Hello, I'm Robin May, Gresham Professor of Physics. Have you ever really hated someone, really, really deeply hated them? Or perhaps you've never hated them? Either way, this is a lecture for you. We're exploring the biology of hatred. What is hatred as an emotion anyway? Can we find it in the brain? Is there a centre for hatred? And if there is, or if there isn't, might there be a way to treat hatred? Can we do things, can we intervene to reduce some of the terrible burden that's associated with hate crimes or mass genocide? Is hatred unique to humans or do other animals hate too? And what might be the future for hatred? Can we conceive of a world in which we can intervene early enough that no one hates anyone and we do away with many of the worst excesses of human behaviours? Listening to the lecture to find out more. Thank you very much. Welcome to all of you in the hall, welcome to those joining online. Um, it's a real pleasure to see you here, even though we're going to be talking about something really quite depressing this evening, uh, which is the theory and practice around why we hate. Those of you at home, you're on your own doing this, but those of you in the hall, I'd be interested to know. Hands up if you've ever really, really hated somebody. Oh, that's quite a worrying number, actually. I think I might leave now. Those of you online can't see that, but there's quite a hating audience here, which is quite scary. Hopefully, not Gresham professors. The rest of you, I'm delighted to hear you've never really hated. Uh, I think you're probably being rather too polite. Most of us at some point, I think, have really kind of revved up our strong dislike, if nothing else, of uh other people. So tonight we're exploring uh why we hate, uh, what we can do about it, and maybe what in the future we might be able to do to try and kind of mitigate some of the worst excesses of hatred. Before we start, though, I think we need to think a little bit about what we mean by this. So, what is hate anyway? And it's actually not as easy to answer that as I think you might think, because as we just sort of alluded to, there's a bit of a continuum between don't really like that, strong dislike, really strong dislike, through to hatred. And many of us uh kind of blur the boundaries there a little bit. Um, if you look in the dictionary, the definition of hatred is intense or extreme dislike. So that kind of dictionary definition recognises that it's on a continuum. But actually, if you are psychologists, there is quite a clear distinction around uh hatred. And that distinction is uh it is usually rooted in one of two ways. It's either an acute or a chronic sort of hatred. So acute hatred is usually framed in result of something that has just happened. So here, for example, uh these people demonstrating um after the disaster in Spain, uh and if you look online at that point, people would say a lot of stuff around hating the prime minister. But actually that's distinct from I think what we might call clinically psychological hatred. They don't really hate the prime minister. What they hate is the action or lack of action in result of something else. And many of us might have had that experience. We might have been out with friends and I hate the current government. Probably you don't actually hate all the members of the current government individually. What you really mean is something they have done or not done is not what I think they should have done, and I really dislike that. So that's kind of an acute hatred, but it's not pathological. Most of us get over it, the government changes, things move on. 25 years later, you don't think to yourself, I still really hate that prime minister. Usually, some people do. In contrast, chronic hatred is the kind of hatred that's really difficult to shake off. This embedded feeling that something or someone is as bad as it can get and you will never change. Okay, and that view uh is usually rooted in two things. It's rooted in your expectation that that thing or that person cannot change. So you hate it because it is uh irretrievably bad in your eyes. So, for example, you know, you hate somebody for doing something, not that they've just done transiently, but that it is a part of their character and they will always do it. I hate this person because they are so mean to people. You don't mean they were mean to that person just now. You mean they are intrinsically mean and they will stay mean for the rest of their lives. And you can't change that, so you hate them. The second point about hatred is it's very often, well not always, but very often embedded in a moral judgment. So you are judging someone who does something you don't like, they can't change it, and that is not just unpleasant, but it is morally repugnant to you. You hate people who believe something or who don't believe something because you believe that it's morally wrong to hold that position, and they're not going to change that position. And that is intrinsically where hatred comes from. And I think it's quite important to think about that definition because uh in some senses we bandy the phrase hatred around quite a lot. And I think particularly when we start to think about things like hate crimes or interventions in society to reduce hate, we need to think about what we actually really mean by that. What are we really worried about? Are we worried about people in the pub saying, I hate the Prime Minister? Probably not so much, as long as I don't actually act on it. Are we worried about people saying I hate that group of people and I wish to commit an act of terrorism against them? Absolutely, we should worry about that. And so we need to make that distinction clear. So when I say things like I hate sprouts, I really do hate sprouts, actually, uh, but I'm not sure that the government needs to intervene to stop me hating sprouts. Uh, and I have to confess that although a sprout is probably never going to change, and so it fulfills the first criteria, I don't think it's a moral judgment about sprouts. And so when I say I hate sprouts, what I actually mean is I dislike