>> c-span, where history unfolds daily. in 1979, c-span was created as a public service by america's favorite-- cable television companies and is brought you today by your cable provider. [applause]. >> let me start off with a fantasy. it involves wealth. i have overpowered his elite guard. i have fought my way into a secret bunker and managed to knock his luger out of his hand, his cyanide pill that he keeps

to commit suicide. he snarls at me and comes at me in a rage. we wrestle. i managed to pin him down, put handcuffs off him-- on him and say adolf hitler, i arrest you for crimes against humanity. this is where the metal of honor version of this fantasy ends and then i think what i do if i had -- hitler in my hands and it's not hard to imagine once i allow myself. is this on? now it's on? okay. so, not hard to imagine once i allow myself. seven his spine at the neck. take out his eyes with a blunt instrument, puncture his eardrums, leave him alive on a respirator tube fed, not able to move, not able to speak cotton

data-- then inject him with something cancers that will infect every single cell of his body. i have had this fantasy since i was a kid and i still do sometimes then when i really think about it, my heart beats faster it is all these plans were like the most evil, wicked soul in history except there's a problem which is i don't believe in the souls and i don't believe in evil and i think wicked is only appropriate for a musical, but on the other hand there are all sorts of people i wouldn't mind seeing killed. on against the death penalty, but i'm for strict gun control, but then there was this one time i was in a laser tag place and i did such a good time until this like pimple kid zap to me like a million times and snickered and made me feel and madly-- unmanly -- unmanly.

so, obviously we have problems with violence. we have used showerheads to deliver poison gas, letters with anthrax, passenger planes as weapons. we are miserably violent species , but there is a complication with that, which is we don't hate violence. we hit the wrong kind of violence because when it's the right to kind we leave then, we pay good money to watch it. we hand out metals, we vote for the people who are masters at it and when it's the right kind of violence we love it and there is no additional complication because the mid as being this miserably violent species, we are also an extraordinarily compassionate one. how do you begin to make sense of us, the biology of us at our best moments and our worst moments and all of these

ambiguous ones between? it is utterly boring to understand the biology of the aspects of your behavior. you are brain your spine pillage or muscles to do something and it you have behaved. what's incredibly complicated is understanding the meaning of the behavior because in one setting firing your gun is some appalling act and in another it's an act of heroic self-sacrifice and one setting putting your hand on top of someone else's is deeply compassionate and another a deep betrayal. the challenges to understand the biology of the context of our behaviors and that one is really really challenging and one thing that is clear is you are never going to really understand what's going on if you get it into your head that you will be able to explain everything, the part of the brain, or the gene or the form on our childhood

experience 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, under our before and all the way to a million years before. to give you some sense of this, you are in some situation. there is a crisis and there's a crisis, writing, violence going on, people running around and a stranger running at you in an agitated state and you can't quite be sure with their expression as. maybe they're angry. maybe there frightened. they have something in their hand that seems like a handgun and you are standing there and you have a gun and they come running out you and you shoot. then it turns out what they had in their hand was a cell phone and said. thus, we ask a biological question, why did that behavior occur in you and what's the central point is that they whole

hierarchy of questions. whited that behavior occur? what went on one second before in your brain that brought about that behavior? to begin to understand that the part of the brain that is at the top of the list of usual suspects is the brain we call the amygdala. you want to think about aggression then think about the brain and you think about the amygdala. if you stimulate the amygdala in an experimental lab you get expressions, humans that have rare type of seizures that start their, rare types of tumors, uncontrollable violence. so, the amygdala is violence except if you sit down your typical of a knowledge as an asset with the amygdala is about that is not the first word that will come out of their mouth. for most people studying it, it's about fear, fear and

anxiety and learning to be afraid. in other words we have just learned something interesting, which is you can't understand the first thing about the neurobiology of violence without understanding the neurobiology of fear and a world in which no amygdala neurons be afraid there would be a lot more of us. the thing that begins to make sense is what parts of the brain doesn't talk to and which regions talks to it in turn. the next region incredibly adjusting is called the insular cortex. the insular cortex is incredibly boring if you are lab rat or any other mammal on earth because it does something straightforward. divided into a piece of food and it is spoiled and rotten and rancid and all of that and as a result your insular cortex activates and triggers all sorts of reflexes. your stomach lurches, you guide,

