S1: good afternoon.
SS: good afternoon.
S1: uh, it's not always the case but today's music actually was related to the lecture the first song was called Do the Evolution, and the second was Strong Enough to be My Man which, will really be more, as far as we're gonna get more like um, Thursday's lecture, but i hope to be able to find another content related theme, music by Thursday too. i actually have no announcements today, although someone else has an announcement about recording the lecture. before i, do that do you have any questions? okay, so here's an announcement about recording. <P :04> 
<MICASE RECORDING ANNOUNCEMENT> 
S1: i always wanted to be part of a corpus. um, okay. what we're gonna do, in, today's lecture, is we're basically done with history, we're done with methods, and we're going on to biopsychology. so we're gonna talk about, biopsychology from a couple of different perspectives, and before i talk about_ we're gonna talk about sorta, biopsychology as it relates to sort of our evolutionary heritage, (but) we're also gonna talk about biopsychology as it relates to the immediate, moment, um, i- i've got names for those kind of causes here in a minute but, uh before i do that i just wanna, sorta make a plea, one of the things that, that i find sort of frustrating or mystifying or, i don't know exactly how to put it but, at the end of the course lots of times students come up to me and they say you know that psychology stuff i really liked it, but i didn't understand why there was all that biology in there. i don't understand what the biology has to do with the psychology and so, i'm gonna make this point a couple of times in the biopsych lectures but i just wanna try to make it, here one time, uh with feelings, which is that, i mean at some level the reason why i find it a frustrating thing is i sorta don't know how to respond to it because while, biology is not what people often think of in psychology when they think about clinical psychology for example, it is the case, that every single thought, emotion, memory, any psychological experience you've had, conscious, unconscious, it doesn't matter what it is, it has a biological component to it. you do not think without biology. you do not experience an emotion, without changes in your biological make-up. those things are mediated at some level by biology. so it's sort of like, i mean in some ways it's sorta like, i_ i- i- it would be sorta like saying, you know, i took a course on driving and i didn't understand they kept talking about the car all the time. that didn't make any sense to me. in some ways that's it i think sometimes it's hard to see as we get into how neurons act, and what evolutionary theory says and what does it have to do with biology_ with psychology, it's easy to lose the connection. but the connection is, the proposition is simply that, our biology, whether we're talking about our evolutionary heritage, or whether we're talking about immediate changes, in uh our biological make-up, influence our behavior and psychological experience. you cannot have a psychological experience, without having the biol- biological component going along with it. again, you know, at the at the extreme, no brain no central nervous system no thought no psychological experience nothing, right? so, what we're gonna do over the next couple weeks, is try to look at, different biological takes, on uh, on uh, behavior. and we're gonna begin by talking about evolution, and behavior, uh and that's what today's lecture is gonna be about entirely, and much of Thursday will be about evolution and behavior too. before_ in_ and in evolution and behavior, essentially what we're asking is, does our evolutionary heritage, does the generations and generations and generations that we've been in an environment, influence, our uh our current behavior. and, one of the things i'm gonna try to do in the lecture, is to try to mark out for you, what is and isn't controversial, among psychologists about the proposition that evolution shapes behavior. so we're gonna spend much of today talking about Darwin, and Darwin's Theory of Evolution so that, uh, w- i make sure that we all, sort of understand what Darwin's Theory of Evolution was about, and then try to apply it to, human behavior. parts of that account are extremely controversial in psychology, and parts of it aren't. and i'm gonna try to help you, see, which is and isn't controversial. and uh, and we'll see that as we go on. uh... the other thing to make as sort of a, a preamble to this also is, is that evolutionary theory, is really, i mean we're gonna be, there's sorta two things that i wanna talk about there're two questions as i talk about in evolutionary theory, that i think you wanna think about as we go through the lecture. the first is is it in fact possible to identify, behavioral candidates for making an evolutionary account? can you find some behaviors that look like maybe evolution shaped them? do you have to make the argument that all behaviors are shaped by evolution? so the first most of what today is going to be about is, can you