Robert Sapolsky: Are Humans Just Another Primate?

good evening and welcome to this month's Pritzker lecture I'm Greg Farrington executive director of the Academy chief penguin as they say or as I say I think that's a it's as good an identity as any tonight it's my pleasure to deduce rot roger Sapolsky from Stanford you've heard of Stanford I presume he's the John a and Cynthia Frey gun professor and he holds joint appointments in biology and neurology and neurological sciences he's also reaches research associate at the Institute of primate research operated by the National Museums of Kenya in Nairobi and the recipient of the MacArthur Fellowship most significantly he's an Academy fellow he's one of us dr. Sapolsky received his BA in biological anthropology from Harvard and his PhD from Rockefeller University in neuro and chronology he's the author of several books including and I love these titles stress the aging brain and the mechanisms of neuron death a guide to stress-related diseases in coping I can't quite decide whether to read it or not he also regularly contributes a journal such as discover science Scientific American Harper's and The New Yorker I hope you read them all now I before the final step of the introduction I will say I'm about to walk out the reason simple my wife and I married our son off on the East Coast we just got back and resumed so we are going to or these bundles of neurons are about to collapse and so we are trying to watch this on the fora tv' version later on even though we regret missing tonight his topic this evening is humans are we just another primate are we just a bunch of neurons please join me in welcoming Robert Sapolsky well thank you it's a pleasure being here and not being jet-lagged so that's a good thing it's also the first time I've lectured next door to an indoor rainforest and underneath a lawn so that's good also ok so starting off I'm both a neurobiologist and a primatologist I sort of alternate between thinking about neurons and looking at primates in their natural habitats and you do that long enough and you eventually start looking at humans kind of strangely you you notice how long guy's canines are for example and you think comparatively or like you see somebody ambling down an aisle and you think about how much anaesthetic it would take to Dar demand their rear-end to take them down and you know you wonder if that person is a monogamous or polygamous primate you know you start thinking about humans and it's mighty hard to sort of wrestle with this issue of well just how much are we just another animal just another mammal just another primate so could it give some thoughts about that this evening ok so starting off doing something that's really very impolite and you shouldn't be doing but I'm going to start off the lecture by complaining about somebody else's lecture and this was a lecture I was at some years ago and this was a conference about Alzheimer's disease and this was a guy who got up who studied fly neurogenetics which amazingly enough is enough of a field to have like warring parties of flying neuro geneticists but this guy got up and sort of made the argument was what was he doing at an Alzheimer's meeting and he went over the fact of how similar flies and humans are and he got up saying basically if any of you know what's right all of you will be studying flies within 10 years and here's the argument he made roughly the same number of genes and a lot of cases the identical gene and the neurons are essentially the same the same resting potentials and neurotransmitters and enzymes some humans have not invented new types of brain cells new types of chemical message we've got the exact same kind that flies dit so he's arguing here that's why you should start studying flies and as far as I was concerned he had just proven why genetics and neurotransmitters etc tell us nothing about what makes humans humans because we've just shown that there's nothing distinct in that realm so what I want to try to wrestle with this evening are ways in which we do have insights when are we special and one are we anything but and broadly I find it sort of useful to think about this in terms of what are the domains in which humans are just like every other animal and nothing special what are the domains where we do the same exact thing as every other beast out there but in a totally novel context and what are the things that we do where it is with absolutely no precedent out there in the animal kingdom okay first example just like every other animal out there here's the scenario you are a hamster your female hamster and what you do is you ovulate every four days or so that's how female hamsters work so you're sitting there in your cage ovulating away every four days and they put in another female hamster and what's going to happen over the subsequent weeks is both of you are going to start lengthening your cycles and eventually synchronize them so that you're both ovulating within a couple of hours each other on the same day then they take a male hamster and put them into the cage with you and that completely desynchronize 'iz and shortens your cycles this is amazing this works totally this way it's all done by way of pheromones chemical olfactory messengers you can prove this low-tech by just like holding the females hamsters nose closed for days or you could do really elegantly and these studies don't put the male in the cage have the cage in an enclosed space and pump the air from the male's cage into this one and it has the exact same effect it's all old factory people understand what parts of the brain process it and works completely and what's totally cool is when you put the two females together it's not random who synchronizes the other the socially dominant one tends to drive the synchronising of the two so everybody knows this totally well studied and this is seen in canines and bovids and felines and under wells you apparently in Iowa you can go into a 7-eleven and buy a can of pig ovulatory synchronising spray and you can go I have no idea why you would want to synchronize your pigs ovulating growing up in New York now there is a vocation or an avocation but you can apparently do that there that there's like these that's how well it's known you can go synchronize your pigs and the amazing thing is it works exactly the same in US where it's known as the Wellesley effect the Wellesley effect first described their study in 1970 of women freshman year and roommates over the course of the year synchronizing their cycles except for women who had close intimate relations with a male it was shown that olfactory dependent and it's the exact same thing and this is well studied enough that like biologists brag about it I remember during college which sit around the dinner table and someone would be saying when we room together this summer I had her synchronized by August first that's how bad it is to hang out with biologists because in US as well it tends to be the more extroverted the more socially dominant person who synchronizes we're just like hamsters some of the time though we have the exact same machinery but we use it in completely novel ways example here okay you got two humans who are going through this obscure ritual they sit facing each other at a table they don't move they don't speak they don't make eye contact nothing more is happening than every now and then one of them lifts their arm and moves a little piece of wood around on the table and if these were the right to human chess grandmasters in the middle of a tournament they are maintaining the blood pressure of a marathon runner for hours and hours on end simply thinking simply doing stuff that no other animal can do which is dry function and every cell on the body with thoughts and emotions and memories and we've got the same physiology but completely novel ways you look at some zebra running for its life that's been half ripped open by a lion and the physiology of what's going on and that zebra is astonishingly similar to what's going on in us when we contemplate mortality or traffic jams or who knows what that's why humans get stress-related diseases we turn on the classic mammalian stress response meant to get you running across the savanna and we turn it on for 30 year mortgages and thus we see some of the time what we're about is using just plain old off-the-rack mammalian physiology but in unrecognizable ways finally is the third domain there's stuff that we do for which there is simply no precedent out there and let me give you an example here a shocking example okay you have a human couple they come home at the end of the day they