Transcript for:
Human Aggression and Cooperation

[Music] Stanford University okay let's get started we pick up with aggression competition Etc and where if we gotten to we are now just about to LEAP to instead of early environment ear hormonal exposure perinatal hormones both pre before and after birth around that time what do they have to do with adult behavior in these Realms so again this is tapping into that same concept from the sex lectures organizational hormonal effects versus activational organizational early in life setting up the nervous system to respond later on to some sort of activational hormone horm Al effect so the basic theme that's come through with the animal studies here has been built around what if you have females who are prenatally or perinatally androgenized exposed to high testosterone levels and what you see is basically the exact same thing as from the sex lectures which is you get a powerful masculinization organizational masculinization effect so that later on these are females who respond to even their low levels of testosterone in the bloodstream with increased levels of aggression more aggressive play bunch of measures like that less maternal behavior when having Offspring a pretty clear literature in terms of prenatal masculinization of aggressive behavior as well as sexual behavior so as usual what about humans and we go back to our two diseases from the other week one was that congenital adrenal hyperplasia business that tumor and the mother that produces vast amounts of among other things an androgen a testosterone derivative which androgenized the fetus or the case with that drug Dees diethyl still best all were some women in the 50s took them for preventing miscarriage and in some cases had androgenic effects back to the same issue as with the sex lectures so what's the behavior of these individuals like and again people were all over that one people were really interested in this both of them kind of burst on the scene congenital adrenal hyperplasia and the dees babies around the same time lots of people started studying these kids as they started growing up with the very simple question here of are they going to be more aggressive than typical girls and ultimately will they be more aggressive women and somewhere between the lines they're also asking the question are they going to be more aggressive than is normal for a typical girl so what began to come out of these studies first off some interesting odd quirky things one is when you androgenized a female fetus human and later on as a child she will have a higher than average IQ whoa H that's kind of interesting stay tuned it turns out that's not at all interesting okay so that was observed another thing more of a tendency towards being left-handed better spatial skills and both of those are attributes that are more common among males than females what else but you know that's all that sort of stuff having to do with ancillary issues but now finally people were then really focusing in on the issues of aggression and by the time these girls were I don't know 10 12 years old or so the findings were abs absolutely clear these kids were way way more aggressive than normal how do you know because they were less interested in playing with dolls than normal girls because they expressed less interest in marriage because they expressed more interest in having a career someday so these were obviously over-the-top rabid Psychopathic androgenized females because they weren't normal they weren't interested in dolls or marriage and were interested in a career this was in every textbook starting in the late 60s and was still there in textbooks by the mid 80s or so Endocrinology textbooks and somewhere in the early 70s or so probably some male endocrinologists kind of discovered that uh you know wanting a career if you're female does not count as uh aggression actually they came up with an even better term assertive dominance how's that for term that just summarizes an entire world view of uh gender differences okay so some male endocrinologist finally figured that out or maybe actually they finally started being some female endocrinologist who pointed out this was gibberish the entire literature went down the tubes had to be started all over oh wanting a career is not being assertively dominantly aggressive if you're female so back to stage one on that whole literature lots of work since then what the literature has generally shown is the left-handedness is there the spatial issues seem to remain the IQ the higher IQ is there what's up with that all that's known is as an explanation you find an equivalently higher IQ in the parents so it's got nothing to do with the androgenization there's some sort of selection going on perhaps who winds up being in a study like this sort of more educated families who knows what but that one turned out to be a red herring what about aggression because now there's been populations of androgenized girls who were now well into adulthood what about antisocial Behavior what about all those sorts of things and in general what is shown is there's not much going on the literature has been pretty ambiguous in terms of any sort of Trends there of different behaviors different attitudes different motivations Etc in these folks as they grow up but suppose what you found was as adults women who had been androgenized as fetuses were now 17 times more likely to start brawls and bar rooms to snipe at people from the tops of water towers things of that sort what would you conclude ooh prenatal testosterone makes you more aggressive as an adult no same confound with these folks is from the sex lectures the other week which is these girls were not just born having been exposed to lots of testosterone and utero and doing something or other to their brain they were born with basically a her Matic profile of genitals that looked like males or interex sexually ambiguous genitals these were the kids who went through a dozen rounds of reconstructive surgery in their first half doz do years of life their first 10 years of life in this part of the body that everyone's interested in but doesn't quite talk about and what's up with that and why aren't I normal and these once again were not girls who grew up with the only thing being different about them their prenatal hormone exposure basically makes the whole literature uninterpretable so what else in terms of prenatal hormone effects another literature that people have looked at which in principle could be extremely formative looking at dizygotic twins non-identical twins so you are a girl you're a diotic twin and you can have a sibling who is either a sister or a brother in other words you may have spent your time in utero with your sibling who either did or did not secrete a certain amount of testosterone during that time do you see any sort of masculinization of aspects of aggressive behavior in girls who are twins with a male sibling rather than a female one and what you wind up seeing is these kids individuals show on the average more aggressive play in childhood more here's the jargony term more Rough and Tumble play more interest in cars mechanical things like that less interest in stuffed animals in dolls small effect very small effect nonetheless it suggests that this is another realm where a little bit of prenatal exposure to testosterone will change the behavioral profile except there's a confound in these studies which is if you were a girl and you have an identical twin who is a boy you are in the Guinness Book of Records okay let's start that one if you are a girl and you have a non-identical twin that's how it works okay I knew I should have checked the notes before coming so you got nonidentical twin who's a boy not only do you spend your prenatal environment being a wash in some of his dribbling hormones but you grow up with him and girls who grow up with boys as brothers as opposed to plants as brothers girls whoa what is happening here okay being a girl growing up with brother brothers increases the likelihood of rough and tumble play because that's what you do with your brother once again uninterpretable literature generally what you see is very very clearcut androgenization of aggressive behavior prenatal testosterone when you're looking at rodents by the time you're looking at primates some pretty strong patterns but nowhere near as dramatic as in rodent species looked at by the time you look at humans maybe just some hints but that at the most one of the most interesting Realms literatures where people have been thinking about prenatal testosterone exposure is work of a guy in the UK at Oxford named Simon Baron Cohen and what he is is basically the world's expert on autism and he has developed what is called the hyper male hypothesis of autism for starters there's a very very big gender skew in autism far more frequent among boys than girls among males than females and what Baron con has done a lot of work on over the years is first looking at a whole array of sex differences between normal human males and females sex differences some of it's the finger ratio stuff some of it is neuroanatomy some of those structural differences in the brain having to do with that some of it is functional spatial skills versus language skills some of it is problem solving and there is sort of a gender difference that tends to come through with that on the average blah blah in that boys males men take more analytical approaches to social problem solving girls women females take more empathic ones so that's a difference okay so he studied all sorts of stuff like that and obviously with hormones as well all sorts of really subtle interesting physical differences whole array of these and what he has shown is that individuals with autism regard regardless of their sex tend to have even more exaggerated versions of those male typical profiles the finger length the analytical focus at the cost of social empathy social affiliation the very strong spatial skills whole bunch of those so he's made a fairly convincing argument I think that is's good something's going on in terms of prenatal androgenization perhaps which produces a more masculinized profile which taken to its extreme winds up being autism in other words normal male behavior is just skating on thin ice before going into this whole realm of sort of dysfunctional socialization lots of stuff with that as we'll see next week some very interesting differences in the wiring of the cortex of people with Autism and males show that same thing just not as extreme okay interesting footnote thing uh Simon bar con is apparently the cousin of Sasha Baron con of Borat which suggests that must be one interesting family when they get together for the holidays okay moving back one more box uh however it's no I'm not going to do that okay moving back one more box now instead of perinatal hormone stuff early envir what about genes what about genes what do genes have to do with aggression competition cooperation empathy Etc if used to be not that long ago if you even raised the possibility that there were genetic