find some behaviors that it looks like we can make an evolutionary argument about? what would you want to look for in a behavior that would be consistent with an evolutionary argument? the second thing is, if you make an evolutionary argument, or any biological argument, how should you interpret the meaning of that? so evolution for example is really a theory, about how environments shape behaviors over millennia. so at some level you can talk about it as being a biological cause, it's our genetics, it's our evolutionary heritage. it's also possible to talk about it as being an environmental cause, one of the thgings that you're gonna see is evolution is very much a theory about the environment. but, i- no matter what if you accept the biological explanation whether it's evolutionary or whether it has something to do with current brain structure and function, how should you interpret it to say that some thi- some behavior is caused by our biology? so for example if i made this argument that said that, there's lots of good evidence that says you know most of us like sweets, most of us like fats now we don't like to say boy i love to eat a big tub of fat but we all like butter on our bread, right? and the reason why we like butter on our bread is cuz it got high fat content. one of the argument_ the reason why we like really good, premium ice creams, is because they have high fat content, that's the main thing that separates a premium ice cream from your run of the mill ice cream. so, um you could make this evolutionary account that said, gee, maybe the reason why we like we tend to universally like sweets and fats, is because of our evolutionary heritage. maybe an_ a taste for those substances, was adapted in our past. maybe we've evolved a preference. for sweet and fat. now does that mean that when you're walking down the street and you walk by the donut place, and you smell the cinnamon rolls, wafting out, which are high both in sugar and fat, you say, i gotta have one. it's not my fault it's my evolutionary heritage i have no choice in this, i'm a highly evolved human being and that's what i've evolved to do is gonna be eat the donut right? so, we wanna sorta try to talk about what the me- what it means to make a biological evolutionary argument. now in talking about biological approaches to behavior, i really do want to make a distinction and the lectures are organized around the basic distinction between two kinds of causes. one kind of cause the cause that people typically think about, when they're talking about biological causes is what we could call the proximal cause. the proximal cause just means the close cause. the immediate cause, same_ it shares the same root as w- words like approximate. it's close, nearby. so in terms of biopsychology when you're looking at proximal causes, you're looking at how current changes in physiology or structure, change behavior. how they're associated with it. so, if you wanna know what happens when people experience love, at the neurochemical level, you're looking for a proximal cause of behavior. um and it is clearly the case that, things like, brain structure and neural functioning, affect psychological experience. if you're in an automobile accident, and have damage to the frontal lobes, it's absolutely gonna change your behavior. if you have, uh damage to the hypothalamus, your ability to regulate hunger and thirst is gonna go out the door. those brain structures, neurotransmitters how neurons fire if you lose for example a neuron, if you lose the myelin sheathing that uh, insulates the neurons s- insulates some of the neurons, which is what happens in n- multiple sclerosis, you will absolutely see behavioral changes. there is a dynamic relationship between the current biological state of the organism, and its behavior. and that's what most of biopsychology looks at. but you can look at the biological influence on behavior in another way, you can look for distal causes, same root as the word distant far away causes. so is there anything not in the immediate moment that shape_ about our immediate biology that shapes behavior, but is there something about our biological heritage that shapes behavior? um is the be- and one way to think about it is is the behavior of our ancestors, currently_ or the behavioral choices that they made, continued to influence our current behavioral choices. uh, in a biopsych- in biopsychology if you're looking for, distal causes, you're essentially looking for evolutionary-based explanations. okay? and again that's what we're gonna try to do today, is to look, at evolutionary explanations of behavior. uh, as we look at them, uh, again, keep in mind that what you wanna know_ what you wanna try to ask yourself are these two questions, are there some kinds of behaviors that are maybe more amenable, more obviously open to an evolutionary account than other behaviors. and two, even if you find an evolutionary explanation for a behavior, what should you make of it? to what extent_ how_ what kind of explanation has that provided for the behavior that you observe? questions?
