captioning sponsored by rose communications from our studios in new york city, this is charlie rose. >> charlie: tonight we continue our journey through the most exciting frontier of science, the brain. our subject this evening is how the brain controls social behavior. more so than any other species, humans are social beings. we depend heavily on each other for safety, survival and companionship. over the course of evolution, humans have adapted not only to a natural world but also to a social one. tonight, we will outline the social skills that separate humans from other species. we will learn how the brain reads facial expressions to determine the thoughts and emotions of others. we will ask what science can teach us about empathy and violence. and we will examine how social skills are compromised in the mysterious disease of autism. for centuries the study of social behavior was left to artists and philosophers, but in the past 150 years biology has emerged as an important tool for understanding the social brain. some of the earliest insights into this were provided by none other than charles darwin. he proposed that social traits could be passed down through evolution much the same as physical traits. expanding on his theory of natural selection, darwin argued that emotions are scroocial to the sur-- crucial to the survival of the species. unfortunately not all of our social behavior is positive. we will also examine tonight the biological basis of violence and aggression. some day science may offer hope for understanding anti-social behavior. joining me this evening, a remarkable group of scientists who have devoted their careers to understanding the social brain. they are cornelia bargmann, she studies the genetic control of social behavior in simple animals such as worms and flies. she is also a professor at rockefeller university. kevin pelphrey, his work uses brain imaging techniques to understand social perception and cognition. he is an associate professor of child psychiatry at yale university. giacomo rizzolatti let's. in 1996 he discovered cells known as miro neurons. they are thought to play many crucial roles in social interburr section. he's a professor. gerald fischbach, victims robbed of their social skill. he's the director of autism research at the simons foundation. and also my good friend and cohost, dr. eric kandel. he is a noble laureate as you know, a professor at columbia university and a howard hughes medical investigator and he has been a good friend to this broadcast. we could not do it without him. he has been the person who has linked our curiosity to an extraordinary amount of research and achievement understanding the brain. so i begin with this question in this episode. social brain. tell me what we mean by that. >> as you pointed out, very nicely in your introduction, we are immensely social beings. we use our social behavior to find a partner, to build a many family, to build a community, to build a culture. and also as you indicate, that can go into disarray and lead to aggression. social behavior is so important that it is conserved in evolution and you findate not only in people but you find it in simple an sulz some of which like ants build complex societies. although much of social behavior's learned, important aspects of it are determined by genes. for example, you can show in flies and in worms and in simple mouse like animals, the single genes control bonding, whether animals will hang together or they go their own way. so genes can have important influences in behavior. moreover, as you indicated with the social brain, social functions are localized in the brain just as sensory functions and motor functions are. in fact, we see in the social brain that there are sensory areas and the motor areas. in the sensory the visual system is very important. faces as you pointed out are extremely important reading other people's emotions. so there are face areas in the brain that respond not only to faces but to emotional expression of faces. there are areas in the brain, sensory areas that responds to the perception of motion. there's one area that involves response to all motion. mechanical motion, movement of a car as well as the movement of you when you're playing golf. there's another area that this feeds into that is specialized just for social motion. it only responds to biological motion, to your playing golf, to somebody walking, to somebody shaking hands. it does not respond to mechanical motion at all. moreover, as you pointed out, parts of the motor systems are committed to social behavior. rizzolatti let's made a discover there are areas in the motor system that responds when the monkey picks up a glass of water. that's not surprising. the motor system is designed to pick up a glass of water. but the amazing thing is, same cells in monkey respond when you charlie rose pick up a glass of water. so they are mirroring your behavior. so empathic identification with another person is mediated through the motor system. we have learned all of this by looking at the emotional brain. >> charlie: autism. we learn about the brain often through disease. what do we know about autism? >> we know that autism is a disturbance in social interaction. we know that its incidence is increasing in part because we're diagnosing it more. and we know a number of interesting features about autism. for example, kids with autism are inward directed. and when they look at one another, they don't look at the other person's eyes. one of the characteristic features of autism is they turn away from looking at the eye. so if you look at a normal image, so you look at a normal person and an autistic person looking at the same image, a blond woman, you see that the normal person focuses on the eyes and the nose. the autistic person cast their eyes downward. does not focus on the eyes, does not focus on the mouth. so you can tell even by watching the eye movements which is part of the biological motion system that there is something different in their interaction. but one of the astonishing things about autism is that some small but very interesting fraction of kids with autism are very talented and they can draw remarkably well. could we have the next visual, please. >> charlie: oh, nadia. >> you know this stuff, charlie. on the left is a drawing of a horse done by nadia when she was five years old. she could do this when she was two and-a-half. she couldn't talk. she had very poor social directions but she could draw a horse that would jump off the page. i compared this horse to a horse natalithat that leonardo de vent