>> that all happens tonight on c-span2's booktv. first up, here's neurobiologist robert sapolsky on human behavior and the role of the brain. [applause] >> 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 hi way into a secret bunker, and i've managed to knock his luger out of his happened, his cyanide ill that he keeps to commit suicide rather than be captured.

he snarls at me, he comes at me in a rage. we wrestle, i manage to pip him down, put handcuffs on him and then say, adolf hitler, i arrest you for crimes against humanity. this is where 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. it's not hard to imagine once i allow myself, sever his spine -- oh. 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 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 heartbeats faster x it's all -- heart beats faster, and it's all these plans for 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 this evil, and i think wicked is only appropriate for a musical. but on the other hand, there's all sorts of people i wouldn't mind seeing killed, but i'm against the death penalty. but i watch all sorts of violent movies, but i'm for very strict gun control. but one time i was in a laser tag place x i had such a good time hiding this the corner shooting at people over and over this this pimpley kid zapped me and snickered at me. essentially, what's obvious here is that i'm your typical human

when it comes to the extremely confusing topic of violation. obviously, as a species, we have problems with violation. we have used 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 pay good money to watch it, we hand out medals, we vote for, we mate9 with the people who are masters at it. when it's the right kind of violation, we love it. and -- violence, we love it. and there's an additional complication. amid us being a miserably violent species, we're 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 in now, one thing that is clear is

it is utterly boring to understand the biology of the of the motoric aspects of your behavior. your brain tells your spine and 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, and in another it's an act of heroic self-sacrifice. in one setting putting your hand on top of someone else's is deeply compassionate, and in another it's a deep betrayal. the challenge is for us to understand the biology of the contest of our behaviors. and that one is really, really challenging. and one thing that's clear is you are never going to really understand what's going on if you get it into your head that you're going to be able to explain everything with the part of the brain or the gene or the hour -- hormone or the childhood experience or the evolutionary

mechanism that explains everything because it doesn't work that way. instead, think 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 in this, okay, so you're in some situation. there's a crisis. there's 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 ask 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 somewhat went on one second before in your brain that brought about that behavior? now, to begin to you understand that, the top of the brain that's at the top of the list of the usual suspects is you want to think about aggression and the brain, you think about the amig da la. rare types of tumors, uncontrollable violence. if you with damage it, you blunt the ability of an organism to be aggressive. so the amygdala is about violence. except if you sirte down your typical -- sit down your typical doctor and ask him what it's about, that's not the first word that's going to come out of their mouths, because for most people studying it what the amygdala is about is 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 neurobiology of violence without understanding the neurobiology of fear. and a world in which no anywhere on need be afraid, there'd be a lot more of us sleeping between lions and lambs. now, the thing to begin to make sense is what parts of brain does the amygdala talk to and which regions talks to it in turn? a next region 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 fete did and rancid and all of that, and what happens is as a result, your insular or cortex activates x it triggers all sorts of reflexes. your stomach lurches, you gag, you spit it out.

you have a gag reflex. very useful. it keeps mammals from eating poisonous foods. you do the same thing with humans, and they're this a brain scanner and their insular cortex activates. we do something p fancier, all we have to do is think about eating something disgusting, and the insular cortex activates. but then something must have more subtle. -- much more subtle. sit down someone 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 at earth, it does 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 the similar billionic thing of -- symbolic thing of mores and standards some 40, 50,000 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, moral disgust, there's that insular that does foodies gust or -- okay, it's in their portfolio now, get me some duct tape. and it has trouble telling the difference. and no surprise, the main part of the brain the insular cortex talks to in the human brain is the amygdala. once it decides this thing is disgusting, you're a couple of steps away from it being scary, it being menacing, it being something to i -- 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 to cured, and some of the time that could take the ultimate sacrifice. and if moral outrage was this abstraction, this 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 make a moral imperative imperative. that's great. but then there's a downside because the ips lahr 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 december gusted by somebody's behavior, which in somebody else's eyes is just a normal, loving lifestyle. disgust is a moving target in time and space. and there's the danger that