SU-M: (xx)
S1: okay well what i want to do then is to start talking about evolutionary theory, and then we're gonna move into psychology. so if you wanna talk about evolutionary theory you have to start with Charles Darwin. not because Darwin was the first evolutionary theorist. he was not. um there were lots of evolutionary theorists, clanking around at the time of Darwin. what Darwin did was got it right, um and i'll try to tell you where he differed from other other evolutionary theorists, as we go along. a few, trivial sort of facts about Darwin, he was born in eighteen-oh-nine, you don't really need to know that, it's just a trivial fact he was born in eighteen-oh-nine in England, um to a wealthy family, uh his mother who died when he was eight, was actually the daughter of the founder of Wedgewood China Company, so, just a little trivia. um, incredibly affluent family, uh Darwin set off to college, and uh wanted_ initially his plan was to become a a medical physician. uh but he didn't stick with that very long. it's not clear whether his decision not to go into medicine was because the lectures were just deadly dull, uh and he just couldn't find any intellectual interest in it in the time, or if it was really an aversion to seeing and performing surgeries surgeries at that time were done without anesthesia. that's a pretty gruesome thing to be involved with, um and so he bailed, uh early on, from his plan to be a physician. he, got his B-A, and uh set out on a journey, uh his first job was an unpaid job. he spent five years as a ship's naturalist, on the H-M-S Beagle. uh again it was an unpaid job what a ship's naturalist was_ did was, uh on ships of the Crown on British ships, the ship's naturalist, would travel around, and and their jobs, were to ex- to examine and write about, the animals and plant life the flora and fauna that they encountered, on the travel, and the H-M-S Beagle was on a round-the-world journey (again it) it took five years. and uh, what Darwin did was he would go do_ collect samples, he would write about his observations, when Darwin came back after five years, he basically never left England again. in fact he basically never really left, um d- his immediate town he suffered for most of his life, from sort of a chronic illness probably contracted, while he was travelling in the tropics on the H-M-S Beagle, but he he didn't, venture forward very much and he had this enormous impact, and he never left England. uh he did continue to collect data for the rest of his life but the way would collect data was, uh he would, write to colleagues, scientists around the world and so for example when we get to the emotion part, he'd ask them, what do people look like when they express happiness in your culture? you know, or here's a drawing show it to some people and tell me, what they think this emotion is. so he would do it all by correspondence. uh he lived to be, uh quite old for the day he lived i think until he was seventy-two. he died in eighteen eighty-two, and and he his uh, another piece of trivia, his uh grave, is uh next to the grave of Sir Isaac Newton, which in some ways is highly appropriate, because, now, Isaac Newton's impact on physical science, is of the same magnitude as Darwin_ i guess you'd normally say it the other way, cuz people always assume Newton's the big guy. Darwin's impact, on biological sciences, is easily as big, as Newton's impact on the physical sciences. um, Darwin's theory of evolution as we're gonna, um, as we're gonna see, in a, in a minute, uh really found_ forms the foundation, of biological sciences today, and uh one of the things that i just wanna say right off the bat is, um bi- evolution is one of those things that, outside of, scientific circles there's still lots of discussion about whether evolution is true or not. now n- i wanna tell you that within scientific circles which is not to say that it's not possible that scientists are wrong, but, within scientific circles Darwin's theory of evolution is not controversial. there are controversies about specific parts, of evolutionary theory, but the idea that organisms evolve, that they adapt to their environments and that it leads to some of these adaptations, are passed on to future generations, is not a_ is not controversial in science you can only find a handful of scientists, in the world right now who would, who uh uh, who would disagree with that i think. um, uh so although evolution is controversial sometimes in, our culture, it's pretty much an assumed truth, within within science. and it's an assumed truth within psychology, all_ what what_ where psychologists start to break down, is in whether or not you can account for, um not just physical changes evolving, but whether or not you can see behavioral changes and i'll try to make that clear as we go along. but, his impact on the biological sciences was enormous. uh and so let me tell you a little bit about the story of what happened so he's travelling around on the Beagle which is when hi- the, origins of his theory of evolution really started happening. he spends five years travelling around and one of the things that he notices over and over again, is that he sees variations, of species in different environments. in particular if you think about the gal- if you go to the Galapagos Islands, one of the things that he was struck by was that there were at least eighteen different versions, of the same species of finch. finch is a little bird right? and, all