the taste of sprouts. That's not hatred. On the other hand, if I say I hate Nazi ideology, which I hope many of you in the room would share, I think that's a reasonable judgment. The judgment there is the whole point about Nazi ideology was it was embedded. It was not a transient thing, it was something that people believed in permanently, and it was morally repugnant, at least to me and hopefully to most of you. And so hatred of that kind of thing is something we need to engage with, and conversely, of course, in that particular example, understanding how the hatred that was part of that ideology came about is going to be really important if we're to try and prevent such things happening again. So, understanding what we mean by hatred, I think, is incredibly important. So, hopefully, if we can all sort of agree on what hatred is, then we can start turning our attention to what it actually is biologically. So, what's happening when we hate something? And again, what I mean here is when we really hate something, not when we just dislike sprouts. And it's actually quite difficult to pin this down. So, for those of you who've been to other lectures in this series on other emotions, some of those emotions have quite clear biological roots. So there are parts of the brain that do particular things, there are disorders in which the emotion is missing or overly present. Hatred is not quite that simple. There has been a little bit of work looking at brain activity and how it relates to hatred. And I particularly like uh this piece of work done relatively recently, um, in which uh the group looked at individual volunteers uh viewing pictures of people that they knew, most of whom were people they knew and either liked or were completely neutral about, you know, the person who delivered their milk or whatever. But one picture was someone they had previously identified as really hating. And uh in an MRI scanner, so in a brain scanner, you can look at which areas of the brain are active in that process. And what you can see in these images here, in yellow, are specific images, it's part specific parts of the brain that light up when these individuals viewed a picture of the person they hated, but not all the other pictures they looked at. So these yellow areas, if you like, are um areas that we kind of associate with the feeling of hatred. Just want to be really clear on this. This is not a hate center. You can't cut these yellow bits out and suddenly miraculously solve everyone's feeling of hatred, but they are areas that are deeply involved in that sense of hatred. And the areas of the brain that are involved are incredibly informative. So there are two, broadly speaking, areas of the brain that light up in this particular experiment. The first is an area in the cortex and the surface of the brain, and that is particularly associated with both aggression and with motor activity, so with movement. And that makes a lot of sense if you think about you know, people's response to hatred, particularly that acute hatred, is very often an aggressive moving one. They might punch someone in the face, right? That so you're activating the area of the brain that is to do with uh responding immediately to the threat, to the hatred threat that you see. The other part of the brain that lights up there gets even more interesting. So in the subcorte, so deeper in, you see a couple of areas of the brain that light up, particularly areas like the insula. And that turns out to be very interesting because those areas are previously strongly associated with a feeling of uh extreme disgust or contempt. So they're the areas that light up when you see something like a pile of vomit. Um, and so you're activating this same feeling of, oh my goodness, there's a dog poo on the street when you see this person that you hate. The sense of disgust for them as a thing, as well as uh as a person, if you like. But what's very interesting is those areas that are associated with contempt and disgust, next to them another area lights up, which is strongly related to romantic love. And that I find quite interesting. So you have these areas that are to do with aggression and violence and stuff, and the same area that lights up when you see, for example, your lifelong romantic partner. And we'll turn to that a little bit later in this lecture, but this idea that actually, as poets have said for hundreds of years, there's not always a big divide between love and hate. And I think understanding more about that uh is interesting both biologically, but also, of course, when we think about how we can better intervene in things that we recognize now as, or you might have historically called crimes of passion or these kind of things. How might we be able to help people who are feeling that transition from love to hate and might do uh an act of violence, for example? Can we intervene earlier and make the world a safer place, essentially? And that, of course, is uh an interesting concept, and actually most of us kind of know this from classical literature and perhaps from our own experiences, this idea of you know having a strong relationship with someone that has turned over. Um, this is uh uh an image from uh uh you know literature of uh one of the earliest classical references to this idea of love turning to hate. Uh, this is Pausanias, the lover of Philip II of Macedon, so the father of Alexander the Great, um, stabbing him to death after he's been jilted uh in the back of the theatre, in fact. And there are loads of examples. If you're a fan of Shakespeare, there's loads of you know, love turns to hate sagas. And unfortunately, of course, we come across many of those uh in real life. And so I think understanding that that blend between love and hate in the brain is a really interesting and challenging area to work on. Okay, so there's a bit of the brain that lights up when we hate. What triggers that activity in the first place, though? What makes us hate? And you might be sitting there thinking, well, that's obvious, isn't it? You know, this really makes me hate something. But actually, it's not that obvious. So