he spit it out and you have a gag reflex. useful. it keeps mammals from eating poisonous foods and if you have a nice human volunteer that bites into this food that's rancid and discussing and they are in a brain scans-- scanner and all we have to do is think about eating something disgusting and the insular cortex activates and then something more subtle. sits down someone in your brain scanner and have them tell you about a time they did something miserable and rotten to another human or tell them about some other occurrence of some human doing something miserable and rhonda someone else and insular cortex will activate. in every other mammal on earth it's discussed, but in as it's also moral disgust and what that tells you is why it is that

something appalling we feel sick to our stomachs. it leaves a bad taste in our mouths. we feel nauseous because our brain invented the symbolic thing of moral standards some 40000 years ago and didn't invent a new part of the brain at the time and instead there was some sort of meeting and they said, okay moral disgust there's that insular that does like food discussed, okay. it's in their portfolio. the insular cortex will also do moral disgust and it has trouble telling the difference had no surprise the main part of the brain, the insular cortex talks to in the human brain is the amygdala because once it decides this thing is discussing, you are couple steps away from it being scary, menacing and something you need to act against.

and lots of ways it's very cool that the insular cortex does this. suppose you see a moral ill and some of the time it can take enormous self-sacrifice and if moral outrage was this abstraction, this sort of distanced state it would be hard to pick up a head of steam to be able to act against it. your stomach churning, that's where the force comes to to make a moral imperative imperative. that's great, but then there is a down aside because the insular cortex is not good at remembering it's only a metaphor that you were feeling disgusted and suddenly you have the whole problem of the world of people who are disgusted by someone's behavior wishing-- with someone else's eyes is a normal life lifestyle. discussed is a moving target in time and space and there is the

danger to the time of being formally-- morally disgusted by something. we know all the ways in which that can get you in trouble and probably most of all every ideologue in history has had a brilliant intuitive feeling for how they insular cortex works, which is if you can get your minion to the point at weight-- when you talk about them live and in the next valley, them who think differently than you, pray differently, love differently if you get your followers to the point that when you would invoke them insular cortex activates because there something disgusting and you are 90% of the way towards pulling out your nine-- successful genocide. the key to every genocidal movement is taking them and turning them into such infestations and malignancy and whatever that they hardly even count as human anymore.

we have this axis between the insular cortex and that a meat cleaver-- amygdala. meanwhile, the most interesting part of the brain a region called the frontal cortex. frontal cortex, i have wasted the last 35 years of my life studying the hippocampus which is done well by me and i think i wish i had studied the frontal cortex, and the most recently evolved part of the human brain. we have more of it than any other species on earth. it makes you do the hardest thing when it's the right thing to do. impulse control and gratification postponement and long-term planning, emotional regulation and what does the frontal cortex spend time doing? sending inhibitory projections to the amygdala hoping to raise 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. believe me you will regret it. the frontal cortex is very often racing to control the amygdala here to there is this the frontal cortex. all it does is occasionally slow down the amygdala and reach to it, but in fact there is by directionality the amygdala has plenty means to talk the frontal cortex. every time we are in a moment of extreme aroused state and we make a decision that is stupid and disastrous the seams of brilliant at the time because as the frontal cortex being marinated in what is down below. in other words, there is this tempting view, the frontal cortex, this shining computerlike part of our brain is marinating in all the emotive yuk going on underneath.

finally, in terms of making sense of the frontal cortex, the whole notion of doing the hardest thing when it's the right thing to do is a value free judgment. would like me by this? sometimes you have to have an incredibly strong aerobically studley frontal cortex to resist the temptation to lie and that's at the centerpiece of some of the most important crossroads in our lives. however, once you decide you are going to lie you need your frontal cortex to do it effectively because it's your frontal cortex that says, remember don't make eye contact, don't use this right cheek muscle, keep your voice under control. it can take a enormously amount of discipline to make the world whole and also a lot of discipline and staying up late and studying to be effective it ethnically cleansing villages.

the frontal cortex is value free in that sense. we have a sense of a couple brain reaches that are pertinent that's what's going on one second before, but no brand is an island and we now have to take a step back. quote was going on in the seconds to minutes before the sensory environment which triggered that amygdala to do this? what is the stimuli coming in? obviously, the scenario we have, the sights, sounds of writing pertinent to making sense there, but then there is a whole world of sensory stuff going on that is subliminal, and that you hardly 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, large , of another race.

