Prof. Robert Sapolsky - The Neuroscience Behind Behavior

thank you let me start off with a fantasy a fantasy I've had it involves well I've overpowered his Elite Guard I've fought my way into a secret bunker and I've managed to knock his Luger out of his hand his cyanide pill that he keeps to commit suicide rather than be captured he snarls at me he comes at me in a rage we wrestle I managed to pin him down put handcuffs on him and then say Adolf Hitler I arrest you for crimes against humanity this is where the the Medal of Honor version of this fantasy ends and the imagery begins to darken what would I do if I actually had Hitler in my hands and it's not hard to imagine once I allow myself sever his spine up I don't know can I is this on now it's on okay so not hard to imagine once I allow myself sever his spine at the neck take out his eyes with a blunt instrument puncture his eardrums cut out his tongue leave him alive on a respirator you know tube-fed not able to move not able to speak not able to hear to see just to feel and then inject him with something cancerous that will infest every single cell in his body now I've had this fantasy since I was a kid and I still do sometimes and when I really think about it my heart beats faster and it's all these plans for like the most evil wicked soul in history except there's a problem which is I don't believe in Souls and I don't believe in evil and I think wicked is only appropriate for a musical but on the other hand there's there's all sorts of people I wouldn't mind seeing killed but I'm against the death camp penalty but I watch all sorts of violent schlocky movies but I'm for very strict gun control but then there was this one time I was in a laser tag place and I had such a good time hiding in a corner shoe people over and over until this like pimply kid zapped me like a million times in a row and then snickered at me and made me feel very unmanly so essentially what is obvious here is um your typical human when it comes to this extremely confusing topic of violence now obviously as a species we have problems with violence we have used shower heads to deliver poison gas letters with anthrax passenger planes as weapons mass rape as a military strategy we are a miserably violent species but there's a complication with that which is we don't hate violence we hate the wrong kind of violence because when it's the right kind we leap in we paid good money to watch it we hand out medals we vote for we mate with the people who are masters at it when it's the right kind of violence we love it and there's an additional complication because amid us being this miserably violent species were also a extraordinarily compassionate and altruistic one so how do you begin to make sense of us the biology of us at our best moments and our worst moments and all those ambiguous ones in between now one thing that is clear is it as utterly boring to understand the biology of the motoric aspects of your behavior your brain tells your spine tells your muscles to do something and hooray you've behaved what's incredibly complicated is understanding the meaning of the behavior because in one setting firing a gun is some appalling act in another it's an act of like heroic self-sacrifice in one setting putting your hand on top of someone else's is deeply compassionate and another it's a deep betrayal the challenge for us is to understand the biology of the context of our behaviors and that one is really really challenging and one thing that's clear is you are never gonna really understand what's going on if you get it into your head that you're going to be able to explain everything with this is the part of the brain or the gene the hormone or the childhood experience or the evolutionary mechanism that explains everything because it doesn't work that way instead any behavior that occurs is the outcome of the biology that occurred a second before an hour before and all the way to a million years before okay so to give you some sense of this okay so you're in some situation there's a crisis there is a crisis there's rioting violence going on people running around and there's a stranger running at you in an agitated state and you can't quite be sure what their facial expression is maybe they're angry maybe they're frightened maybe it's threatening they've got something in their hand that seems like a handgun and you're standing there and you have a gun and they come running at you and you shoot and then it turns out that what they had in their hand was a cell phone instead and thus we asked a biological question why did that behavior occur in you and what's really the central point is that's a whole hierarchy of questions why did that behavior occur what went on one second before in your brain that brought about that behavior now to begin to understand that the part of the brain that's at the top of the list of usual suspects is a brain region called the amygdala you want to think about aggression and think about the brain you think about the amygdala if you stimulate the amygdala and an experimental lab animal you get an outburst of aggression humans who have rare types of seizures that start there rare types of tumors based on the amygdala uncontrollable violence if you damage the amygdala you blunt the ability of an organism to be aggressive okay so the amygdala is about violence except if you sit down your typical and MacDowell adjust and ask them what the amygdala is about that's not the first word that's going to come out of their mouths because for most people studying it with the amygdala is about is fear fear and anxiety and learning to be afraid in other words we've just learned something very interesting which is you cannot understand the first thing about the neurobiology of violence without understanding the neurobiology of fear and world in which no amygdaloid neuron need be afraid there'd be an awful lot more of us sleeping between lions and lamps now the thing to begin to make sense of what the amygdala is what parts of the brain does a talk to and which regions talks to it in turn now next region that is incredibly interesting is called the insular cortex now the insular cortex is in fact incredibly boring if you're a lab rat or any other mammal on earth because it does something very straightforward you bite into a piece of food and it's spoiled and rotten and fetid and rancid and all of that and what happens is as a result your insular