what you say, I really hate that, is not necessarily the same for the person next to you, right? And by definition, many of us hate things in other people that the people the people themselves like in themselves. Uh, and so the trigger for hatred can be quite uh complicated. But perhaps the most widespread and reliable way to trigger hatred, unfortunately, is this idea of group identity, and particularly the idea that psychologists refer to as in-group versus out-group behavior. And we as a species are uh disappointingly good at doing in-group and out-group behaviors. And if you think about it, I'm sure uh all of you in this room, if I asked you, would have that sense of identity. You hopefully don't use it to hate people, uh, but you grow this sense of in-group identity very rapidly. So, for example, many of us spend our weekends at sports matches, for example, doing things like this. You put on a scarf or a uniform or whatever, you join a group, I'm an Everton supporter, I'm a whatever it is, um, and you form a sense of identity with the group you're in. That sense of identity bonds you to people who are in the same group, but automatically distances you from people who are not part of that group. Hence things like football rivalries and these kind of things. And that sense of in-group identity and therefore a resistance to people from outside your group is incredibly deeply ingrained in humanity. And it underpins, unfortunately, many of the most kind of egregious examples of mass hatred from history. So, why do we have this incredibly strong sense of in-group identity? Well, it probably is because over evolutionary time, this has been incredibly important and incredibly beneficial. So for most of our history as a species, we have lived like this, right? In small groups, initially hunter-gatherer groups, later on forming agricultural groups. Um, but the group identity was absolutely linked to your chance of survival. So you're in a small group that was primarily family related, but not always. So we know from genetic data that there was some flux between groups. But nonetheless, the group as a whole worked as a team, if you like, and we know very clearly that individual humans are pretty poor at surviving on their own. In the wilderness, groups of humans are really good because of our ability to communicate and to do things together. To make that work, you have to have strong group coherence, right? If you're hunting and gathering, you know, somebody needs to go hunting, somebody needs to gather, somebody needs to be looking after the babies, whatever it is. You need a team identity. So for most of human history, your in-group was your survival factor. Conversely, your out-group was the biggest risk you faced. At best, a new group arriving was a major competition, right? They were hunting the same things and gathering the same things and so on and so forth. That's the minimum. At worst, they were a major threat. They might come and steal your partners, kill your babies, do whatever. Um, and so over most of evolutionary time, we have been selected to favor in-groups and select strongly against out-groups, and this idea that you strike first before they can strike you. And it is that ingrained evolutionary process, I think, that drives a lot of the problems we have today with hatred. Because we are programmed to look for similarity and difference in each other. We are looking, even perhaps now in this room, we are looking at things we have in common with people and things we have different. That might be we're all members of the same family, or we're all members of the same country, or it might be we all go to the same club, uh, we went to the same school, doesn't matter. But probably as you're listening to this, you're kind of thinking already of the warm feeling you get, right? If you meet someone on the bus and you're making conversation and they say, Yeah, I went to that school, I went to that school too. And immediately you have this, oh, they're probably quite nice. Not necessarily, right? They might be awful. But you have this predisposition to say, aren't they? Went to my school, I bet they're decent human beings. In contrast, you know, you're sat next to this person and you think you know really well, and you say, I don't know, uh, I'm a huge uh whatever, Arsenal fan, and they're like, oh, I hate Arsenal thing. Oh, that's a shame. I quite liked you until then. Uh, you've got this immediate difference because you've declared your ownership or you're belonging to a different group. So we are pre-programmed to look for similarities and differences. And of course, the easiest way over sort of biological evolutionary time is to look for a very visible signal of are you with me or against me? And one easy, very obvious signal of that is skin colour. So, one of the key things that we have to think about if you're thinking about visible differences is that idea of similarity. Um, so if you're thinking about uh what is the easiest way, how do I know whether you're in my group or out of my group, you can look at somebody quite obviously. And then a straightforward thing is if they have a different skin colour, then you know to a first approximation, they're not immediately closely related to you, right? There are all sorts of caveats there, but in principle, different skin colour, you're a different group. You clearly don't know that someone with the same skin colour is the same group as you, but it's that very easy, very superficial way to say that person's a different group. Same thing for all sorts of other signs and signals, gender is another one, right? I'm a man, you're a woman, or we're immediately different. You might be closely related, but you are part of a different group. You have a different set of drivers. That process of visible signals, biologically, is a kind of first proxy. Clearly, it's a pretty rubbish one for all sorts of reasons. And so, what's happened over time is that we as humans with culture have started to put on additional levels of signals. So, in this particular image, for example, you can see another one that we do all the