your brain processes that in 50 milliseconds, one 20th of a second your brain has distinguished that incorrectly. wise that? turns out to be interesting piece of the wiring of the amygdala. suppose you look at someone and there something in their hand. what happens? the information goes from your eye to this waystation in the brain and eventually gets to your visual cortex in the first layer sits in there and spends time and eventually you of a four dimensional picture and eventually some neurons in your cortex says i believe that they have a god and let's wake up the amygdala and know about it. that's the simple part. turns out there's a shortcut of the waystation where sensory information comes in shortcut

strictly to the amygdala. in other words, the amygdala knows there's a handgun while your visual cortex is still fussing around with the pixels. that's helpful. it turns out you need all those computational players in your visual cortex to tell what's they are accurately. in other words, the amygdala gets sensory information that's emotionally rate aroused before your conscious cortex does and the accuracy is not great. mouse, if you are tired, hungry, if you are in pain, if there's a bad smell, any of those things happening you are biasing the amygdala towards mistake in a facial expression for a threatening one. mistaking a cell phone for a handgun and all of that occurring in the seconds before. now, we need to take a step further back. what about hours to days before.

how is that affecting how sensitive you are to sensory information then-- what we moved into is the realm of hormones. in that regard amid a gazillion hormones that are pertinent, to stand out above all other. first of all the hormone of testosterone. is the reason why males in every culture in every species on earth are such pays in the asses. testosterone doesn't cause aggression. it buys you towards interpreting ambiguous social information is being threatening, provocative. take someone and pump them up with testosterone and they decide the neutral facial expression seen for a 20th of a sash-- second are threatening. suddenly the amygdala is agitated.

what testosterone does is exaggerates pre-existing tendencies. it sensitize you to whatever social learning you've received about what kind of aggression is justified in what is then. the single most interesting thing about testosterone is even that is not what it does. testosterone doesn't make organisms more aggressive. it makes organisms more likely to do whatever behavior is needed to hold onto high status when it's being challenged it. if you are baboon that means aggression because if someone is threatening you that is the entire world of a baboon. in humans, put someone in economic gain where you get high status by being generous in the offers you an testosterone gives people more generosity. the problem is we reward

aggression with status so readily and that also tells you if you have gazillion buddhist monks shot up with testosterone they would be running around in frenzied gang stewing random access of kindness. this is not a hormone that is the problem, but the values and rewards replace on aggression. the other hormone that has just as an undeserved reputation is this hormone oxytocin. oxytocin is officially this hormone. oxytocin is a miss causing bonding between mothers and infants and pair bonding between monogamous couples in in may she more expressive than more cooperative and charitable and trusting and there's a whole new horrifying field of neuroscience

called in a row if you spritz oxytocin up people's noses they are more likely to believe all sorts of gibberish of people trying to sell you stuff whether it's their political viewpoint. if they could spray oxytocin through the fence at costco all over this country, what it would do to the economy. okay, so oxytocin promotes this pro social behavior until you look more closely. recent work shows that exactly what oxytocin does, makes you more cooperative and generous, charitable with people who you categorize as being just like you. makes you more prosocial towards in the group members and when it comes to outgroup members it makes people more xenophobic and more preemptively aggressive and less cooperative the greatest study was a couple years ago

with a group in the netherlands where they got their usual lab rats which was college volunteers. they gave everyone this is standard classic problem in philosophy, the runaway trolley problem. is it okay to sacrifice one person pushing them in front of a runaway trolley to save five. they start of establish based on levels in which people would be willing to push someone to save five. now, 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 your stereo typical duct-- dutch name. a third of the time either of the two groups that people in holland tend to have a life outgroup hostility towards, germans. world war ii. or, people with muslim names, so you now have the scenario do you push dirk in front of the

trolley? to you push auto in front of the trolley? and what they show is give people oxytocin and they are less likely to sacrifice dirk wears they can't leap fast enough to push wolf came onto the track. oxytocin doesn't make us nicer. it to makes us nicer to people who we are already nice to an exaggerates us to them contrast. how about weeks to months before? this is now entered the realm of neural plasticity, the fact the brain can change and respond to experience. for example, if you just spent the last few months mired in trauma and stress your amygdala will have grown larger. it will have formed a new connections. the circuits will be more excitable and your frontal cortex will have become more sluggish and atrophy. in other words, at the critical moment the amygdala is in a more