elements to aggression you would be hounded out of certain Realms of social science it was viewed as wildly incorrect wildly offensive hidden agendas out the Wazoo for some reason this began to pass in the early '90s or so there were studies in the mid 80s studies conferences in the mid 80s where there were protests they were picketed because in meeting that was considering the sociology of aggression the this of aggression the biology the genetics the inclusion of it was the grounds for the picketing a number of those were cancelled by the National Institutes of Health under public pressure of certain interest groups all of that it used to be viewed as outrageously offensive the notion that genes have anything to do with aggression so there's two ways of showing that that's wrong the first is to sit somebody down and make them go through the last 15 lectures in this class or the other is to reflect on the fact that you would leave like a three-year-old in the care of a Basset Hound but not with a pitbull oh there are breed specific differences in behavior that if nothing else is a demonstration of it that dog breeds have been bred for 20,000 years or so to differ in levels of aggression and levels of affiliation all of that people who for some bizarre reason follow bull fighting there are lines of bulls different ranches in Spain and Mexico where they have been famous for centuries for the particular fighting style of the bulls that they breed their CH jeans have something to do with it of course they do because hormones have something to do with it and because receptors and because enzymes and everything with that it is impossible to have talked about any of the stuff on the far right of the chart without inv genes a ludicrous view so what is known about the relevance of genes to aspects of aggressive behavior first off at this stage there's been a whole bunch of studies many of them winding up in some very visible journals where people find a gene implicating it in abnormal levels of aggression one of those sorts of behaviors typical strategy these might be genetically engineered animals to remove that Gene or there might be a spontaneous mutation and all of these report that these are animals with a whole bunch of these mutations um that these are animals with abnormally high levels of aggression that's kind of a clean experiment if you go in and thanks to a mutation or chopping out one particular Gene and now you've got a lot more aggression in that individual that kind of suggests that that Gene has something to do with aggression perhaps a whole lot what are all the problems with that other ways that that Gene could be affecting Behavior which indirectly winds up getting to aggression one possibility what if that's a gene that is relevant to impulsivity and this is an individual who if you gave the mouse a different realm of tests would be you know shouting its love to the world at an impulsively High rate just as it's being aggressive at an impulsively High rate maybe it's a gene having to do with impulsivity maybe it's a gene having to do with one of the things we heard the last lecture what are the environmental releasing stimuli that cause aggression to occur what's one of the most reliable ones pain oh it turned out a number of these strains of mice that were identified with a gene knockout that here's a gene which can cause aggression it turned out that these were genes that made animals that were much more sensitive to pain and they were more likely in a pain state to displace aggression onto something else or as was shown in some of these these were animals who were more aggressive but they were also more affiliative and they were more everything their just level of arousal their generic level of arousal was a lot higher so all these caveats an awful lot of the genes that popped up and the first generation of those sorts of studies that looked solid that were replicated a lot of them instead had to do with indirect routes rather than directly with aggression itself so what about the genes that have held up and the really like plausible candidate ones we've covered some of these already the serotonin synthesis genes and the serotonin receptor genes and the dopamine receptor genes all of those have been very solidly implicated really careful research the molecular biologists teaming up with behaviorists who knew what they were doing a genetic component and what you know by now that it's absolutely about is this this figure again that's the case with all of these CH oh my God there's not genes causing aggression we know exactly this one modulation all that stuff again depending on the environment and the environment in the realm of genes relevant to aggression the environment is overwhelmingly about abuse and stress early in life so that's about as far as the genes will get you there which is plenty good because this is exactly how the genes should be relevant to behavior this is how all genes are relevant to behavior remember our ultimate punchline from the behavior genetics at the end of the day it actually doesn't make any sense to ever say what any Gene does only what it does in the following range of environments in terms of that what you beginning to find is this still sort of growing field which is beginning to look at differences in these genotypes these different versions of these genes in different populations in different cultures and that's just beginning as a literature I'm not impressed enough with the findings yet that it's worth passing them on but that is going to be a very interesting field finally there's always this puzzle with any of these of oh you've got some Gene that's predisposing you towards being aggressive if you were abused in childhood we still know nothing nothing in terms of that Gene that Gene's got no predictive power as to whether this will thus be someone who grows up and is a sociopathic murderer or if this is someone who grows up and is just an unbelievably nasty Monopoly player that factor again that same deal ooh major frontal cortical damage disinhibition you can't regulate your behavior no science in terms of the neurobiology as to why One turns into a IAL murder and the other one who doesn't catch clues that the family wants to eat dinner again it's the same puzzle over and over and again you could begin to guess what the differences are going to be problems in some of these Realms with these aggressive genes and different upbringings different stabilities and families different relationships different Role Models you can be often running with that one one final domain in genes and aggression and only a handful of you the other lectur knew who that guy Charles Whitman was who was the guy who climbed up the Texas tower all of that okay so here's another chance to sort of score points in the mass murder realm how many people have ever heard of a guy named Richard Speck wow very few No Hands okay no that's a bottle going up not a hand okay Richard Speck was once one of the most notorious people in America Richard Speck was a nightmare sociopath who in 1968 committed a crime that just stunned the entire country people wrote songs about it it was just as brutal as one could imagine he broke into the apartment of eight uh nurses living in Chicago eight student nurses and slaughtered them all and this was you know this was shocking on a level that's hard to describe Richard was The Nightmare sociopathic murderer so he gets sent off to prison eventually for life and in the process at some point or other he's getting some physical exam somebody takes a blood sample something and a lab technician notices something interesting in his blood examining the carot types the structures of his chromosomes and they discovered that he had an extremely rare chromosomal abnormality females XX males XY every now and then you get somebody where something screws up and what you now get is x y y you get an extra Y chromosome and suddenly this had to be the explanation for what was going on males are a total pain in the ass all over the world and they've got those Y chromosomes oh my god the guy has two Y chromosomes in every single cell this explains it and this suddenly started this hysteria about violence and the xyy maale senators were bellowing in Congress about how we needed to screen our school teachers to make sure none of the men had XY y profiles the military was all set to start testing recruits for x y y although it's not clear if that would get you in or would it get you out so how that one worked but they were suddenly interested tons of work went into it this flurry of excitement special funding we need to be on top of this and by the early '70s what was clear was there was no relationship whatsoever so that one went down the tubes and then in one of those ironic ending departments it was eventually discovered that the lab technician had blown it had done the kot typing wrong and he really wasn't an xyy male despite that lab technician then having called up the newspapers he was a normal XY sociopathic maale so that one was up there for a while more Realms of don't overvalue the genetic evidence so that shifts us now one step further back and now beginning to look at whole populations whole populations not yet on the genetic evolutionary level but what do things like ecology have to do with levels of aggression what does culture have to do with it what does factors like that and there's a really interesting array of findings out there first off one important dichot when looking at traditional human cultures is how people make their living and the one that's pertinent here is the dichotomy between pastoralist people and everybody else pastoralist people pneumatic pastoralist people these are cow people these are people who wander around with their goats or their camels these are the Shepherds in contrast to traditional agriculturalists or far rarer traditional hunter gatherers so nomadic pastoralists versus everyone else and what a boatload of anthropology has shown is nomadic pastoralists have higher rates of violence both within group and between group nomadic pastoralists are vastly more likely than other groups to have standing armies Warrior classes to have leadership be derived from people who have had the most success as a warrior to have myths built around their religion that success in war violent Acclaim in war is your gateway to heaven or whatever afterlife is viewed as most desirable this is a consistent finding lots and lots of these cultures nomadic pastoralists are the ones who came up with Warfare on a certain level and Warrior classes and this makes perfect sense because one feature of being a nomadic pastur list is you're nomadic at certain times of year there's one subset of the whole village who's off 15 mil away where there's some good grazing another group is on the other side and what this sets you up for is something that farmers never have to worry about somebody can't come and rustle your farm away at night but people can come and steal all your animals Warrior classes so that at any given point if people are dispersed there