being morally disgusted by something is the litmus test between right and wrong. and probably most of all, every idealogue 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 is something just disgusting about them, you're 90% of the way towards pulling off your successful genocide. a key to every good sort of genocidal movement is taking them and turning them into being such infestations and malignancies and whatevers 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 brain far and away, a region called the frontal cortex. frontal cortex -- identify just wasted the -- i've just wasted the last 30 years of my life studying a part of the brain called the hippocampus. i wish i'd been studying the frontal cortex. it's the most recently evolved part of the brain. we've got more of it than any other species on earth, and it makes you to the harder thing when it's the right thing to do. in 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? seasoning 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 da that if i were you. i know this seems like a

brilliant idea right now, but believe me, you are 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 so occasionally go slumming down to the amygdala and preach to it about, like, them presence or whatever. but -- temperance or whatever. the amygdala has plenty of means to talk to the frontal cortex. what's that about? every time we're this 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 this what's down below. in other words, there's this very tempting view the frontal corps text host recently evolved, it's this gleaming, shining, computer-like part of our brain. it's sitting there just marinating this all the emotive yuck going on underneath its bidirectional communication.

now, finally in terms of making fun of this frontal cortex, the harder notion of doing the right thing to do is a value judgment. what do i mean by this? sometimes you have to have an incredibly strong, aerobically studly frontal cortex to resist the temptation to lie. and that's at the centerpiece of some of the most important set of crossroads in our lives. however, once you decide you are going to be lie, you need your frontal cortex to do it effect effectively because it says, okay, don't make eye contact, keep your voice under control. it could take an enormous amount of discipline to go and effectively, like, make the world whole this a better place, but it can also take an awful lot of discipline in staying up late and studying to be effective as ethnicically cleansing villages. the frontal cortex is value-free in that sense.

okay. we've gotten a sense of a couple of the brain regions 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 to minutes before in the sensory environment which triggered that amygdala to do this or 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 tough that's going on that's subliminal that you hard lu even know is there, and if you did, not in a million years would you think it's pertinent. for example, when you have to make split second decisions, you are more likely to mistake a cell phone 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 that incorrectly. why is that? that turns out to to have a reay 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 a handgun. the information goes from your eye to this weigh station of the brain and eventually gets to your visual cortex and sits there ends and some time and figures out what the pixels are, and then the next layer turns the line into curves and eventually you've got a four-dimensional sort of picture. 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 weigh 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 to out you need all those computation allayiers 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 finishing 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 cell phone 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 to days before? how was that affecting how sensitive you are to sensory information which then talks to

your amygdala and the solar cortex and all of that? be what we've moved into here is the realm of hormones, in that regard, amidst a million that are pertinent, two of them stand out. first one, the inevitable usual suspect which is testosterone. it's the reason why males in every culture and every species on earth are such pains in the asses. testosterone does not cause aggression. what it does is bias you towards interpreting ambiguous social information as being threatening, as being provocative. take somebody and pump 'em up with testosterone, and they decide that neutral facial expressions seen for a twentieth 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

exaggerates pre-existing tendencies. what it does is sensitize you to whatever social lure learning you've received about what kind of aggression is just fine and what isn't. now, the single most interesting thing about testosterone is even that's os not what -- that's not what it really does. testosterone doesn't make organisms more aggressive, it makes more organisms more likely to do whatever behavior is needed to hold onto high status when it's being challenged. okay. is if you're a baboon, what that means is a aggression. because if somebody's threatening you, it's all about aggression. that's the entire world of the baboon. remarkably, in humans put somebody in an economic game where you get high status by being generous in 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 the if you took a goo zillion buddhist monks and shot 'em up with testosterone, they'd be running around in frenzied gangs doing random acts of kindness -- [laughter] 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 to days, the other hormone that has just as undeserved of a reputation but in to opposite direction is this hormone oxytocin. now, it's officially the grooviest hormone on earth because oxytocin's famous. it causes bonding between mothers and infants and pair bonding between monogamous couples, and it makes you more expensive and emotionally sensitive and more cooperative and more charitable and more trusting, and there's a whole new horrifying field of neuroscience called neuromarketting -- [laughter]