cortex activates and it triggers all sorts of reflexes your stomach lurches you gag you spit it out you you have a gag reflex very useful it keeps mammals from eating poisonous foods and you do the same thing with human get a nice human volunteer who inexplicably is convinced to bite into this food that's rancid and disgusting and they're in a brain scanner and they're insular cortex activates we do something fancier all we have to do is think about eating something disgusting and the insular cortex activates but then something much more subtle sit down someone in your brain scanner and have them tell you about a time they did something miserable and rotten to some other human or tell them about some other occurrence of some human doing something miserable and rotten to somebody else and the insular cortex will activate and every other mammal on earth it does gustatory disgust but in us it also does moral disgust and what that tells you is why it is if something is sufficiently morally appalling we feel sick to our stomachs it leaves a bad taste in our mouths we feel soiled by it we feel nauseous we feel because our brain invented this symbolic thing of moral mores and standards some 40 50 thousand years ago and didn't invent a new part of the brain at the time and instead there was presumably some sort of big committee meeting and they said okay I'll discuss there's there's that insulator that does like food disgust there's okay it's in their portfolio now give me some duct tape the insular cortex is now gonna do moral disgust as well and it has trouble telling the difference and no surprise the main part of the brain the insular cortex talks to you in the human brain is the amygdala because once it decides this thing is disgusting you're a couple of steps away from it being scary it being menacing it being something you need to act against now in lots of ways it's very cool the insular cortex does this because suppose you see some moral ill that needs to be cured and some of the time that can take an enormous self-sacrifice that could take the ultimate sacrifice in some cases and if moral outrage was this abstraction this just the sort of distanced sort of state it would be hard to pick up a head of steam to really be able to act against it the viscera your stomach churning that's where the force comes to to make a moral imperative imperative that's great but then there's a downside because the insular cortex is not very good at remembering it's only a metaphor that you were feeling disgusted and suddenly you have that whole problem of the world of people who are disgusted by somebody's behavior which in somebody else's eyes is just a normal loving lifestyle disgust is a moving target and time and space and there's the danger to decide that being morally disgusted by something is a pretty good litmus test for deciding between right and wrong and we sure know all the ways in which that can get you into trouble and probably most of all every ideologue in history has had a brilliant intuitive feeling for how the insular cortex works which is if you can get your minion to the point that when you talk about them them living in the next Valley them who think differently than you who pray differently who love differently if you can get your followers to the point that when you invoke them insular cortex activate because there's something just disgusting about them you're 90% of the way towards pulling off your successful genocide key to every good sort of genocidal movement is taking them and turning them into being such infestations and malignancies and whatever's that they hardly even count as human anymore okay so we've got this sort of axis between the insular cortex and the amygdala meanwhile we've got the most interesting part of the brain far and away a region called the frontal cortex frontal cortex I've just wasted the last 35 years of my life studying a part of the brain called the hippocampus which is kind of interesting and like it's done well by me and I've been you know that's right but I wish I'd been studying the front the frontal cortex it's the most recently evolved part of the human brain we've got more of it than any other species on earth and what does it do the frontal cortex makes you do the harder thing when it's the right thing to do and impulse control and gratification postponement and long-term planning and emotional regulation and what does the frontal cortex spend an awful lot of time doing sending inhibitory projections down to the amygdala hoping to race there in time to say wait a second are you sure that's really a handgun wait a second I wouldn't do that if I were you I know this seems like a brilliant idea right now but believe me you were going to regret it the frontal cortex very often racing to try to control the amygdala now there's this picture of the frontal cortex all it does is occasionally go slumming down the amygdala and preach to it about like temperance or whatever but in fact there's bidirectionality the amygdala has plenty means to talk to the frontal cortex what's that about every time we're in a moment of extreme aroused state and we make a decision that is hideously stupid and disastrous that seems brilliant at the time because that's the frontal cortex being marinated in what's down below in other words there's this very tempting view the frontal cortex most recently evolved it's this gleaming shining computer like part of our brain it's sitting there just marinating and all the emotive going on underneath it's bi-directional communication now finally in terms of making sense of this frontal cortex the whole notion of doing the harder thing when it's the right thing to do is a value free judgement what do I mean by this sometimes you have to have an incredibly strong aerobic least ugly frontal cortex to resist the temptation to lie and that's at the centerpiece of some of the most important sorta crossroads in our lives however once you decide that you are going to lie you need your frontal cortex to do it effectively because it's your frontal cortex that says ok remember don't make eye contact don't use this right cheek muscle at that point because you're going to be tempted to twitch keep your voice under control it could take an enormous amount of discipline to go and effectively like make the world whole in a better place but it can also take an awful lot of discipline and staying up late and studying to be effective at ethnically