is still a designated age group of individuals who are out there to defend the collective herds of the group so you see that in the United States where that has had an interesting manifestation is where people settled in the original 13 colonies from which part of the United Kingdom and some very influential sort of studies really interesting creative ones pointing out that the American South was disproportionately settled by sheep people from the northern ends of the British Isles in other words nomadic pastoral shifting to another realm of anthropological designation these are people who who disproportionately have come from cultures of Honor cultures of honor where people are willing to kill over very symbolic slights rather than over material conflicts where there are vendettas within group there are vendettas between groups where it is honorific to have to avenge a which you do not necessarily find in agriculturalists cultures of honor and that goes hand in hand with nomatic pastoralism and what you get there typically are very clear rules about enforced Hospitality for guests and very clear rules of the the circumstances of aggression retributive ones over symbolic affronts and that's really clear difference regionally in the this country interesting sociologist University of Michigan named Richard nesbet and he grew up in the South and I actually heard him once give a talk where he talks about how when he was about 18 or so he left the south for the first time and joined this very strange culture at Harvard University as an undergraduate and he was dumbfounded by how different of a world this was people didn't shoot relatives at picnics at barbecues which sounded to totally factious but when you look at the higher crime rates in the American South it is not occurring in urban areas urban crime is roughly equivalent in all throughout the United States it is not due to higher rates of what they call 7-Eleven robberies which is just material gain robbery of that sort it is murders of honor it is people who know each other at Social settings people who have some insult have something that has nothing to do with material wealth that this is where the disproportionate violence comes from in the American South and prompted by that nesbet did one of the alltime interesting studies this famous amazing study so he's at the University of Michigan and he Rec recruits volunteers student volunteers who believe they're going in to do a you know Hopscotch tester some such thing and they're going in but he made a point point of finding out where everyone came from and he got a fairly even distribution between the relatively few students at Michigan from the American South and then students from the more traditional North so they get into the psych building each individual who's coming for their appointment and they take the elevator and they come out and they walk down the hall and this is where the experiment happens this bit has somebody working on the project a Confederate on the project I say making a lame pun okay so a Confederate on the project person working on the project and this was a big beefy guy and the whole idea was that this big beefy guy was going to do something insulting to this individual walking down the hallway all male here's what they did they clearly did a lot of thinking in designing the study in terms of what single word this person was going to say and this is what he wound up saying this the volunteer would be walking down the hall Here Comes This Big beefy guy moving fast and he comes by him bumps into him with his shoulder walks past and says watch it and then disappears volunteer comes in to start their study and quickly they look at blood pressure and heart rate and stress hormone levels and testosterone levels and get a typical participant in this study from the north and they come in and they're a little bit irritated and what a jerk and all of that and it's all over with 2 minutes later get people from the American south on the average massive stress response hypertension elevated testosterone levels big Regional differences these are some of the physiological pictures of cultures of Honor what else what other interesting things about ecosystems or ecology or cultural aspects another dichotomy that is really consistent and this one Maps pretty readily on that past list versus everybody else the sorts of cultures and the level of violence that are generated in cultures that live in deserts versus rainforests and once again deserts are where you are far more likely to find nomadic past lists rainforests hunter gatherers mixture of hunter gatherer small farm agriculturalist two totally different worlds of occupations and what you see is far higher rates of violence within group and between group in desert dwellers and that Maps very logically on to pastoralists versus everybody else desert dwellers open Savannah grasslands that's where you see the warrior classes that's where you see raing of other tribes that's where you get that pattern virtually none among the hunter gatherers I might point out something which will become sort of focused on more in a lecture in about a week or so um I should point out that uh desert dweller nomadic past are also the cultures on this planet that invented [Music] monotheism consistent difference desert dwellers tend more towards monotheism and it was invented by desert nomadic pastelist rainforest cultures far disproportionately tend to be polytheistic and this is not remotely surprising if you're living in a rainforest and there's 10,000 different types of edible plants around there it doesn't take a lot of work to come up with a notion that there's lots of different spirits and God Gods out there what the desert is about is One Singular baked truth there of surviving that's where monotheism was born monotheism historically is more associated with cultures that invented Warfare and invented Warrior classes and rating and things of that sort that's kind of interesting okay moving on more cultural differences one of the great great predictors of having a society with lots of violence in it and lots of warfare elsewhere is a culture that has lots of cultural myths of victimization we have been screwed historically because of this this this and this and coupled with that an ethos of not turning the other cheek but instead of Retribution cultures that have strong sort of histories and or myths of victimization and strong values built around retribution are extremely violent societies and often really bad news as neighbors what else amazing study that got published about a year ago which is on the recommended reading list for this is not required but this was a deeply interesting study it was one of those Game Theory studies it was a game a little bit like prisoners dilemma not exactly the same but the same sort of Notions that you could be very generous in your game playing style you could be absolutely rational fair you could be exploitative a whole range of possibilities what these guys did in this study was take scads of people from 40 different countries no they didn't from 16 19 they took from a bunch of different countries bunch of different countries and just to control for things all of the subjects were University students so you're selecting for a fairly homogeneous Bunch both within group and across these different countries and what they did was they had people play these games and they have the option for what is called altruistic punishing which we will hear more about in a little while which is you have the option to expend some of your resources your points your chips whatever you can spend to punish the other individual for cheating and the question of course becomes how much are you willing to spend to punish somebody when they've been cheating against you when they've been stingy when they haven't reciprocated all of that first finding which is everybody across all the countries averaged out to the same rate the percentage of resources that someone is willing to expend on punishing a cheater so no particular cultural differences there but then they identified another interesting realm of game Behavior here which they called antisocial punishment which is where it's not that you are expending some of your resources to punish somebody for having cheated it's where you're expending resources to punish someone for having been overly generous and that pops up in certain sorts of games it is not terribly common when it's the person who is choosing with their opponent but when you have a third party you have no cultural differences at the rate at which they are willing to punish cheaters but here's where the differences came in the rate at which people would punish unexpectedly generous players and you got a big spread the lowest rate at which this happened was nicely as it turned out people from this country which is kind of nice people from England and of course who else the ever useful Scandinavians with their powerhouses of the cells and their other cliches all set so the Scandinavians come through yet again but for once we're able to hang out with them and actually count as having a good profile the lowest rates of people being willing to do this nuto antisocial punishing in those countries in between rates number of Middle Eastern countries a large number of Eastern block countries in other words Slavic ones that used to be part of the Soviet Union Korea and turkey those were the middle ones which ones had the worst rates I will just read the two countries here that were way up there a big gap between them and the rest of the countries one was Greece and the other were the Arabic Emirates on the Saudi Arabian peninsula where people are willing to spend more to do antisocial punishing than they are willing to spend to punish cheaters extraordinary finding people from Muscat which was where the University was those students were more willing to punish someone for being unexpectedly generous than for somebody cheating on a Game Theory social contract totally amazing so what's that about when they actually question people you see things with people from there along the lines of if people start doing that of being all generous like that it's just going to up the ante for everybody everybody's going to have to start doing that that's an interesting piece of reasoning but when you look at a larger level what these researchers then showed was a predictor across all these different societies of the rate of this antisocial punishment levels of trust in the society some standard metrics used by sociologists who were interested in this concept of social capital how much Social trust there is in the society how much participation there is how much of a sense of ethicacy and what you see is the lower the levels of social capital in these societies the higher the rates of this antisocial punishment totally interesting study next in the realm of culture what what are people doing these days what is sort of the science and the research these days trying to make sense of terrorism and the sort of cultures that give rise to them and