hysterical state in the frontal cortex has that much less capacity to get there in time and say wait a second are you sure before you pull the trigger okay. separate back further, back in years, decades, how that adolescence? what's going on in adolescence is relevant to this one second of whether or not you pull the trigger. 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 point. amazingly the frontal cortex, the last part of the brain to mature is not fully online until you are about 25. that explains an enormous amount of freshman year in college, the last part of the brain to fully mature. what is that mean? it means adolescence and early adults time of life where environment and experience are

sculpting your frontal cortex into the adult version you will have in that one critical moment deciding with the alchemists. that also tells you that if this is the last part of the brain to mature it is the last-- it is the part of the brain least chain by genes and most shaped by environment. stepping further back to your childhood, fetal life. obviously pertinent because that's when your brain was being constructed, the people of also learned experience during that period causes changes in the epigenetic changes causing permanent changes and some jeans and parts of your body are turned on forever after another genes are turned off lifetime consequences. in other words, childhood matters, one of the monette-- molecular mechanisms by which childhood matters.

if you budget your fetal nine months they've been high levels of stress hormones from mom's circulation has she's stress, as an adult thanks to epigenetic changes during your fetal life your amygdala will be hyperactive and you will create higher levels of stress hormones which makes the amygdala more reactive in the frontal cortex sluggish, so events back in fetal life. back even further, back to when you were a fertilized egg and a bunch of genes, obviously genes have tons to do with everything, but here's a great temptation to decide that genes are determining anything. genes determine essentially nothing when it comes to behavior because genes were different in different environments and the most pertinent example here is a gene called-- do not even dream of writing that down.

it comes in a bunch of different flavors and variance and if you have one particular variant you are significantly more likely as an adult to commit antisocial violence. if and only if you were abused as a child. if you are not, having that gene variant has zero increasing your risk factor. it's not your genes, it's the way your genes interact with your environment and starting with fetal life the interaction between genes and environment will shape enormously what's state world read is in in that critical second of do you pull the trigger or not. you got to go even further back past you as a single organism. how about your ancestors? what were they up to? if your ancestors were pastoralists, people wandering deserts and grasslands with their herds of camels or cows or goats the arts-- odds are they

would have created a culture of honor. high levels of violence, warrior classes, that's the whole world of if you come and take your camel and you do nothing about it the next day they take your entire herd and your wives and daughters to with violence going on for centuries and if your ancestors were of a cultural or of honor centuries later it still influence in the values you are raised including within moments of birth how often mothers hold their children. centuries worth of that. steps further back, where are the cultural differences coming from? one example of the comic you look at people living in deserts and historically they are likely to come up with mono theistic religions. people in rain forests come up with polytheistic religions. people in east asia who live in flat plane area growing rice

requiring collectivists farming and you get a collectivist mindset about cooperation. people until countries growing wheat and an individual families in need at the same individualistic mindset as in people living in manhattan, all ecologically shaped. then we go even further back. 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 primates have virtually none and another extreme immensely high levels and there's all sorts of biological traits that go along with the two extremes and what about us? we are somewhere in the middle between the two extremes. in other words, if you want to understand why did this behavior kurt laseak you have to take into account everything from one second before to a year to a

million years before that. complicated. that's useful. how about its complicated and you better be real careful and real cautious before you decide you understand causes and behavior especially if its behavior you judge harshly because really things can go wrong and we have a very dark's history of that occurring precisely for those reasons. for me, when i looked all of this information the single thing i find to be most important has to do with change. every single biological fact that i've given along the way is subject to change over time. echo systems change. thousands of years ago the sahara was a lush grassland filled with the pose and giraffe cultures change. in the 17th century the scariest people in all of europe

or the swedes who spent the whole century rampaging all over europe and the swedes have not had a war in 203 years. they changed and most of all brains change. circuits form, neurons we can, patterns grow, parts of the brain expand and as a result people change and they change extraordinarily. some examples of it? change in people that can occur over the course of decades. a man who moves me enormously by the name of john newton, a british theologian who is a leading abolitionist playing a central 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 two decades as a local parks and still infesting in the slave trade and growing rich from it until one day something changed in him.