talk they eat dinner they talk they go to bed they have sex they talk somewhere they go to sleep the next day they do the same exact thing they come home they talk they eat they go to bed they have sex they talk somewhere they go to sleep they do this every single night for 30 days hippos would be repulsed by this hardly anybody in the animal kingdom has non-reproductive sex like that and nobody talks about it afterward and we're suddenly in a very novel terrain here in terms of making sense of us and some of the time when you look at our communication patterns sexual behavior our human a tendency at times to confuse sexuality with aggression in those around there is no precedent we are on our own okay so that is an organizing way to think about when we're just like the others partially so or not in the slightest okay so how to begin to think about this so what we'll look at first are some really interesting domains the theme over and over again where we have some of the building blocks exactly the same but we use it in ways that are just unprecedented now a lot of this over the years has consisted of what we're initially shocking findings oh my god chimps make tools jane goodall reporting that in the 70s and that force an entire redefinition of what humans are what makes us unique what we'll see here is that business about softening the barrier between what we are and other species has gone in all sorts of directions nonetheless in each case us using things in a very novel way first example any of us when we were brought up on all those like National Geographic specials and those ones on some animal species they would always be the same like stentorian narrator at the end saying something like a man is the only animal that kills for pleasure and like that was one of our defining things and as people have done more and more primatology it's clear we are not the only species that kills all sorts of the Gir currencies and other species where it could be violent cold blooded hot blooded premeditated planned it can be Machiavellian in terms of its strategic consequences it could be savagely bludgeoning it could be just like we do when we kill another member of our own species and most remarkably it's not even unique to us anymore to have organized violence so here's one example from one of the troops of baboons that I study and this is a male who had joined one of the troops a few weeks before as an adolescent and the only way to describe this guy is he had terrible political skills and he was hassling all sorts of guys he had no business going anywhere near and one evening a coalition of six of them ganged up on him and this is what was left in the morning we are not the only species that kills and in this organized way an even more dramatic example this is a bunch of chimps and carrying out starting off what is called a border patrol these are all the male's of one group and on occasion what they do is get into a very agitated sort of emotionally contagious state of going and checking out the border of their territory and if they encounter another chimp from the next Valley over they will attack and kill him total premeditated behavior and what is very significant is almost certainly all of these male chimps are brothers or close cousins be really scared when the males in the next Valley over are getting along with each other because this may be one consequence what's roast most remarkable reported by Goodall is in at least one of these instances the males and this group managed to eradicate every member of the neighboring group and this is a proto example of genocide killing individuals not for who they are but for what group they belong to so we are most definitely not the only species that kills and even in an organized way so what's special about us absolutely some of the time we are doing nothing more subtle than what chimps are doing when they make weapons bludgeoning each other but some of the time we could be aggressive passively some of the time we can look the other way we can pretend we didn't hear some of the time we can do nothing more physically taxing than pulling a trigger some of the time we can dam with faint praise we can be aggressive in all sorts of novel ways here is an astonishing example because this is a job that is possible to do and this is job for a handful of people living just outside Las Vegas these are people who in the morning they get up and they make sure they get their kids off to school and as they head out they're reminded don't forget to pick up the dry cleaning and they get caught in a traffic jam and they're all anxious about getting to work late but then the traffic clears and they get there just on time and it all works out okay and then they start their job which is sitting in a little cockpit simulator and controlling a drone bomber in Iraq running on bombing runs this is done at Navis Air Force Base just outside Las Vegas what people there do is they sit and they operate sort of drones and Iraq releasing Hellfire missiles there and they spend the day killing people on the other side of the planet and at the end of the day they pack up and they drive on home and they're in a rush because they want to get to their little girl's ballet performance and afterward they hug her and can't believe they can love somebody this much and the next day they are off sending Hellfire in Mesopotamia and no surprise there are astonishingly high rates of psychiatric problems among these people this is like no other species out there so we shift to another domain theory of mine theory of mine is a very hot topic among cell psychologists developmental psychologists the whole business about understanding that another individual has different information from you and that they will behave strategically in a way reflecting that that's classic developmental psychology when do kids first start to show theory of mind developmentally there's all sorts of tests where you could say so the little girl comes home and where is she going to look for her toy in this rumor that room and when does a kid first distinguish between what they know about where the toy is because they were just told something happened while the kid was off at preschool and what the little kid knows when is the first time they realized that somebody else is a separate entity and could have separate knowledge and typically theory of mind starts appearing between like ages 3 & 5 both of my kids got in on their 3rd birthday so that was very and what you see is this is really impressive and in lots of realms this is viewed as a defining feature of humans but it turns out that theory of mind is not unique to us all sorts of studies one style here you take two chimps from a social group with their ranks known and you put them on either side of this sort of enclosure and they're both sort of kept off at the sides there and in the middle there is a screen and at one point you've got the low-ranking chimps human comes out puts a banana down just on the side of the screen half the time the screen is transparent half the time the screen is solid in other words half the time that high-ranking guy you can see that a banana was just put there half the time he can't then you let both chimps come out and you asked as the subordinate guy try to get the banana and you see that chimps have a whole theory of mind algorithm the low ranking guy what he does is if the big guys scary guy was able to see the banana being put there little guy doesn't even bother trying to get it because he's not going to have a chance if the solid screen was up he knows the other guy doesn't know what's in there he goes and grabs the banana or suppose the high-ranking scary guy over there has seen the banana put there but then he's taken out and the different high-ranking scary guys put in low ranking guy goes for the banana he understands that guy knows there's a banana there this guy doesn't he understands that another chimp has different thoughts and can act strategically to take advantage of that that's totally wild this completely blues sort of developmental theory of mind human people out of the water so we're not so unique with that where are we unique though in the capacity to do what's called secondary theory of mind to understand that that individual doesn't know that that individual knows that that individual understands something about that individual and what you wind up getting is this is why we could make it through a performance of Midsummer's Night Dream and can't in terms of trying to keep straight of wait who knows what about who and what happened when and chimps would not put up with us because