the sort of ideologies that give rise to them a number of basic dichotomies one is a camp that views it as always abnormal sociopathic Behavior another is a camp that just views terrorism as extremes of ideology the first one is much more about individual dysfunction and ooh this is a neuros psychiatric problem perhaps the second one is one more a feature of cultures that have extremely strong ideology so that's one division in there as to how to think about it in the community another division is really interesting and it's one my reading of this literature that has totally thrown people in the field for a loop forever there has been a profile a demographic and psychological profile of individuals who are terrorists all the way back to the people who did the Boston Tea Party in this country the IRA all sorts of stuff like that the hag which was an Israel terrorist acts before independence studied in a whole bunch of these that there tends to be a rather consistent profile of these individuals who would be terrorists young male socially isolated socially unaffiliated in terms of relationships relatively uneducated background history of childhood abuse and another factor which has just completely slipped my mind what was it oh you all know okay so that's exactly what you find in these folks a picture of isolated sociopathic individuals who already have a history of antisocial behavior these e people who if they hadn't stumbled into this cause would be spending their time mugging old ladies that would be that profile and you look at these various groups and that has been a consistent one terrorism in the recent years particularly Middle East fundamentalist is a completely different profile it is not young men it tends to be educated well off people in their 30s and 40s overwhelmingly middle class or upper class backgrounds next it's not just middle-aged males it's females it's women to a much higher extent than seen in any previous sort of population dealing with terrorism next what you see is these are individuals who on the average tend not to have had any direct exposure to the uh suppression that they are fighting against as opposed to the sociopathic model a classic picture with Ira gunman the father was taken away by the whoevers shot never came back again and they were passed on the family mantle the current picture is very different one no direct experience of the persecution finally tending not to have particularly high levels of religiosity and this is this very contemporary profile where you get these 40-year-old Engineers who are suicide bombers where they go home they say goodbye to their families they make a videotape sort of wishing everybody well and after having quit their job and paying the rent one extra month and off they go and blow themselves up people I sense in the field haven't a clue how to make sense of what this is about very new challenging feature one interpretation one is of a school pushed by people like Phils zardo here in the psychology department incredi influential psychologist who has a general theme over the years has argued for the stance that under the right circumstances under the right coercive circumstances virtually anybody could do anything that is appalling zimbardo who did the famed Stanford Prison study the other view is okay this isn't a lesson that anybody could wind up being this violent if look at them they're an engineer and they've got a master's degree and all of that instead it is simply an outcome of a lot of what terrorism is about these days a very novel world of international terrorism rather than within country suddenly you have a world of people who need to be able to do things like get passports and fly elsewhere and be able to navigate customs and things of that sort it is suddenly selecting for a more sophisticated population of individuals you know the jury's out on all of this but this seems to be a very challenging thing for that field okay so now this allows us to push one step further back I'm going to skip over a few things there now in so far as we are looking at culture and in so far as we have looked at anthropological differences and in so far as we have looked at anything having to do with genes we now have to talk about Evolution because that's where the genes came from of course so on first pass it's absolutely simple to understand what evolution has to do with aggression which is evolution selects for higher and higher levels of aggression because that's what you need to succeed unless you grew up watching certain types of television programs in which case Evolution selects for no aggression occurring because animals behave for the good of the species okay so sorting through that beginning now to imply some of our foundations from that world individual selection kin selection reciprocal altruism and the modern version of group selection so so where do these play out first how do these play out in terms of increasing the likelihood of aggression and antisocial Behavior individual selection males that is absolutely simple in every culture on this planet and in every social species know in the vast majority of social species that have been looked at the majority the major cause of aggression in that Society or species is malale male violence over reproductive access to female that is close to a universal that is the most common form motivator of violence on this planet humans and otherwise so that one's easy to come up with in terms of obvious stuff one classic study inanely controversial one that appeared to be the landmark demonstration of some of the same in humans traditional tribe hunter gatherer down in Venezuela in the Amazon called the yanam mama who have been The Darlings of sort of high testosterone male anthropologists for decades that these have been intensely studied people many decades now predominantly by an anthropologist named Napoleon shagon who is now a Meritus at Santa barbar but he's been a major figure in anthropology for a long time and these people are insanely aggressive incredibly High rates of violence between groups within groups sufficiently so that the written monographs on the yanam mamamo with titles like yanam Mamo The Fierce People things of that sort and about 15 years ago shagon published a paper in science using decades worth of data showing that the more people particular men in this Society in this tribe the more people you have killed on the average the higher your reproductive success that's it that's it that's everything right there that's Darwin all over the place just play it out over time and this is dramatic selection in a traditional Human Society the reproductive rewards of violence and murder very major influential study picked up by all the newspapers and it has been completely mired and controversy ever since all sorts of ethical sort of attacks on shagon most of which that have not stuck but some really really telling dissections of the work ripping it apart on statistical grounds I don't think it's actually for real but that as easily interpreted within that framework then more Realms of violence individual selection of rangat hands raping each other rape in other species rape among humans which of course brings up the question of whether rape is more about passing on copies of your genes or more about power and subjugation and the overwhelming sense in the field is it's about the latter it does not have a whole lot to do with where a world where you have to start counting numbers of copies of genes and thinking about adaptiveness of strategies next individual selection explaining another realm of violence in most cultures and in an awful lot of species looked at the second leading cause of violence is males attacking females over denial of sexual access and this is amazingly common all over the place the second leading cause of violence on this planet across humans and different cultures and obvious easy individual selection explanation there finally another realm individual selection the world of female female competition and infanticide competitive infanticide we know how to run all of those so lots of reasons within the framework of individual selection to see where you are increasing rates of aggression next kin selection you're going to know that one as well two brothers or eight cousins and that whole strategy and that's why related individuals cooperate with each other in circumstances of aggression chimpanzees chimps are function where females are the ones who pick up at puberty and go elsewhere so all of the adult males in a chimp group are brothers first cousins things of that sort and thus you get one of the outcomes of that that high levels of male male cooperation and as we heard that has been reported by Goodall and others to result in things that look absolutely like organized Warfare and genocide eradicating all the males in a group in the next Valley over purely along kinship lines what else other primates Old World primates monkeys like baboons aggression is very much between lineages than within same exact kin ction sort of arguments so what happens when you get to humans things get more complicated of course the first one being that a relative relatives is a relative term in that it is a sliding scale wonderful quote to that effect a bedwin quote which is it's my brothers my cousins and I against the world and it's my brothers and I against my cousins as in who counts as an us and who counts as a them is a sliding measure it is a relative measure what you see is by the time you get to humans capacity for very rapid shifts of us them along lines of relatedness now one of the readings which I can't remember now if I actually did stick in an assignment but one of the readings looks at the classic social biological interpretation of making sense of aggression along lines of kin select C what do you make of child abuse what do you make of homicidal parents damaging parents how do you make sense of that in a are you out of your mind this is copies of your genes there the challenges to that and this is a couple daan Wilson who University of Toronto I think who have for decades been working in this area showing things like a child is more likely to be abused by a stepfather than a biological father wonder what that's about kin selection that's easy a child is more likely to be abused by a paternal grandparent than a maternal one kin selection explanation more certainty of paternity when something is going through a female line so they've done all these studies showing that degree of relatedness explains a fair amount of the variability in patterns of violence within families problem with it two problems one is there's been a lot of failure of replications in other societies the Scandinavians for example don't see that pattern when they study it the other is there's alternative models there's economic models for example when times get tough in terms of displacement Family Violence increases families with stepfathers on the average are under more economic duress than families with biological fathers greater likelihood of violence there it is a very