time. We often put on uniforms. Okay, we are putting on a uniform to declare our membership of a group and our difference to another group. This person is a member of a group, a particular army, a particular country. If you're wearing that uniform, you're in my group. If you're wearing a different uniform, you are definitely not in that group. Okay. And so we do that. We put on that might be an army uniform like this one, or a school uniform. It might be a badge, uh a football scarf, a special hat, doesn't matter. We are displaying a signal of our group identity. And that becomes very interesting when we think about uh how we respond differently to groups. And one of the things that's most interesting is this idea of uh individual homogeneity or heterogeneity. And what turns out to be true for all groups, regardless of what group it is, is that if you are in a group, you believe quite strongly that your group is very diverse. In contrast, you believe that all other groups are much more homogeneous. So you will hear people say this, I suspect we might have heard this example. Uh so for example, if you ask a classical uh white racist, you know, what do you think of someone who is black? They'll say, they're all the same. You know, by straight determination, that is clearly completely untrue. But there is a sense of, oh, these people who are different to me are all the same. You ask the same white racist, what about white racists? And they'll say, Oh, we're really different. All sorts of people hold these views from all sorts of different backgrounds, which again is clearly not true. Uh, but there is a sense of I am representative of the full diversity of humanity. That group over there that I hate is all the same and they're somehow different. And if you look, it doesn't matter what kind of discrimination you're looking for, that is a classic, a repeated theme. People say, all whatever, insert your group you like, all people of this race, of this religion, all vegetarians are the same, uh, all meat eaters, we're really diverse. Uh, and that is a kind of repeated theme that you see. Therein lies, I think, both a problem and an opportunity. There is an opportunity here, we'll talk about it in a minute, that if you can overcome that and start to make people realize that is not always true, you can start to break down some of these hatred barriers. And so uh events in which people demonstrate the great diversity of groups that apparently are different to yourself is a good way of breaking down some of these ideas of hatred. I think, for example, things like um if you look at gay pride festivals, where people are deliberately celebrating the diversity of a group that over most of history has been vilified as all the same and all a bit odd, um, that is a good way to demonstrate to people and to bring, kind of break down some of these early barriers around hatred. So hatred is very often rooted in this idea of in-group versus out-group identity. Interestingly and slightly disappointingly, it's not just us that do this. It's really quite hard to ask another animal, a non-human animal, whether it hates. And so we don't really know for sure that hatred is not a completely human-specific emotion, but there's pretty good evidence that at least one other species has an emotion very similar to hatred. And that other species is our closest relative, the chimpanzee. So chimpanzees, as you know, have many behaviours that are very similar to humans. They do all sorts of things that look awfully like us. And unfortunately, uh, they also do things that are the kind of worst part of human behaviour, including apparently hatred. And this is largely uh the result of documentation from Jane Goodall and her team. And Jane Goodall, as you all know, uh, you know, pioneering primatologists who did extensive studies of chimpanzees in the wild. And back in the 1970s, she documented uh this series of events over about four years, actually, 74 to 78, uh, which have become known as the chimp wars, in which she witnessed firsthand, and her team witnessed first hand, uh, essentially an act of genocide by one group of chimps against another. So there were two uh rival sets of chimps in this particular forest area. And over the course of about four years, one troop apparently deliberately hunted and killed and ultimately exterminated chimps belonging to the other group. And actually, one of the most disturbing things about this whole episode is if you look at the footage and the documentation. There are acts that we would say if they were humans, acts of appalling barbarism, things like chimps celebrating over the dead bodies of the chimps they've just killed, carrying corpses around, dismembering them deliberately, and doing many of the things that we associate with horrendous human hatred-driven conflicts today. And so very depressingly, unfortunately, it looks like hatred has been around at least for as long as humans as a species have, and chimps themselves have existed, so several million years. We don't know, of course, whether this is also holds true for species that we share a much older evolutionary ancestry for. It's quite difficult to ask a cat or a dog, for example, whether it hates another cat or a dog. But at least for our kind of closest relatives, this does seem to be a conserved emotion. So, as you might expect then, if this idea of hatred has been around for at least as long as we have been around as a species, and as we know, it's an incredibly powerful emotion, you might expect that this in-group behavior that uh drives a lot of hatred is itself quite strong. And you would be right. It is both a very strong emotion and one that is depressingly easy to precipitate. So let me give you an example of that. Here you have uh specimen A, aren't they cute? Butter would not melt in their mouths. Um this is a group of six-year-olds, it's not this particular group, but six-year-olds. Um, and there was a very interesting study in which uh six-year-olds in a uh school were invited to participate. And what happened? They came into school, uh and when they came into school, they were given either