they can't do secondary theory of mine so again initially we're seeming not quite so unique and then we're taking a basic primate attribute and putting into very novel realm next the Golden Rule virtually universal in every culture either doin to others then do or don't do in to others as you wouldn't want to have them do to you and what game theorists have formalized in ways of how do you maximize play to maximize cooperation and what you see is the most efficient strategies often are built around golden rule type interactions tit for tat you can show mathematically in terms of these games like the prisoner's dilemma what you have most of efficaciously is you begin by cooperating if the other individual cooperates you continue to cooperate if they cheat against you the next time you cheat in return if they've gone back to cooperating you do as well you do a tit-for-tat strategy and this is something the mathematics of this is studied by game theorists and economists and war strategy people and all of that and it's all built around we are rational enough to come up with ways of maximizing different strategies but then it turns out we're not the only species that does tit for tat first example here we have this terrifying nightmarish creature the vampire bat haunts our nightmares the vampire bat in actuality when it's out drinking the blood of something or other is actually a female just getting food for her babies because vampire bats aren't actually drinking the blood they're storing it in a throat sack they fly back to their nest Dischord the blood to feed their babies now here's the interesting thing which is that vampire bats have communal nests a whole bunch of different females have their infants in there and the females come back and disgorge the blood and feed everybody's kids everybody is feeding everybody else's kids it's a system of stable reciprocity now make the bats think that one of them is cheating on them one of them is holding back bat flies out and you net the bat bring it down and what you do is you pump up the throat sack with air so that the throat sac is extended way out and gorged and you push the bat back into the nest there and everybody is sitting there saying oh my God look at how much blood she's got there and she's not feeding my kid and the next time around nobody feeds her child they do its hit for tat strategy even more amazing example in part because of the species having so few neurons here we leave mammals behind and talking about fish fish classic research with stickleback fish okay make a stickleback fish believe that its territory is being invaded what do you do you put a mirror up against the side of its tank and within seconds its attacking its image there now you make the fish believe it has a coalitional partner here's what you do you take a second mirror and put it perpendicular to them and now what's happening is every time he's lunging forward his reflection is doing it there and he's saying I have no idea who that guy is but he's great because every time he's keeping the other guy out there and this is great we got this stable partnership be a team now now make the fish think his partner is cheating in their social contract take the mirror and angle it back a bit so the image is deflected backward so now he's sitting and he's going at his image there and he sees the guy moving forward but he sees the guys not moving forward that much and he said they're saying that bastard I can't believe it here we are I'm blistering my lips here against this guy's lips it's kind of weird the way that worked but I'm defending this right oh yeah he's just pretending to go forward but I see he's not going all the way there he believes his partner has cheated on him and the next time he sees his image he doesn't attack it he's tit for tat and back so we are not the only species that is capable of doing that sort of optimization what is unique about us though is a very subtle elaboration on the golden rule in tit-for-tat ink not doing to others as you would have them do unto you but when do you deal with the fact that one individual may have diff and desires than another one as to what counts as what is reciprocity and no animal out there could understand what's going on in this quote built around that not all humans have the same goals so yes we're not the only ones with some variant on the golden rule but we are vastly more subtle in terms of how to think about it and what we do with it next domain one of these areas that seems just defiantly human empathy the capability of feeling someone else's pain that is at the core of so much of what makes us human and what is clear is we are not the only species wonderful work in a lot of realms some of the best by primatologist named Franz Duval Demerol University and what he shows is something that sure looks like chimp empathy here's what he shows his captive animals one scenario some low ranking guy idiotically challenges some high ranking male and gets pounded second scenario low ranking guys sitting there minding his own business high ranking guy is in a bad mood and pounds him first case the guy asked for it second case innocent bystander and what Duvall has shown is in the aftermath of this the other chimps are far more likely to come and groom the guy who is the innocent bystander than the guy who started the trouble and was asking for they understand intentionality and they understand that this guy did nothing wrong and they do what is the chimps equivalent of consoling someone else they groom someone else all sorts of suggestions that we are not the only species with empathy but what about us where do we wind up using it in very unique ways that way transcend chimps choosing who it is their good a groom based on whether or not they have been an innocent bystander what we do is send it into an area of abstraction like no other species let me give you an example here okay so you look at this picture this picture of this dog whose paw has been caught in some sort of trap it's come off necrotic and you were sitting there saying oh my god this is her was this some illegal poaching was this somebody abusing the dog this is terrible that poor animal you are feeling empathy for a member of another species that is essentially unprecedented out there in the animal world you are feeling badly you are feeling pain for this dog who isn't of your species but we could take it further so we look at for example one of our classic paintings in the last century and we focus in on the center and we look at the horse there in Guernica knowing that this was recording the historical event of the fascists firebomb in Guernica barns burning animals stuck inside and here is just the personification of terror and this horse and we sit here and we feel badly for this horse this horse who's painted on a canvas who doesn't even exist we feel badly for this horse caught in this imaginary painted bomb barn during this fire bombing this is a realm of empathy unmatched but we could take it even further this is a painting by an expressionist German painter Franz Marc shortly after World War one who like many in his generation had his mind and everything else melted in the trench warfare and a painting he did shortly afterward and this painting was called the fate of the animals and what we see in the very center is this animal surrounded by the sheer chaos of perhaps trench warfare this animal stuck in the middle of sheer chaos this animal baying at the moon and terror and pain and you look at the animal and it's not even obvious what species it is it's of no known species you are not feeling badly for this animal you were fat and feeling badly for the animals the fate of the animals and abstraction on that level by contemplating the pain of a member of the species that only exists when painted here these are relative empathy that are unmatched ok another domain how we anticipate things pleasure anticipation of pleasure and what we've learned is the brain chemistry this is remarkably similar in us and all sorts of other mammalian species and it's got tons to do with this neurotransmitter called dopamine dopamine is all about reward dopamine when it's released in certain circuits in the brain mediates a lot of reward cocaine works on dopamine neurons causing them to release dopamine all sorts of you for ants do as well dopamine is about pleasure that's what people used to think as you would see an experiment like this you take a monkey and from out of nowhere you just give it a reward in this case from outta nowhere you just give it a food reward not as shown here but it just gets a reward from out of nowhere