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, if they could spray oxytocin through the vents in costco all over this country -- [laughter] what that would do to the economy. so ox to city toe sin promotes pro-social behavior until you look more closely. what recent work shows is that's exactly what it does. it makes you much more cooperative and general rouse and charitable and all of that with people who you categorize as being just like you. it makes you 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 it okay to sacrifice one person in order to save five? there's a whole world of research done on that. they sort of establish the levels. now what they did was they gave the person they were pushing onto the track a name. a third of the time the person would get a name that, apparently, is just like your stereotypical dutch name, dirk or peter or something like that. a third of time or the remainder or of the time either of the two groups, the people this holland have hostility towards. germans, oh, that's right, world war ii, or people with muslim names. so thousand you've got the scenario, do you push dirk in front of the trolley? otto?

mahmoud and what they show is give people oxytocin, and they're less likely to sacrifice dirk whereas they can't leap fast enough of to push wolfgang and mahmoud. it takes us nicer to people we're already predisposed towards being nice to. it exaggerates us/them contrasts. okay, now stepping back further, how about weeks to months before? and this has now entered the realm of neural plasticity, the fact that the brain can change in response to experience. 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 have formed new connections. the circuits there will be more excitable, and your frontal cortex will have become more sluggish and at tofied. in other words, at that critical moment, the amygdala is in a more hysterical, hyperactive

state, and the frontal cortex has less capacity to get there in time and say, wait a second, are you sure before you pull the trigger there? now going back years, decades, how about adolescence? what's going on in adolescence that 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? adolescence and early adulthood is the time of life where environment and experience are sculpting your frontal cortex into the the adult version you

are going to have in that one critical moment there 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 changes, jar done in the -- or jargon in the field, causes permanent changes in genes to or parts of your body turned on forever after, other genes are turned off with lifetime consequences. ah, in other words, childhood matters. this is one of the the the molecular mechanisms. and as a pertinent example of that, if you have spent your fetal nine months being bathed

in high levels of stress hormones from mom's circulation because she is extremely dressed, as an adult thanks to end genetic changes, your amygdala's going to be hyper-reactive, and you're going to secrete higher levels of stress her moans 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, to when all you were was a fertilized egg and a bunch of genes. here is great temptation to decide that genes are determining anything, genes determine essentially nothing when it comes to behavior because genes work differently this different environments. and the most pertinent example here is a gene maoa, do not dream of writing that down. it comes in a bunch of different

flavors, and if you have one particular variant, you are very significantly more likely as an adult to commit antisocial violence. the if and only if you were abused as a child. the 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 interact with your environment. and thus, starting with fetal life, the interactions between genes and environment are going to shape enormously what state your brain is in in that one critical second now of do you pull the trigger or not. okay. but you've 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 with their herds of camels or cows or goats, the odds are they would have invented a culture of honor, high levels of

contributive violence, 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 take your entire herald, wives and daughters too. 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 are the cultural differences coming from? ..

>> >> if you are talking about pod the genes or the evolution and jeans then that has collected different primates to have different lovell's of aggression and it immensely high levels with biological traits that go along with the two extremes but what about us? we are somewhere right in the middle between the two extremes in other words, if you want to understand why did this behavior occur take into account from everything before.

it is complicated. that is very useful but you better be real careful and cautious before you decide you understand the causes of behavior especially if it is behavior that you judge harshly because things can really go wrong with the wrong attribution with a very dark stained history of that occurring precisely for those reasons. when i look at all of disinformation the single thing i find to be most important task to be change the ecosystem's change with this a hero was a lush grasslands filled with hippos and giraffes cultures change in the 17th century the scary is people and all of europe for the swede to spend the whole century

rampaging all over europe and they have not had a war in 203 years most of all breens change circuits form patterns grove and as a result people change extraordinarily some examples so a man who moves me enormously was a british theologian who played a central role in the beginning of the 1800's and england he spent the early decades captain of the slave ship after he retired he spent decades as a local person still investing in the slave trade what he is

most known for historically in the hymn amazing grace as the lead pilot in one of the bombing squadrons one of the star pilots and 50 years later to the day he came to a ceremony in pearl harbor to come forward in broken english to apologize some of the elderly survivors on the ground and spent the rest of his wife close with some of them. think about the transformation and then to