of these different versions were clearly members of the same mainland's finch, that he observed, but as he travelled around the Galapagos he noticed that, on different environments in different islands, the finches were subtly different. so for example on one island he would find that the finches look just like all the other finches except that their beak, is really short and really thick, really tough. he'd go to another island and discover that the finches looked just alike except that their beaks, are long fragile slender things. and he notices, that as he looks at, their diets what they eat in the different uh environments he notices that on the island where the finches have the short tough beaks, their diet consists primarily of hard, nuts. and on the r- island where they have the long thin beaks their diet consists primarily of insects that bore into, the bark of trees. so what Darwin says is ah, these organisms are adapting to their environments. okay? they're changing anatomically, in ways that fit the environment. i mean think about it how nice it is if you're on an island where your main diet is gonna be these, hard to crack nuts, it's gonna be great to have a beak that's really tough. on the other hand if you're on an island where your primary diet is gonna be these little insects that bore in isn't it great, that you have this long thin beak, um, to uh get in to those insects. so what he noticed was that, organisms adapt to their environments. and that's evolution. Darwin's not the only one who, notices that. lots of competing theorists are noticing the same thing, that in_ that organisms seem to, match with, adapt to their environments. what Darwin does that's different, from the other theories of evolution, is propose that the mechanism by which that adaptation occurs, and the mechanism that he proposes is natural selection.<P :05> now i wanna spend a little bit of time talking about natural selection because, but f- first i'll just read this definition which is <READING> any inherited characteristics, that increase the likelihood of survival in reproduction are selected for, </READING> if it helps you it's gonna be selected for, <READING> and any that decrease the likelihood of survival, are selected against. </READING> now, uh, one of the things that's, hard to get about natural selection is often, people think about natural selection as being this sentient knowledgable all-knowing guided planful, thing out there, as though, nature natural selection has a grand plan for each of us, and it's gonna determine what things are good and what things are bad. um in fact last night i was watching with Michael we were flipping through the Discovery Channel and they had a program on, about, these guys who were diving down to three hundred feet underneath the water trying to find a species of fish, and they found this one incredibly ugly fish, it was um, it looked like a bowling ball, only, it was a really ugly bowling ball, and it had lost its ability to swim, what it did was walked across the bottom, on its little fins so its fins were useless now it's just this big beach-bally kind of thing. useless for swimming but good for walking right? and the narrator on this, made this statement, which just almost sent me over the edge. the narrator said, evolution has taken care of two problems at once. while taking away the ability to swim it has given the fish the ability to walk on the bottom as though evolution knew what the hell it was doing, right <SS LAUGH> evolution doesn't, know what it's doing. that's not what evolution is about. evolution, is a probabilistic occurrence. basically what evolution boils down to is it says that things that work, are gonna be more common, and things that don't work, in a particular environment, are gonna become less common. if the environment changes, evolution didn't know that, right? so if the environment changes something that at one point worked really well, doesn't work anymore if it doesn't work anymore it's gonna be selected against, so, there's always this temptation to think that evolution is moving us, in a direction towards always higher performance that's not what evolution is doing at all. evolution is a pressure to match your characteristics with your enviro- with your environment, and really not your characteristics, your offspring's characteristics. evolution is a theory about how environments shape, organisms over time. okay? it's not, it's not a knowledge-guided there's nothing sentient about it, it just says if there's something that works in an environment, that thing is gonna become more prolific, and if something doesn't work in an environment, that thing is gonna become less prolific. again notice that although evolutionary theory is always thought of as a biological account, in many ways you can argue that evolutionary theory is the ultimate environmental explanation of behavior, cuz it says it's the environment, that determines selection criteria that determines how things happen. um, so i think this is a kind of complicated uh uh statement it's it's a little easier to be breaking, natural selection down into sort of what are the assumptions that are embedded in here and look at, uh a couple cases. so there are really four assumptions that are in that definition, of natural selection. <P :09> the first, is that <READING> members of a spec- members of a species, have characteristics that vary. </READING> what do i mean by that? all that statement really