convenient -- de vinci. there are many mozart. to be a great composer, many kids start composing at a very early age. three, for, five. mathematicians can start early. but pa caus piccasso claimed you couldn't get a sense until you were nine, 10, 11 years old. he could not draw a horse like that when he was five years old. the fact they are compromised in some ways kids with autism can have remarkable strength. i think that supports a point that is emerging in a number of these programs that howard gardner has made, that there are multiple intelligences. you can be strong in some things and weak in others and conversely you can have serious compromise of function and do exceedingly well. that probably holds for the two of us. >> charlie: this is charles darwin's book, the expression of the emotions in man and animals. darwin was amazing. >> amazing man. he was without a doubt the most important biologist who ever lived. he not only formulated the theory of evolution but he realized that behavior evolved. just like body parts evolve, so does behavior evolve. you can see examples of human behavior in simpler animals. and since emotion is an important feature of behavior, you can see expressions of emotion in animals and you could detect that. he looked around at different groups of people living throughout the world and he realized that they all had a fixed number facial expressions. six or seven that expressed different emotions. and those are conserved. so whether you're living in the orient or living in america, you express emotions in exactly the same way through the same facial expressions. >> charlie: this is an extraordinary idea and we explore the social brain with our group of experts. understanding how this remarkable idea takes place in our brain. >> most animals, most living things spend at least part of their life in association with others of their own kind. and we know that even in the way we talk about schools of fish or flocks of geese or hives of bees, that groups of animals are often units that are traveling through time and are behaving together. so they have to recognize each other, they have to communicate with each other and they have to generate coherent behaviors. what eia wilson noticed a naturalist about the middle of the last century is that many of the social behaviors that animals have are recognizably similar to each earth, related to each other, even in animals that are different and widely separated by evolution. when you make an observation like that in biology, very often what it means is that there's an underlying genetics. that's very ancient, that is contributing to this same output in lots of different animals. and that idea of taking different genes that sort of flowing them through the different animals and using them for social behavior in a variety of animals is the idea that builds on the idea that there's a genetics of social behavior. now eil wilson himself was not a jeanette es that wasn't his concern but the idea that grows out of different animals and the idea of biology of social behavior. >> fortunately she is a geneticist and she's made a wonderful discovery about genes and social behavior. >> if we could have a movie, i'm going to show you the organizism that my lab works on which is a very simple worm. and this worm is tiny and it lives in the it eats bacteria but it has a number of interesting behaviors and among those as shown in this movie are that it's a friendly worm. and so if we look at a group of worlds together, here we -- worms of together, here we see the worms are associating with little black worms and they're gathered together in two little cluster of animals. most of worms want to spend most of their time with other worms except they'll wander off and come back and join the group. this isn't about food, there's food everywhere. it's not about mating, this is a family show. it's about the animals preferring to associate with each other. >> charlie: why do they prefer to be with each other? >> well, they accomplish certain things within the group. they create an environment that's locally better for themselves so they're actually solving certain problems in their environment within a group. that's what animals in general are doing when they create a social environment. sometimes it's a good idea to be sociable and sometimes it's not. so for example during mating seasons or spawning season, one sex associates more with out and lots of herding species, the females form groups but the mails don't. what we find in these worms is that we can actually describe the different changes in behaviors based on genes that some worms are sociable and other worms are more solitary. we can describe the difference between them based on a single gene that varies between them. they have a high level of activity of the gene will tend to spend most of their time alone. with low level activity will spend their time together. we can actually trace out differences between individuals. not just the overall broad things that everyone shares but even some of the systems for dialing behavior up. >> charlie: you look at their genes and see how this happens or why this happens. >> yes. it turns out this particular gene is called mpr-1 and it's a neuropeptide recour receptor. it's a particular system that lets groups of neurons that can be quite broadly scattered coordinate their activities. >> charlie: let me move to primates and tell me what we have learned about social interaction among primates. >> well, i think we're one mechanism which we just call it, it's very important in showing how monkeys interact with one another. especially this discovery of mirror neurons show there's a specific way in which the animals and humans as well, we'll talk later about humans, have knowledge on it. the so in other words there are these neurons which fire both, one you observe something or one you do the same thing. the type of knowledge you get is committeely different from that that you can get -- so what you are doing inside my brain became my behavior. so it is a specific type of link which cannot be substituted by ananything. you do something that enters my brain as a motor system. and that's my experience. so somehow we share the experience. it's not only a way to understand because then there are many other ways in which we can understand the behavior of others. but this one has this unique stuff how we shared experiences. >> charlie: you did some mirror neuron experiments with a champ pan see in 199 . >> yes. we started in 1992. >> charlie: tell us about it. >> what you see here you see the experiment and