and that part of the brain releases dopamine that's not how it actually works when you've now set up an experiment as follows this monkey has been trained that when the little light comes on it's one of those sessions where I can now get food and it knows that if I press this lever ten times after a little bit of a delay I'll get some food if I press the lever ten more times I'll get some more food it understands the task so what do we have here we have first a signal the light coming on saying it's one of those sessions we're starting one of those then the monkey does the work and then with a delay it gets the reward and what everyone initially thought was dopamine would go up after the reward that's not when it goes up it goes up when the signal comes on what's this this is the monkey they're sitting and saying I know this I know the drill I know this I'm on top of this this is gonna be great I know what I do now this is completely perfect 100% I'm going for today dopamine is not about pleasure it's about the anticipation of pleasure it's about the pursuit of happiness rather than happiness itself and what's most remarkable is experimentally if you block that rise of dopamine from occurring you don't get the work you don't get the behavior this is not only the anticipation but this is what is capable of eliciting directed behavior amazing elaboration on this which now begins to tell us something real familiar okay so in this study lab eration rather than this design you press the lever or right number of times you get reward do the work you get a reward hundred percent of the time that's how it works now instead shift to where you get the reward only 50% of the time you do the work and only about half the time you get the reward so what happens to dopamine levels there this is what they do they go through the roof because what have you just done you've introduced the word maybe into the equation and maybe is addictive like nothing else out there because the light comes on and you're doing the I know how this works this is going to be great but I screwed up last time because I didn't get the food but this time I'm feeling good today but I'm a total screwup and I'm inadequate in junior high school and it was terrible and I kept but maybe this time this is my lucky to end just vacillating all over the place what we see here is dopamine comes pouring out like mad it's the uncertainty of the reward and here's the really elegant thing they did in that study now instead of a 50% reward rate either a 25 percent or 75 percent these are diametrically opposite states worse news better news the only thing they have in common is you've decreased the level of unpredictability and the rise and dopamine winds up being halfway between the 50% and the hundred and what's this about this is the world of brilliant social engineering by humans say in Las Vegas who understand how to design a place to take a curve where somebody has a gazillion of 1% chance of getting a reward and making you think because it's the special day in this casino and you especially are so much tilted to the right that you are going to get and humans are profoundly manipulable in this realm and it turns out so are other species the exact same neural chemistry so what winds up being unique about us and what you see is with humans it's the time dimension you get the signal you do the work you get the reward and the question becomes how much time lag time can there be between the work and the reward to still elicit the behavior to still get the work coming out and we have just entered uniquely human terrain there for the very simple reason that probably most of us recognize which is somewhere along the way almost all of us worked very hard in school to get good SAT scores to get into a good college to get GRE stick into a good grad school to get a good job to get in the nursing home of our choice there sort of thing and what we see is this astonishing ability of humans to keep those dopamine levels up for decades and decades waiting for the reward and in the most bizarre unique realm of this in humans sometimes we could maintain it with a belief system where the reward doesn't come in our lifetime the reward comes after our death the reward comes in our afterlife the reward comes unto the next generations and there's no monkey out there who's willing to lever press all the time because of what st. Peter is going to think somewhere down the line so that is unique about us another domain culture culture now if you're a primatologist and anywhere in the past if you ever said the word culture they would instantly die you tenure because you obviously were not serious and couldn't understand the difference between a disney wildlife cartoon and the real world and these days the two hottest words in primatology are culture and personality culture in terms of the non genetic transmission of learned behavior either intra or inter generationally and by that classic rule of social anthropology we are not the only species that has culture we have chimps who not only have twenty twenty-five different ways of making tools but they're young learn from their mothers how to do this this is passing on in this culture and one particularly great study what was shown was among chimps daughters learn the techniques much better than because when they're little the sons were way too distracted to pay attention to what mom's doing with the termites stick there the daughters learn the new techniques much faster this is cultural transmission social anthropologists have conniptions over this but this meets the formal definition an animal cultures can be even more subtle than the mere passing on the information of how you make your termite stick and this is some work that my wife and I did some years ago studying our baboons out in East Africa showing a very unique case of cultural transmission in a different species this was a troop of baboons we were studying in East Africa where just happened the neighboring troop had within its territory a tourist Lodge with a garbage dump and the baboons and that neighboring troop spent most of their day just sort of foraging on the leftover food in this garbage pit really charming and in fact we did some studies on those animals they would get elevated cholesterol levels insulin levels triglycerides tooth decay all of that so they're feasting they're on a westernized diet they also get the first markers of metabolic syndrome so they're having to find time they're eating the leftover British desserts from this tourist Lodge and what evolved was a subset of the males and our troop going over in the morning to do the same at one point then there was an outbreak of tuberculosis which turned out to be due to contaminated meat at the tourist Lodge which was winding up in this garbage dump TB goes like wildfire and non-human primates it is not festering there for years while you can be thomas monde writing thousand word novels about it it goes through groups of primates like wildfire and it killed most of the animals in this troop and it killed all the animals from our troop that were going over to their the forage so ok so 50% of the males in this troop had just been killed critically it was not random which males died what sort of males would be doing this number one it had to be the most aggressive males on the troop because you're going over to the neighbors to fight your way in among twice as many males to try to get some of your guard bitch some of their garbage second baboons do most of their social grooming and gossiping and stuff first thing in the morning if these guys were picking up to run over and fight for garbage instead these were the least socially affiliated nails so suddenly what you have is a troop where the surviving males are the least aggressive most socially affiliated ones and this transformed the atmosphere of this troop they became far more social the average distance between them decreased the whole lot far less aggression you see males carrying infants around all over the place these good-guy males you see something extraordinary if you are a primatologist - baboon ologist this picture is more shocking than if this was like showing baboons flying or being photosynthetic or these are two male baboons socially grooming each other male baboons do not groom each other they try to rip each other's faces open in this troop the males groom each other and you have this completely different atmosphere and what qualifies this as a culture is as new males join the troop males growing up elsewhere and transferring it as adolescents it takes them about six months to take on this behavioral