a yellow or a blue jacket to wear. And they were saying, You're in the yellow team, and you're in the blue team. That was it. There was no instruction about what you had to do in that team other than your yellows and your blues. And then they were given that all-powerful prize that we know is driving most human behaviour, the sweetie. Um, and they were given Skittles, these uh colour sweets, and they were told you can either give Skittles to other children or you can punish them for stuff you don't like by taking Skittles away. And within literally within minutes, what you started to see was that children given a yellow jacket would reward other yellow jacketed children and steal skittles from blue-jacketed children, and vice versa. Ten minutes previously, they didn't belong to that group, but by giving them a group identity, you have precipitated this idea of in-group versus out-group difference. And in this case, it's just a bit of skittle exchange. Although I don't know, stealing a skittle from a six-year-old, that's a pretty big crime. Um, but but you can see quite easily, unfortunately, how you can drive very, very dangerous behaviours simply by telling people they belong to a group. And that, of course, is the root of many things we do as a society, and in some cases you have to do that, it's really important. So if you think about uh creating an army, for example, you need to make a really strong sense of in-group identity between very diverse people in your army. We take people from all over uh the country, for example, to join our army. They have nothing in common often, other than their interest in joining the army, but they have to form a strong in-group identity. And so there are very easy ways to do that, like, for example, giving them a uniform. This is obviously a picture from a long time ago. Uh, you know, if you're in a red coat, you're with me, if you're not in a red coat, you're not. If you're carrying a particular shield, you're with me. If you're not carrying a shield, you're not, so on and so forth. And that enforces this strong in-group identity. It's a powerful emotion when you're fighting a war. Unfortunately, it's difficult to turn it off. And so it's not a surprise in some senses that you might create a very strong in-group identity that helps you fight a war. But unfortunately, when you've started to win, you can't just switch it off. And if not for no reason, do we therefore see uh often atrocities and crimes on the back of conflict because you have driven such a strong sense of in-group behavior that when you are dealing with, for instance, prisoners of war, you still see them as an out-group that is of less value than your in-group and therefore reasonable to subject to acts of violence or other things. And so uh that idea of in-group and out-group behavior very, very strongly linked to this kind of uh identity that you give people. So that's all a bit depressing. It's a really powerful emotion, it's quite easy to make, very difficult to turn off, and leads to violence. There's not much uh good news in here. So, is there anything we can do uh to make things a bit brighter? Can we potentially tackle hatred and use our understanding of the biology of hatred to rectify things? And happily there are, uh, although none of them are easy. So the easiest way, or the most obvious way, if you like, to tackle hatred is with its opposite, which is compassion. So hatred relies on this idea that the thing you're hating is different to you. Compassion is the opposite. Compassion is understanding that we are all have some similarity. So, for example, if you see someone who's homeless, you might think to yourself, I'm never going to be homeless, I've got nothing to do with that person. If you can envisage yourself as being homeless, then actually you start to have compassion. And it's quite difficult to hate someone or some group which has some similarity with you. This idea of empathy of being able to put yourself into someone's shoes is a really important way of combating hatred. And the easiest way to do that is to try and break down this sense of otherness that comes with in-group versus out-group behavior. So, activities in which people from apparently distinct groups do things together are incredibly powerful ways to combat hatred. So, for example, if you bring different religious communities or different ethnic communities or different members of different groups together, and you start to see things like: I always thought, I don't know, I am religion A, and I always thought that people of religion B, I don't know, ate something different. And then you find yourself in the same queue at the same canteen eating the same sandwich, and it starts to push home this message that actually your in-group identity and your out-group otherness are not completely set in stone. And so there's very good data that the more you can bring groups together, and whether that's community groups or religious groups or whatever, the more difficult you make it for people to stick to their in-group ideology and therefore to stick to their price of hatred. Hence the success of programs in which, for example, you have reconciliation between different groups, or you bring people with racist ideology together with people that they were previously racist about and try and highlight the similarities we have. Those things are clearly quite difficult to do. Um, there are, however, I think, things that are simpler to do where we think about the indirect signals that are associated with group identity. And we have a sort of live example in the UK here from very recent times when we have things like the flag campaign. Ostensibly, that is a positive signal about enhancing group identity, right? Let's all be proud about our UK-ness. The problem is anything that enhances in-group identity, by definition, enhances out-group otherness. So if you are encouraging people to say we are all members of the same country, and isn't that wonderful, you are by implication, even if you don't want to, by implication, you are saying other countries are different. They are out-groups. And