take his goal as a souvenir with the japanese and 50 years later he is writing a letter to that man's grandchildren and that just mesmerizes me with the idea along the trenches of france could retrieve the body from no-man's land and soon they help each other carry the bodies and dig graves in the frozen ground and then prayed to gather and then share christmas dinner and exchange gifts by the next day they were playing soccer

together and to exchange addresses before the officers had to arrive when all it took was a couple of hours to complete the reorganized the sense and with them being the faceless coward's behind the line. sometimes but historically so with the massacre a brigade of american soldiers

into gang rape women and girls in mutilating bodies because ultimately they slap of you rest and not a singular instance but the massacre was stopped by one man and to put under attack to view that incomprehensible sight of american soldiers shooting elderly women in taking up the babies and their mothers to shoot them as to who is tussore then he took a

helicopter landed it between the last group of surviving villagers and soldiers coming at them with their weapons and said if you do not stop but i will mow you down and nobody had fancier neurons and thus. no fancier than any of us. those who'd just the history with extraordinary human change or study the science of how we more readily go from the worst of our behaviors' to the best are destined not to have these moments like these.

so now we will stop at this point if there are any questions? [applause] >> what is happening in the future of neurology for understanding the brain better for better outcomes?. >> i will pick up this book you can see this on the left page it is a bunch of graphs that they're doing like this

for a long stretch then do that. that is publications by a year in various topics 2002, 2006, the number of papers in the medical literature everything about it has been learned in the last two years 1985 there were zero papers published and every single one the vast majority comes to the last short amount of time. to understand epilepsy is a neurological disease. we're only 50 years into understanding what those formations with dyslexia. but the vast majority are 10

or 20 years old and we will learn more and more of that the extent to which we are biological organisms and their behaviors have to be evaluated in that realm. for my money, that eventually makes words like evil absurd but also were the punishment for justice very questionable as well. that would require an enormous reshaping of how we deal with the most damaging of human behavior is because the that can be thought about the context of biology. >> i have a sense in my life to be exposed to a number of techniques for creating

people that are like that. for example, like a buddhist those undergo psychoanalysis or group therapy there are those but what i am wondering about is why those are not customary? they do not have a program to cause the people in the community. there are packages that can do that. why is that?. >> easy punchline is because it is really hard to do. one example that comes to

mind for decades for millennia has a dichotomy in four decades this has been floating around. if you bring people together they get to know each other they will recognize there all the same it will be wondrous and it will be terrific and that is the motivation for all sorts of these programs for palestinian and israeli teenagers and irish kids and northern irish catholics and what that extremely large literature intergroup conflict that is one is really that is a good guy

that can generalize to other groups but nevertheless wide as it winds up making things worse? you have to get everybody on equal ground. if anything other than that they will make things worse so these are done easily but they're all workable. >> talk about the critical time of adolescence of what we consider right and wrong how you have those that are inundated with violence or media that desensitizes them to acts of violence?. >> i am horrified on all that as a pair -- parent i

can show you papers of video violence and never really feel like to go down to the basement of the staff heard medical library to pullout journals from the '60s the exact same papers all you need to do is replace the word television with videogames. radio violence in the 1930's like detective stories every single generation has wrestled with this. going to the massive literature on the average all forms of violence cause a short-term burst and violent behavior and individuals to have long-term consequences to have a very familiar punchline violent media makes aggressive individuals more aggressive. no effect on anybody else it legitimizes individuals and

already have a predisposition. that does not invent aggression it exacerbates that tendency. so in that regard no more like the of coffee, -- cop drama those who are vulnerable a more visible and negative miss reform of a reality. >> in your talk you point out how complicated to explain the behavior in the example is an to be a police officer and a lot of the neuroscience in the

courtroom in trying to use a brain scan and but in with those brain scans. >> that is a great question. there are some very scary people who argue with the times that neurosciences know where ready for prime time but just to give you a sense where the plays a role in american criminal justice system, the gold standard for those who've committed a crime is so organically impaired they cannot be held responsible for their action that is a way to show psychosis so that is based on the individual of a

