, you know, and you can then correlate with
Speaker 1: starting differences in their brain structure or the way that
Speaker 1: their brain changes over time. And I think that's really
Speaker 1: exciting because we can then also relate that to UH
Speaker 1: cognitive tests. So, you know, some of the initial stuff
Speaker 1: that we're getting is you know, so if you're pretty
Speaker 1: really good at UH planning, for instance, there's a task
Speaker 1: called the Tower of London, which you move sort of
Speaker 1: rings around on three pegs, and you have to do
Speaker 1: it in a particular order. Uh. If you're good at that,
Speaker 1: you learn stone tool making faster slightly. Yeah. I think
Speaker 1: that's really really fast because we're actually making these links
Speaker 1: between particular cognitive operations and kind of types of stone
Speaker 1: toolmaking that we can see in the archeological record. Now,
Speaker 1: now that the test subjects who learned how to make
Speaker 1: stone 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: act We've got a big pile of stuff we've still
Speaker 1: got to go through in that study. Um, but you know,
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 have any hard conclusions
Speaker 1: 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.
Speaker 1: Um um so. But there's a lot more to be
Speaker 1: done with that. And one of one of the things
Speaker 1: that it bothers me is we always do these studies,
Speaker 1: you know, with the the typical college undergraduates, and they're
Speaker 1: not generally known for being particularly good with their hands.
Speaker 1: Um so. Um. I would really like to expand into
Speaker 1: different populations in different ages and um but you know,
Speaker 1: we're just getting started, because that's where you would find
Speaker 1: individuals who were skilled craftman uh craft people in other
Speaker 1: school in other areas, right yeah, yeah, yeah, and just
Speaker 1: just people that are more commonly doing work with their hands,
Speaker 1: you know. Um. Now, I work with people out when
Speaker 1: we go do excavations in Ethiopia and the far um
Speaker 1: you know is there's their pastoral lists. They have herds
Speaker 1: of animals, and they you know, they make little walls
Speaker 1: out of stone all the time, and I mean they're
Speaker 1: a lot more handy. They might pick it up a
Speaker 1: lot faster. So obviously getting the population you want is
Speaker 1: one experimental challenge. I would imagine another one if you're
Speaker 1: if you're trying to do neuroimaging while people are engaging
Speaker 1: in tool tool making. The I mean, don't you have
Speaker 1: to hold still? So for fm R I, Yes, for
Speaker 1: fm R I you do UM. So there is you know,
Speaker 1: a couple kinds of workarounds. UH. One of them is
Speaker 1: 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 unconstrained way. Then
Speaker 1: you walk them over to the scanner about half an
Speaker 1: hour later if they've been doing this for half an hour, uh,
Speaker 1: and you collect an image of where the glucose built up. Right. Um.
Speaker 1: So this is great because you can do it um
Speaker 1: and have them do real tasks outside the scanner. UM.
Speaker 1: But it's limited because you know, you've got time averaged
Speaker 1: over half an hour, and you can only do a
Speaker 1: couple of different conditions because it does involve radiation exposure
Speaker 1: and you don't want to give anybody too much and
Speaker 1: so you know, um, the fm R I you mentioned,
Speaker 1: you have to be still. But we can take advantage
Speaker 1: of the fact that a little theoretical, but neuroscientists have
Speaker 1: largely converged on the idea that one of the ways
Speaker 1: we understand what we see other people do is to
Speaker 1: internally simulated ourselves in fact using the same neural systems. Uh.
Speaker 1: And this is probably an important way that we learned
Speaker 1: from others as well, which is an important research question too.
Speaker 1: But we can take advantage of that, and we show
Speaker 1: people films of toolmaking in the scanner and so this
Speaker 1: is most directly relevant to observational understanding 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. Uh, So that's
Speaker 1: another sort of workaround. And uh a colleague of mine,
Speaker 1: Shelby Putt, is using something called functional near infrared spectrography
Speaker 1: anyway f near as anyway is what I what I remember, UM,
Speaker 1: and that actually uses near infra red visible light that
Speaker 1: can penetrate the cranium and get some information on blood
Speaker 1: flow from the superficial areas of the brain, and that
Speaker 1: you can wear while you're doing something as well. So
Speaker 1: there's some a few workarounds that you can do to
Speaker 1: actually use neuroimaging techniques. And I wonder, UM, are there
Speaker 1: I don't know if anybody's looked at this, but would
Speaker 1: there be differences in the brain between UM, doing doing
Speaker 1: a task and stone tool creation and simply imagining the task,
Speaker 1: Because of all, you know, we've looked on the show
Speaker 1: a bunch of times about simply imagining doing something is
Speaker 1: very 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 we're
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 they're very reliant I think, on actually doing it.