style it is this transmission of culture so we are not the only ones in ways that are previously thought to be unique to us so what's unique about human culture is just the sheer Magisterial complexity of it the fact that there's no other species on earth would ever dream of trying to do something like this we just do stuff culturally that just leaves the others in the dust not only things like this but not only are we able to kill not only are we able to kill in an organized premeditated way but uniquely we are able to kill out of ideology out of theology out of a thought out of an idea and that's a realm of culture like nothing else out there chimps may eradicate their neighbors but chimps will not do so because the neighbors have a different economic system or believe there's a different sort of God listening to their prayers and in that realm our cultural attributes are apps solutely unique ok so that now brings us into a realm where rather than all of this stuff about we have the same basic building blocks as every other species out there but we use it uniquely now looking at realms where there is simply no precedent nothing else out there does the sort of stuff that we do and giving two examples here first one is personified in the personification on this these are two quotes from this wonderful book by Ruth Gendler called the book of qualities which each page is this personification of the different emotion and they're wonderful they're great and what you have are these like very strange ways of talking about compassion or anxiety or anything and we understand what she's talking about we understand because we do things like have symbols and metaphors and parables and analogies and figures of speech and this is something that no other species has out there and we can suddenly understand all sorts of things we know that when the captain of the ship isn't asking for more than just hands when he's asking for the hands to be on deck we know that the hands represent something we understand that Kafka's metamorphosis was not a book about entomology we understand that a piece of cloth can represent deep deep societal values and it could be deeply offensive if somebody else is trying to burn that flag and we also understand that the right person putting the right collection of ink on a piece of paper and what that music stands for is Napoleon getting his ass kicked outside of Moscow and what we also understand is the phrase Napoleon getting kicked there outside of Moscow what that actually stands for was thousands and thousands of soldiers dying cold and hungry far from home we can do things that are astonishing and unique in the realm of metaphor but what's most interesting about it is how our brain processes it because we have in some ways a classic mammalian brain but we've got to handle something utterly unprecedented here the notion of metaphors and symbols so how does the brain do it a turn out in a very unexpected way okay first example you and in this case you could be virtually any mammal on earth you have just eaten a piece of food that is rotten it is spoiled it is fetid is God knows what it tastes absolutely disgusting and in the process of spitting it out there's a part of your brain that activates something called the insula cortex which has a lot to do with gustatory processing it tells you when you've just eaten something disgusting it also activates if you smell something disgusting it also activates uniquely in us if we think about something we find to be gustatory disgusting and suddenly you can have people activating their insula usually in brain scanning machines when they contemplate eating all sorts of stuff that in your particular culture counts as disgusting and this is all mediated by this part of the brain the insula which is just underneath the surface of one of the cortices there and is totally cool and it's connected with gustatory and that's how it works in mammals but then we've to contemplate being disgusted by something else we contemplate being disgusted by what humans are willing to do to each other and we wallow in it and we think about it and we come up with ideas like just hearing about this makes me sick to my stomach just knowing people can do things like that makes me want to puke makes me feel queasy I just have a dirty taste in my mouth says here and we'd have a metaphor with it and when we are contemplating moral disgust the same part of the brain activates you sit somebody down and get them to recount a moral failing of theirs and this part of the brain activate we not only do gustatory disgust we do moral disgust with the same part of the brain how could that be because when we evolve this capacity for moral disgust we didn't come up with a new brain region we just forced this insula to expand its portfolio and in some way the brain handled this very abstract concept in this totally literal way this is another version of eating disgusting spoiled food a certain concreteness there and how the brain handle next example somebody pokes your finger with a pin and it hurts and there's all sorts of parts of your brain that activate to tell you things like it was a pin rather than my fingers on fire there's other parts saying it was your finger rather than your toe it was telling you the intensity all sorts of like pain ohmmeter very concrete areas but then there's a part of the brain called the anterior cingulate which is more involved in the evaluative aspects what does it mean that I'm having this pain or sit and contemplate right now your finger being poked like that and think of and you will activate your entire anterior cingulate it will be this part of the brain that gets active and it responds not only to you being in pain but you imagining you're being in pain now what you do instead is ask the person to sit there and contemplate the finger of their beloved being poked and the same part of the brain activates on a very literal concrete level this part of the brain feel someone else's pain this is a part of the brain that is a core of empathy no wait a second this part of the brain tells you whether you were being eaten by piranhas on your feet or whether your shoes are too tight this part of the brain tells you whether it's good news or real bad news and all this value of stuff this part of the brain tells you when somebody else is feeling pain and when we came up with this metaphor of psychic pain we jammed it into the same old place where we had calluses in sending information up to our pain centers and very interestingly this part of the brain is hyperactive in people with major clinical depression people who are pathologically feeling the pains of everything and fascinatingly there's a neurotransmitter called substance P and substance P has a whole lot to do with anterior cingulate function and it's got something to do with pain pathways and everybody's known this for centuries and there are drugs which will block the action of substance P and they often have antidepressant action so here we have the part of your brain that does physical pain when we developed apps capacity to read about refugees on the other side of the planet and psychic pain gets processed in the same way more examples some brilliant recent work totally amazing study that was done recently here's what's done researchers got the volunteers to come in and in the first scenario they asked the person to tell them something about what their high school was like or some such thing as part of this psych study and afterward they say well we can't pay you for doing this but just as a token do you want this new fountain pen or do you want this package of hand wipes and those are the two geegaws and you know fifty-fifty now instead the subjects come in and they're asked to tell about a time where they had a grave moral failure a time where they did something awful afterward you say well we can't pay you but here's a choice you can have pen or the hat and a way disproportionate percentage asked for the hand wipes they're feeling dirty afterward they want to cleanse themselves and in remarkable elaboration what they now did in this study was everybody had to come in and tell about their sins and then afterward half the people were given an opportunity to go to the bathroom and wash up half were not they come back to the room and as things were staged some assistant comes into the room holding a whole stack of papers and trips and drops all of them if you've just washed your hands after talking about your sins you are less likely to get up and help this person pick this stuff up you have washed away your sins you have washed away this incentive