cleansing villages the frontal cortex is value-free in that sense ok so we've gotten a sense of a couple of the brain regions here that are pertinent so that's what's going on in one second before but no brain is an island and what we now have to do is take a step back so what was going on in the seconds two minutes before in the sensory environment which triggered that amygdala to do this where that frontal cortex to do that what are the stimuli that are coming in there now obviously in the scenario we have the sight the sounds of this rioting perfectly pertinent to making sense there but then there's a whole world of sensory stuff going on that's subliminal that you hardly even know is there and if you did not in a million thing years would you think it's pertinent for example when you have to make split-second decisions you are more likely to mistake a cellphone for a handgun if the person holding it is male is large is of another race your brain processes that in 50 milliseconds that is one twentieth of a second your brain is already distinguishing the incorrectly why is that that turned out to have a really interesting piece of the wiring of the amygdala okay so suppose you look at somebody and there's something in their hand that's either a cell phone or handgun so what happens the information goes from your eye to this Waystation of the brain and eventually gets to your visual cortex and a first layer there sits and spend some time and figures out what the pixels are and then the second layer turns the pixels into lions and the next layer turns the lines and to curves and eventually you got a four-dimensional sort of picture of whatever and then eventually some neurons in your cortex says oh my I believe that's a handgun and let's go wake up the amygdala and let it know about it that's the simple part it turns out there's a shortcut the very first way station where sensory information comes in shortcuts directly to the amygdala in other words the amygdala knows there's a handgun while your visual cortex is still fussing around with the pixels there that's very good that's very helpful that it gets that information quickly but it turns out you need all those computational layers in your visual cortex to tell what's there accurately in other words the amygdala gets sensory information that's very emotionally aroused before your conscious cortex does and the accuracy is not great and thus if you're tired if you're hungry if you're in pain if there's a bad smell around if any of those things are happening you are biasing the amygdala towards mistaking a neutral facial expression for a threatening one mistaking a cellphone for a handgun all of that occurring in the seconds before okay but now we need to take a step further back what about hours two days before how was that affecting how sensitive you are to sensory information which then talk to your amygdala and sturla cortex all of that what we've moved into here is the realm of hormones in that regard amid a gazillion hormones that are pertinent two of them stand out above all others first one the inevitable usual suspect hormone that's got to be pulled in at this point which is testosterone okay what is testosterone about testosterone is the reason why males every culture and every species on earth or such pains in the asses testosterone causes a gret testosterone does not cause aggression what testosterone does is bias you towards interpreting ambiguous social information as being threatening as being provocative take somebody and pump him up with testosterone and they decide that neutral facial expressions seen for 20th of a second are threatening take testosterone and that brief exposure to that neutral facial expression and suddenly the amygdala is all agitated and frothing at the mouth what testosterone does is it exaggerated Spri existing tendencies what it does is sensitize you to whatever social learning you've received about what kind of aggression is just fine of what kind isn't now the single most interesting thing about testosterone is even that's not what it really does testosterone doesn't make organisms more aggressive what testosterone does is it makes more organ organisms more likely to do whatever behavior is needed to hold on to high status when it's being challenged ok if you're a baboon what that means is aggression because if somebody's threatening you it's going to be all about aggression that's the entire world with a baboon remarkably and humans put somebody in an economic game where you get high status by being generous and the offers you make and testosterone makes people more generous the problem isn't that testosterone causes aggression the problem is that we reward aggression with status so readily and what that also tells you is if you took a gazillion Buddhist monks and shot them up with testosterone they'd be running around and like frenzied gangs doing random acts of kindness to see who could do the most of them most quickly the problem here is not the hormone it's the values and the rewards that we place on aggression okay meanwhile in that span of hours today's the other hormone that has just as undeserved of a reputation but in the opposite direction is this hormone oxytocin now oxytocin is officially to sort of use endocrine jargon it's officially the grooviest hormone under because oxytocin's by now-famous it causes bonding between mothers and infants and pair bonding between monogamous couples and it makes you more expressive and emotionally sensitive and more cooperative and more charitable and more trusting and there's a whole new horrifying field of neuroscience called neuro marketing where if you spritz oxytocin up people's noses they're more likely to believe all sorts of gibberish and nonsense of people trying to sell you stuff whether it's their political viewpoint or some geek awe I mean if they could spray oxytocin through the vents and like Costco all over this country what that would do to the economy of like sort of the nonsense that people would buy okay so oxytocin promotes pro-social behavior until you look more closely and when recent work shows is that's exactly what oxytocin does it makes you much more cooperative and generous and charitable all of that with people who you categorize as being just like you it makes you pour more pro-social towards in-group members and when it comes to out group members it makes people more xenophobic and more preemptively