Speaker 1: All Right, we're gonna take a quick break, but we're
Speaker 1: gonna jump right back in with our interview. Alright, we're back.
Speaker 1: Just recently, I happened to be reading a couple of
Speaker 1: papers in UM I think Frontiers in psychology. I believe
Speaker 1: about the possible role of UM possible role of tool
Speaker 1: use in the development of consciousness. UH. The the idea
Speaker 1: under this new framework was that maybe consciousness has something
Speaker 1: to do with creating states of objectivity in the mind
Speaker 1: where you can sort of like imagine and correctly judge
Speaker 1: the properties of an object that is not yourself. Um.
Speaker 1: I don't know if you've read that, Marissano. No, this
Speaker 1: was I'm sorry. I can't remember the guy's name, but
Speaker 1: he's from Europe somewhere. I think he might have been
Speaker 1: 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 consciouness. This is great for me. Actually, I told
Speaker 1: you how I, you know, got into this. I thought
Speaker 1: I wanted to be a philosopher and I'd love to
Speaker 1: get around to consciousness. They say, you know, wait till
Speaker 1: after you have tenure, maybe wait to get longer than that,
Speaker 1: you know, tell your all the time. Um, but I
Speaker 1: do think there is a potential that they're there might
Speaker 1: be some way we could gain insight there. You know,
Speaker 1: if you think about what are the things that actually
Speaker 1: require consciousness, like what is consciousness actually good for? Um?
Speaker 1: And you know some people have said basically nothing uh phenomenal,
Speaker 1: you know, but but if there is something that it's
Speaker 1: good for. It's for tasks that require attention. I mean,
Speaker 1: that's what consciousness is. It's attending to things, uh, really
Speaker 1: getting the whole brain on board, uh, you know, and
Speaker 1: focusing on on this one thing. Um. And I think
Speaker 1: that learning a skill like stone toolmaking is the kind
Speaker 1: of thing that demands that concentrated attention. And if consciousness
Speaker 1: is the way that you get that, if consciousness is
Speaker 1: the feeling that you have when you fully attend to things,
Speaker 1: then then then maybe there is a relationship there. I
Speaker 1: mean some of the other things people you can as
Speaker 1: you know, you can get into a car and uh
Speaker 1: start thinking about something else and drive to work when
Speaker 1: you meant to go to the store and so forth,
Speaker 1: which is you know, this sort of zombie stuff is
Speaker 1: pretty scary actually the things that you can you without
Speaker 1: being aware of it. Um. But things people can't do
Speaker 1: are sort 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 studying uh,
Speaker 1: people who are learning, um, rather than you know, expert
Speaker 1: performance is still interesting in many ways, UM, but if
Speaker 1: you want to get at the real demands for something
Speaker 1: like conscious attention, that's going to happen when you're figuring
Speaker 1: it out later on. And I mentioned to some of
Speaker 1: the people that can make a hand acts 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 know, I give demonstrations of napping and
Speaker 1: then I will always wind up cutting myself because trying
Speaker 1: to talk about it and do us you know, and
Speaker 1: you're not focusing on it. UM. So yeah, is the
Speaker 1: more skills you get, the more you can ignore the
Speaker 1: low level stuff and think about something else, you know,
Speaker 1: like making it a really appealing hand ax versus just
Speaker 1: trying to get something you can use. Do you happen
Speaker 1: to find that the most beautiful hand axes are also
Speaker 1: the best to like, the most functional, useful or those
Speaker 1: things generally aligned or not aligned. You'd be surprised the
Speaker 1: things that we don't know about stone tools because of
Speaker 1: the amount of time that it takes to do proper
Speaker 1: experimentation and actually test these sorts of things. So that's
Speaker 1: something that people are interested in, but there's only been
Speaker 1: a handful of experiments UM that actually looked at you know,
Speaker 1: is the symmetry of the hand acts make it a
Speaker 1: more or less effective butchery tool? Um? Does the straightness
Speaker 1: of the edge matter? Um? Do any of the things
Speaker 1: to the thinness of it matter? Uh? And to the
Speaker 1: extent that has been shown, like the things like symmetry
Speaker 1: don't seem to really matter very much for the function
Speaker 1: uh the Uh the evenness of the edge does seem
Speaker 1: to be important, and that might be aesthetic for some people. UM.