so these signals that may be there for very, very positive reasons actually inevitably lead to the risk of emphasizing otherness and risk. And so perhaps instead of signals that say, here is a group and it's different to other groups, we should be thinking about celebrating groups as a whole. So signals where you say, there is a group here, there's a different group, but it's exactly equivalent over here, are very powerful ways of highlighting both group identity but also the similarities we share between groups. And so there's a strong uh incentive, I think, to think about how we maintain both that uh individuality but also that that sense of purpose together with other groups. So that's one strategy, um, but people by definition will continue to hate and will continue to act upon it. We have done that for probably millions of years and we'll continue to do so. So we still need a strategy to tackle hatred on an individual basis. And uh, in particular in our modern social media-driven world, uh, one of the most frequent sources of problems for hatred is social media and all the stuff that's associated with it. That has led to this uh discussion of a response to that, which is the idea of counter-speech, the idea of not letting stuff go when people say stuff that is uh inappropriate, that is hate-driven, but tackling it with speech back. That seems like a pretty sensible way to go forwards and is really important when you consider the massive wave. So this is uh data from Facebook, plenty of other social media platforms exist, um, uh, looking at the number of hate-driven posts that they have removed uh per quarter. And what you can see here, I mean, this graph gets up and down, obviously, uh, the the going down is largely a response to much more stringent activity against it rather than the world suddenly becoming a much more benevolent place, unfortunately. Um, but what you see is even now, you know, when we're taking really strong lengths to try to uh clamp down on this, uh, Facebook is still taking down about a million posts a month for hate speech. That's an awful lot of hate out there in the ether. So, how can we combat that? And there's been some very interesting work looking at what is the most effective way to combat hatred in social media. Um, and so this study from a couple of years ago looked at three different approaches to tackle hatred. Okay, so one thing you can do is you can try and trigger that sense of empathy in the person doing the hating. So in the blue box over here, we're saying this is hurtful. You're upsetting people, and you're trying to trigger this idea that, oh, I didn't really mean to do that. You're triggering, trying to stimulate empathy in the person who's posted, in this case, a tweet, but it could be other social media. Or you can do what's in the red box, which I think is a for those of us who are British in the audience, it's a terribly British thing to do, isn't it? To be, well, try and sort of laugh this off in a slightly disapproving way, and it will all be fine. Uh, you know, I don't I suspect many of us have found ourselves in a position where, you know, you're in a social circumstance and someone says something that's actually a bit inappropriate. I don't know, oh, I really hate the French. And you try and say something like, Oh, you're not going to France on holiday this year, then, Kevin. Um, and and hope that in somehow making light of it, you will point out to Kevin that he shouldn't have said that in the first place. Um and that is, you know, that it varies by culture, but that is quite a common response, I think. So kind of using a humorous but slightly pithy way to respond is is in the red box. Or in the green box, you can remind people that there are consequences to hate speech. So in this case, uh, this is this, yeah, you can see this too. Um, this is this sort of idea of your mum might see this and tell you off. Uh, there are consequences to hate speech. And you can post things like, you know, uh hate speech is a crime, and the police might come and knock on your door, whatever it is, there is a penalty associated with this. So in this study, uh, what they did was they uh identified hate speech in uh Twitter in this case and responded randomly with one of these three approaches to the individual doing that. And what they found was quite interesting. So the first thing they found, uh, depressing for those of us who tried that terribly uh you know tug-in-cheek British response, humor is completely ineffective. So uh the red bar at the bottom, you can you can make a humorous quip and say, well, you know, uh you won't be going to France anymore, has no effect at all. People don't notice they don't respond, uh, they don't take down their hate tweet, they keep it there, um, it's rubbish. So don't try that at home. The other two approaches, reminding people there are penalties or trying to get them to empathize with the person they are hating against, are pretty effective. So you can see here that both of those approaches statistically significantly led people to delete the offensive tweet they posted in the first place. So that's a good start of a 10, right? You tell people that's really naughty, don't do it again, or you're really hurting people, and more often than not, they take the tweet down. The problem is, if you look at what happens next, so if you tell them you're gonna get punished, they take the tweet down, but then they do it again. So the green bar here shows they repost or post another hate tweet just as frequently as they would have without hat in the first place. So although telling them they're gonna get penalized makes them take the tweet down, it doesn't change their behavior. But the interesting bar is the blue bar. If you can make them empathize and take away the post in the first place, they are less likely to post the hate post again later on. You have permanently, or at least in the course of this trial, altered their likelihood of hating again. Because you have triggered this idea that actually that outgroup you're hating, whatever it was, immigrants, people with a different skin