aggressive and less cooperative and the greatest study showing this was a couple years ago and this was a group in the Netherlands where they got their usual sort of lab rats which was college volunteers from some like university there and what they did was they gave everyone the standard classic problem in philosophy the runaway trolley problem is that okay to sacrifice one person push him in front of a runaway trolley to save five and there's a whole world of research done on that so they sort of established the baseline levels at which people would be willing to push somebody just save five now what they did was they gave the person they were pushing on to the track a name a third of the time the person would get a name that apparently is just like your stereotypical Dutch named Dirk or Peter or something like that a third of the time or the remainder of the time either of the two groups that people in Holland tend to have a lot of out-group hostility towards Germans oh that's right world war two or people with Muslim names so now you've got the snare do you push Dirk in front of the trolley do you push Auto in front of the trolley do you push Mahmud in front of the trolley and what they show is give people oxytocin and there are less likely to sacrifice Dirk whereas they can't leap fast enough to push Wolfgang and a mood there under the tracks oxytocin doesn't make us nicer and makes us nicer to people we're already predisposed towards being nice to it exaggerated s' us them contrasts okay so now stepping back further how about weeks two months before and this is now entered the realm of neural plasticity the fact that the brain can change in response to experience and for example if you've now just spent these last few months mired in trauma and stress your amygdala will have grown larger it will form new connections the circuits there will be more excitable and your frontal cortex will have become more sluggish and atrophied in other words at that critical moment the amygdala isn't a more hysterical hyper reactive State and the frontal cortex has as much of that much less capacity to get there in time and say wait a second are you sure before you pull the trigger there you can see that changing okay but stepping back even further now going back years decades how about adolescence what going on in adolescence is relevant now to this one second of whether or not you're going to pull that trigger and the central fact of the adolescent brain is that all of the brain is going full blast fully mature except for the frontal cortex which is still half-baked at that point amazingly the frontal cortex it's the last part of the brain to fully mature it is not fully online until you are about 25 years old which explains an enormous amount of freshman year in college it's the last part of the brain to fully mature what does that mean it means adolescence and early adulthood is the time of life where environment and experience are sculpting your frontal cortex into the adult version you are gonna have in that one critical moment they're deciding what the outcome is what that also tells you is if this is the last part of the brain to fully mature it's the part of the brain least shaped by genes and most shaped by environment okay but now stepping even further back how about back to your childhood back to your fetal life obviously pertinent because that's when your brain was being constructed but what people also have learned in recent years is experience experience during that period causes changers jargon in the field epigenetic changes causes permanent changes in some genes and parts of your body are turned on forever after other genes return to offer lifetime consequences ah in other words childhood matters this is one of the molecular mechanisms by which childhood matters and is a very pertinent example of that if you have spent your feet'll nine months being just bathed at high levels of stress hormones from Mom's circulation because she is extremely stressed as an adult thanks to epigenetic changes during your fetal life your amygdala is going to be hyper reactive and you're gonna secrete higher levels of stress hormones which makes the amygdala even more reactive and makes the frontal cortex sluggish so events back in fetal life but going back even further okay back to when all you were was a fertilized egg and a bunch of genes now obviously genes have tons to do with everything here but here is the great temptation to decide that genes are determining anything genes determine essentially nothing when it comes to behavior because genes work differently in different environments and the most pertinent example here is a gene called mono amine monoamine oxidase a mao-a do not even dream of writing that down but Mao a comes in a bunch of different flavors a bunch of different variants and if you have one particular variant you are very significantly more likely as an adult to commit antisocial violence if and only if you were abused as a child if you weren't having that gene variant has zero increase in your risk factor it's not your genes it's the way the genes and react with your environment and thus starting with fetal life the interactions between genes and environment are going to shape enormous li what state your brain is in in that one critical second now of do you pull the trigger or not okay but you got to go even further back past you as a single organism how about your ancestors what were they up to for example if your ancestors were pastoralists people wandering deserts and grasslands with their herds of camels or cows or goats the odds are they would have invented what is called a culture of honor high levels of retributive violence clan vendetta's warrior classes that's the whole world of if they come and take your camel and you do nothing about it the next day they'll come and take your entire turd herd and your wives and daughters to clan violence going on for centuries and what is clear is if your ancestors were of a culture of Honor centuries later that's still influencing the values with which you were being raised including within moments of birth how often mothers are holding their children so centuries worth of that okay but steps further back where the cultural difference is coming from from ecosystems one example of that you look at people living in deserts and historically they're likely to come up with monotheistic religions look at people and rainforests and they