Speaker 1: The sort of extreme thinning of the hand axes that
Speaker 1: we find very appealing, I think because it's hard to
Speaker 1: do is something that you know, maybe somewhat beneficial because
Speaker 1: you have the tool you're carrying around is lighter. Um.
Speaker 1: But thus far, there's not a lot of evidence that
Speaker 1: things we think of is really aesthetically important about hand
Speaker 1: axes are particularly functionally important. So there's another question we
Speaker 1: may not know the answer to. But do you think
Speaker 1: in general, is it more widely assumed that people in
Speaker 1: the prehistoric times would make a hand ax and and
Speaker 1: that would be their hand accidentally carried around with them,
Speaker 1: or is it something that would be made on site
Speaker 1: when it was needed. Yeah, I mean, I think it's
Speaker 1: important to uh, for archaeologists and for everybody to to
Speaker 1: remember when we think about the past that these is
Speaker 1: a huge amount of time over a large area, UM,
Speaker 1: and they probably did just about everything at one uh
Speaker 1: time or another. Um. I it's some sites where you're
Speaker 1: sitting close to raw materials, uh, you know, like there's
Speaker 1: a site of box Grove, it's it's pretty close to
Speaker 1: these chalk cliffs where the flint is coming right out.
Speaker 1: They seem to have used them lightly and discarded them,
Speaker 1: probably made them pretty close to the time that they
Speaker 1: were going to use them, and that sort of thing. UM. Elsewhere.
Speaker 1: They may have actually carried them around for when you
Speaker 1: don't have as much rock, you know, and you're going
Speaker 1: far from the source, you probably take the hand x
Speaker 1: with you, and when it gets dull, you re sharpen
Speaker 1: it and all these sorts of things. Maybe you keep
Speaker 1: using it till you've whittled it down the way we
Speaker 1: do a pencil nub, you know. Uh, so this is
Speaker 1: an area people try to understand, um, basically the economics.
Speaker 1: This is sort of an economic question. Uh, you know,
Speaker 1: when does it make sense to just toss the hand
Speaker 1: axe versus you know, carrying it with you and resharpening it.
Speaker 1: And it seems to be driven by the things you
Speaker 1: would expect it to be driven by, like distances from
Speaker 1: raw materials and the kind of activities that you're doing.
Speaker 1: So you probably get asked this question a lot, especially
Speaker 1: this year since it's such a milestone year for the film.
Speaker 1: But we recently talked about the about two thousand and
Speaker 1: one of Space Odyssey on the show, Um, what are
Speaker 1: your thoughts about two thousand one Space Audience? Specifically of course,
Speaker 1: these scenes of these these ancient creatures engaging in tool
Speaker 1: used for the first time. Yeah, well, I mean as
Speaker 1: you may you may be aware of that two thousand
Speaker 1: one was actually UH produced in consultation with archaeologists and
Speaker 1: palaeo anthropologists, so it was informed by current UH speculations
Speaker 1: hypotheses about the origins of technology at the time. UM
Speaker 1: I think that we have a a different view and now,
Speaker 1: UM I think if you would ask most most archaeologists
Speaker 1: about the origins of tool use and technology, they get
Speaker 1: very excited about things like cooperation and collaboration UH as
Speaker 1: as being a real turning point for for humans, and
Speaker 1: we are a 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 making 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 go too heavy on that, because
Speaker 1: there actually is uh empirical are there are empirical arguments
Speaker 1: that they can be made about this, in particular looking
Speaker 1: at comparisons across species and the importance of cooperation versus
Speaker 1: competition in different contexts. So there is a framework for
Speaker 1: for doing this. But it is interesting to think about
Speaker 1: our biases. But are certainly two thousand one fantastic film.
Speaker 1: I like I wish the introductory segment where a little
Speaker 1: bit quicker because I like to use it in my classes.