paranoid schizophrenic from 1840. that is the legal standard that that is the basis by which the legal system works the legal system and it has incorporated zero neuroscience the realm of those who do know the difference between right and wrong cannot regulate their behavior. where is that? that is damaged to the frontal cortex. that is the appropriate thing to switch but you only get one as a reward. or you could get five than to say i know how that works

then they go for the wrong one of the last instant. then you pass that test. nonetheless you cannot regulate that behavior. there's no state in the country through the criminal court. to horrifying statistics 25% of the men on death row have a history have head trauma to the frontal cortex. bided time you are five years old that social economic status is a predictor of the level of stress hormones in your bloodstream and the less frontal maturation so few were foolish enough to pick the wrong family to be born

into that is already going to impact metabolism of your frontal cortex by age five of your oldie three steps behind with frontal regulation behavior so in that realm the consequences are enormous and huge of the underappreciated. >> the question of the role of testosterone and the consequences. if it is related to a status of where does that act in the brain? in those that affect their aggression of the adults? would a pharmaceutical route to be

for any type of cognitive training? i feel like that is something they haven't done. >>. >> which part of the brain has the most part of receptors for testosterone? the amygdala is ground zero does testosterone causes those amygdala neurons to five-year for the aggressive output? not at all. only if they were already firing testosterone makes the fire faster. does not turn on the music if bulbs the volume of already turned on. get rid of the male so what

if we pharmacologically block the effects what do pc garett is a track record not working very well? the two places is india and the state of texas chemical castration that block testosterone receptors that is the equivalent for intractably violent sexual offenders and that shows it has no effect whatsoever. because such aggression has very little to do with aggression or sexual of the diva domination and fere and issues like that. if you take any mail on earth to take out his testes

that was the first experiment with endocrinology then they would wrestle him down and get rid of them and then on the average will aggression go down? it never goes down at zero the critical thing is the more experienced the male had being aggressive prior to castration the more it will stay there after word. in other words, the more experience you have with aggression the less it is dependent on hormones and more of a function of social learning. that is not much of a panacea. >> final question and hopefully more optimistic. >> with the big dilemma

emerging with chronic stress what they can do for people who have been on multiple to workers overseas now they're coming back and ending their lives if people have tried meditation or yoga are there other ways with the example of testosterone with the amygdala are there ways to reduce the size of the aggression?. >> the realm that is ptsd with sexual violence ptsd to become hyperactive overgeneralized my lab was

doing gene therapy work for a while in ways as a circus trick that would not help pay minimal but ptsd is the thing that is ever cured. but something fascinating and horrifying has emerged what is ptsd about? it is the fear and watching your buddies killed left and right and with that extraordinary finding they

get ptsd at the same rate as warriors in the battlefield. drone operators sitting in a suburb of edwards air force base in then to a dropoff of clothing at the cleaners in barely and then to russia out at the end of the day to about a concert then to kill the other side of the world they have ptsd as the same rate of sexual soldiers and that is completely challenge the notion of what it is about. it isn't about anything more abnormal and that causes an enormous rethinking of what ptsd is about.

the man named david grossman they very influential book that extraordinary percentage of people wear their lives were on the line and then never fired their guns there was enormous in addition with 40,000 rifles left that reflected the majority of them but a majority of them were loaded repeated the and were just about to shoot that i better go again with the enormous inhibitions and he argues with the greatest bit of optimism killing somebody faceless on either side of the planet is easy but those eyes they see 10 feet away

there is enormous inhibition that is something for optimism there but u.s. military now trains more drone pilots and actual pilots. >> remember what i said before about castrating males? just told the brat and try not to fall into too much despair i spend time on the college campus i tried to console myself that this will generate a whole new generation of activism but if that produces 10 times the activism the '60s did that will be an uphill battle over the next four years i don't have a lot of brown's -- ground you can watch this day by day i live

in mali and in california. thank you. [applause] [inaudible conversations]

. >> they couple nights ago i asked for a show of hands how many had been to charleston and oboist -- almost everyone in the room.