uncontrolled literature that is sort of viewed as the classic and in other people's view the most ideologically extreme way in which sociobiologists think about something as bizarre and challenging as close relatives killing each other one final realm which is in terms of this us them stuff the point here being how do you decide who's an Us and Them and suddenly we're in our world of ethology do we make some us them dichotomies more easily than others do we have prepared learning to see some differences as more Salient than others and us thems that remains immensely controversial subject in terms of what are the natural categories that young kids divide people up by are kids colorblind in terms of skin color are kids blind in terms of body types in terms of some such things lots of work in this area how natural are some of the usan dichotomies that we tend to come up with stay tuned about 20 minutes and you will see not very natural at all as soon as you get to humans all this social biology stuff with kin selection is interesting but as soon as you get to humans you get to something vastly more interesting and important back to our recognizing relatives realm the business of how we interact not with our relatives but with people who we feel as close to as if they are relatives pseudo kinship and what you see in culture after culture is brilliant manipulative skills on the part of powers that be to make some non-relatives feel more related to each other than they actually are what's this about this is military indoctrination the whole point or one of the main points of military training early on is to get people to become a band of brothers a band of pseudo kin shipped relatives to increase the cooperativity later on to increase the odds that you were willing to give up your life for the person next to you culture after culture is great at doing this Warrior cultures for example the Messi in East Africa they have a Warrior Stage When You're 15 you go become a warrior roughly 15 and you stay that way for a decade and you protect the cows and you raid the neighbors and once you're you become an elder and get married then to a 13-year-old but what you've got there is the entire structure of warrior life is built around pseudo kinship they live separately from everybody else they use kinship terms for each other for the rest of their lives their wife will refer to somebody from their warrior class as her brother and- law Warriors are not allowed to eat their own food they can only share their food with another Warrior all built around generating pseudo kinship other version at other more industrialized versions of it the Israeli military for example allows kids when they are signing up after high school to join particular units as a group a group of friends from their High School increasing the pseudo kinship element there more of that something that was absolutely unprecedented when you look at the difference between kinship and pseudo kinship World War II United States hugely heterogeneous country obviously blah blah Melting Pot all of that and World War II was sort of the peak of that picture and what you got in many many fighting units was something straight out of Central casting in these inspirational movies there's McCarthy from Boston and sapola from Philadelphia and Kowalski from Chicago and then the southern guy and the Jewish guy from who knows where and they're all together and they're a fighting unit and American unity and all of that and what does that produce something that was virtually unprecedented in Warfare if you were American soldier in World War II and you were of German American or German ancestry you would on the average almost certainly share more genes and common with the people you were trying to kill than the people you were willing to give up your life for as you had classically heterogeneous troops on the American side completely unprecedented so this business of pseudo kinship historically Vietnam was apparently a major failure of military pseudo kinship mechanisms in that something unprecedented was done there which was people were not kept in stable units fighting units instead people were constantly shuttling in and out and you would get these nutty circumstances apparently where you'd there in the middle of a firefight and the person over here is some kid who showed up this morning and the guy here if he survives this he's shipping out home to Hawaii tonight and who feels like a brother no one Vietnam had an unmatched degree of breaking up Unity of troops why was that done in Vietnam something that kept happening as soon as they allowed units to remain more stable the rates at which soldiers were shooting their officers would go way up so another perhaps version of cooperation hand in hand with the pseudo kinship is of course the flip side pseudo speciation the mechanisms the psychological the propagandistic mechanisms that are available to make them seem as different from you as possible not just different sorts of people but pseudo speciation they are so different they hardly even count as humans it doesn't count as much when you kill them and endless Realms of That World War II propaganda in the United States about various ethnicities that we were fighting against pseudos speciating various genocides the Rwandan one the sort of Call to Arms there was Kill The Cockroaches kill the Cockroaches the hu tribes killing the tosis there and this was pseudo speciation let me give you an amazing example of this which occurred in this country not all that long long ago around 1990 an astonishing piece of pseudo speciation that happened in this country 1990 First Gulf War uh Kuwait was slant drilling oil from underneath Iraq's land Iraq got pissed off invaded them and suddenly we had the first Gulf War United States goes in there and to drive the Iraqis out of Kuwait and ultimately has to make the decision of whether to follow them into Iraq and overthrow Saddam Hussein and that wasn't done but so this war going on very early on it was absolutely clear where it was heading which was that the uh diplomacy was failing and the United States was beginning to pull together a coalition of various countries that would be unified Force fighting against Iraq but it had not yet been authorized by US Congress as an act of War suddenly into this came a woman a refugee from Kuwait City Refugee she was a nurse who worked in a hospital there she had managed to get out of Kuwait after the Iraqis had invaded and she came and testified in Congress about an appalling thing that she had witnessed which was when the Iraqis came in and took over their Hospital not only did they steal all the supplies they used they took the newborn infants out of the incubators and left them out to die and Shi the incubators back to Iraq everyone was flabbergasted by this this was every newspaper in the country everybody learned about this everybody suddenly learned my God they leave babies out to die these people hardly count as human and critically that war was authorized by Congress by just a couple of votes of senators and at least a half dozen of them cited this incident and helping them decide this was something that had to be done this was a deciding factor in us going to that war and the remarkable thing is it never happened the nurse was not a nurse from Kuwait City she was the niece of the Kuwaiti ambassador to the United States she had been trained by a public relations firm paid for by the US government to make up the story and she sat in our Congress on live TV in front of the entire country lied like crazy and we went into that war with a 92% approval rate one gigantic piece of pseudo speciation my God they leave babies out to die it will hardly count killing them they're hardly even human and the coverage of when it was revealed what was actually going on with this person didn't come anywhere close to front page in any newspaper in the country buried down in there virtually the entire country came out of that incident having learned how inhumane those people hardly count as human Okay 5 minute break our principles of individual selection kin selection reciprocal altruism begin to give us insight into circumstances where Evolution should select for more aggression for more Warfare along those lines now the flip side what is it in the Realms of these basic building blocks of evolution that will push for more cooperation more empathy more affili ation less violence individual selection level we already know some of these examples which is that whole world of alternative male strategies that whole world of sometimes if you're a male baboon you could pass on lots of copies of your jeans by fighting like mad and being high ranking and sometimes it's by bypassing all of that and being a nice guy having an affiliative relationship and female choice being the thing that winds up increasing the number of copies of your your genes so the possibilities of alternative mating strategies the possibilities of of course parental behavior and all we need to do there is switch over to the world of South American pair bonding monkeys and those are not animals with particularly High rates of aggression so all of those are circumstances where that could potentially be perfectly genetically viable alternatives to ooh natural selection selects for higher degrees of violence because it passes on more copies of your genes okay kin selection so we've just gone through kin selection in so far as it can generate pseudo kinship and make you a better more murderous soldier who is more willing to give up your life for your Band of Brothers and conversely pseudo speciation they hardly even count as humans the flip side of course is ways in which the human capacity for pseudo kinship can be used to increase violence and to make things more Peaceable and to make people feel more connected with each other this is a ritual in all sorts of societies where you generate pseudo kinship as a means of generating peace one example traditional bedwin Society here's what happens you have two groups who have been having tensions who've been fighting who've been having some Clan warfar as whatever and they have now figured out a way to have a treaty to stop fighting with each other here is the ritual that is done which is a bunch of the old guys from each of the groups come and they sit down and they start exploring each other's genealogies who was your great-grandparents who was your great great great going through all of that and at some point one of them has the job of making up an imaginary relationship between the two groups Chuck are you kidding I had a great great grandfather named Chuck also we're relatives a ritual absolutely transparent that people go through there to generate a supposed rationale for relatedness a big ceremony of pseudo kinship another one is seen in some Aboriginal groups in Australia apparently this is a motif that pops up often in Aboriginal rock art and apparently it's this symbolic version of this phenomenon okay you've got somebody wandering through the great back of Beyond there and there are very few sources