Speaker 1: But we had to sit there for like half a
Speaker 1: students aren't up for it. Um. Yeah, so I think
Speaker 1: it's uh. They did their best to work with the
Speaker 1: current understanding at the time. It's a great movie. This
Speaker 1: is another realm where we might ask you to speculate
Speaker 1: if you're comfortable. But one of the things we talked
Speaker 1: about with two thousand one was the idea that you know,
Speaker 1: so when the the ape like creatures first encounter the
Speaker 1: monolith in the in the Savannah, um, they they are
Speaker 1: changed in some way. But it's often assumed that maybe
Speaker 1: this is some alien technology that goes in and changes
Speaker 1: something in their brain. But an interpretation we talked about
Speaker 1: in the episod so it is one that that's actually
Speaker 1: not what happens. That what happens is they see this
Speaker 1: object in their environment that it's nothing like the rest
Speaker 1: of their environment. It looks completely artificial, and it's simply
Speaker 1: seeing that spurred something in their imagination that allowed them
Speaker 1: to to take up the tools. Um. And that makes
Speaker 1: me wonder about what what what would you imagine could
Speaker 1: be the role of simply seeing things in the environment
Speaker 1: to inspire the taking up and creation of tools. Yeah,
Speaker 1: I mean it's probably, uh, probably very important. I think
Speaker 1: this is the kind of thing that that archaeologists are
Speaker 1: loath to actually talk about because you're talking about like, uh,
Speaker 1: you know, individual acts of invention um that happened in
Speaker 1: the past. Whereas the sort of the record that we
Speaker 1: have is this really really high level, average sort of
Speaker 1: sort of thing. Um. So it's hard for us. I mean, clearly,
Speaker 1: you know, we shouldn't forget these things are inventions. They're
Speaker 1: not like mutations or just inevitable things that happened like
Speaker 1: somebody at some point had a new idea and did it,
Speaker 1: and then whether they were inspired by particular things in
Speaker 1: their environment. We like to think about, well, what kind
Speaker 1: what were the kinds of things that they commonly encountered,
Speaker 1: and we could have some leverage to talk about that.
Speaker 1: You know, if they moved into a bit of a
Speaker 1: of a foraging niche, then they may be around these
Speaker 1: animal bones, you know, if there are stones available, Uh,
Speaker 1: if they cracked nuts, um occasionally, as chimpanzees do, you're
Speaker 1: going to accidentally fracture the rock and and you know,
Speaker 1: you could imagine imagine an aha moment there, but those
Speaker 1: are things that are very difficult to actually get to. Um.
Speaker 1: What I what I will say about the vision in
Speaker 1: in two thousand one is that it is an idea
Speaker 1: of a transformative moment um. And this is something that
Speaker 1: was also very current and maybe is to a certain extent,
Speaker 1: the idea that the invention of the earliest owned 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 hypothesis right now is that, yeah, it was
Speaker 1: just too too hard in particular the investment in learning
Speaker 1: how to do this. Uh, you know they did there
Speaker 1: were smaller brained individuals. They didn't have the same learning
Speaker 1: capacities that we have. And for whatever at the time,
Speaker 1: I think there was too steep a cost, and occasionally
Speaker 1: it seemed worth it, but only a few individuals would
Speaker 1: learn and and then they had to spend so much
Speaker 1: time figuring it out that you know, it was didn't
Speaker 1: really give them that much of an advantage, and then
Speaker 1: it was just lost in a small population. And no,
Speaker 1: we did it for however long you know, um, but
Speaker 1: you go 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
Speaker 1: is 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 messed around for a long time until something
Speaker 1: changed about the cost benefit equation. I think so many
Speaker 1: tantalizing mystery I'm just imagining these sort of many dark ages. Uh,
Speaker 1: and they're learning Huh. Yeah, I mean if you think
Speaker 1: of these small groups very isolated, you know, I mean,
Speaker 1: somebody could have a great idea and then you know,
Speaker 1: they have a bad year and everybody dies and nobody
Speaker 1: thinks of it again for five years. I'm sorry we
Speaker 1: keep asking you to speculate about stuff. Uh, these are
Speaker 1: the kind of questions we love to ask. But yeah,
Speaker 1: I mean, obviously people should understand that they're there are
Speaker 1: tons of limitations on what we can know empirically about
Speaker 1: things this far in the past. So besides what we've
Speaker 1: talked about so far, what else do you find most
Speaker 1: fascinating about studying stone age technology? Like? What what really
Speaker 1: gets your gears going about it? I mean, I I guess, uh,
Speaker 1: one thing, maybe it's a bit a bit technical. We
Speaker 1: we we started to talk about the relationship between stone
Speaker 1: toolmaking and language, and uh, one of the ideas that
Speaker 1: we discussed is that it created selective pressures of 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 uh, sequential actions is similar
Speaker 1: to 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 sequences 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 supports that
Speaker 1: idea that there is overlap, particularly in what people call
Speaker 1: Broca's area of the inferior frontal gyrus, which is related
Speaker 1: to language processing but also uh to putting together complex
Speaker 1: actions of other kinds. Uh. And so currently what we're
Speaker 1: working on is actually putting people in the scanner or
Speaker 1: showing them videos of toolmaking, have them listen to language. UH.