to help someone else all this suggesting something about so pure has something to do with how we think about moral failures and what sort of impaired imperatives come out of that absolutely wild another example here in this study people were coming up to some psych department and their University and it was going to be some puzzle solving who knows what and unknown to them of course the actual experiment took place in the elevator get in the elevator and there's somebody waiting there ready to get in also is holding a whole a stack of papers and barely and holding on to a drink and the person says can you do me a favor can you just hold on to this because I got to pull these together and half the cases the person the subject was asked to hold a cup of warm hot coffee and half the cases it was a cup of iced coffee a hot cup or a cold cup then they go in and they do this very brief test and then afterward they're asked to assess what was the the tester like how did you feel about them hold the warm cup in your hand and you were more likely to assess this person as having had a warm personality we confuse the part of the brain that's telling us something about temperature here is somehow confusing no no no no that's a metaphor a warm personality this person is a total ice queen whatever and we'll freeze all of Narnia over and just because you were holding the cup of ice and our brain has a lot of trouble telling those apart another example here subjects were being put through a study and they were sitting in a chair like the comfy sofa on the left or this stark one on the right there and they're reading somebody's job resume and or some some scenario and they're asked to make assessments afterward sit in the chair on the right and you are more likely to judge the people you read about as being more serious having more gravity about them being more focused you're sitting there and where you're sitting is changing your perception and what we have they didn't ask in the study there but I think what we can almost certainly agree is that people who sat chairs on the right are more likely to perceive people as being hard asked and again metaphor is being mixed here's one of the most fascinating ones this was a recent study where people read a stretch of a page about American history and it was either written in a conventional way or a way that very much personified the United States as an organism it was in America's infancy that it first began to do what it was after the Civil War that America had a growth spurt wherever so either neutral or in a personified way and in the study before you read this you either read something neutral or you read something about the health risks of bacteria and what they showed was if you were thinking about the United States is being personified and you've just read about scary bacteria in question years afterward you were more hostile to immigration you are more likely to view immigrants as dangerous pathogens coming in this is an absolutely wild way in which this metaphor stuff is abstract as you can get is inadvertently being processed by the brain in the most concrete little ways and out comes all sorts of ways in which we are subtly being shaped by this phenomenon and a lot of researchers in the field of sort of neurobiology of moral behavior note that essentially what we do with our conscious decision making is justify the intuitions in the visceral responses we have already had and some of the time this is disastrous in Rwanda during the Hutu genocide against the Tutsis one of the figures of propaganda that the Hutu used was Tutsis in on the radio and the newspaper and anything were never referred to as Tutsis they were only referred to as cockroaches and you get people to a point we're hearing a reference to an entire other people he activates your insular cortex and you've got somebody who's just ready to jump in with the bloodshed but some of the time we can use that for a better outcome the political scientist Robert Axelrod has written a lot about this and written about the powers of symbols in terms of solving world problems and the power of symbolic concessions and what he does are studies that show things like he will talk to some really right-wing military as rayleigh leaders and some major radical Hamas leaders and he will get quotes out of them like the Hamas person saying if peace is going to go forward these Raley's have to at least once say we got screwed in 1948 it was not fair that our land was given away and the Israeli Hawks their sandy they're saying peace is going to go forward they've got to get that protocols of the Elders as I and crap out of their high school textbooks not we need to get a better deal with water rights or mineral rights or how armed the Palestinian police force can be or any of that but purely about symbolism and what he emphasizes is how powerful these symbols are not one to previously warring nations figure out how to share a river but when the king of one comes to the funeral of the leader of another and pays attention to the religious symbols of there's huge potential power there now the other domain that the last oh man I want to talk about where we have simply no precedent out there is in some ways even more abstract in this world of metaphor and it could be summarized here in this way which is this human ability in some settings to gain the strength and the will to do something from the irrefutable evidence that that something cannot be what do I mean by that let me make this a little bit less abstract and instead a quote from Kierkegaard and if you subscribe to this particular type of belief system this notion that what religiosity is often about is the ability to hold two contradictory facts in your head at the same time or two contradictory beliefs let me make it a little bit less abstract than that this is a nun named sister Helen Prejean and lots of people probably saw the movie back when dead man walking which was about her this is a nun who has spent her time ministering to the needs of men on him on death row in a maximum-security prison somewhere down in the south and inevitably she is in asked by all sorts of people when hearing she has spent her life solace saying these terrifying evil creatures who are as damaging as any humans can be saying how can you do this how can you have just spent your whole life doing this and she always has the same answer the less forgivable the fact the less forgivable what the person has done the more we must find the means to forgive them the less lovable the person is the more we must find the means to love them and as a strident atheist this strikes me as one of the most irrational nutty magnificent things we are capable of as a species the more something cannot be the more we have to make sure it is and to finish up here in lots of ways that is the realm where we can do our most uniquely human things built out of a danger of a certain human wisdom you sit there and you look at enough about what's going on in the world and you learn enough about it and you become wise about it and there is almost an inevitable conclusion that you have to reach which is none of us can make things better because we're too small and they're too big and they're too powerful and it's not going to matter anyway and none of us can make things change and what we have to deal with is the notion that the more clearly irrefutable and arguably it's the case that you cannot make a difference the more that must be the motivation to make a difference and have that as a moral imperative so at the end of the day we do smelly stuff just like hamsters and we do strange things with our stress hormones but at the end of the day this realm of being able to take abstractions and turn metaphors into things as powerful as the most visceral of sensory effects and to do all of this in a context of moral imperatives we are an entirely different planet from other species so let me stop at this point and I guess there is time for questions so I'm going to come around with a microphone and just as Greg mentioned earlier we're videotaping this for our audience at home so I'd like to have a show of hands and I'll come around with microphone that way everybody here and at home will be able to hear your questions I know somebody's got a question there we go or if you really want to shout out loud I'll then power phrase your question for everyone else with with those comments your final comments about what makes us unique what would you call that realm our ability to constantly confuse the real with a metaphorical parenthesis how our brains evolutionary challenge to have come up with