of water there's a water hole up ahead you've just walked 10 miles to come to it and you suddenly notice a stranger coming towards the water hole from the opposite direction and this is a water hole that is essential for you to survive you're not going to be able to walk far enough to get to the next water hole maybe what you should do just in case this person winds up being aggressive is you should attack him first a virtual guarantee of aggression here's a ritual that has been worked out instead that bypasses it the two individuals sit down around the water hole and each starts giving their genealogy I am the son of who's the son of who's the son of into the next bar mitz for whatever oh we're relatives let's share some water they don't fall for it for a second but it a totally artificial mechanism of pseudo kinship to make it possible for two strangers to share this absolutely essential for Life Resource and not try to kill each other same sort of thing pseudo kinship in all sorts of historical examples of revolutions revolutions generating pseudo kinship what is often the term people use for each other after the revolution sisters brothers unite pseudo kinship terms in French for example there's the informal two tents and there's the more formal one and you're supposed to use the more formal one with sort of in the outside world and in the aftermath of the French Revolution it became illegal to address somebody a stranger in the formal tense it always had to be with the familial two cense there pseudo kinship more and more of it so this brings up what is initially a really really depressing set of studies which turn out to have a very nice optimistic resolution to them very disturbing work work done by a number number of labs over the years most notably Elizabeth felt who is at NYU and this is work using functional brain Imaging amydala all of that you put people in a brain scanner actually you put one in and you put them in one at a time and what you do is you're flashing up pictures to them flashing up pictures of people of faces of faces at a rapid speed so there's virtually no conscious processing this is all tapping into subliminal stuff and what she reported and what has been replicated by another a number of other groups since then is that you get activation of the amydala on the average in people when you subliminally flash up pictures of somebody of another race whoa that is distressing to have been found that is not a good thing because this is totally rapid subliminal stuff and replicated some of the best people in the field showing this my God the amydala has an us them that's in effect there in a quarter second after seeing something this is hopeless we are so dichotomized this is a disaster in the years since then much more interesting stuff has emerged and this has predominantly been researched by Susan Fisk at Princeton showing that it doesn't necessarily work this way okay here's what you do first version you tell somebody I'm going to be flashing a pictures of faces and while you're lying there in the brain scanner and what you do is you force them to look at the picture in a way where in a purely mechanical visual viewing you're going to say some of the pictures have a big red dot right in the middle of it and anytime one of those comes up I want you to press this button in other words just process the picture for just a vis ual pattern you do that and the amydala doesn't activate when you see a picture of somebody of another race okay this is not very exciting now the next thing she would do get people to start thinking categorically here's what you do she would now have people going in there saying I'm going to give you a bunch of pictures flashing of pictures and what I want you to do is to stop I'm going to stop at some of them and I want you to look closely and tell me do you think this person is older than age 30 or younger than age 30 in other words what you have just requested the person to do is think of the face in the picture as belonging to a category rather than as an individual you're going to look at this picture now and you don't really need to care who the person is or what they look like or anything like all you need to do is think of them as part of a category and when you bias people like that and you flash up the picture of somebody from another race the amydala gets even more activated you have primed somebody to think not about individuals but to make them think of people in categories finally what she shows is exactly the opposite now what she does is prime something a totally neutral sort of priming to try to get people to think of the person in the picture as an individual and she asks totally innocuous neutral things along the lines of I want you to look at the picture I know this sounds silly but I want you to look at the picture and tell me do you think is this the kind of person who likes Coke or Pepsi totally sort of diagonal orthogonal to all of this stuff get someone doing that and now the amydala doesn't activate all you need to do in that study is subliminally Prime someone to think of someone who they're about to look at as an individual rather than as part of a category than as part of a group this is not rebuilding Society so that we change our USS this is a minor prompt 30 seconds before somebody as the pictures flashed at them that's all it took in these studies more good news emerged which was that you would also see separate of these sorts of manipulations long-term developmental aspects that were predictors of this phenomenon people who grew up in racially and ethnically diverse neighborhoods didn't have this amig effect people who had had a significant relationship with a significant other of another race did not have this amydala reaction there so the easy sort of solution to this being depressing okay Early Childhood exposure throughout life that's great that's very good news but even more remarkable in her studies is just a prompt prompt somebody to think of that person as an individual and your amydala is not doing and US them with them anymore now this whole business about if you grew up in a diverse neighborhood that Taps into a whole field of called Contact Theory the notion that aggression is decreased affiliation is increased if people have grown up with lots of contact with people from other cultures other societies other religions all of that or if people live in contact with them and in general what this lar literature shows is it does work that way contact Theory growing up in diverse neighborhoods growing up in diverse communities increases the likelihood of a broader umbrella of what counts as in us that's good where does it not work one realm where most of the Studies have shown this is a realm that's totally heartwarming and it would be great if it did work but most of the studies show that it doesn't these are the circumstances where somebody puts up the money to take some really poor Irish Catholic kids in Belfast and some really poor Irish Protestant kids in there during the worst of the civil unrest there and they get to go to some place wonderful and far away and they all go to summer camp together and they have teams that are mixtures of the kids by different religions and they're growing they're growing to recognize each other as individuals or the versions lots of which have been tried of sort of Retreats or even camps for Palestinian teenagers Israeli teenagers these are the leaders in the future they will go back and have learned they're not so different after all they're kind of just like us what those Studies have generally shown is that doesn't work it works for only a little while you can't just pull it off on a two-e camping trip it takes more sustained exposure it basically requires growing up in or living sustainedly in so that's been a disappointment one additional disappoint Mo with the contact Theory literature which is one of the papers which again I think I put in the suggested reading okay so you've got two different groups two different populations two different ethnicities whatever and they are living in generally the same area but nonetheless segregated within group in smaller areas one scenario here's the region where these two groups live and there's an absolute boundary between them here instead there's sort of an undulating boundary it's less clear and critically there's more surface area there's more interfaces between the two groups there's more domains of experiencing people from the other group finally versions where instead you have pockets of different groups embedded in other ones and that being a completely different scenario where in fact you maximize the perimeter that you get there and what's been shown in this one study that I recommended that you guys look at is the more contact the more interfaces between the two groups and living situations doesn't guarantee that people will get along better what you will find is there's intermediate points where the contact profile increases aggression because what it does is you just barely have a critical mass of people on your side to Be an Effective group to fight with them you see totally different outcomes depending on the spatial characteristics of the subgrouping and what people showed in this paper was they then analyzed the different ethnic distributions in the Balkans the Bosnian more the croatians all of that and seeing that this was extremely predictive of where the violence took place in terms of where you had what they viewed has the least optimal set of interfaces of contact between groups more contact is not necessarily always equal more understanding and we're all just the same more contact can equal in some cases more irritation and more resources and more Unity to do something about it okay more of pseudo kinship so this whole notion again of pseudo kinship we are species where we're not recognizing individuals by smell all that we're doing that cognition stuff but don't forget the kabut study but we're doing that cognition stuff and thus we can do pseudo kinship and thus we could be manipulated by powers that be by governments by religions into viewing non-relatives is more related to us and all of that these are very abstract processes and it brings up another realm an extremely abstract realm that pushes for more cooperation and less violence and this goes back to what I was talking about the other day the neurobiology of symbols how we code for certain types of symbols certain metaphors in our brain and that's back to that whole world of you're using the same part of the brain for disgusting food and moral disgust warm drink warm personality that weird concrete literalness because you got to put metaphors somewhere when humans started developing them the outcome of that being that metaphors can be extraordinarily powerful and and a number of researchers probably the person most visible in this realm an e an economist University of Michigan named Robert Axelrod has doing a whole lot of work showing in a sense the importance of symbols in peacemaking and it makes perfect sense you take the extreme