something changed and he celebrated the think he's most known for historically in a him he wrote, amazing grace. another example, a man who on the morning of december 6, 1941, was the lead pilot and one of the bombs quadrille that took off from an air force base in japan and attacked pearl harbor. he was one of their star pilots and 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 spend the rest of his life close with some of them. think about that transformation. if one of those men he befriended had become a captive during world war ii he might've happily walk them to death in the bataan death march and if he

had been a captive of one of those american men he might very well have died. instead, 50 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 mesmerizes me was the first winter of world war i. 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 the france people would be up to come out and retrieve body from no man's land and bury them. so, german and british troops came out and retrieve the bodies into soon they helped each other carry the bodies and soon they helped each other dig graves in the present ground and then they prayed together with a dead and then they shared christmas dinner and then they exchanged

gifts and by the next day they were playing soccer together up and they hold no man's land and exchanging addresses to get together and see each other after the war was over in those truces went on for two to three days until the officers had to arrive and a 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 peoples a sense of who counts as an us and 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 pawns. sometimes change can occur in the course of the seconds to minutes. historically, probably the single biggest four in terms of consciousness from the vietnam war was a brigade of american soldiers going into an undefended village full of civilians and killed between 350

and fight of hundred of them, gang raped women and girls before mutilating potter-- bodies. utterly nightmarish because it occurred. the us government covered it up for as long as possible because ultimately they did slapping of a few risks and because it was not a singular incident it was one of the nightmares of the vietnam war. the massacre was stopped by one man, a man named hugh thompson. thompson was piloting a helicopter gunship over the village and seeing american soldiers firing activity. they are under attack by viacom, landed there, got out and was reviewing the and conference both side of american soldiers shooting elderly women, taking 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 a them. he took his helicopter, landed in between the last group of surviving villagers and american soldiers coming at them with their weapons, landed his helicopter and turned his machine dawns on the american soldiers and said if you do not stop i will know you all down. what's most important to me is, none of these guys had fancier neurons than any of us. 's same neurotransmitters, same genes, same enzymes, no fancier than as. what i think we are left with is a version of that in evitable cleat shape your those that don't study history will repeat it. what we have here 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 is any questions. what-- [applause]. [applause]. [inaudible] >> what's happening in the future of a knowledge that would give us hope for understanding the brain better than having better outcomes. >> okay. let me just take this book here. lets us see. haven't read this yet, but i skimmed it for the pictures. year is one figure. i don't know if you concede on the left page, a whole bunch of graphs do like this for a long

stretch and suddenly they do that. of those are the number of publications by year in various topics i talk about. for example, at the top one, 2002, 2006, 2010, the number of papers in medical literature concerning the topic of oxytocin and trust. anything about it has been learned in the last 10 years. care we have brain and aggression, 1985, essentially zero papers published by the last decade more than 2000. every single one of these vast majority of what we have learned has come in the last whatever short amount of time. we are only couple hundred years into understanding epilepsy is a neurological disease and not demonic possession. only about 50 years into understanding certain types of learning disabilities are due to micro malformation the cortex with people in dyslexia and is not laziness, the vast majority

of these factoids are 10, 20 years old. we will learn more and more of that stuff and what we will learn more and more is to recognize the extent to which we are biological organisms and our behavior has to be evaluated in that realm. for my money that eventually makes words night-- like soul or evil absurd and medieval, but also makes words like punishment or just-- judgment very questionable as well and i think it will require reshaping of how we think we deal with the most damaging of human behaviors because none of that can be thought outside the context of biology. >> you did mention bouchard, buddhist, but i have a sense that in my life been exposed to a number of techniques for creating people that are like

that, for example buddhist, people who practice. people who undergo psychoanalysis or theories, activities that come from that. group relation work, group therapy. there are tools that have that effect. what i'm wondering about is why those things are not customary. they are not institutions. we don't have, for example, a program to cause people in the community to meet together. there are packages that can do that, but it doesn't happen. why is that? >> of the easy punchline is because they are usually really hard to do.

what example, so you have conflicting groups that for decades have had us, then-- them dichotomies in their head and for decades this notion has been floating around called contact theory which is if you bring people from opposing groups together they get to know each other and they will recognize that we are all the same and it will be wondrous and we will be terrific and that's the motivation for all sorts of these programs, taking palestinian and israeli teenagers and putting them in summer camps. irish kids, northern irish catholic and protestant, endless versions of these and what that literature has showed is that when it works right it reduces conflict and can cause lasting changes in perception where people can generalize beyond not just now i know there is one israeli and i know who is a good

guide and can generalize even to other groups. nonetheless, most of the ways in which you set those up wind up making things worse because it's a very narrow domain where these -- you have to get everyone on equal ground with shared goals and an absence of any symbols used provocative and if you have anything other than that you will make things worse in other words, none of these things are done easily, but they are all workable. >> you talked about the critical time of adolescence and development and what we consider right and wrong. how do you address the generation of coming up with being inundated by violence in the media, video games and it sort of desensitizes them to acts of violence? >> i as a parent am horrified by that stuff and can easily go off