come up with polytheistic religions look at people in East Asia who live in flat plain areas and they grow rice which requires collectivist farming and you get a very collectivist mindset about cooperation get people in the hill countries there and they grow wheat which is done in individual families and you get the same individualistic mindset that you get in people living in Manhattan all of it ecologically shaped but then we gotta go even further back because if you're talking about genes anywhere along the way you're talking about the evolution of the genes and what you wind up seeing is evolution has sculpted different primate species into having different characteristic levels of aggression some primate species have virtually none at another extreme high levels and there's all sorts of biological traits that go along with the two extremes and what about us we're somewhere right in the middle between the two extremes okay so in other words if you want to understand why did this behavior occur you've got to take into account everything from one second before to a million years before okay so what do you conclude from that ooh it's complicated okay that's very useful but how about ooh it's complicated and you better be real careful and real cautious before you decide you understand the causes of a behavior especially if it's behavior that you hunt judge harshly because things can really go wrong with the wrong attributions and we have a very dark stained history of that occurring precisely for those reasons now for me when I look at all of this information the single thing that I find to be most important has to do with change every single biological fact that I've given long the way here is subject to change over time ecosystems change thousands of years ago the Sahara was a lush grassland filled with hippos and giraffe cultures change in the 17th century the scariest people in all of Europe were the Swedes who spent that whole century rampaging all over Europe and the Swedes have not had a ward in 203 years they changed and most of all brains change circuits form neurons weaken patterns grow parts of brains expand per and as a result people change and they could change extraordinarily some examples of it change in people that can occur over the course of decades a man who moves me enormous Lee a man by the name of John Newton he was a British theologian he was a leading abolitionist played a central role in the role in the banning of slavery at the beginning of the 1800s in England John Newton spent the early decades of his adult life as the captain of a slave ship and after he retired from that he spent decades as a local parson still investing in the sleigh if trade and growing rich from it until one day something changed in him something changed something changed and he celebrated it and the thing that he's most known for historically in him that he wrote Amazing Grace another example an am a man named Zen Jia Bay who on the morning of December 6 1941 was the lead pilot in one of the Bombardier squadrons that took off from an Air Force Base in Japan and attacked Pearl Harbor he was one of their star pilots he led one of the divisions there and 50 years later to the day as an old man he came towards a ceremony at Pearl Harbor commemorating it as an old man came forward in broken English and apologized to some of the elderly survivors on the ground there and spent the rest of his life close with some of them think about that transformation if one of those men that he befriended had become a captive is's during World War two he might have happily walked him to death in the Bataan Death March and if he had been a captive of one of those American men who had killed him he might very well have taken his skull as a souvenir which was a standard thing done in the Pacific during World War two with dead Japanese and instead fifty years later he's writing a letter to that man's grandchildren consoling them when grandpa has died change can occur even faster over the course of hours and the example that just mesmerizes me was the first winter of world war one the Christmas truce of 1914 powers-that-be had worked out a truce that was supposed to go for a couple of hours and the idea was along the trenches of France people would be able to come out and retrieve bodies from no-man's land and go and bury them so German and British troops came out and retrieved bodies and soon they helped each other carry the bodies and soon they helped each other dig graves in the frozen ground and then they prayed together over the dead and then they shared Christmas dinner and then they exchanged gifts and by the next day they were playing soccer together up and down no-man's land and exchanging addresses to get together and see each other after the was over and those truces went on for two to three days until the officers had to arrive and threatened to shoot these men unless they went back to killing each other and all it took was a couple of hours to completely reorganize these people's sense of who counts as an assassin to them and us being all of us in these trenches on both sides dying for no damn reason and them being the faceless powers behind the lines using us as just pawns and sometimes change can occur in the course of seconds two minutes now historically probably the single biggest horror in terms of American consciousness from the Vietnam War was the malai massacre a brigade of American soldiers went into an undefended village full of civilians and killed between 350 and 500 of them gang-raped women and girls beforehand mutilated bodies utterly nightmarish because it occurred because the US government covered it up for as long as possible because ultimately they just did slapping of a few wrists and because it was not a singular incident it was one of the nightmares of Vietnam War the Nilay massacre was stopped by one man a man named Hugh Thompson Thompson was piloting a helicopter gunship flying over the village and was seeing American soldiers firing activity oh they're under attack by Viet Cong landed there got out and was viewing the incomprehensible sight of American soldiers shooting elderly women digging out babies from underneath the bodies of their mothers and shooting them and figured out what was happening and Hugh Thompson got into his helicopter and in the course of minutes undid every bit of training he had had as to who is an us and who is of them he took his helicopter