 Rwy'n cymdeithasio y cwrdd iawn i ddim o'n ffordd o ysgol, ac rwy'n cael eu pethau ysgol i Americai Ffordd. Mae rwy'n cael ei bod yn oed yn cyffredinol, ond rwy'n cymdeithasio. Ond yma, rwy'n gobeithio bod gennym eu gwaith. Mae'r ysgol yn ymddangosu bod ysgol yn y ffordd o'r ffordd o'r ffordd yn y gallu wahanol. Mae'n amser i gyffredinol, mae'n gwybod i Gyslaw. Mae'r gyffredinol yn unig o'r Ssr, oherwydd e'u cyfrifiadau. There'd been a series of rather ill-tempered meetings between Boris Yeltsin and other foreign powers and he was in the US for a meeting with Bill Clinton and there was a press conference afterwards and we're going to show you a clip from the press conference. And what you watch out at the top for three things. First of all, laughter is contagious. If you want people to laugh, get them laughing and laughter will spread and it will increase. See how that happens in this what's about to unfold? y dyn ni, watch Bill Clinton. He is looking for a reason to laugh, and the reason he finds is his name is mentioned, and he uses that as a reason to laugh, and then he uses a stand-up comedy technique called topping, which once he got the laughter going, you keep it going by saying other things. So here we go. Statement yesterday in the United Nations, and if you looked at the press reports, one could see that what you were writing was that today's meeting with President Bill Clinton was going to be a disaster. Big laugh again. Ychwanegwch gyda'r fawr ymlaen i'r gweithio. Now for the first time I can tell you that you're a disaster. Now it works. Yelton's laughing. Sure you get the right introduction there. There's your topper. I hope you're right to answer it. Briefly, things just get completely derailed. Well, it's interesting. It's often shown nowadays. If you go to find this on YouTube, it'll be, oh, look at this hilarious blooper when Bill Clinton just started giggling. It's absolutely deliberate. It's one of the most careful uses and the most successful uses of laughter I think probably we've ever seen that happened to be captured on film from such a high status politician. What is actually going on there? Why did the laughter work and what was Bill Clinton doing to ensure that it worked? Well, he was actually leaning on quite a few very basic aspects of laughter, sometimes which can be quite not obvious to us. That's because when we think about laughter as humans, we think about jokes and we think about comedy. That's what we think laughter is. But actually laughter is primarily a social emotion. It's an emotion that we express with incredible frequency when we're around other people. So you're 30 times more likely to laugh when there is somebody else with you than if you're on your own and you'll laugh more if you know those people and you'll laugh more if you like those people. That's because it literally lives in social spaces. It is a social emotion. We do laugh on our own, but it's so much more likely to happen with other people. And within those contexts, we're laughing very often actually as part of the interaction that we're having. We're not just kind of broadcasting laughter at each other. So here's an example of two friends who've come in to take part in a study in my lab. Not the most fun. So all that's happening here is the experiment is explaining what's going to happen. They know they're being filmed. Next to each other, but you can't. They're often smiling and laughing. So then I just see both of you. Quite often, exactly the same time. And then the second she's going to leave the room and look at how they use laughter then. So they're watching her. In the second, they'll look at each other and both smile. So just perfect. Some alternatey there on the smiling. And again, then she's about to leave. This is a weird situation. Coming into a lab to do an experiment is odd. People are a little bit tense. Look how they react door is closed. A big laugh between the two of them. That's because in these interactions, these social interactions we're having with other people, most of the time when we laugh, we're actually laughing for largely communicative reasons. We're laughing to share emotions and express emotions that tell people something about what's going on in the interaction. So we will laugh to show that we are fond of the people that we're with. We will laugh to show affection. We will laugh to show affiliation. We will laugh to show we're part of the same group as people. We will use laughter to indicate that we are playing. Playful behaviour is incredibly important to humans, particularly when they're infants, but in fact about our whole lives. One of the reasons for that is play is an ancient mammal behaviour. We are not the only animal that plays. All mammals play when they're juveniles. Some mammals, like humans and otters and dogs, play their whole lives. One of the ways that we use laughter, particularly this is very obvious when you look at other primates, is actually we use laughter to indicate that we are playing. So what could be just a violent act becomes a playful act because you're