on a rant about the bad consequences and i can find papers that are looking at video violence in the desensitizes fx and if i really feel like going to like the basement and the stanford medical library pullout journals from the 60s, there are the exact same papers were all you need to do is replace the word television with videogames. radio violence in the 1930s with like detective stories. every single generation has wrestled with this and we go through the massive literature looking at each new incarnation and what you see is on the average all of those forms of violence cause a short-term burst and violent behavior in individuals, but in terms of whether it has long-term consequences in every one of those rounds you get a familiar punchline, violent media makes aggressive individuals more aggressive with no effects on anyone else because it

legitimizes and habituated disinhibit's individuals who are ready have the predisposition just like testosterone it is not in that aggressive, but exasperates pre-ambition social tendencies towards. the good news is, it's no worse than like cop dramas sitting by fireside chats in the 1930s with the radio. the bad effects are nonetheless those who are vulnerable it's a more vivid more real form of imitating awful reality than anything that's been invented before, but general effects turn out not to be terrible. >> hello. in your talk you point out how complicated it is to explain a behavior and the example you use is that you can put that-- try to figure out that thing in the hand is a gun and obviously could be anyone in that

situation. a lot of neuroscience has been brought into the courtroom-- the classroom also to use a brain scan to explain something, but in particular in the courtroom where do you see that headed where people are bringing brain scans and say my brain made me do it rather than me or whatever >> great question. there is some very scary smart people at times taking the viewpoint that neuroscience is nowhere for prime time. to give you a sense of where neuroscience plays a role in the criminal justice system, the gold standard for deciding someone has committed a crime is so organically impaired that they can't be held responsible for their act is if they basically cannot tell the difference between right and wrong which is usually a way of describing extreme schizophrenic psychosis. this is called the m'naghten

rule based on an individual almost certainly a paranoid schizophrenic hearing voices attempted to assassinate the prime minister england in 1840. that is the legal standard in the united states based on neuroscience from 1840. that is the basis by which the legal system works. the area that the legal system in the us has incorporated exactly zero neuroscience is the realm relational impairment, the roma people who do know the difference between right and wrong who nonetheless cannot regulate their behavior. wears that? that's when you see damage to the frontal cortex and you can someone there who can tell you absolutely which is the appropriate thing to switch for, you can only get one as a reward or if you reach for one eminem you get five as every ward and they will say i know how it works and they go for the wrong

one of the last instance. when you have frontal damage he passed the test and you know the difference between right and wrong and nonetheless you cannot regulate your behavior. there is no state in this country that readily accepts volitional impairment in a criminal court. to horrifying statistics pertinent to that, 25% of the men on death row in this country have a history of concussion head, to their frontal cortex. other four-- were fine fact, by the time you are five years old the socioeconomic status of your parents is a predictor of the levels of stress hormones in your bloodstream. to goes in the direction of the more poor you are the more stress hormones in the more stress hormones the less frontal maturation. by kindergartner ses, if you

were foolish enough to have picked the wrong family to have been born into that will already impact metabolism, the thickness of your connections being made. by age five, you are already three steps behind in terms of frontal regulation behavior because of the differences in this country, so in that realm i think the consequences are enormous and usually underappreciated. >> i will total-- i will try to articulate my question. so, if it's not related to aggression, but testosterone is related to an increased reward, where does it act in the brain? does it act in the brain and they've given some a kids may suffer with impacts in the brain that might affect their aggression as adults, would a

pharmaceutical fruit be at all suggested before they-- before any kind of cognitive training? i mean, because the drug industry will latch onto anything, but i feel like that is something they haven't done, but i don't think it's a long-term solution either. >> which part of the brain has the most receptors for testosterone? the amygdala. the amygdala is ground zero for sensitivity to testosterone. does testosterone cause the 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 pumps the volume if it's already been turned on. so, let's make the world better place here, how about we get rid of those males, maybe not that.