means is, members of a species are not identical to each other there is some variation some of us are tall some of us are short. some of us have brown eyes some of us have blue eyes, some birds in the Galapagos have relatively tough beaks, some have relatively fragile beaks, right? there's just variation. uh one of the concerns that people have right now about modern agricultural, practices by the way, is that what we've done in modern agricultural, practices which work well in our industrialized environment right now, but one of the things that we've done is we cut down, the variability, so for example there are very few, species of corn, all those vra- vra- i mean veri- veri- d- varieties of corn, all of those varieties of corn are genetically pretty identical to each other, which makes them very vulnerable if the environment suddenly switches, because there is no variability. natural selection first you have to assume that there's variability, in uh, in the, species. the second thing is is that at least some of these characteristics are passed on genetically. now Darwin, didn't know about genetics, what Darwin argued was that there had to be some mechanism he didn't know what it was but that there had to be some mechanism, of passing on characteristics from one generation to another, uh one of the ironies, is that Mendel who was working, around the same time as uh, as uh Darwin a- apparently sent Darwin a copy of his uh manuscript where he laid out the basics of genetics, uh and in those days when you got a manuscript, a book you still had to cut the pages, so people have found this book and_ Darwin's library is still preserved if you're, if you, you're a very special person you can go in and, go in and sit in Darwin's chair and be in Darwin's library, and people have done research in there and found the books that were on his library at the time of his death, and there was a copy, of Mendel's book, which was onl- which had only been opened to about the, twentyfifth page and then, Darwin got bored with it apparently and put it up, so sort of ironic that the mechanism that he needed for his theory really to sort of flush it out, was there he just didn't know about it didn't read it, but um the- you have to assume that characteristics have to be passed on. evolution happens across generations. it does not happen in a lifetime. it does not happen in two lifetimes. it happens across many many many generations it is a relatively slow process... third, some of those characteristics will aid survival, and reproduction it's really what should go on it's really, evolution is really about reproductive success, so, some of these things will aid survival so, if you're, a bird, in the Galapagos Islands, and you have developed with the tough beak, relative to your neighbor, fragile Fred right? then if your d- if the diet on that island is in fact these tough nuts, your strong beak's gonna be an advantage to you. you're gonna have more access to food which means you're gonna be healthier, which means you're gonna be more resistant to disease which means you're gonna be more fertile which means you're gonna have more offspring, to the extent that your beak, is passed on genetically, your offspring are gonna have the same advantages that you had over your rivals, at that time, they're gonna have the same advantages. so that over time, over generations, what you oughta see is the number of tough-beaked birds, goes up in this environment, in contrast if you were in the environment where it's the thi- it's the insects boring in, if you have a thin delicate beak, you're gonna have an advantage over the tough-beaked ones who can't get to 'em, right, can't get to the bugs. so, it basically says that some of these characteristics are gonna aid survival, right, and reproductive success. okay? the last point, is simply to say, that, it really has to translate to, reproductive success, it's not just that it helps you, uh, uh do well, but it helps it increases the chances of your offspring surviving, and, and your offspring in turn reproducing. well the last assumption just says <READING> species produce more offspring than survive to be adults </READING> really, that some organisms die before procreating themselves. if every member of every species, survives and reproduces at the same rate, you will not have evolution you will not have natural selection, cuz, evolution natural selection really is about differential success, in reproducing. okay? with me? now there are a couple of things that i wanna point out about these, uh, uh about these assumptions. and again, it's this that sets Darwin off, from other people. why is evolutionary theory basically widely accepted in the biological sciences? and at least in most respects in psychology well, lots of reasons. one reason why evolutionary theory in general is accepted is because uh we have, uh a fossil record, that shows a fairly steady progression, of changes. you can see where environments change and organism change organisms over generations change in response to that environment. the fossil record provides pretty good continuous evidence, of this progression from presumably single-celled organisms, um up through complex multicelled organisms, by the way, and up is even a bad word to use there i mean you could make the argument that the most successful, evolutionary organism right now is a viru- are viruses, or bacteria i mean there are far more of them than there are of us. there are more