Speaker 1: We use computational methods to to parse the structure of
Speaker 1: the language and the structure of the toolmaking, and we
Speaker 1: see if the kind of the syntactic structure that we
Speaker 1: see in the toolmaking and in the language produces the
Speaker 1: same responses in the brain. And uh, that's not done yet,
Speaker 1: but so far we have some encouraging results along those lines.
Speaker 1: So this, this idea that uh, basic action sequencing and
Speaker 1: statistical learning that you would have for putting together complex
Speaker 1: actions provided the foundation for language evolution is something that
Speaker 1: I would like to continue pursuing. That's fascinating. I mean,
Speaker 1: if you even if you just think about your experience
Speaker 1: in there, there are ways that putting together a sentence
Speaker 1: can sometimes feel somewhat analogous to step by step activities
Speaker 1: with the hands, like the way that uh, you know,
Speaker 1: if you're used to speaking or if you're used to
Speaker 1: doing an activity, it can happen like we were talking about,
Speaker 1: mostly unconsciously. But then there are those moments where you
Speaker 1: feel you're maybe ready to break the sentence or something,
Speaker 1: and you slow down and it becomes more conscious. Um
Speaker 1: in anyway, that's just what made that made me think
Speaker 1: of very much. So, uh, you know that Morton Christiansen
Speaker 1: is another colleague of mine that's written a bit about
Speaker 1: the concept of language as a skill, and you think
Speaker 1: about it, uh, try not to think about it while
Speaker 1: I'm speaking. And that that's the point, because if you're
Speaker 1: attending to exactly how you're enunciating the words and so forth,
Speaker 1: you lose the threat of what you're trying to say.
Speaker 1: So you need to be able to very rapidly translate
Speaker 1: sort of a high level and tension into very particular
Speaker 1: motor actions. And then when you talk to me, I
Speaker 1: have to very rapidly translate what you're saying into a
Speaker 1: sort of a loose summary. I mean, I can't remember
Speaker 1: exactly what you said five minutes ago, but hopefully I
Speaker 1: have a general idea of what we've been talking about. Uh.
Speaker 1: And so this is skill. It's it's just like when
Speaker 1: you uh A famous example a is you know, skiing
Speaker 1: down a mountain slope. I mean, initially, if you don't
Speaker 1: know what you're doing, you're focused on how you're positioning
Speaker 1: your feet and so forth. Later on you can ignore
Speaker 1: that and focus on, you know, skiing the slope, and
Speaker 1: and so your focus of attention moves um in this
Speaker 1: the same in language and toolmaking, and I think the
Speaker 1: neural systems are related to each other. Yeah, it's kind
Speaker 1: of like how if you I think they're actually even
Speaker 1: studies of this that if you focus too consciously on,
Speaker 1: say like shooting a basketball, you get worse at it. Yeah, yeah, exactly.
Speaker 1: Experience the flow, you know, you have to, you have to,
Speaker 1: you have to automate a lot of it. Well, Detrich,
Speaker 1: this has been so great. Thank you so much for
Speaker 1: joining us today. Thank you, thank you. I really enjoyed it. Alright,
Speaker 1: So we hope you enjoyed our conversation with Dietrich Stout.
Speaker 1: I know Robert and I did. Um So if you
Speaker 1: want to follow up and check out any of the
Speaker 1: centers we mentioned, like the Center for Mind Braining Culture
Speaker 1: that's c MBC, dot Emory, dot E d U, but
Speaker 1: you can also we'll put a link to that on
Speaker 1: the landing page for this podcast. You can also check
Speaker 1: out the Paleolithic Technology Laboratory site at scholar Blogs, dot Emory,
Speaker 1: dot E d U, slash Stout Lab. And then there
Speaker 1: was one more thing that Dietrich emailed me about. So
Speaker 1: he talked in the interview about the role of sound
Speaker 1: in toolmaking, and so he sent me actually a link
Speaker 1: to a study where you can be a participant in
Speaker 1: trying to It's a study where they ask you about
Speaker 1: your experience with certain types of you know, like playing
Speaker 1: a musical instrument or something like that, and then you
Speaker 1: get to listen to different stone napping sounds and estimate
Speaker 1: the size of the chip that was produced by the
Speaker 1: sound you're listening to. Oh nice, I guess not produced
Speaker 1: by the sound, but that the sound was correlated with
Speaker 1: And we'll make sure the link for that is on
Speaker 1: the landing page as well. In the landing page for
Speaker 1: this episode, you will find it. It's stuff to Blow
Speaker 1: your Mind dot com. That's our mothership. That's where we
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