rationalist view of humans as economic machines and what peacemaking is going to be purely about is figuring out contested resources and how they are going to be divided up and what axel another show instead is this whole irrational realm of be respectful of somebody else's symbols and figuring out how you're going to divide up the land suddenly becomes a lot less important the power of symbols over rational contested resources and he studied things like how a critical thing that happened in peace coming to Northern Northern Ireland was at one juncture a bunch of the sinen however that's pronounced the exmilitary wing of the IRA that were just beginning to have extremely mistrustful negotiations with some of the Protestant sort of unionist and all of that they did something outrageous they sent a 50th wedding anniversary gift to this guy Ian Paisley who was the murderous head of the sort of protestant death squads there somebody just decided to try this and this was a massive breakthrough any anyone who saw that movie Invictus who have read about it the utter Brilliance of Nelson Mandela of having spent his time in prison learning to be completely fluent in Africans so that when he was sitting down and starting to negotiate with these people the fact that he could sit there and speak in their language a language that is so Laden with symbolic importance to Afric coners that that was a gigantic symbolic coup of Mandela embracing the sport that was the very symbol of a parod of Mandela doing very subtle things that a number of people pointed out who were involved in the negotiations okay Mandela just when he has gotten out of prison and he's about to meet with some of the leaders of the government and some of the most right-wing opponents to any sort of peace and so we need a conference room and no that's not what he did he insisted they would have the meetings in his home his home that he had just returned to okay well let's clear off the dining room table no that's not what he did he would insist they did this in the living room where they would sit down on stuffed armchairs and couches and something that he did apparently always at these is he would sit down on the couch and gesture to whoever was likely to be the most impossible Foe and say come sit next to me sit next to me on the couch and would proceed to jump up at various points to say can I get you some more tea do you want some more there would be food there would be biscuits there would be whatever brilliant brilliant use of symbols if I'm sitting here and this guy keeps jumping up and getting more cookies just when I was getting a hankering for some more cookies maybe not so different after all people who get cookies for other people make the world more peaceful or something or other what Axel Rod has also shown in some of his work is the potential for it really interesting stuff he will for example he and people working with him have interviewed say Hamas leaders in Palestinian in the Gaza and the West Bank some of the most most sort of opposed to the existence of Israel most confrontational groups and he gets quotes from their leaders along the lines of if the Israelis would ever once just say we got screwed in 1948 and we're sorry it happened we would be willing to make peace and then he goes and talks to some Israeli generals and who are some of the most right Wing ones he selects them for that and they sit there and they say stuff like if the damn Palestinians would ever just get the anti-semetic garbage out of their school books we'd be able to think seriously about peace the next day it's not about water rights it's not about return of land it's not it's just about are they going to respect our symbols and the legitimacy of our history and the accuracy of it enormously potentially powerful interventions there okay so kin selection most importantly pseudo kinship moving on now reciprocal altruism where does that come in in terms of potentially making for more peace and what's clear is in principle it should never do it if you're playing only a single round of a game with someone a game in the prisoner's dilemma sense because there's absolutely no reason to cooperate because you were never going to face the person again and this is something that was called by the zoologist Garrett Harden the tragedy of the Commons in a circumstance of shared resources but limited responsibility and limited repeated interactions you have to select for selfishness you have to select for what is termed a Nash equilibrium where the only possible rational thing to do there is to not cooperate so how do you ever get cooperation to evolve in groups of organisms so back to the same axle Rod his work with computer tournaments there with a Tit for Tat seeing that under some circumstances one of them can dominate t for Tata is a great optimal one in the real world though how do you ever jumpstart cooperation how do you ever get one of those strategies going when the starting state is complete lack of cooperation we already know one example which is founder populations that whole business about get an isolated population has a higher coefficient of relatedness in bread out of kin selection establish High degrees of cooperation they come back and it's this group selection phenomenon of you better become as Cooperative as them or you're not going to be able to compete you can see the same exact thing in circumstances where it is not a founder effect of a population goes away for a while and then comes back but where a population is functioning in that way amid a sea of non-cooperators in New York City in the 1980s there was this totally weird phenomenon and that there were two ethnic groups that were moving into New York at a much higher rate than in the past Korean immigrants and Lebanese immigrants and both groups happen to gravitate towards grocery stores the Korean Community fruit vegetable stands uh the Lebanese Community more regular old grocery stores and they were incredibly successful and these popped up all over the place and the people who already had the fruit and vegetable STS and stuff started complaining that they were at an unfair disadvantage how come because these Korean shop owners would cooperate with each other they would give each other interest free loans that's not fair that's not fair that they're being nice to each other we can't compete and the same thing with the Lebanese grocery owners that you had people doing reciprocal altruism in a community of trust and what they were immediately doing was out competing the non-cooperators and amid these bizarre demands for like Banning Korean fruit and vegetable stands or somewhat like this was a point of great hostility during that period in New York City because those people were cheating they cooperated with each other so either join in or you will be driven to Extinction so that is one possibility what are the other circumstances in formal Game Theory play that favors the emergence of cooperation critical one repetition that you're going to play against this individual more than just once if it's one time it's tragedy of the commons there's absolutely no reason to select for repeated to select for cooperation repeated interactions and it opens up the possibility of you being punished for being a cheater what they call the shadow of future retribution one qualifier with that though you need to have multiple rounds of interactions but it can't be a known number of rounds you can't know how many rounds it's going to be think through this you know that this is the very last round you are going to play and once the only logical thing to do is to cheat the very last round functions as if it was a tragedy of the common single game single round game so the only logical thing to do is to cheat in the very last round in which case the only logical thing to do is to cheat in the next to the last round and the next to the last a known number of rounds of interactions immediately does in cooperation because it sort of flows backwards with this collapse of the system next next thing that favors it is what is called open book play by people in the business which is you will be playing against a number of different individuals and you know pairs going cycling through and the critical thing is when you begin to play with someone else they can know your record as to how you played in previous games in other words once you bring in reputation when reputation can be possible suddenly you select for cooperation next what's shown is that if you have people playing in multiple games games with each other especially when they're unsynchronized you select for cooperation as well what's this about what you do is if one of the games makes it very very easy in terms of payoff for cooperation to get established if you intermix rounds of that game with a game in which there is very little motivation for cooperation starting what you see is a psychological bleed over if you're cooperating with this person in this game which is now done here down done here it greatly increases the odds of when doing the other game of beginning to cooperate as well multiple games and it does not take much to see that this is more like the real world than playing prisoners dilemma with one single individual next the possibility of punishing someone when they are a creep and that's what we heard about before what is term now in the field altruistic punishment if somebody does something crummy to you you are allow to expend a certain amount of your resources to take more of the resources away from them that selects for cooperation something that even selects faster is second party altruistic punishing you're not taking part in the game you're watching these two individuals but you have the power to use some of your resources to punish a cheater an outside enforcer that selects for cooperation even faster then and something that is even more effective which is termed secondary altruistic punishing here's what you do what you do is somebody people are observers of other people's interactions and seeing if they're cheating and they can do some altruistic punishment if they think this individual is a jerk and all of that but here's what you do if there's a circumstance where somebody cheats and this third party individual doesn't punish them they get punished what's that about that's honor code violations the that's the expectation that you were supposed to report someone who has had an honor code violation and if you don't you will get punished that selects for cooperation really fast also and all of these these have been computer tournaments and all that you know that world of research by now finally more subtle stuff give the person the opportunity to drop out of the game to secede from the game give the person the opportunity to not play against you but to choose I'll play against all these other individuals but not that one begin to put that power in there and you select for cooperation that much faster so that's some good news final level final level at the group selection level group selection not in our behaving for the good of the