of them in this room than there are of us, but we often talk about when we talk about up we're really talking about going up in complexity of the organism. so as you move up in the complexity of the organisms up to humans, you you see a fairly clear progression. similarly a second reason if you look in different species, you find similar anatomical structures, serving very different functions. so our hand, and a bat's wing, are anatomically very similar, they serve very different functions, but they look very similar, suggesting that at some point way back in the evolutionary history, we were_ we had a commonality. right? but then the environment changes for bats they evolve certain things that that facilitate them flying, we evolve things that in- facilitate our grasping, right? but it looks like there's some commonality across species, commonality in structure. the third and probably most compelling reason is because we can in fact see evolution in action. how can we see evolution in action given that i told you that evolution is a very slow process? well it's a slow process generationally, but if you find an organism that has a quick generational half-life, you can actually see things happening you can see evolution happen. there are lots of organisms that have very very quick generational lives, insects, tend to have quick genera- you can run through a bunch of insects in two months, bunch of generations, bacteria even better, you can run through generations of bacteria in twenty-four hours, and we see evolution in action. one of the persistent problems today in medicine, is the evolution, of uh antibiotic resistant, bacteria, and it's a clear case of evolution. so, think about it. you have bacteria, that vary in some of their characteristics. one of the characteristics that they vary in, is how much peni- let's just take penicillin as an example, how much penicillin does it take to nuke the bacteria. some bacteria, (if) some members of this of the same strain of bacteria it turns out, maybe go <SOUND EFFECT> with a little penicillin, they fall over and, kick their little legs so to speak and they're dead. other bacteria you have to just bomb 'em with lots of penicillin, before you're gonna nuke 'em, so, they vary in their susceptibility, to penicillin, right? that's the first thing. second, those characteristics are passed on genetically, and remember that bacteria just divide and then you've got two replicas, of the original and so they're passed on genetically. three, some of those characteristics aid survival. in a pre-penicillin environment it doesn't matter but if suddenly you're in an environment where there's penicillin, having a resistance to penicillin is gonna aid survival. so when you start introducing penicillin, that is a selection pressure, you start putting penicillin in, it suddenly makes disease resistance, i mean penicillin resistance, a survival characteristic. notice again nobody thought this out nobody said gee we're gonna design a bacteria that's gonna be resistant to penicillin so that when penicillin, comes along it's gonna be resistant to it. it's just, there's variation, suddenly an environmental press comes on, species produce more offspring than survive to uh reproduce themselves, once you introduce penicillin into the environment most members of the species die off. the only ones that don't die off are the ones that are highly resistant to penicillin. they go on, to reproduce, and you have now a higher proportion just like with the birds in the Galapagos, you now have a higher proportion of, penicillin-resistant bacteria. so we believe it because we've seen it, in action, i mean you can see evolution happening. i noticed that natural selection began at first with environmental change. somebody asked me well are we_ a- after the last class somebody asked me, well are we affecting our evolution, are we taking over for natural selection well, w- we are nature. i mean we're all part of nature, natural selection just says when the environment changes, or the environment puts a press on it so if we introduce penicillin or another problem is pesticides, we introduce pesticides into the environment, some of the pests, are gonna be resistant to those. we are exerting selection pressure, uh on the envir- th- through the environment on those organisms, if you start using pesticides you can guarantee that you're gonna start seeing, pesticide-resistant, insects, if you use antibiotics you're gonna guarantee that you're gonna see, antibiotic-resistant strains of penicillin, i think there's one version of staph infection right now that's in Japan where, there is one known antibiotic that works and and sure as the sun rises, that go- the the bacteria will evolve a resistance to that version of penicillin too so it's a constant race of whether you can come up with a new, sort of version of penicillin, or antibiotics. okay? now psychologists don't question, psychologists are happy with this, psychologists think when it comes to okay so what about evolution in psychology? well psychologists are also very comfortable with the notion that brain physiology, physical anatomy, has evolved over time, and the argument if you were gonna make an evolutionary argument about this goes basically well if you look across species what you see is sorta this progression toward complexity, that there's something about centrally organizing information processing, which is what the nervous system is really about, it's about