something as novel as moral abstractions and have duct-tape it into some part of the brain that lizards use and the ability for us to flip back and forth and the ability to build entire worlds of good or bad acts out of that how is that different from the realms of philosophy or religion well depending on your tastes that's not different in the slightest or it's a completely different way of thinking about it it's obviously part of that when you have a nun saying things like my central credo is the less lovable someone is the more I must find the means to love them that is at the centerpiece of that style of thinking and as shown there it could be framed theologically and is shown in lots of other cases it need not be and one final question would be how can all of that be cultivated well that's I don't know come on he's a professor I don't know let's see I think for starters it suggests we should give tubercular meat to all of the aggressive males on this planet beyond that I'm not willing to be quoted any more questions hi my sister has a chronic disease and she works in an office with a man with a dog it's not her dog and so certain day she'll feel really awful she doesn't say anything she goes in she sits at her desk and the dog knows the dog comes up it's always there it's there every day but will come up on those days and she said it will sit under her desk and sometimes put its head on her foot lean against her it somehow feels that now what is that it looks like empathy is she's giving off something I don't understand what that is and what the difference is when you say when you show the picture of the dog it's seeing it looks a lot like the same thing okay I very carefully word of that conclusion they're saying there's hardly any other species out there that does that just in preparation for that one there's every now and then amazing examples of a lion who is killed a gazelle and finds the baby and imprints on it and YouTube is full of those things and they're totally but they are extremely rare events they're not rare events when they come to dogs for the very simple reason that we've spent twenty thousand years selectively breeding dogs to want to be humans where dogs can do stuff that other apes cannot do they could do gaze following they could do that with humans all dogs can do that chimps cannot because we have bred them to be fantastically attuned to our emotional states and that's fairly unprecedented what's the really cynical way of reinterpreting that is part of that dog empathy stuff when you're really upset is you're just pumping out all these fear pheromones that just smell miserable to that dog and it better make you feel better before you stink up the whole room it's probably not quite that cynical let's see more question next question from the left okay so my question is how many of the things that you've labeled as uniquely human could be reduced to the ability of us to you know for language in this process of abstraction to be able to know more decipher distinguish between aspects of reality so we could pinpoint in if you don't have the development of language you wouldn't be able to do that and second of all connected to that if su savage wimba is able to teach the bonobos design language and that sort of thing then to what degree would you say these things are uniquely human great um bringing in the whole issue of language it is absolutely central and what a lot of debates about in terms of sort of the cognitive sophistication of people as they grow up is built around is it possible to have certain states of mind before you have words for it moral development things of that sort and things like bonobos with American Sign Language when they start learning words that are fraught with moral content then I think we have a discussion as long as kanji is still getting a vocabulary mostly about simple nouns and verbs it's in a different domain they know what you would call in political scientist philosopher Lundrigan George Lake Hoff over at Berkeley has written tons about the symbolic power of words that's a realm that even the most successful of sign language chimp studies have not gotten anywhere near so I think language is incredibly important in that regard where would you put a policy in the realm of things with the humans versus animals disastrously human now not only are we capable of coming up with theologies ideologies not only are we capable in every culture of coming up with strictures on behavior that are framed ethically but we are come up with the means to personally evade it over and over and in lots of ways you know the really scary individuals for this planet are not the ones who say everybody says X is a criminal thing to do but I disagree what's really scary is the person who says everybody says X is a criminal thing and I agree but here's why I'm a special case right now and what humans are magnificent at is setting up sets of rules and then deciding why you are justified and being freed from them so it is one of the more corrosive spin-offs of sort of our systems of ethical behavior the notion that it doesn't count with me when I did it it means something different because it's a separate compartment take our next question from the right hi I'm curious about your take on the role of entertainment and with human beings I mean passive entertainment like movies and so on it seems to be something that would feed into exactly what you're saying about the empathy the separated empathy and interactions and I'm curious if there are any forms that you see of entertainment needs in different animals that might have different manifestations hmm great question a lot of there's this whole world with captive primates of trying to come up with environmental enrichment for them so that they are not quite as crazed in captivity as they would have been otherwise and a lot of people have discovered in their primate centers that various primates like to watch movies like to watch films often like what they like to watch is like National Geographic specials of like chimps killing little defenseless birds and stuff but what for them I don't know but I feel pretty certain it's impossible for a chimp to get into a state where it's really really upset about Bambi's mother or it's really really upset about what Lenny does to George at the end or was it George to Lenny and Of Mice and Men George the Lenny okay it's been a while we're like other species and raqqa to sit there and remember a story from their childhood or see a movie and burst into tears because of the empathy they're feeling for this bunch of pixels up there that's very unique more questions another one right here you've described a lot of the plasticity of our physiology is it possible that the words we use and our experiences and our associations like where we have come from and what we've seen actually determines both form and function of the brain great absolutely and that's encapsulated when we could talk about child abuse child abuse that's not physical child abuse that's purely verbal and a world in which kids can grow up traumatized childhood derive PTSD all of that from an abusive environment that was entirely a verbally abusive environment and PTSD induces very characteristic for changes in the brain so there we have the power of the word big time sometime that pen is more destructive than the sword and uh okay that metaphor went nowhere but yes absolutely what's the impact of now that we're learning all of this about the brain and you're saying but the interior court hard at the brain cingulate yeah and like companies like neuro focus with advertising in our brains being manipulated with this type of advertising what what's the effect of the brain in the future with this being overcharged well we've had no shortage of people who understand all those principles for a long long time and often they've made very good livings as charismatic religious leaders and governmental leaders and all that sort of thing it simply has gotten better and better as a science here's a word that should give all of us shivers a new word it used to be the people would be neuroscientists but now you could be a neuro economist and study human decision-making economic to see you can be a neuro linguistic an be a neuro philosopher you could be studying neuro marketing and there are people who now study why Pepsi people prefer Pepsi yet because of the certain types of advertising everybody believes they actually prefer coke until they were given by well let's give them a big grant and do some gene therapy and clone these people and centrifuge all the Pepsi drinkers and we'll understand and this