species but as we know the more modern version of it selection for traits that are only manifest at the level of whole group a always loses to B but groups of a always defeat groups of B all of the stuff we've been seeing people suddenly cooperating with each other as a small group and driving the non-cooperators out of business that's a group selection argument going on there so you can have that as a means for generating a lot of cooperation that's great that makes the world a better place unless there's a downside to it and back to chimpanzees what do you have when a bunch of related shimps are having not individual fights with males from the next Valley over but functioning as a group you are having an example of group selection which thus brings up one of the most profoundly scary things on this planet which is when you got a bunch of males who are getting along well with each other and they're beginning to look at the neighbors cuz lots of males cooperating together can make for some very bad neighbors as some people in the field have emphasized a decrease in homicide within a group is a prerequisite for inventing genocide between groups so group selection is not always this magical founder effect of everybody wanting to learn the new folk songs what you've got instead are circumstances where it can go very wrong final amazing example showing the emergence of cooperation and this was not a game theory demonstration this was not an experiment this was a real event that happened and an extraordinary one this occurred during World War I a lot of people have learned have heard about a phenomenon that happened there a historical incident that was very very cool but pales in comparison to what I'm about to tell about in 1914 the first Christmas of World War I somehow the decision was made that there was going to be a truce on Christmas day all of the fighting up and down the trenches was going to cease for 24 hours and had has been documented it was amazing and bizarre men out of the trenches playing soccer with each other from different sides a bunch of German and French guys playing against some British and German guys on the other side people exchanging gifts people exchanging helmets as souvenirs people singing together people getting Drunk Together from the two opposite sides and eventually when the officers got them to go back to their job they return to trying to kill each other amazing bizarre incident what was very striking about it is it extended actually 2 or 3 days extra longer than planned because the officers couldn't get people to stop doing this that's very cool but that's an outside force already establishing the cooperation here's something much much more impressive and this happened in World War I and it didn't take a bunch of generals or heads of states to negotiate a truce the way in which trues would spontaneously emerge over and over again across the trenches how do you generate a reciprocally altruistic Cooperative relationship with the enemy in the trenches over there where you don't speak the same language and you don't even see their faces here's what you do you take your best Gunner and have him come up and lob a shell 20 yards behind the trench there and blow up a tree now have your Gunner lob a shell to hit the exact same spot again and do it again and do it again do it a bunch of times what are you communicating to the other side this guy is really good and we're choosing not to put the missile down on top of you what are you going to do about it and then the other side would get out their best Gunner and do the thing in return and you have just worked out a non-aggression Packa and this is occurred over and over again in the trench warfare documented in Letters by soldiers back home to parents saying hi Mom and Dad things are okay here you should I hope you're worrying less cuz we've worked out something things are a lot better here there's a lot less people getting hurt working it out along those lines working out a tit fortat uh vulnerability where you had to have a forgiving Tit for Tat what if somebody messed up and accidentally dropped a shell into the trench on the other side they got one shot back letters dear Mom and Dad things are okay here we had an incident the other day we had this new Gunner who didn't really understand how things work and I heard he killed four people on their side they shot one back they took out three of our people but everything is okay now Tit for Tat complete with a forgiving element this happened again and again and again in the trench warfare and the only thing that stopped it from spreading is the fact that the officers kept insisting that nobody else was doing this and these guys were going to get shot in court Marshal if they didn't stop this and if they had only had cell phones if they only had communication if they only had a way of knowing up and down the line that everybody was doing this they would have stopped the war not with a treaty not with generals not with heads of state not with diplomats but simply a bottom up way of evolving cooperation and they would have stopped the war if they knew that they weren't the only ones wanting to do this amazing historical incident okay so this gets us to the end of aggression as you probably noticed this has gone on way long this is the longest amount of material we spend on anything in the course and each year it actually gets longer and I actually think I know the reason for it three and a half lectures ago where did I start off talking about my recent uh exposure to human aggression which was my doing it and tripping up that jerk playing soccer and everybody was all excited let me tell you about another time the most serious time I have ever been exposed to human aggression this took place when I was about 20 and this was first year that I was doing research in East Africa during that time the fame notorious dictator ID Amin was running Uganda and he was a night M he was just killing people left and right destroying the country as documented cannibalizing he was a nightmare of a dictator around the time he made a mistake this was spring of 1979 which is he invaded Tanzania and took over some of the land there thinking the tanzanians wouldn't fight back and he miscalculated the Tanzanian Army counterattacked and drove them out of Uganda and decided to drive all the way up to kalala the capital of Uganda and they overthrew idin he fled the country and the country was liberated they continued through there and they opened up a carrier to the Kenyan border so it was now a swath all through the southern part of the country that was controlled by tanzanians so the day after the tanzanians got things to the Kenyan border I went into Uganda okay why this was like amazing this was history happening you were hearing like on the BBC that people were dancing in the streets in kalala they had been liberated amazing chance to see history this was throughout College I had been spending a lot of time with Quakers and wrestling with those issues and figured if there is anything that counts as a just War this would be it what does this seem like all these philosophical principles this actually of course was not what was going on I was a 20-year-old male and somebody had been staying with me and no longer was and I was all bummed out and thus I did sort of a very 20-year-old male adolescent primate thing which is figuring some violence would do some good things for my brain neurochemistry and I wanted to go see a war so I went off to Uganda hitching through there and it was appropriately exciting and some things happened that scared the beesa out of me and at some point I finally decided I have had enough I want to go back to Kenya I want to feel safe again so I'm hitching back but I had one last thing that I want to do which was since I was a kid I had grown up reading about the expl and the search for the source of the Nile and all of that the source of the White Nile is in Uganda it comes out of Lake Victoria in a town called Toro and there's a spot there a bridge where you can go and stand and here is where the Nile River begins and I had to see this before leaving and I managed to get a ride into there and I managed to get over to this bridge and stood there and there was this sort of dam thing that was built at this bridge was on top and there was the slle where all the water came spritzing out and starting the Nile and I stood there and I looked over the side and what I saw was there was a Ugandan soldier who had been taken down there was a staircase along the side down to some sort of panel for controls or whatever and a Ugandan Soldier had been taken down the steps his hands tied behind his back and a rope tied around his throat and attached to the panel so that as the water level Rose he would eventually be swept off his feet and would be strangled and drowned in the water and this body had obviously been there for days it was bloated it was floating there it was being bashed around in the waves there were Crocs trying to get at it and looking at this guy a total storm of emotions thinking good that's what you deserve being in the Army for Amin then thinking no wait a second this is probably some poor guy was forced to do it and was just following orders then thinking no I know what I think of soldiers who just follow orders and thinking whoa I would love to get a lot closer and see what's happening down there and thinking I want to get as far away from here as possible and I stood there for an hour and a half at that spot staring at this guy until some Tanzanian soldiers chased me away from there and I think now 33 years later that I lecture longer and longer about aggression each year because of that guy what do we do here in our business we have have this General notion that if we are rational if we are learned if we are scholarly if we respect thoughts and truth and all of that we will make a world a better place all of us who are propes have somewhere in there this totally ridiculous belief that if you're allowed to lecture at a subject long enough it will give up and go away and that will be the cure for World aggression if everybody can only be lectured to about the frontal cortex it will Sol solve World violence but the basic problem is that aggression is such a messy set of behaviors schizophrenia no question about it bad news Alzheimer's disease Childhood Cancer global warming all of these unassailably bad news but aggression is a whole lot more complicated because of that point where we started with which is the same exact behaviors and depending on the context it could be something that will get a medal for someone someone you will want to mate with vote for reward cheer on join in and in another setting it is the most frightening possible thing that can happen to us and it's the same behaviors in all those cases and it's for that reason that violence is always going to be the hardest subject for us to understand biologically and it's for that reason that it's always going to be the one we have to try hardest to understand and for more please visit us at stanford.edu