processing information, taking input from the world, doing something with it, and putting out a behavior, right? that if you look at what happens to sort of that central processor in your lowly striped bass, you got a bunch of ner- nerves together that just sorta_ we call 'em ganglions just sort of very primitive, um uh meaning simplistic, uh information processing, controls things like breathing and reflexes and stuff like that not a lot of higher order computational power in your basic, striped bass, um nor a lot of sensory processing processing and stuff it's a fairly simple sensory world if you're a striped bass. as you go up, across species, again up in terms of complexity, as you go up you see sort of regular organization so, this part of our brain the hindbrain we'll talk about that when we get to brain physiology, but the hindbrain and the bass, are really pretty similar, and they control similar functions it's breathing and all those kinds of basic survivals. when you get up a little bit more complex more sensory, uh processing is involved, you get the evolution of things called a midbrain just a little bit of bulging around, what was just the ganglion, well in humans that, part is right here. it's called the midbrain, it's the second, structure to evolve sort of, evolutionarily, and it processes sensory information. and then as you get up in cats and primates and humans what you get is the forebrain this last part, which is, um where the cortex is where most of what we think of thought and if consciousness resides anywhere, and it most surely does, it resides somewhere in the cortex, language resides there all kinds of higher functioning more complicated functioning reside there. so, psychology'd be perfectly happy saying well what you get is this evolution of physiology. there was something about information processing, that's adaptive, that aids in the survival and reproduction of the species, and so that's what's happened, we've filled the niche, right, um, by going down this trail. where psychologists start to depart, is when you start talking about, evolutionary influences on current behavior. so we're not looking about the structure of the species, we wanna know, can i explain something in the moment? so can i explain for example the fact that if i go, <SMILES> how's everybody doing? you all assume i'm, more likely happy, than unhappy. or if i went, <SCOWLS> so what do you wanna know? <SS LAUGH> you're gonna be, more likely to assume that i'm, angry than not angry and in fact i need to cut the language out, i don't say so what do you know i just go <ANGRY FACIAL EXPRESSION> you're not gonna say boy he's a happy camper. right? you're unlikely to do that. can we explain that behavior, evolutionarily. notice now we're not talking about, physiology so much, as we're talkin' about a behavior in the moment. and notice that unlike physiology there's no fossil record you can appeal to, you can't say gee, four million years well that's a t- four hundred thousand years ago, how did people signal happiness? there's no record. you can't tell. so evolutionary theorists, who are trying to explain current behaviors, are always in the position of having to look at something that they see now, and see if they can tell, a story, an evolutionary account, and then the trick, that separates evolutionary psychology from other approaches, that have been taken to this is, can you make a novel prediction? can you go out and test it, find evidence now so again what separates from just an as so story is, can you s- tell your story your theory and then say and if this is true, i oughta be able to see why, and then go out and see if you see why. so, the first candidate for that kind of behavior, is gonna be, emotions. can you explain can you offer an evolutionary account, for emotions? now the first person, to make the argument, that, maybe our emotions evolved again notice, it's a different game here. we're talking about explaining behavior, not physiology now. can we understand emotional expression, things like smiling crying disgust anger, can we explain that by appealing to our evolutionary heritage? the first person to make that argument was Charles Darwin. not surprisingly. uh Darwin in eighteen seventy-two, believed that facial expressions, um, did in fact evolve i'll give you his language and then try to explain what it is. he believed that they evolved from quote serviceable associated habits, of behaviors what the hell is that right? so here's what a serviceable associated habit is, what Darwin argued was well lots of behaviors have lots of things that sort of consistently go along with them. so for example if i'm gonna attack this_ i won't but if i were gonna attack this person right here, right? any way you look at it if i'm gonna attack you, i gotta_ i'm gonna go something like this, why am i gonna go something like this <ANGRY FACIAL EXPRESSION> well, i need to be in a position where i can lunge forward, remember we're a preverbal society, i need some way that i can lunge forward, and i'm gonna be tense, cuz my emotions_ i mean my_ i want to be ready, right? i need to be able to punch i'm a whole lot easier i- to punch if i'm like this <ANGRY FACIAL EXPRESSION> than if i'm like this.