colour, people who belong to a different club, you have triggered this idea that they are actually not quite as different as you thought they were, and you've permanently altered that person's likelihood of hating against them. And so I think that is a very encouraging piece of data about how you might start to intervene, uh particularly in kind of social media, but in other areas too. Uh so my kind of lesson for uh for this evening is if you go home later on on public transport and someone says something inappropriate, uh, don't tell them the police are gonna come for them. Definitely don't give them a joke, but do try and remind them they're hurting people, and maybe you'll have a small impact on their kind of hate behaviors going forwards. Um but don't do it if they look like they're gonna punch you in the nose. I don't want any injuries on this. Okay, so hatred is a kind of long programmed thing, it's an evolutionary programmed thing. There are some things we can do against it, uh, but it's tricky. What about biologically? We said at the start of this lecture uh that there's no single region of the brain that drives hatred, but there is a complicated mesh of things which work together. Um, can we learn more about the biology of hatred? And perhaps ultimately, could you imagine inventing a drug that could be taken to stop people hating? Wouldn't that be amazing? So, for those of you who've been to some of these lectures on other emotions before, this is usually the part of the lecture where I show you a brain image and I say this is an individual who's had a stroke or had some other thing, they've lost this bit of the brain, and ta-da, they no longer have emotion X. The disappointing is I'm not going to show you that. I'm going to show you a perfectly normal brain because we have never identified any patient who has a brain lesion or a genetic component or anything else which stops them hating. Which is kind of interesting in its own right, although slightly depressing. So there are people out there who are incapable of lots of different emotions because of particularly isolated brain damage. But as far as we know, nobody in the world who is incapable of hatred because they've lost a bit of the brain. Probably because, as we said at the beginning, it's involving lots of different areas of the brain working together. So there's no evidence for a specific genetic basis to hatred or a specific brain region for hatred. But there is some interesting data that suggests that our patterns of hatred may have some level of dependency on our brain connectivity. And actually, it comes from a very interesting and completely unrelated area where people were studying individuals suffering from serious depression. And in this particular study, what they're looking at is not individual areas of the brain that light up or don't light up during depression, but the connectivity of different parts of the brain together in that disorder. And so these different coloured areas are different parts of the brain. And you can look to see how the different areas of the brain talk to each other during particular conditions. And you can draw maps of connectivity like this, in which the lines join parts of the brain that are talking to each other, if you like. And what you can see in this diagram at the bottom here is that the blue lines are what is happening in those of us who don't have depressions' brains most of the time, the parts of the brain that are talking to each other in blue. And in red is the different pattern you see in individuals with major depressive disorders. And what you see immediately is that the lines are not in the same place, right? There are some lines where both blue and red overlap, like the one on the far side over there. So that link is the same in all of us, but there are other areas where the link is either present or absent only in people with depression. So there is different linkages between different parts of the brain. And what turns out to be quite interesting, you don't have to understand the base of this graph, but these two graphs show the linkage patterns between individuals without depression and individuals with depression. And if you recall back to the beginning, what you see is the areas where those patterns are different are the same areas that we saw in that original MRI scan lighting up when people hate people, right at the beginning of the lecture. So, insular, for example, is one of the areas that is differently connected in this. And so actually, and this generated quite some big headlines at the time, there was this idea that people with depressive disorders have a dysfunction in what's called the hate circuit in the brain. Unfortunately, uh there is no evidence that people with depressive disorder actually have differences in how they hate. So they apparently hate people just as much or as little as the rest of us do. So this does not appear to be a difference in their ability to hate or their likelihood of hating. And in fact, uh, very sadly, it seems to be more related to the sense of self-hatred, of self-loathing that often accompanies depression. So it looks like this altered connectivity is driving that sense of self-reflected hatred rather than external hatred, which is sort of doubly uh depressing. But it does suggest that there is a link between this connectivity in the brain and its ability to generate feelings of hatred that maybe in the fullness of time might help us tackle that. So that might sort of suggest that uh we're gonna struggle to come up with an anti-hate medicine, and that's it's probably true, uh, but there is maybe a little tiny chink of uh of possibility here. Um, and it's a bit of a stretch, but go with me on this. So uh we clearly don't know from other animals other than maybe chimps whether hatred is an emotion that they have. I can't tell if I go home with my dog really hates that cat or whether it's just gonna try and chase it. Um but we do know from a lot of studies that you can trigger very potent aggression, uh, which is not a million miles away from hatred, in other animals through particular chemicals. And