landed it between the last group is surviving villagers there and American soldiers coming at them with their weapons landed his helicopter and turned his machine guns on the American soldiers and said if you do not stop I will mow you all down and what is most important to me is none of these guys had fancier neurons than any of us same neurotransmitters same genes same enzymes no fancier than any of us what I think we're left with here at the end is a version of life that inevitable exasperate in cliche those who don't study history are destined to be able to repeat it what we have here I think is the opposite those who don't study the history of extraordinary human change and those who don't study the science of how we more readily go from the worst of our behaviors to the best ones are destined not to be able to repeat unbelievable magnificent moments like these so let me stop at this point and if there's any questions ok ok someone coming into microphone what's happening in the future of neurology that would give us hope for understanding the brain better having better outcomes ok let me just take this book here that I happen to see sitting here let's see I haven't read this yet but I skimmed it for the picture okay here's one figure I don't know if you could particularly see it on the left page it's a whole bunch of graphs and the whole point is it's a bunch of graphs that are doing like this for a long stretch and then suddenly they do that what those are are the number of publications by year in various topics I talked about for example at the top one two thousand two two thousand six two thousand ten two thousand the number of papers in the medical literature concerning the topic of oxytocin and trust everything about it has been learned in the last ten years here we have brain and aggression 1985 there were essentially zero papers published by the last decade more than 2000 every single one of these the vast majority of what we've learned has come in the last whatever short amount of time we only a couple of hundred years into understanding that epilepsy is a neurological disease and not demonic possession we're only about 50 years into understanding certain types of learning disabilities are due to micro malformations in the cortex and people with dyslexia and it's not laziness or lack of motivation the vast majority these factoids are 1020 years old and all that's gonna happen is we're gonna learn more and more of that stuff and what we're going to learn more and more is to recognize the extent to which we are biological organisms and our behaviors have to be evaluated in that realm for my money what that eventually does is make words like soul or evil utterly absurd and mean evil but it also makes words like punishment or justice very questionable as well I think it will require an enormous reshaping of how we think we deal with the most damaging of human behaviors because none of it can be thought of outside the context of biology well you did mention Rashard Buddhists but I have a sense that in my life at least have been exposed to a number of techniques for creating people that are like that for example Buddhists people who practice be possible people who undergo psychoanalysis or series activities that come from that group group relations work or group therapy there are tools that have that effect what I'm considered what I'm wondering about is why those things are not customary not they're not they're not institutions we don't have for example UDC so doesn't have a program to to cause people in the community to meet together there are packages that can do that but it doesn't happen and what's why is that well the easy punchline is because they're usually really hard to do one example that comes to mind okay so you've got conflicting groups that for decades for millennia have had us of them dichotomies in their head have been at each other's throats and for decades this notion has been floating around among psychologists something called contact theory which is if you bring people from hostile opposing groups together and they get to know each other they're gonna recognize hey we're all the same there and it's going to be wondrous and we're all going to be like singing Kumbaya and this is going to be terrific and that's been the motivation for all sorts of these programs taking Palestinian and Israeli teenagers and putting them in summer camps Irish kids Northern Irish Catholics and Protestants all of those endless versions of these and what that extremely large literature is shown by now is when it works right it absolutely reduces intergroup conflict can cause lasting changes in perception where people could generalize it beyond not just ooh now I know there's one Israeli I know who's actually good guy good could generalize can generalize even to other groups of them nonetheless most of the ways in which you set those settings up wind up making things worse because it's very narrow domains where these things I you've got to get everybody on equal grounds they have to have shared goals they have to have an absence of any symbols that reviewed is provocative and if you have it anything other than that you're gonna make things worse in other words none of these things are done easily but they're all workable that's a question he talked about the critical time of adolescents in the development of what we consider right and wrong and how do you address the generation of coming up that have been just inundated with violence within their media within their video games that they play in the defense of it sort of desensitizes them to acts of violence okay I as a parent and absolutely horrified by all that stuff and can easily go off on to a rant about all the bad consequences of it and I could find papers now that are looking at video violence and the desensitizing effects and and if I really feel like going down too like the second sub-basement and sort of the Stanford Medical Library and pull out journals from the 60s and there are the exact same papers there where all you need to do is replace the word television with video games television radio violence in the 1930s with like detective stories of who knows what every single generation is wrestled with us and when you go through the mass of literature looking at each new incarnation what you see is on the average all of those forms of violence cause a short term burst in violent behavior and individuals it dis