<RELAXED FACIAL EXPRESSION> right? so what Darwin argues is well maybe, this behavior, that really has nothing to do with the attack it's the preparation for the attack, but it has nothing to do with the attack directly, maybe this behavior is the serviceable associated habit meaning, maybe, organisms, that were able to pick up, on the intent, from just the expression, would have some advantage. i mean if i go like this, <ANGRY FACIAL EXPRESSION> he can either decide, to prepare himself and fight back, or he can decide to run, either way, he's at a better advantage, than if he's standing there clueless while i'm getting over here ready to attack him, right? so what Darwin argues is, that essentially maybe emotional expressions evolved as a mechanism of communication. it's an extremely profound point <S1 LAUGH> i argue cuz, you're in a preverbal society, and what emotions allow you to do is to make internal intentions, public. it allows you to say i'm gonna beat you up, but you don't have a language that says i'm gonna like beat you up. or oh i sure am happy you're here friend, when you can't say, gee, i'm so happy you're here friend. it allows you to communicate internal hidden states to make them visible and Darwin's argument was, that organisms that that picked up on that, that detected that, would have a survival advantage a reproduction advantage, that if you're the type of person, there's variability sensitivity, of these expressions, if you're the type of person who displays and decodes the expressions, you're gonna be more likely to survive in the wilderness in the desert, okay? now consistent with that, argument, are just a few things, first is that, if you look at the facial neuro-muscular mechanisms, fun to say that three times they show continuity from higher primates to man. all that means is that again just like you wanna see continuity, in the, in the uh the b- evolution of the brain, you'd like to see continuity in the f- in the physiology that would support emotional expressions you wouldn't want to find that only humans are able to go rrrr. <THREATENING FACIAL EXPRESSION> if we're the only species that can go rrrr, <THREATENING FACIAL EXPRESSION> then, the- it's hard to imagine that evolution coulda done that, cuz it shoulda happened over time, and shaping it. the second thing is that facial expressions in humans really do (carry) close similarity to animal responses, that have presumably again originally serves some, function relating to defense. again if uh if you're watching in a horror movie, and you are genuinely frightened in the middle of a horror movie, you're not likely to go wow, <SURPRISED, PLEASED FACIAL EXPRESSION> right? you just, you don't do that (approach) thing right? when you're frightened you go aaahh <SURPRISED, SCARED FACIAL EXPRESSION><SS LAUGH> like that, right? just like a horse shying away. again when you're angry you don't very often see people who are really really ticked off go, except Clint Eastwood, <NONCHALANT FACIAL EXPRESSION> go ahead, make my day you know it just doesn't happen when you're angry you're in someone's face, you're just like this little critter right here, <POINTS TO POWERPOINT SLIDE> right? so it looks like there's a_ and then my favorite is that some emotional expressions, seem to resemble reflex and reactions to nonsocial stimulus so take something stinky, and put it in front of a person and they'll go ugh. <DISGUSTED FACIAL EXPRESSION> just like this, just that's disgusting, right? so, try turning in a paper that you started writing at three A-M and finished at four A-M to your G-S-Is ask them to read it and watch them while they read it, and you'll see the exact same facial expression, of disgust at this stinky piece of work, um the same way you know when you se- don't like something i mean think about it when you don't like something, the expressions that you make are really <DISGUSTED FACIAL EXPRESSION> oh, that's terrible. how could he do that? how could he say that right? so again it seems to be related. now so far we got an as if story. seems like there's this communication. what's the evidence for it? well now we need a new hypothesis. the new hypothesis is that, these emotional expressions, oughta hold true cross-culturally. people from different cultures, oughta be able to identify similar emotional expressions, and in fact Eckman does that. Eckman goes out and finds the last civilization where television hasn't been introduced yet, and shows them pictures, of people doing different displays of emotion. and asks them in their own language to describe it, and when people see this, <POINTS TO POWERPOINT SLIDE> they basically say oh that's disgust. and when they say this <POINTS TO POWERPOINT SLIDE> they say that's, [SS: sadness. ] sadness. when they see this, fear. right? when they see this, <POINTS TO POWERPOINT SLIDE> happiness. did i get those right? oop, i got surprise and fear wrong ugh, good thing i wasn't on the subjects list so um, surprise and fear it turns out that if you go cross-cultural, you do this study over and over again not only are people who've never seen T-V when shown these photos, identify them correctly, but cross-culturally, you find incredibly high levels of agreement, about these six emotional expressions, joy disgust surprise sadness anger fear there's some evidence that contempt, may also be a relatively universal emotional expression. so the argument goes there's evidence that these expressions, there have been some evolutionary advantage to, being able to detect them if they're universal, but other emotional expressions, vary widely by culture. we'll pick up there, on Thursday. thanks a lot.
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