at least lets castrate-- well, no. well, okay how about if we pharmacologically block the effects of testosterone and what you see there besides it being mighty scary is a track record of not rewarding well in a number of places. on earth the two places where it's most unexplored is india and the state of texas there have been state ordered chemical castration's, drugs which are given that block testosterone receptors which is the equivalent of removing testosterone usually for intractable violent sexual offenders. what the literature shows is essentially has no effect whatsoever because such aggression has very little to do with aggression and very little to do with sexuality and as a whole lot of domination of the issues like that. pertinent to that you take an e-mail on earth of any known a species and take out his testes

and that was almost really the first experiment ever done in endocrinology about 10000 years ago. suddenly, he was a more tractable mail work if you castrate a male of any species out there on average levels of aggression go down. they never go down to zero. the critical thing is the more experience that mail had been aggressive prior to castration, the more it will stay there afterwards. in other words, the more experience you have with aggression the less dependent it is on hormones and the more the function of social learning, so that unfortunately or otherwise -- final question. >> final question. hopefully more optimistic. so, you mentioned the courtesy of the amygdala enlarging with

chronic stress and there are things perhaps we could do for people who have experienced chronic stress like people that have been on multiple tours overseas. that we are having people do that more often they are coming back and ending their lives. i'm wondering, i know people have tried meditation, maybe yoga, but are there ways that even with the example of testosterone and really the amygdala that is the role of the amygdala. are there ways we can reduce the aggression or the size of the amygdala? >> the realm where that's than most studies is with ptsd, combat, ptsd and sexual violence ptsd where you see with the ptsd there you get expansion of the amygdala. it becomes hyper reactive and overgeneralized into it being a

terrifying world out there. my lab for a while was doing gene therapy work on trying to protect the amygdala from stress hormones in ways that was kind of useful, but it won't help a mammal anytime in the next century or so. ptsd is not really anything that is ever keyword. people learn how to manage it, contain it, but there's no clear biological cure. something fascinating and horrifying has emerged in the literature in recent years. what is ptsd about? it's obvious that it's fear, terror, the trauma of people trying to kill you, of watching your buddies killed around you left and right. it's anchored in fear and the fear of the violence that may harm you and those who you love, but the fault-- field had to accommodate an extraordinary finding in recent years which is drone operators get ptsd.

they get ptsd as of the same as do warriors the battlefield. drone operators sitting there living in some suburban of an air force base 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 this simulator 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 grove in a ballet concert to go back to killing on the other side of the globe the next day. these people at ptsd at the same rate as 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 than-- and terrifying than the notion of someone killing us, but rather it's the utterly bizarre and abnormal notion of us killing someone else and that is causing enormous rethinking what ptsd is about and a lurking in there is

a little bit of optimism. a man named david grossman, a kernel of us military road if influential book analyzing 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. there is an enormous-- after the battle of gettysburg there was something like 14000 rifles left next to the dead in the field 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 load, i better load again, i better load again. he argues somewhere in there is the greatest bit of optimism asking people to kill someone faceless on the other side of the planet is easy. asking them to kill someone

who's eyes they see from 10 feet away hand to hand is an enormous innovation is that. that is some room for optimism there. nonetheless, in the context of the us military now training more drone pilots than actual pilots. [inaudible] >> well, remember what i was saying before about pastored e-mails work i don't know just hold our breath and try not to fall into too much despair. i spend my time on college campus and keep trying to console myself that this will i generate a whole new generation of activism like if it produces 10 times the activism's that say the 60s did it will still be an uphill battle to a do the damage over the next four years, i suspect. i know have a whole lot of grounds for not being despaired in these times and you guys get

to live here and watch this day by day. i at least get to live out mama landed california. okay. thank you. [applause]. >> here's a look at some a current best-selling nonfiction book. topping the list is nutrition, fax or fuel. next is astrophysicist, by

option be by facebook chief operating officer sheryl sandberg. they get their advice on perseverance. forth on the list is retired admiral william a craven self-help book. followed by a nebraska senator, the vanishing american adult here to learn more to going into afterwards this weekend when the senator will be our guest saturday at 10:00 p.m. and sunday at 9:00 p.m. eastern. our look at the best-selling nonfiction books according to publishers weekly continues. number eight on the list is jd fans with his book hillbilly eligibility. next on the list's new yorker staff writer david graham with killers of the flour milling about a string of murders in oklahoma during the 1920s,

targeted members of the osage indian nation. wrapping up, shattered by jonathan allen and amy barnes. the book takes a behind-the-scenes look at hillary clinton's 2016 presidential run. many of these authors have or will appear on book tv. you can watch them on our website, book tv.org. .. and if you do take pictures please tag the liber on social media. up until the last few decades