you hear the action potential. it has the signal of the brain. so what you have to follow is simply to correlate what is going on the screen and the nose and you will see that every time the monkey grasping an object you hear the action potential. and then the strange thing is one person will do the same thing. you will hear exactly the same action potential. so it's the same neuron which is the trigger either by monkey grasping or by the person grasping. it's kind of dialogue. you see or you hear, or you listen. >> charlie: so what social traits can mirror meurnz account for? >> well, i think this capacity to have a common experience. so the knowledge which mirror neurons provide is kind of from internal, from my point of view, it's a experiential thing. i can understand you, let's imagine that i'm in the bar and i am grasping something. i can understand because i am thinking about oh well if he's grasping probably he will drink. but i can understand immediately and usually that's what you do. that i will drink. so that type of experience is shared immediately, that i think is the normality of mirror neurons. >> the discovery of them is one of the major discovery of the last 20 years in neuroscience because it taught us several different lessons. one is as he indicated, the appreciation that one has in one's brains, the capability of understanding another person's action. that when somebody does something, your own nervous system goes off as if you're carrying out the action yourself although your hand doesn't move. that's number one. number two, we used to think that the sensory systems and motor systems are completely separate. this practicing of sense rea information, your movement is occurring in his motor system. so a fraction of the cells involved in picking up this pencil will respond when you pick up your pencil. it's in the motor system that he discovered this remarkable thing. so he made us realize that the motor systems have sensory cognitive cape bl tease. it's an extraordinary answer. >> charlie: so what are things that mirror neurons allow humans to do that no other species can do. >> there is some evidence but actually we are the only species which are good at imitating. we are the only species -- that's why we have culture. because what you discovered, i can imitate you, eric can imitate. so we have culture. we are unable to imitate we have no culture because something discovered disappears. and monkey could not do that. so that's why we think in monkey is not for imitation but for understanding. and on the top of it, it goes up our capacity. >> i think there's a very important issue here. you use the word in and giacomo has written about that. it's a signal which you've discovered as a correlate, a neurocorrelate of understanding another individual's action. and i think that goes mimicry, to me it always has anyhow. something very profound about how animals, people can communicate at a very deep level. so i think it's more than, to me it's been more than mimicry. >> can you imagine how much learning must go on. it's really sort of an implicit mechanism that doesn't involve motor movements. it's not thought that maybe children learn aspects of language acquisition by seeing their mothers move their mouth, the mother's mouth. the child sees that and learns to do this intuitively. it's really a remarkable insight. >> so very much inspired by work in labs looking at the monkey using single cell recordings, we're interested now in understanding these mechanisms in humans. and so humans have the ability to social perceive others. it's quite extraordinary doing this automatically unconsciously. we look around as we're sitting around this table. we're able to understand the motives of other individuals, the psychological dispositions, their intentions, their actions, etcetera. so we're interested in how do we do this in humans. there are areas of the brain that's involved in social perception and i wanted to highlight one region we've been studying quite a bit in our laboratory, the superior sulcus region. it's highlighted here in blue. you put it in reference to two regions that jump mow has talked about nerms of mere -- terms of mere neurons. one of things ha that we discovd this area in yellow responds very strongly to motion. well it responds to just about any type of motion. so we shared now different types of motion two biological, two non-bbiological. i mean something very simple. looking at how people are walking, pointing, where you're looking, etcetera. all of these things are very very important cues for social perception. i can understand where you're looking is where your interest currently lies. that's where your attention is. this is a brain region that we have to four different types of motions. we showed the same still law, the triple -- still law, the triple cull susresponded to the biological motion compared to non-biological motion. at this point in the visual stream is making this fundamental categorical distinction between what out in the environment is biological, animate, something to pay attention to you because it demands a different way of interaction can provide you clues about social perception versus things that are mechanical. and it's important to emphasize sort of taking this to humans and i think also back into monkeys which we were talking about iation. the way we're thinking about this is on the one hand what i'm telling you is there's an is he is qui --he is compared to a non-social, more general processing region. but we think that these work together. the mirror neurons are representing the action of reaching. we're doing this interesting simulation type of computation and they're getting to hippic h- mimicry. it told these other regions that this is biological versus non-biological motion. this process is happening whereby this region is integrating the context of that action. understanding i'm reaching into a glass, understanding integrating the motion that i might be thirsty, etcetera. so it gets you to the intention of the action, okay, instead of simple mimicry. the last thing i wanted to mention about the superior sulcus, i wanted to bring us into the area of autism. one of the fundamental goals is to try to understand why children with autism, how difficult it is perceiving other people intentions in particular and their actions. so one thing we did, we showed children with autism in typically developing kids, children with autism you're typically developing children, we showed them biological and non-biological motion. we could see in their non-biological motion area they're respon