so this is best studied in in rodents, and so in mice, for example, um, you might know if you keep mice that mice are highly territorial and can be extremely aggressive against each other. That aggression can be stimulated by the presence of specific volatile molecules that are released normally in things like male mouse urine. So there's a molecule called SBT, um, or one with the delightful name of dehydrobrevocomin, which are molecules that are secreted into mouse urine. And if another mouse smells them, it drives very potent aggressive responses. Kind of like mouse hating, really. And so this has stimulated for many years this idea that could there be evidence in humans of something similar. And there is a bit of sort of anecdotal evidence, for example, that uh you know, particular areas where particular scents are can apparently lead to more aggression or less aggression. There's been a lot of studies in things like pub toilets and these kind of things about whether we might be inhaling pheromones from each other that are more likely to make us aggressive. Pretty much no robust science on that uh to date. But this idea of uh volatile chemicals perhaps driving hatred and aggression in humans is a persistent one. Um, and there is a little bit of evidence that is partially true, and I particularly love it because it's a study that I think is just incredibly elegant. And it concerns uh this molecule called hexadecanol. And hexadecanol is uh something that we secrete, uh most mammals do, so mice also produce this. And the reason we're interested in this is because in mice it alters behaviour quite dramatically. We produce hexadecanol too, and more importantly, we have a very, very closely conserved receptor for it that doesn't seem to have changed over evolutionary time, suggesting that as well as making the chemical, we still have the means in ourselves to detect it. Um, and so people are interested in this as a possible volatile signal that drives that might influence human behaviour because it influences mouse behaviour. We produce it in uh breath, in our skin, in our feces and things, and and the one I particularly like is particularly abundant in babies' heads, um, uh, which I really love. And it people have said for many years, or maybe this is something that you know, I don't know if those of you who've had babies or other people's babies, often people cuddle babies and go and they kind of inhale their heads, which is a bit of a weird thing to do. Um, but uh but there is an idea that that is driving kind of strong uh behavioral signals from the baby's head. So there's lots of uh hexadecanol in babies' heads and in lots of other places. Um, and so people have speculated it might be altering human behavior, and indeed it does. Um, and this is a great study done fairly recently, which I really love uh about this. So, in this study, volunteers were taken, and volunteers were allocated money, okay? And uh they could allocate money to each other. So I could give you some money, and I could give you some money, and I can decide how much money to give you and how much to keep myself. Um, and you, as the recipient of that money, you have two options. You can either take your money and say thank you very much, or if you think you've been treated unfairly, and this is the this is the bit I love, you can punish the person who gave you the money, and you can punish them with a blast of unpleasant noise. Um and you can choose how bad that is. You can turn the volume if you really think they were something unfair, you can blast them with a really high volume. Um, and if you think it was a bit unfair but not too bad, you can turn the volume down a bit. So it's a measure of aggression. Clearly, it's not ethical to get people to punch each other, but blasting them with noise is kind of okay. So you can do this study, you can say allocate money and see how people respond. And then you can do uh a measure of uh how aggressive people are in those circumstances. So you uh you can work out just how much kind of a painful noise you subject your opponent to, and you and it's a measure, it's a quantitative measure of aggression. Um and here's the fabulous finding they had. So you do this for people in a normal setting, and what it turns out is you get a range of uh responses. So this is so the bars here show how loud the noise was that the people punished their opponent with. And what you see is it on the left hand side, your left hand side, uh, is that people are pretty good at punishing what they feel is unfair behavior normally. If you, unbeknown to them, put hexadecanol in the room. So they're breathing this thing in, they're less likely to blast at the person with noise. So superficially, this is great. You can waft hexadecanol into a room and everyone just chills out a bit and is less hating. Wouldn't that be fabulous? But there is a slight downside here, which is if you look in more detail at this, the people they, the volunteers they had in the study, obviously, were a mixture of men and women, like all good scientists. And this is the pool data, but now if you split it by gender, look at this. This is not so good, is it? It turns out that men, we're so chilled out, sniff a hexadecanol, we turn the volume right down. Women, oh my goodness, they turn it up big time. And in fact, it's an amazing piece of data. It is almost completely bimodal. So women, given a whiff of hexadecanol, all get much more aggressive. Men get much more chilled out. Which sort of leads me to think, on the one hand, it's kind of optimistic, maybe you can intervene in the future and come up with an anti-hatred medication. On the other hand, it does worry me the idea that we may have a world in which the men are all chilled out and the women are really, really aggressive all the time, which is quite a scary thought. So perhaps to finish with our perhaps our best advice is to not hold your hopes out for a medication, but to do something that we know is incredibly good at overwhelming hatred, uh, which is finding the person you hate and giving them a good hug instead. Thank you very much indeed.