losing the laughter show. This is a game. I'm not going to hurt you. I'm not going to kill you. I'm not going to do anything threatening. This is fun. We are playing. We laughter can be used as an invitation to play. Come on, join in. Let's have fun here. Let's do this. Let's change the mood. And in fact, if you look at humans and how they use laughter, they will use laughter very commonly as a way of de-escalating a stressful situation and using the laughter to improve everybody's mood. It's an unbelievably effective tool for this. And the really important part of this isn't just that laughter is a bit of magic sauce that kind of makes everything better. It only works if everybody laughs. And when you laugh, you seem to be able to regulate emotions in a way that improves the mood, particularly in a stressful situation, and makes everybody feel better. It makes difficult situations more happy situations. And that, of course, is an extremely important function of laughter. So people will use laughter in situations where you might imagine they might be cross. Like, here I am at work and hilariously you've thrown yellow paint all over me because we're having that kind of day. And he's laughing to show he's okay. He could get angry. He could be upset. He could say, shut up now that's enough. No, the laughter is shared and it's playing the role here. That's it's doing its job. It's working. So we're building on this sort of straightforward ancient mammal behaviour for demonstrating play, inviting to play. We've kind of built up into this extraordinarily complex behaviour which we use communicatively to show affection, to show we understand people, to show we agree people, we recognise what they're saying, but also to regulate the emotional state of the group of people that we're in with and to try and make things better. Now there are other ways you can regulate emotions. You can regulate emotions by threatening everybody or frightening everybody. Laughter is taking you in a different kind of direction. I think it's very interesting scientifically how completely totally we have ignored laughter. If I go into Web of Science which is the major sort of database for published papers and I put in the terms emotion expression fear, I'll get back about 6,000 papers. If I put in the term emotion expression laughter, I'll get back about 150 papers. There just is not a great deal of research into laughter. And it's interesting if you look at the roots of where all this comes from because most of the work that we do in emotion in my field of psychology and neuroscience builds on the work of Charles Darwin. Now Charles Darwin wrote a really beautiful book about emotions in humans in other animals. And in that he's kind of the first person to set out the idea that actually some, not all, but some of the emotions we experience actually have an older evolutionary history. So anger in a human and anger in a dog might share some features in common. He wrote about lots of emotions and all the negative emotions he wrote about fear, anger, disgust, sadness. We carried on researching for the next 150 years. He also talked a lot about laughter and we pretty much ignored that. See laughter Darwin thought at its heart was an expression of joy. It's a joyful behaviour and that's kind of capturing the nature of play. Play is a joyful behaviour. If everything else is equal, children will play. If children feel safe and comfortable and they're not being made to do something else, children will play. It's like a default state and laughter maybe is a kind of default joyful state for normal human interactions even when we grow up. But how do we get there? All we need to learn how to use it. This is just a study that we did at the Science Museum and the only important thing you need to know about this is we asked a lot of people what laughter sounded like. We had nearly 2,000 people and this is the age range of the participants along the bottom. We're testing children from the ages three and upwards. What we're doing is we're playing them different kinds of laughter and we're saying does that laughter sound like that person's helplessly laughing, spontaneous laughter or is that communicative laughter? Is that someone laughing in a conversation? But you do sound quite different. Children don't know what you're talking about. They hear laughter. As we get older you can see that blue line is everybody getting better quite quickly at spotting that spontaneous helpful up. You think of the last time you were laughing and you could not stop that spontaneous laughter. But actually the red line is showing how people improve at recognising this communicative use of laughter and actually we are not peaking in our performance at this until we start to get into our late 30s. And that's because we have to learn about laughter in social situations. If no one can tell you, you cannot read a book. The only place you learn about how to use laughter and all of the things that you can do with laughter is in interactions with people. The other psychological phenomena that