inhibits it but in terms of whether it has long-term consequences and every one of those realms you get a very familiar punch line violent media makes aggressive individuals more aggressive and has no effects on anybody else because what it does is legitimizes and habituates and dis inhibits individuals who already have the predisposition towards just like testosterone that does not a good invent aggression it exacerbates pre-existing social tendencies towards it so in that regard the good news is it's no worse than like you know cop dramas sitting by the like fireside chats in the 1930s with the radio there the bad effects are nonetheless those who are vulnerable this is a more vivid more visceral more real form of imitating an awful reality than anything that's been invented before but the general effects turn out not to be terribly malevolent yeah oh hi well in your calculate how complicated it is to explain a behavior and you know the example you use well you could put that the person with the you know trying to figure it up the thing in the hand was a gun could be a you know obviously a police officer I mean it could be anybody in that situation and a lot of neuroscience has been brought into the courtroom I mean for that American brought into the classroom to to try to you know use a brain scan to explain something but I wondered and in particular in the courtroom how do you say where do you see that hit you know where people are bringing brain scans and says well the brain you know my brain made me do it rather than me or whatever I'm a great question insanely contentious field there's some very scary smart people I've had to argue with the times sort of taking the viewpoints that Neurosciences know we're ready for prime time yet for its appearance in courts just to give you a sense of where neuroscience plays a role in the American criminal justice system the gold standard for deciding that somebody who's committed a crime is so organically impaired that they can't be held responsible for their acts is if they basically cannot tell the difference between right and wrong which is usually a way of describing extreme sort of schizophrenic psychosis this is something called the McNaughton rule and was based on an individual almost certainly a paranoid schizophrenic who delusionally hearing voices attempted to assassinate the Prime Minister of England in 1840 that's a legal standard in the United States based on neuroscience from 1840 I mean I don't think horses you to even evolved brains at that point and that's the basis by which the legal system works the area that the legal system in the United States has incorporated exactly zero neuroscience is the realm of volitional impairment the realm of people who do know the difference between right and wrong who nonetheless cannot regulate their behavior where is that that's when you see damage to the frontal cortex and you get somebody there who can tell you absolutely which is the appropriate thing to switch for you can reach with 5mm s but you only get one as a reward or if you reach for 1mm you get five as a reward and they will say yeah I know how it works I need to reach for the one because then I get much more eminent and they go for the wrong one at the last instant when you have frontal damage you pass the McNaughton test you know the difference between right and wrong and nonetheless you cannot regulate their behavior there is no state in this country that regularly accepts volitional impairment defenses in an Criminal Court - horrifying statistics that are pertinent to that 25% of the men on death row in this country have a history of concussive head trauma to their frontal cortex other horrifying factoid by the time you are five years old the Oh economic status of your parents is a predictor of the levels of stress hormones in your bloodstream what do you know what goes in the direction of the poorer you are the more stress hormones and the more stress hormones the less frontal maturation by kindergarten your SES by kindergarten if you were foolish enough to have picked the wrong family to have been born into that is already going to impact the metabolism of your frontal cortex the thickness of it the number of connections being made there by age five you were already three steps behind in terms of from for regulation behavior because of SES differences in this country so in that realm the consequences I think are enormous and hugely underappreciated I'll try not to kill eight my question it has to do with the role of testosterone and then maybe they and maybe some consequences of it and what we can do about it so if if if it's not related to aggression but it's related to the an increased reward for status where does it act in the brain does it act in the brain and then given that so many kids may suffer especially these days with impacts in the brain that might affect their aggression as adults they have some that you given the violence in the world today would a pharmaceutical route be at all suggested before they get before any kind of cognitive training because it's a you know the drug industry will latch on to anything but I feel like that's something they haven't done I don't I don't think that's a long-term solution either great ok which part of the brain has the most receptors for testosterone the most sensitivity to it makes total sense the amygdala the amygdala is ground zero for sensitivity to testosterone does testosterone cause amygdala neurons to fire to in effect invent aggressive outputs not at all if and only if the neurons are already firing testosterone makes them fire faster testosterone does not turn on the martial music it ups the volume if it's already been turned on now in terms of okay so let's make the world a much better place here how about we get rid of all those mails okay maybe not that okay so at least let's castrate and well now that's not very well what about okay how about if we pharmacologically block some the effects of testosterone and what you see there besides it being mighty scary is a track record of not working very well in a number of places on earth the two places where it is most been explored is big surprise India and the state of Texas there have been state ordered chemical castration z' drugs which are given which block testosterone receptors which is in effect the equivalent of removing testosterone from the scene usually for intractable violent sexual offenders and what