is like people are soon going to be making livings understanding how you get marketing things to work on people and it's not going to be anything new we've done it forever it's just going to be more scientific more syllables in the name our next question from the far left in your studies about what animals do and working to relate that to humans there's a language that some animals use that maybe we're just beginning to understand dolphins elephants simians whatever the family would be so for making our judgments our analysis on their actions of their activities are we missing something or we have yet to learn more about their language about me maybe indicating something more that's going on great what I would say at this point is what's known about some spectacularly subtle communication systems and other species ranging from elephants communicating to each other by the vibration from their footsteps - you know electric fish that court other electric fish with electric songs things of that sort you know amid all that complexity there two things we do that no other species does we can communicate about absolutely abstract States we can talk about existentialism and chimps as far as we know don't or we can accept the same over-the-top emotional expressions that all sorts of other species have but we can do that talking about events that occurred 2,000 years ago or events occurring on the other side of the planet so we can have far more abstract language or we can use our most emotional you know anger works in the Syst like in every other species but in very abstract context that seems absolutely unique on the other hand everybody in the field 50 years ago would have had all sorts of things listed or unique to us that no longer are so maybe stay tuned sometimes they see things that sort of like an expression of for lack of a better term collective consciousness sort of when we see recently Tunisia Egypt and so on maybe even prior to the first that this current war on Iraq when prior to the war millions 10,000,000 people some people estimate around the world on the same day decided they were going to go out and do something so we see us operating you've been talking a lot about how we operate as individuals but is there any sort of conception about why periodically we see people move forward in that way not just preparing for the next Super Bowl but you know it's sort of not coming out of the blue we could look at those things but why that kind of phenomenon happens and it's not exactly a herd response but well I'm not sure if one could document that something like that actually occurs at an above chance level or if the chance occurrences of it just make a big impact and you disproportionately overvalue with that sort of thing but I think in a broader sense what that shows is if you want to understand how really complex systems work complex systems like a cell or an individual or society one thing that's absolutely clear is you can't understand it merely by breaking it down into its little component parts and understanding every little bitty component part and then just glue them all back together you are never going to understand a human by having sequenced all of their genes you're never going to understand like why a cloud doesn't rain during a drought by studying it under a microscope you can never figure out why a society or even a crowd of people rioting in a soccer stadium do what they do by looking at the actions of only a single individual instead we have all of these nonlinear non-additive the emergent properties and that is a very vibrant area of research complexity and emergence but what it should caution against is this extreme faith and reductionism and in my world what that translates into over and over is don't be overly impressed what genes have to do with the brain let's see any more questions yeah next question comes from the back of the room in the center so this is a little bit similar I was going to ask since there is some small portion of our genes that are unique from the other primates what do we know about what about our behavior is caused by our unique genes ok great question one of these like great urban myths if you were stuck in certain types of classes in college background is that we share like ninety eight point nine percent of our DNA with chimps and that was one of those like ridiculous soundbite things like yes Einstein failed math when he was a kid and there's like alligators in the sewer system in Manhattan and and we share 98% of our DNA with chimps and so they sequenced the human genome now about a decade ago and about five years ago the chimp genome was sequenced and it was possible to you know finally sit with these two mile-long printouts and see what was in common well and it turns out that we share like ninety eight point nine percent of our DNA with chimps it was absolutely true and was not based on ridiculous guesses in the 1980s when that soundbite first came out it was based on very solid science then some that was done at Berkeley then the sequence comes out and yes indeed there is that much overlap so of course the question then becomes where's the differences what are the Chinetti x of what distinguishes us from chimps so people have studied this right off the bat about half the differences in gene expression have to do with genes coding for olfactory receptors chimps have a better sense of smell than we do all sorts of genes they have for olfactory receptors we've been activated into what are called pseudo genes what that tells us is if like you wipe out half of a chimps sense of smell genetically you're halfway there to making a human okay this is not very impressive okay so what other genes have been identified some having to do with like the size of the pelvic arch we walk upright they don't as often some of it turns out have to do with body hair they're covered with fur and you know it's only some humans that have like you know the guys with hair on their shoulders that are all unsettling and you know versa genetics there's some genetics about immune recognition you know we keel over with certain diseases that chimps don't we can survive tuberculosis for years chimps don't they can handle simian aids in ways that we can't the human version so it's differences immune function some aspects of reproductive isolation so you're unlikely to get chimp human hybrids oh that accounts for almost all the genetic differences where are the genes that are relevant to the brain and it turns out there's hardly any and the few that have been identified make perfect sense because these are not genes that make it possible for us to have metaphor or genes that because going back to that first slide we've got the same nervous system basically the chimps - there's only one difference which is we've got like three times as many neurons and what the genetic differences are our genes having to do with the number of rounds of cell division during fetal brain development essentially what that says is take a chimp brain feedly and let it go two or three more rounds of division and you get a human brain instead and outcome symphonies and ideology and hopscotch and everything else there what that tells you is with enough quantity you invent quality its to sheer numbers and out of that emerges in this nonlinear non reductive way all the stuff that makes us human what those genes are about is producing a brain a human brain of a certain sort of level of qualities but it has nothing to do with what particular qualities there are so we have time for one more question okay or maybe we'll wrap it up there please join me in saying thank you to dr. suppose

Channel: worldinformant

Views: 870,384

Rating: 4.8313441 out of 5

Keywords: Robert, Sapolsky, religion, morality, ethics, science, Christ, Christian, Christianity, Muslim, Islam, Jew, Judaism, Buddhism, Buddhist, evolution, truth, justice, lawful, Arabic, interview, talk, news, conspiracy, speech, lecture, politics, government, commentary, discussion, middle east, economy, finance, hot topics, documentary, philosophy, spirituality

Id: YWZAL64E0DI

Length: 76min 9sec (4569 seconds)

Published: Wed Mar 02 2011

Reddit Comments

[u/Maestrotx]

He has an entire lecture set devoted to these kinds of topics labeled behavioral Bio:

https://www.youtube.com/watch?v=NNnIGh9g6fA&list=PL848F2368C90DDC3D

[u/nate263]

Really interesting.

Irrelevant observation: He looks like Kevin McDonald wearing a beard.

[u/Kosmozoan]

I still find this talk utterly fascinating.. even after having already watched it at least a dozen times before. :P

[u/Aschebescher]

Informative and entertaining. Perfect.