have this kind of trajectory where you don't see peak performance until people are approaching middle age are social skills. They're things like empathy, theory of mind. Now that suggests that actually we should think about this social use of laughter and using laughter in this kind of rich complex way is something that really is a very important social skill and I think you could see that with Bill Clinton. What happens when this goes wrong? I did a study a couple of years ago with some colleagues at UCL who were very interested in the sort of developmental risk factors that mean that you might have serious problems with your emotion regulation as an adult. So they did this study with boys who are teenagers and who are at risk of psychopathy. That means they have two sets of traits. They have conduct disorders so they are poorly behaved. They behave aggressively, they behave in a criminal way and they have another characteristic which is they are high in callous and unemotional traits. What this means in shorthand is these boys behave badly and they do not care if they hurt you. Now they're being compared here to boys who have conduct disorders but who do feel bad if they hurt you and normally developing boys and this is the brain system that's lit up when you hear laughter at all so you can see there's auditory processing, you can see the social meaning of laughter is getting through. Within this we found very selective activation that was reduced in the boys at risk of psychopathy in areas here and here which are to do with contagion. They don't show that priming response when they hear laughter at all and if you ask them they do not find laughter as contagious. Now think what that means for their social interactions. They're not joining in with people laugh. They're not learning how to understand laughter when they hear someone laughing when they're older. They may mis-abriact and think they're being laughed at. So all of this kind of difficulty built in. Laughter is sticky. We showed in a study last year that if you add laughter onto very bad jokes what's orange and sounds like a parrot, a carrot, people think the joke is funnier if you add laughter to it even though you're asking them to rate how funny the joke is. It kind of sticks to things around you and it's incredibly interesting actually how you look at people using laughter in the workplace. There's now a growing literature showing that in high stress occupations where people need to work as a team like the police, like nurses, like medics, like people in the fire service, what you find is that they use jokes in a very profession-specific way. They often have quite dark senses of humour and that's doing three things. It's excluding people who are not part of their group. It is helping them deal with the stress and it's helping them bond. It's coming back to this role of laughter as a way of creating and making social bonds, reinforcing that group behaviour. Now what this means in practice I think is actually most jobs require people working in a team. Most jobs have moments of stress. We could learn a lot from thinking about this. In fact, if we go back to that video of Bill Clinton what you can see as I pressed the wrong button is that actually he was using almost everything I talked about here. He uses contagion to get the laughter going. He laughs the laughter spreads. First it doesn't get Yeltsyn in but it gets everybody else in and then it starts to work on Yeltsyn. He uses straightforward recognition just as a reason to laugh. That is my name, ha ha ha ha. And then when there's a comment about things of Bill disaster he starts really laughing and he uses a topper to keep it going. But he's really really careful with the laughter. He does some other things as well. He's clearly showing this is fine. This is anticipated to be a difficult situation. It becomes a less stressed situation because it's not an angry man shouting at everybody. This is funny. This is hilarious. He sends out that invitation to play and people join in. And the other thing that he's doing there is he's showing great affection. He's very careful to show that he's laughing with Boris Yeltsyn. This guy is hilarious. He's not going, that guy is an idiot, let's laugh at him. So in fact all the way across the board here at almost every possible level he's using laughter in this really nuanced way and in fact this is something that we're all doing or have some understanding of and it's really worth taking this seriously. Things like this get called bloopers. We think of a laughter session or comedy as being like relief or breaking the ice but actually those situations where people are just playing when there's just fun happening the places where laughter happens that's when the real emotional and social work of a team is occurring. That's where we're making and maintaining these social bonds. That's where we're getting closer to each other. So sometimes although it feels like a bit of fun it really is worth listening to your laughter and taking that laughter very seriously indeed. Thank you.