the legislate and what the literature shows is essentially it has no effect whatsoever because such aggression has very little to do with aggression that has very little to do with sexuality it has a whole lot to do with domination and fear and issues like that pertinent to that you take any male on earth of any known species and take out his testes and that almost certainly was the first experiment ever done in endocrinology about 10,000 years ago when like some bull chased some people around the backyard one time too many and they wrestled him down and got rid of the testes and suddenly he was a much more tractable male if you castrate a male of any species out there on the average levels of aggression go down they never go down to zero though and the critical thing is the more experienced that male had being aggressive prior to castration the more it's going to stay there afterward in other words the more experience you have with aggression the less it is dependent on hormones and the more it is a function of social learning so that unfortunately or otherwise is not much of a panacea there see final question final question hopefully a more optimistic more optimistic note so you mentioned the chronicity of the amygdala enlarging with chronic stress and there are things perhaps that we could do for people who have experienced chronic stress I'm thinking of people who have been on multiple tours overseas and have done to be exposed to horrendous things and do horrendous things so now that we're having people do that more often they're coming back and then ending their lives and I'm wondering I know people have tried meditation maybe yoga might work but are there ways that even with the example of testosterone and really the amygdala that the role of the amygdala and in invoking aggression are there ways that we can reduce the size of the aggression or the size of the amygdala yep the realm where that's been most studied is with PTSD combat trauma PTSD and sexual violence PTSD where you see with the PTSD there you get expansion of the amygdala it becomes hyper reactive it is over generalized into it being a terrifying world out there my lab for a while was doing some gene therapy work on trying to protect the amygdala from stress hormones in ways that like as a circus trick was kind of useful but it's not going to help a mammal anytime in the next century or so my sense from sort of the clinicians I've spent my time around is that PTSD is not really anything that's ever cured people learn how to manage it how to contain it there is no clear biological cure for it but something fascinating and horrifying has emerged in the literature in recent years what is PTSD about it's obvious to anyone have its fear its terror it's the trauma of people trying to kill you of watching your buddies killed around you left and right it's it is anchored in fear and the fear of the violence that may harm you and those who you love but the whole field has had to accommodate an extraordinary finding in recent years which is drone operators get PTSD they get PTSD at the same rate as do warriors out in the battlefield drone operators sitting there living in some suburb of Edwards Air Force Base somewhere out there who get up in the morning and remember to drop off the clothing at the cleaners and get into traffic jams and barely make it to work on time and then sit in a simulator there for eight hours blowing up people on the other side of the planet and then rush out at the end of the day to watch their little girl in a ballet concert and then go back to killing on the other side of the globe the next day these people have PTSD at the same rate as do the actual soldiers and that is completely challenged the notion of what it's about it's not the fact that there is nothing more abnormal and terrifying to us than the notion of somebody violently killing us that rather it's the utterly bizarre and abnormal notion of us killing someone else and that's causing an enormous rethinking as to what PTSD is about and lurking in there is a little bit of optimism a man named David Grossman who was a colonel in the US military wrote a very influential book called on killing analyzed the history of the extraordinary percentage of people throughout Wars in the middle of battle where their lives were on the line at any given second who nonetheless never fired their guns that there is an enormous inhibition against doing that after the Battle of Gettysburg there was something like fourteen thousand rifles left next to the dead in the field there that were collected the majority of them had not been fired the majority of them had been loaded repeatedly I'm just about to shoot I better low I better load again I better load again enormous inhibitions against that and he argues that somewhere in there is the greatest bit of optimism asking people to kill somebody faceless on the other side of the planet that's easy asking them to kill somebody whose eyes they see from 10 feet away hand to hand there's historically an enormous inhibition against that that's some room for optimism there nonetheless in the context of the US military now trains more drone pilots than actual pilots oh well remember what I was saying before about castrating males or oh I don't know just hold our breaths and try not to fall into too much despair I don't know I spend my time on the college campus and I keep perhaps delusionally trying to like console myself that this is gonna like generate a whole new generation of active some like if it produces 10 times the activism that say the 60s did it's still gonna be an uphill battle to undo the damage that's gonna be done in these next four years I suspect so I don't know I don't have a whole lot of grounds for not being despairing in these times and you guys get to live here and watch this day by day I at least get to live out in la-la land out in California and sort of ignore it when we want to okay so thank you [Applause]

Channel: The Artificial Intelligence Channel

Views: 107,687

Rating: 4.8938055 out of 5

Keywords: ai, artificial intelligence, deep learning, machine learning, deepmind, robots, robotics, self-driving cars, Robert Sapolsky, Stanford University, Neuroscience

Id: 7htlm3DQ_so

Length: 55min 50sec (3350 seconds)

Published: Tue Jan 16 2018

Reddit Comments

[u/fortwaltonbleach]

anything sapolsky is gold.

[u/[deleted]]

This guy is likely one of my favorite intellectuals of our time